Skip to main content

Leptin in farm animals: where are we and where can we go?

  • A. R. G. Wylie (a1)

Fat affects meat quality, value and production efficiency as well as providing energy reserves for pregnancy and lactation in farm livestock. Leptin, the adipocyte product of the obese (ob) gene, was quickly seen as a predictor of body fat content in animals approaching slaughter and an aid to assessing reproductive readiness in females. Its participation in inflammation and immune responses that help animals survive infection and trauma has clear additional relevance to meat and milk production. Furthermore, almost a decade of discoveries of nucleotide polymorphisms in the leptin and leptin receptor genes has suggested useful applications relating to feed intake regulation, the efficiency of feed use, the composition of growth, the timing of puberty, mammogenesis and mammary gland function and fertility in cattle, pigs and poultry. The current review attempts to summarise where research has taken us in each of these aspects and speculates on where future research might lead.

    • Send article to Kindle

      To send this article to your Kindle, first ensure is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

      Note you can select to send to either the or variations. ‘’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      Leptin in farm animals: where are we and where can we go?
      Available formats
      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about sending content to Dropbox.

      Leptin in farm animals: where are we and where can we go?
      Available formats
      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about sending content to Google Drive.

      Leptin in farm animals: where are we and where can we go?
      Available formats
Corresponding author
Hide All
Accorsi PA, Camberoni A, Isani G, Viggiani R, Monari M, De Ambrogi M, Munno A, Tamanini C, Seren E 2005. Leptin does not seem to influence glucose uptake by bovine mammary explants. Journal of Physiology and Pharmacology 56, 689698.
Adachi H, Takemoto Y, Bungo T, Ohkubo T 2008. Chicken leptin receptor is functional in activating JAK-STAT pathway in vitro. Journal of Endocrinology 197, 335342.
Ahima RS, Flier JS 2000. Leptin. Annual Review of Physiology 62, 413437.
Ahima RS, Dushay J, Flier SN, Prabakaran D, Flier JS 1997. Leptin accelerates the onset of puberty in normal female mice. Journal of Clinical Investigations 99, 391395.
Ajuwon KM, Kuske JL, Anderson DB, Hancock DL, Houseknecht KL, Adeola O, Spurlock ME 2003. Chronic leptin administration increases serum NEFA in the pig and differentially regulates PPAR expression in adipose tissue. Journal of Nutritional Biochemistry 14, 576583.
Almeida SEM, Santos LBS, Passos DT, Corbellini AO, Lopes BMT, Kirst C, Terra G, Neves JP, Goncalves PBD, Moraes JCF, Weimer TDA 2008. Genetic polymorphisms at the leptin receptor gene in three beef cattle breeds. Genetics and Molecular Biology 31, 680685.
Altmann M, von Borell E 2007. Leptin as an indicator for carcass composition in farm animals. Animal Science Journal 78, 449459.
Altmann M, Sauerwein H, von Borell E 2005. Relationship between plasma leptin concentrations and carcass composition in fattening mutton: a comparison with ultrasound results. Journal of Animal Physiology and Animal Nutrition 89, 326330.
Altmann M, Sauerwein H, von Borell E 2006. Plasma leptin in growing lambs as a potential predictor for carcass composition and daily gain. Meat Science 74, 600604.
Amarante AFT, Bricarello PA, Rocha RA, Gennari SM 2004. Resistance of Santa Ines, Suffolk and Ile de France sheep to naturally acquired gastrointestinal nematode infections. Veterinary Parasitology 120, 91106.
Amills M, Villalba D, Tor M, Mercade A, Gallardo D, Cabrera B, Jimenez N, Noguera JL, Sanchez A, Estany J 2008. Plasma leptin levels in pigs with different leptin and leptin receptor genotypes. Journal of Animal Breeding and Genetics 125, 228233.
Amstalden M, Garcia MR, Williams SW, Stanko RL, Nizielski SE, Morrison CD, Keisler DH, Williams GL 2000. Leptin gene expression, circulating leptin, and luteinizing hormone pulsatility are acutely responsive to short-term fasting in pre-pubertal heifers: relationships to circulating insulin and insulin-like growth factor 1. Biology of Reproduction 63, 127133.
Anagnostoulis S, Karayiannakis AJ, Lambropoulou M, Efthimiadou A, Polychronidis A, Simopoulos C 2008. Human leptin induces angiogenesis in vivo. Cytokine 42, 353357.
Aoki N, Kawamura M, Matsuda T 1999. Lactation-dependent down regulation of leptin production in mouse mammary gland. Biochimica Biophysica Acta 1427, 298306.
Ashwell CM, Czerwinski SM, McMurtry JP 1998. Turkey leptin (ob) mRNA, partial cds. GenBank Accession Number AF082501.
Ashwell CM, Czerwinski SM, Brocht DM, McMurtry JP 1999. Hormonal regulation of leptin expression in broiler chickens. American Journal of Physiology – Regulatory Integrative and Comparative Physiology 276, R226R232.
Ashworth CJ, Hoggard N, Thomas L, Mercer JG, Wallace JM, Lea RG 2000. Placental leptin. Reviews of Reproduction 5, 1824.
Asiamah PA, Betchel DG, Waldner C, Buchanan FC 2009. Effects of leptin Arg25Cys on peripheral mononuclear cell counts and antibody response to vaccination in beef cattle. Animal Genetics 40, 783787.
Attig L, Djiane J, Gertler A, Rampin O, Larcher T, Boukthir S, Anton PM, Madec JY, Gourdou I, Abdennebi-Najar L 2008. Study of hypothalamic leptin receptor expression in low-birth-weight piglets and effects of leptin supplementation on neonatal growth and development. American Journal of Physiology Endocrinology and Metabolism 295, E1117E1125.
Bado A, Levasseur S, Attoub S, Kermorgant S, Laigneau JP, Bortoluzzi MN, Moizo L, Lehy T, Guerre-Millo M, Le Marchand Brustel Y, Lewin MJM 1998. The stomach is a source of leptin. Nature 394, 790793.
Bagnasco M, Kalra PS, Kalra SP 2002. Plasma leptin levels are pulsatile in adult rats: effects of gonadectomy. Neuroendocrinology 75, 257263.
Baile CA, Della-Ferra MA, Martin RJ 2000. Regulation of body fat mass and metabolism by leptin. Annual Reviews of Nutrition 20, 105127.
Banos G, Woolliams JA, Woodward BW, Forbes AB, Coffey MP 2008. Impact of single nucleotide polymorphisms in leptin, leptin receptor, growth hormone receptor, and diacylglycerol acyltransferase (DGAT1) gene loci on milk production, feed, and body energy traits of UK dairy cows. Journal of Dairy Science 91, 31903200.
Barb CR, Kraeling RR 2004. Role of leptin in the regulation of gonadotropin secretion in farm animals. Animal Reproduction Science 82–83, 155167.
Barb CR, Barrett JB, Kraeling RR, Rampacek GB 2001a. Serum leptin concentrations, luteinizing hormone and growth hormone secretion during feed and metabolic fuel restriction in the prepubertal gilt. Domestic Animal Endocrinology 20, 4763.
Barb CR, Hausman GJ, Houseknecht KL 2001b. Biology of leptin in the pig. Domestic Animal Endocrinology 21, 297317.
Barb CR, Hausman GJ, Czaja K 2005. Leptin: a metabolic signal affecting central regulation of reproduction in the pig. Domestic Animal Endocrinology 29, 186192.
Barb CR, Hausman GJ, Ramsay TG 2006. Leptin in farm animals. In Endocrine update series (ed. DV Castracane and MC Henson), pp. 263308. Springer, New York, NY, USA.
Barkan D, Hurgin V, Dekel N 2005. Leptin induces ovulation in GnRH-deficient mice. FASEB Journal 19, 133135.
Barowicz T, Pieszka M, Pietras M, Kedzior W 2005. The effect of serum concentration of leptin in fatteners on their productivity. Journal of Animal and Feed Sciences 14, 329332.
Beam SW, Butler WR 1999. Effects of energy balance on follicular development and first ovulation in postpartum dairy cows. Journal of Reproduction and Fertility Supplement 54, 411424.
Bellmann O, Wegner J, Teuscher F, Schneider F, Ender K 2004. Muscle characteristics and corresponding hormone concentrations in different types of cattle. Livestock Production Science 85, 4557.
Berg EP, McFadin EL, Maddock KR, Goodwin RN, Baas TJ, Keisler DH 2003. Serum concentrations of leptin in six genetic lines of swine and relationship with growth and carcass characteristics. Journal of Animal Science 81, 167171.
Bertrand JK, Green RD, Herring WO, Moser DW 2001. Genetic evaluation for beef carcass traits. Journal of Animal Science 79, E190E200.
Bjørbæk C, Uotani S, da Silva B, Flier JS 1997. Divergent signaling capacities of the long and short isoforms of the leptin receptor. Journal of Biological Chemistry 272, 3268632695.
Blache D, Tellam RL, Chagas LM, Blackberry MA, Vercoe PE, Martin GB 2000. Level of nutrition affects leptin concentrations in plasma and cerebrospinal fluid in sheep. Journal of Endocrinology 165, 625637.
Block SS, Butler WR, Ehrhardt RA, Bell AW, Van Amburgh ME, Boisclair YR 2001. Decreased concentration of plasma leptin in periparturient dairy cows is caused by negative energy balance. Journal of Endocrinology 171, 339348.
Block SS, Smith JM, Ehrhardt RA, Diaz MC, Rhoads RP, Van Amburgh ME, Boisclair YR 2003. Nutritional and developmental regulation of plasma leptin in dairy cattle. Journal of Dairy Science 86, 32063214.
Bokkers EAM, Koene P 2003. Eating behaviour, and preprandial and postprandial correlations in male broiler and layer chickens. British Poultry Science 44, 538544.
Bonnet M, Gourdou I, Leroux C, Chilliard Y, Djiane J 2002. Leptin expression in the ovine mammary gland: putative sequential involvement of adipose, epithelial, and myoepithelial cells during pregnancy and lactation. Journal of Animal Science 80, 723728.
Bonnet M, Faulconnier Y, Leroux C, Jurie C, Cassar-Malej I, Bauchart D, Boulesteix P, Pethick D, Hocquette J-F, Chilliard Y 2007. Glucose-6-phosphate dehydrogenase and leptin are related to marbling differences among Limousin and Angus or Japanese Black x Angus steers. Journal of Animal Science 85, 28822894.
Borghetti P, Saleri R, Mocchegiani E, Corradi A, Martelli P 2009. Infection, immunity and the neuroendocrine response. Veterinary Immunology and Immunopathology 130, 141162.
Boucher D, Palin MF, Castonguay F, Gariepy C, Pothier F 2006. Detection of polymorphisms in the ovine leptin (LEP) gene: association of a single nucleotide polymorphism with muscle growth and meat quality traits. Canadian Journal of Animal Science 86, 3135.
Bovine Genome Sequencing and Analysis Consortium 2009. The genome sequence of taurine cattle: a window to ruminant biology and evolution. Science 324, 522528.
Brandt MM, Keisler DH, Meyer DL, Schmidt TB, Berg EP 2007. Serum hormone concentrations relative to carcass composition of a random allotment of commercial – fed beef cattle. Journal of Animal Science 85, 267275.
Brody S 1945. Bioenergetics and growth. Hafner Press, New York, USA.
Bruggeman V, Onagbesan OM, Decuypere E 2000. Body weight, fat content, liver weight and plasma leptin concentrations in broiler breeder females reared under ad libitum feeding, restricted feeding or combinations of both until age of first egg. British Poultry Science 41 (suppl. 1), 5759.
Buchanan FC, van Kessel AG, Boisclair YR, Block HC, McKinnon JJ 2007. The leptin arg25cys affects performance, carcass traits and serum leptin concentrations in beef cattle. Canadian Journal of Animal Science 87, 153156.
Buchanan FC, Fitzsimmons CJ, van Kessel AG, Thue TD, Inkelman-Sim DC, Schmutz SM 2002. Association of a missense mutation in the bovine leptin gene with carcass fat content and leptin mRNA levels. Genetics Selection Evolution 34, 105116.
Buchanan FC, van Kessel AG, Waldner C, Christensen DA, Laarveld B, Schmultz SM 2003. An association between a leptin single nucleotide polymorphism and milk and protein yield. Journal of Dairy Science 86, 31643166.
Buettner C, Pocai A, Muse ED, Etgen AM, Myers MG Jr, Rossetti L 2006. Critical role of STAT3 in leptin’s metabolic actions. Cell Metabolism 4, 4960.
Bungo T, Shimojo M, Masuda Y, Tachibanab T, Tanaka SJ, Sugahara K, Furuse M 1999. Intracerebroventricular administration of mouse leptin does not reduce food intake in the chicken. Brain Research 817, 196198.
Burt DA 2004. The chicken genome and the developmental biologist. Mechanisms of Development 121, 11291135.
Butler WR 2005. Inhibition of ovulation in the postpartum cow and the lactating sow. Livestock Production Science 98, 512.
Butler PJ, Woakes AJ 2001. Seasonal hypothermia in a large migrating bird: saving energy for fat deposition? Journal of Experimental Biology 204, 13611367.
Cameron JL, Nosbisch C 1991. Suppression of pulsatile luteinizing hormone and testosterone secretion during short-term food restriction in the adult male rhesus monkey (Macaca mulatta). Endocrinology 128, 15321540.
Cameron ND, Penman JC, McCullough E 2000. Serum leptin concentration in pigs selected for high or low daily food intake. Genetics Research 75, 209213.
Campfield AL, Smith FJ, Guisez Y, Devos R, Burn P 1995. Recombinant mouse OB protein: evidence for a peripheral signal linking adiposity and central neural networks. Science 269, 546549.
Caro J, Kolaczynski J, Nyce M, Ohannesian J, Opentanova I, Goldman W, Lynn R, Zhang P, Sinha M, Considine R 1996. Decreased cerebrospinal-fluid/serum leptin ratio in obesity: a possible mechanism for leptin resistance. Lancet 348, 159161.
Cassy S, Picard M, Crochet S, Derouet M, Keisler DH, Taouis M 2004. Peripheral leptin effect on food intake in young chickens is influenced by age and strain. Domestic Animal Endocrinology 27, 5161.
Chebel RC, Susca F, Santos JEP 2008. Leptin genotype is associated with lactation performance and health of Holstein cows. Journal of Dairy Science 91, 28932900.
Chehab FF, Lim ME, Lu R 1996. Correction of the sterility defect in homozygous obese female mice by treatment with the human recombinant leptin. Nature Genetics 12, 318320.
Chehab FF, Mounzih K, Lu R, Lim ME 1997. Early onset of reproductive function in normal female mice treated with leptin. Science 275, 8890.
Chelikani PK, Glimm DR, Kennelly JJ 2003. Tissue distribution of leptin and leptin receptor mRNA in the bovine. Journal of Dairy Science 86, 23692372.
Chelikani PK, Ambrose DJ, Keisler DH, Kennelly JJ 2009. Effects of dietary energy and protein density on plasma concentrations of leptin and metabolic hormones in dairy heifers. Journal of Dairy Science 92, 14301441.
Chen G, Koyama K, Yuan X, Lee Y, Zhou YT, O’Doherty R, Newgard CB, Unger RH 1996. Disappearance of body fat in normal rats induced by adenovirus-mediated leptin gene therapy. Proceedings of the National Academy of Science USA 93, 1479514799.
Chen Y, Heiman ML 2000. Chronic leptin administration promotes lipid utilization until fat mass is greatly reduced and preserves lean mass of normal female rats. Regulatory Peptides 92, 113119.
Chilliard Y, Delavaud C, Bonnet M 2005. Leptin expression in ruminants: nutritional and physiological regulations in relation with energy metabolism. Domestic Animal Endocrinology 29, 322.
Cinti S, Frederich RC, Zingaretti MC, De Matteis R, Flier JS, Lowell BB 1997. Immunohistochemical localization of leptin and uncoupling protein in white and brown adipose tissue. Endocrinology 138, 797804.
Cinti S, De Matteis R, Picó C, Ceresi E, Obrador A, Maffeis C, Oliver J, Palou A 2000. Secretory granules of endocrine and chief cells of human stomach mucosa contain leptin. International Journal of Obesity 24, 789793.
Colditz IG 2002. Effects of the immune system on metabolism: implications for production and disease resistance in livestock. Livestock Production Science 75, 257268.
Coleman DL 1973. Effects of parabiosis of obese with diabetes and normal mice. Diabetologia 9, 294298.
Considine R, Sinha M, Heiman ML, Kriauciunas A, Stephens TW, Nyce MR, Ohannesian JP, Marco CC, McKee LJ, Bauer TL, Caro JF 1996. Serum immunoreactive leptin concentrations in normal-weight and obese humans. New England Journal of Medicine 334, 292295.
Coop RL, Holmes PH 1996. Nutrition and parasite infection. International Journal for Parasitology 26, 951962.
Corva PM, Fernández Macedo GV, Soria LA, Papaleo Mazzucco J, Motter M, Villarreal EL, Schor A, Mezzadra CA, Melucci LM, Miquel MC 2009. Effect of leptin gene polymorphisms on growth, slaughter and meat quality traits of grazing Brangus steers. Genetics and Molecular Research 8, 105116.
Crouch JS, Smith TR 2004. Detection and identification of the leptin binding protein in dairy cattle. FASEB Journal 18, A1228.
Cunningham MJ, Clifton DK, Steiner RA 1999. Leptin’s actions on the reproductive axis: perspectives and mechanisms. Biology of Reproduction 60, 216222.
Dai HC, Long LQ, Zhang XW, Zhang WM, Wu XX 2007. Cloning and expression of the duck leptin gene and the effect of leptin on food intake and fatty deposition in mice. Asian-Australasian Journal of Animal Sciences 20, 850855.
Daix M, Pirotte C, Bister JL, Wergifosse F, Cuvelier C, Cabaraux JF, Kirschvink N, Istasse L, Paquay R 2008. Relationship between leptin content, metabolic hormones and fat deposition in three beef cattle breeds. Veterinary Journal 177, 273278.
D’Andrea M, Pilla F, Giuffra E, Waddington D, Archibald AL 2008. Structural analysis and haplotype diversity in swine LEP and MC4R genes. Journal of Animal Breeding and Genetics 125, 130136.
Daniel JA, Whitlock BK, Baker JA, Steele B, Morrison CD, Keisler DH, Sartin JL 2002. Effect of body fat mass and nutritional status on 24-hour leptin profiles in ewes. Journal of Animal Science 80, 10831089.
Dekkers JCM 2004. Commercial application of marker- and gene-assisted selection in livestock: strategies and lessons. Journal of Animal Science 82, E313E328.
Delavaud C, Bocquier F, Chilliard Y, Keisler DH, Gertler A, Kann G 2000. Plasma leptin determination in ruminants: effect of nutritional status and body fatness on plasma leptin concentration assessed by a specific RIA in sheep. Journal of Endocrinology 165, 519526.
Delavaud C, Ferlay A, Faulconnier Y, Bocquier F, Kann G, Chilliard Y 2002. Plasma leptin concentration in adult cattle: effects of breed, adiposity, feeding level, and meal intake. Journal of Animal Science 80, 13171328.
De Pedro N, Martinez-Alvarez R, Delgado MJ 2006. Acute and chronic leptin reduces food intake and body weight in goldfish (Carassius auratus). Journal of Endocrinology 188, 513520.
De Souza MJ, Metzger DA 1991. Reproductive dysfunction in amenorrheic athletes and anorexic patients: a review. Medicine and Science in Sports and Exercise 23, 9951007.
De Vuyst EA, Bauer ML, Cheng FC, Mitchell J, Larson D 2008. The impact of a leptin gene SNP on beef calf weaning weights. Animal Genetics 39, 284286.
Diamond FB Jr, Eichler DC, Duckett G, Jorgensen EV, Shulman D, Root AW 1997. Demonstration of a leptin binding factor in human serum. Biochemical and Biophysical Research Communications 233, 818822.
Diskin MG 2008. Reproductive management of dairy cows: a review (part 1). Irish Veterinary Journal 61, 326332.
Doepel L, Lapierre H, Kennelly JJ 2002. Peripartum performance and metabolism of dairy cows in response to prepartum energy and protein intake. Journal of Dairy Science 85, 23152334.
Dridi S, Buyse J, Decuypere E, Taouis M 2005a. Potential role of leptin in increase of fatty acid synthase gene expression in chicken liver. Domestic Animal Endocrinology 29, 646660.
Dridi S, Swennen Q, Decuypere E, Buyse J 2005b. Mode of leptin action in chicken hypothalamus. Brain Research 1047, 214223.
Dunshea FR, D’Souza DN, Pethick DW, Harper GS, Warner RD 2005. Effects of dietary factors and other metabolic modifiers on quality and nutritional value of meat. Meat Science 71, 838.
Dyer CJ, Simmons JM, Matteri RL, Keisler DH 1997. cDNA cloning and tissue-specific gene expression of ovine leptin, NPY-Y1 receptor and NPY-Y2 receptor. Domestic Animal Endocrinology 14, 295303.
Ehrhardt RA, Slepetsis RM, Bell AW, Boisclair YR 2001. Maternal leptin is elevated during pregnancy in sheep. Domestic Animal Endocrinology 21, 8596.
Ehrhardt RA, Greenwood PL, Bell AW, Boislair YR 2003. Plasma leptin is regulated predominantly by nutrition in preruminant lambs. Journal of Nutrition 133, 41964201.
Ehrhardt RA, Slepetsis RM, Siegal-Willott J, Van Amburgh ME, Bell AW, Boisclair YR 2000. Development of a specific radioimmunoassay to measure physiological changes of circulating leptin in cattle and sheep. Journal of Endocrinology 166, 519528.
Elsasser T, Ingvartsen KL, Kahl S, Capuco AV 2006. Endocrine effects on immune function: defining opportunities based on knowledge from growing calf and peri-parturient animal models. In Ruminant physiology (ed. K Sejrsen, T Hvelplund and MO Neilsen), pp. 415447. Wageningen Academic Publishers, The Netherlands.
Esslemont RJ, Kossaibati MA, Allcock J 2001. Economics of fertility in dairy cows. In Fertility in the high-producing dairy cow (ed. MG Diskin), Occasional Publication no. 26, pp. 1929. British Society for Animal Science, Penicuik, Midlothian, UK.
Fabian J, Chiba LI, Kuhlers DL, Frobish LT, Nadarjah K, McElhenney W 2003. Growth performance, dry matter and nitrogen digestibilities, serum profile and carcass and meat quality of pigs with distinct genotypes. Journal of Animal Science 81, 11421149.
Faggioni R, Feingold KR, Grunfeld C 2001. Leptin regulation of the immune response and the immunodeficiency of malnutrition. FASEB Journal 15, 25652571.
Farooqi IS, Jebb S, Langmack G, Cheetham C, Prentice A, Hughes I, McCamish M, O’Rahilly S 1999. Effects of recombinant leptin therapy in a child with congenital leptin deficiency. New England Journal of Medicine 341, 879884.
Fei H, Okano HJ, Li C, Lee G-H, Zhao C, Darnell R, Friedman JM 1997. Anatomic localization of alternatively spliced leptin receptors (Ob-R) in mouse brain and other tissues. Proceedings of the National Academy of Sciences, USA 94, 70017005.
Ferris CP, McCoy MA, Lennox SD, Catney DC, Gordon FJ 2002. Nutrient utilisation and energy balance associated with two contrasting winter milk producing systems for high genetic merit autumn calving dairy cows. Irish Journal of Agriculture and Food Research 41, 5570.
Feuermann Y, Mabjeesh SJ, Niv-Spector L, Levin D, Shamay A 2006. Prolactin affects leptin action in the bovine mammary gland via the mammary fat pad. Journal of Endocrinology 191, 407413.
Fitzsimmons CJ, Schmutz SM, Bergen RD, McKinnon JJ 1998. A potential association between the BM 1500 microsatellite and fat deposition in beef cattle. Mammalian Genome 9, 432434.
Forbes AB, Warren M, Upjohn M, Jackson B, Jones J, Charlier J, Fox MT 2009. Associations between blood gastrin, ghrelin, leptin, pepsinogen and Ostertagia ostertagi antibody concentrations and voluntary feed intake in calves exposed to a trickle infection with O. ostertagi. Veterinary Parasitology 162, 295305.
Fortes MRS, Curi RA, Chardulo LAL, Silveira AC, Assumpção MEOD, Visintin JA, de Oliveira HN 2009. Bovine gene polymorphisms related to fat deposition and meat tenderness. Genetics and Molecular Biology 32, 7582.
Frederich RC, Hamann A, Anderson S, Lollmann B, Lowell BB, Flier JS 1995. Leptin levels reflect body lipid content in mice – evidence for diet-induced resistance to leptin action. Nature Medicine 1, 13111314.
Freeman DA, Lewis DA, Kauffman AS, Blum RM, Dark J 2004. Reduced leptin concentrations are permissive for the display of torpor in Siberian hamsters. American Journal of Physiology: Regulatory, Integrative and Comparative Physiology 287, R97R103.
Friedman JM, Halaas JL 1998. Leptin and the regulation of body weight in mammals. Nature 395, 763770.
Friedman-Einat MT, Boswell G, Horev G, Girishvarma IC, Dunn Talbot RT, Sharp PJ 1999. The chicken leptin gene: has it been cloned? General and Comparative Endocrinology 115, 354363.
Friggens NC 2003. Body lipid reserves and the reproductive cycle: towards a better understanding. Livestock Production Science 83, 219236.
Garcia MR, Amstalden M, Williams SW, Stanko RL, Morrison CD, Keisler DH, Nizielski SE, Williams GL 2002. Serum leptin and its adipose gene expression during pubertal development, the estrous cycle, and different seasons in cattle. Journal of Animal Science 80, 21582167.
Gardan D, Gondret F, Louveau I 2006. Lipid metabolism and secretory function of porcine intramuscular adipocytes compared with subcutaneous and perirenal adipocytes. American Journal of Physiology Endocrinology and Metabolism 291, E372E380.
Garnsworthy PC, Fouladi-Nashta AA, Mann GE, Sinclair KD, Webb R 2009. Effect of dietary-induced changes in plasma insulin concentrations during the early post partum period on pregnancy rate in dairy cows. Reproduction 137, 759768.
Geary TW, McFadin EL, MacNeil MD, Grings EE, Short RE, Funston RN, Keisler DH 2003. Leptin as a predictor of carcass composition in beef cattle. Journal of Animal Science 81, 18.
Gertler A, Simmons J, Keisler DH 1998. Large-scale preparation of biologically active recombinant ovine obese protein (leptin). FEBS Letters 422, 137140.
Gill JI, Bishop SC, McCorquodale C, Williams JL, Wiener P 2009. Association of selected SNP with carcass and taste panel assessed meat quality traits in a commercial population of Aberdeen Angus-sired beef cattle. Genetics Selection Evolution 41, 3647.
Golden PL, Maccagnan TJ, Pardridge WM 1997. Human blood-brain barrier leptin receptor binding and endocytosis in isolated human brain microvessels. Journal of Clinical Investigations 99, 1418.
Gorocica-Buenfil MA, Fluharty FL, Bohn T, Schwartz SJ, Loerch SC 2007. Effect of low vitamin A diets with high-moisture or dry corn on marbling and adipose tissue fatty acid composition of beef steers. Journal of Animal Science 85, 33553366.
Gorocica-Buenfil MA, Fluharty FL, Loerch SC 2008. Effect of vitamin A restriction on carcass characteristics and immune status of beef steers. Journal of Animal Science 86, 16091616.
Gosman GG, Katcher HI, Legro RS 2006. Obesity and the role of gut and adipose hormones in female reproduction. Human Reproduction Update 12, 585601.
Grasso P, Leinung MC, Ingher SP, Lee DW 1997. In vivo effects of leptin-related synthetic peptides on body weight and food intake in female ob/ob mice: localization of leptin activity to domains between amino acid residues 106–140. Endocrinology 138, 14131418.
Greer AW, Boisclair YR, Stankiewicz M, McAnulty RW, Jay NP, Sykes AR 2009. Leptin concentrations and the immune-mediated reduction of feed intake in sheep infected with the nematode Trichostrongylus colubriformis. British Journal of Nutrition 102, 954957.
Guilherme C, Bianchini A, Martinez PE, Robaldo RB, Colares EP 2004. Serum leptin concentration during the terrestrial phase of the Southern elephant seal Mirounga leonine (Carnivora: Phocidae). General and Comparative Endocrinology 139, 137142.
Guilmeau S, Buyse M, Bado A 2004. Gastric leptin: a new manager of gastro-intestinal function. Current Opinion in Pharmacology 4, 561566.
Guo YK, Chen H, Lan XY, Zhang B, Pan CY, Zhang LZ, Zhang CF, Zhao M 2008. Novel SNPs of the bovine LEPR gene and their associations with growth traits. Biochemical Genetics 46, 828834.
Halaas JL, Gajiwala KS, Maffei M, Cohen SL, Chait BT, Rabinowitz D, Lallone RL, Burley SK, Friedman JM 1995. Weight-reducing effects of the plasma protein encoded by the obese gene. Science 269, 543546.
Harris RBS 2000. Leptin – much more than a satiety signal. Annual Reviews of Nutrition 20, 4575.
Hausman GJ, Dodson MV, Ajuwon K, Azain M, Barnes KM, Guan LL, Jiang Z, Poulos SP, Sainz RD, Smith S, Spurlock M, Novakofski J, Fernyhough ME, Bergen WG 2009. The biology and regulation of preadipocytes and adipocytes in meat animals. Journal of Animal Science 87, 12181246.
Hayes BJ, Bowman PJ, Chamberlain AJ, Goddard ME 2009. Invited review: genomic selection in dairy cattle: progress and challenges. Journal of Dairy Science 92, 433443.
Hen G, Yosefi S, Ronin A, Einat P, Rosenblum CI, Denver RJ, Friedman-Einat M 2008. Monitoring leptin activity using the chicken leptin receptor. Journal of Endocrinology 197, 325333.
Henry BA, Goding JW, Alexander WS, Tilbrook AJ, Canny BJ, Dunshea FR, Rao A, Mansell A, Clarke IJ 1999. Central administration of leptin to ovariectomised ewes inhibits food intake without affecting the secretion of hormones from the pituitary gland: evidence for a dissociation of effects on appetite and neuroendocrine function. Endocrinology 140, 11751182.
Henry BA, Goding JW, Tilbrook AJ, Dunshea FR, Clarke IJ 2001. Intracerebroventricular infusion of leptin elevates the secretion of luteinising hormone without affecting food intake in long-term food-restricted sheep, but increases growth hormone irrespective of bodyweight. Journal of Endocrinology 168, 6677.
Henson MC, Castracane VD 2006. Leptin in pregnancy. Biology of Reproduction 63, 12191228.
Higashiyama Y, Abe H, Hayashi M, Hodate K 2003. The comparison of plasma level and mRNA expression of leptin from Japanese Black steers and Holstein steers. Livestock Production Science 81, 247255.
Hileman SM, Tornøe J, Flier JS, Bjørbæk C 2000. Transcellular transport of leptin by the short leptin receptor isoform ObRa in Madin-Darby canine kidney cells. Endocrinology 141, 19551961.
Hill RA, Margetic S, Pegg GG, Gazzola C 1998. Leptin: its pharmacokinetics and tissue distribution. International Journal of Obesity and Related Metabolic Disorders 22, 765770.
Hocquette J-F, Gondret F, Baeza E, Medale F, Jurie C, Pethick DW 2010. Intramuscular fat content in meat-producing animals: development, genetic and nutritional control, and identification of putative markers. Animal 4, 303319.
Hocquette J-F, Lehnert S, Barendse W, Cassar-Malek I, Picard B 2007. Recent advances in cattle functional genomics and their application to beef quality. Animal 1, 159173.
Horev G, Einat P, Aharoni T, Eshdat Y, Friedman-Einat M 2000. Molecular cloning and properties of the chicken leptin receptor (CLEPR) gene. Molecular and Cellular Endocrinology 162, 95106.
Hossner KL 1998. Cellular, molecular and physiological aspects of leptin: potential application in animal production. Canadian Journal of Animal Science 78, 463472.
Houseknecht KL, Portocarrero CP 1998. Leptin and its receptors: regulators of whole-body energy homeostasis. Domestic Animal Endocrinology 15, 457475.
Houseknecht KL, Baile CA, Matteri RL, Spurlock ME 1998. The biology of leptin: a review. Journal of Animal Science 76, 14051420.
Houseknecht KL, McGuire MK, Portocarrero CP, McGuire MA, Beerman K 1997. Leptin is present in human milk and is related to maternal plasma leptin concentration and adiposity. Biochemical and Biophysical Research Communications 240, 742747.
Houseknecht KL, Mantzoros CS, Kuliawat R, Hadro E, Flier JS, Kahn BB 1996. Evidence for leptin binding to proteins in serum of rodents and humans: modulation with obesity. Diabetes 45, 16381643.
Howard JK, Lord GM, Matarese G, Vendetti S, Ghatei MA, Ritter MA, Lechler RI, Bloom SR 1999. Leptin protects mice from starvation-induced lymphoid atrophy and increases thymic cellularity in ob/ob mice. Journal of Clinical Investigation 104, 10511059.
Hube F, Lietz U, Igel M, Jensen PB, Tornqvist H, Joost HG, Hauner H 1996. Difference in leptin mRNA levels between omental and subcutaneous abdominal adipose tissue from obese humans. Hormones and Metabolic Research 28, 690693.
Huff-Lonergan E, Baas TJ, Malek M, Dekkers JC, Prusa K, Rothschild MF 2002. Correlations among selected pork quality traits. Journal of Animal Science 80, 617627.
Huising MO, Geven EJW, Kruiswijk CP, Nabuurs SB, Stolte EH, Spanings FAT, Verburg-van Kemenade BML, Flik G 2006. Increased leptin expression in common carp (Cyprinus carpio) after food intake but not after fasting or feeding to satiation. Endocrinology 147, 57865797.
Ingvartsen KL, Boisclair YR 2001. Leptin and the regulation of food intake, energy homeostasis and immunity with special focus on periparturient ruminants. Domestic Animal Endocrinology 21, 215250.
International Chicken Genome Sequencing Consortium 2004. Sequence and comparative analysis of the chicken genome provide unique perspectives on vertebrate evolution. Nature 432, 695716.
International Chicken Polymorphism Map Consortium 2004. A genetic variation map for chicken with 2.8 million single-nucleotide polymorphisms. Nature 432, 717722.
Iqbal J, Pompolo S, Considine RV, Clarke IJ 2000. Localization of leptin receptor-like immunoreactivity in the corticotropes, somatotropes and gonadotropes in the ovine anterior pituitary. Endocrinology 141, 15151520.
Ishii S, Shibasaki T, Murakami T, Shima K, Wakabayashi I 2000. Response of leptin mRNA to 24-h food deprivation and refeeding is influenced by age in rats. Regulatory Peptides 92, 4550.
Isse N, Ogawa Y, Tamura N, Masuzaki H, Mori K, Okazaki T, Satoh N, Shigemoto M, Yoshimasa Y, Nishi S, Hosoda K, Inazawa J, Nakao K 1995. Structural organization and chromosomal assignment of the human obese gene. Journal of Biological Chemistry 270, 2772827733.
Ji S, Willis GM, Scott RR, Spurlock ME 1998. Partial cloning and expression of the bovine leptin gene. Animal Biotechnology 9, 114.
Jiang Z, Gibson JP 1999. Genetic polymorphisms in the leptin gene and their association with fatness in four pig breeds. Mammalian Genome 10, 190193.
Jiang Z, Pappu SS, Rothschild MF 2007. Hitting the jackpot twice: identifying and patenting gene tests related to muscle lipid accumulation for meat quality in animals and type 2 diabetes/obesity in humans. Recent Patents on DNA & Gene Sequences 1, 100111.
Johnson RM, Johnson TM, Londraville RL 2000. Evidence for leptin expression in fishes. Journal of Experimental Zoology 286, 718724.
Johnson DE, Ferrell CL, Jenkins TG 2003. The history of energetic efficiency research: where have we been and where are we going? Journal of Animal Science 81, E27E38.
Kadokawa H, Martin GB 2006. A new perspective on management of reproduction in dairy cows: the need for detailed metabolic information, an improved selection index and extended lactation. Journal of Reproduction and Development 52, 161168.
Kadokawa H, Blache D, Yamada Y, Martin GB 2000. Relationships between changes in plasma concentrations of leptin before and after parturition and the timing of first post-partum ovulation in high-producing Holstein dairy cows. Reproduction, Fertility and Development 12, 405411.
Kadokawa H, Blache D, Martin GB 2006. Plasma leptin concentrations correlate with luteinising hormone secretion in early postpartum Holstein cows. Journal of Dairy Science 89, 30203027.
Kawachi H, Yang SH, Hamano A, Matsui T, Smith SB, Yano H 2007. Molecular cloning and expression of bovine (Bos taurus) leptin receptor isoform mRNAs. Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology 148, 167173.
Kawakita Y, Abe H, Hodate K 1999. Molecular cloning and recombinant preparation of bovine leptin. South African Journal of Animal Science 29, 210212.
Kawakita YH, Abe H, Hodate AK, Iguchi A, Kobayashi M, Mori T, Kasai K, Tanai Y, Kanbe Y, Mashayama H, Asada T, Miyashige T 2001. The relation between plasma leptin concentrations and carcass lipid contents in Japanese Black steers. Livestock Production Science 73, 2534.
Kelesidis T, Kelesidis I, Chou S, Mantzoros CS 2010. Narrative review: the role of leptin in human physiology: emerging clinical applications. Annals of Internal Medicine 102, 93100.
Kelly AK, McGee M, Crews DH Jr, Fahey AG, Wylie AR, Kenny DA 2010. Effect of divergence in residual feed intake on feeding behavior, blood metabolic variables and body composition traits in growing beef heifers. Journal of Animal Science 88, 109123.
Kennedy GC 1953. The role of depot fat in the hypothalamic control of food intake in the rat. Proceedings of the Royal Society of London. Series B, Biological Sciences 140, 578592.
Kennes YM, Murphy BD, Pothier F, Palin MF 2001. Characterization of swine leptin (LEP) polymorphisms and their association with production traits. Animal Genetics 32, 215218.
Kershaw EE, Flier JS 2004. Adipose tissue as an endocrine organ. Journal of Clinical Endocrinology and Metabolism 89, 25482556.
Kile JP, Alexander BM, Moss GE, Hallford DM, Nett TM 1991. Gonadotropin-releasing hormone overrides the negative effect of reduced dietary energy on gonadotropin synthesis and secretion in ewes. Endocrinology 128, 843849.
Kochan Z, Karbowska J, Meissner W 2006. Leptin is synthesized in the liver and adipose tissue of the dunlin (Calidris alpina). General and Comparative Endocrinology 148, 336339.
Komatsu T, Itoh F, Kushbiki S, Hodate K 2005. Changes in gene expression of glucose transporters in lactating and non-lactating cows. Journal of Animal Science 83, 557564.
Komisarek J, Dorynek Z 2006. The relationship between the T945M single nucleotide polymorphism in the leptin receptor gene (LEPR) and milk production traits in Jersey cows. Animal Science Papers and Reports 24, 271277.
Kong HS, Oh JD, Lee SG, Hong YS, Song WI, Lee SJ, Kim HC, Yoo BH, Lee HK, Jeon GJ 2006. Association of polymorphisms in bovine leptin gene with ultrasound measurements for improving in Korean cattle. Asian-Australasian Journal of Animal Sciences 19, 16911695.
Konigsson K, Savoini G, Govoni N, Invernizzi G, Prandi A, Kindahl H, Veronesi MC 2008. Energy balance, leptin, NEFA and IGF-1 plasma concentrations and resumption of post partum ovarian activity in Swedish Red and White breed cows. Acta Veterinaria Scandinavica 50: record no. 3.
Kononoff PJ, Deobald HM, Stewart EL, Laycock AD, Marquess FLS 2005. The effect of a leptin single nucleotide polymorphism on quality grade, yield grade, and carcass weight of beef cattle. Journal of Animal Science 83, 927932.
Kuehn LA, Nonneman DJ, Klindt JM, Wise TH 2009. Genetic relationships of body composition, serum leptin, and age at puberty in gilts. Journal of Animal Science 87, 477483.
Kulcsár M, Jánosi S, Lehtolainen T, Kátai L, Delavaud C, Balogh O, Chilliard Y, Pyörälä S, Rudas P, Huszenicza G 2005. Feeding-unrelated factors influencing the plasma leptin level in ruminants. Domestic Animal Endocrinology 29, 214226.
Kulig H, Kmieć M 2009. Association between leptin gene polymorphisms and growth traits in Limousin cattle. Russian Journal of Genetics 45, 738741.
Kumar B, Francis SM, Suttie JM, Thompson MP 1998. Expression of obese mRNA in genetically lean and fat selection lines of sheep. Comparative Biochemistry and Physiology, Biochemistry and Molecular Biology 120, 543548.
Kuo AY, Cline MA, Werner E, Siegel PB, Denbow DM 2005. Leptin effects on food and water intake in lines of chickens selected for high or low body weight. Physiology and Behaviour 84, 459464.
Lagonigro R, Wiener P, Pilla F, Woolliams JA, Williams JL 2003. A new mutation in the coding region of the bovine leptin gene associated with feed intake. Animal Genetics 34, 371374.
Laud K, Gourdou I, Belair L, Keisler DH, Djiane J 1999. Detection and regulation of leptin receptor mRNA in ovine mammary epithelial cells during pregnancy and lactation. FEBS Letters 463, 194198.
Licinio J, Negrao AB, Mantzoros C, Kaklamani V, Wong ML, Bongiorno PB, Negro PP, Mulla A, Veldhuis JD, Cearnal L, Flier JS, Gold PW 1998. Sex differences in circulating human leptin pulse amplitude: clinical implications. The Journal of Clinical Endocrinology and Metabolism 83, 41404147.
Liefers SC 2004. Physiology and genetics of leptin in periparturient dairy cows. PhD thesis. University of Wageningen, The Netherlands.
Liefers SC, Te Pas MFW, Veerkamp RF, Van Der Lende T 2002a. Associations between leptin gene polymorphisms and production, live weight, energy balance, feed intake and fertility in Holstein heifers. Journal of Dairy Science 85, 16331638.
Liefers SC, Veerkamp RF, Te Pas MFW, Delavaud C, Chilliard Y, Van Der Lende T 2002b. A missense mutation in the bovine leptin receptor gene is associated with leptin concentrations during late pregnancy. Animal Genetics 35, 138141.
Liefers SC, Veerkamp RF, Te Pas MFW, Chilliard Y, Van Der Lende T 2005. Genetics and physiology of leptin in periparturient dairy cows. Domestic Animal Endocrinology 29, 227238.
Liefers SC, Veerkamp RF, Te Pas MFW, Delavaud C, Chilliard Y, Van Der Lende T 2003. Leptin concentrations in relation to energy balance, milk yield, live weight and estrus in dairy cows. Journal of Dairy Science 86, 799807.
Lin J, Barb CR, Matteri RL, Kraeling RR, Chen X, Meinersmann RJ, Rampacek GB 2000. Long form leptin receptor mRNA expression in the brain, pituitary, and other tissues in the pig. Domestic Animal Endocrinology 19, 5361.
Litten JC, Mostyn A, Laws J, Corson AM, Symonds ME, Clark L 2008. Effect of acute administration of recombinant human leptin during the neonatal period on body temperature and endocrine profile of the piglet. Neonatology 93, 171177.
Liu SM, Adams NR, Briegel JB, Smith TL, Martin GB 2007a. Effect of genetic resistance to gastrointestinal nematodes on plasma concentrations of insulin-like growth factor-1 and leptin in merino sheep. Australian Journal of Experimental Agriculture 47, 905911.
Liu XJ, Dunn IC, Sharp PJ, Boswell T 2007b. Molecular cloning and tissue distribution of a short form chicken leptin receptor mRNA. Domestic Animal Endocrinology 32, 155166.
Loiselle MC, Ster C, Talbot BG, Zhao X, Wagner GF, Boisclair YR, Lacasse P 2009. Impact of postpartum milking frequency on the immune system and the blood metabolite concentration of dairy cows. Journal of Dairy Science 92, 19001912.
Lord GM, Matarese G, Howard JK, Baker RJ, Bloom SR, Lechler RI 1998. Leptin modulates the T-cell immune response and reverses starvation-induced immunosuppression. Nature 394, 897901.
McFadin EL, Keisler DH, Schmidt TB, Lorenzen CL, Berg EP 2003. Correlations between serum concentrations of leptin and beef carcass composition and quality. Journal of Muscle Foods 14, 8187.
Maciel MN, Zieba DA, Amstalden M, Keisler DH, Neves JP, Williams GL 2004. Chronic administration of recombinant ovine leptin in growing beef heifers: effects on secretion of LH, metabolic hormones and timing of puberty. Journal of Animal Science 82, 29302936.
Madeja Z, Adamowicz T, Chmurzynska A, Jankowski T, Melonek J, Switonski M, Strabel T 2009a. Effect of leptin gene polymorphisms on breeding value for milk production traits. Journal of Dairy Science 87, 39253927.
Madeja ZE, Warzych E, Peippo J, Lechniak D, Switonski M 2009b. Gene expression and protein distribution of leptin and its receptor in bovine oocytes and preattachment embryos produced in vitro. Animal 3, 568578.
Maffei M, Halaas J, Ravussin E, Pratley RE, Lee GH, Zhang Y, Fei H, Kim S, Lallone R, Ranganathan S, Kern PS, Friedman JM 1995. Leptin levels in human and rodent: measurement of plasma leptin and ob RNA in obese and weight-reduced subjects. Nature Medicine 1, 11551161.
Malik NM, Carter ND, Murray JF, Scaramuzzi RJ, Wilson CA, Stock MJ 2001. Leptin requirement for conception, implantation, and gestation in the mouse. Endocrinology 142, 51985202.
Mann GE, Mann SJ, Blache D, Webb R 2005. Metabolic variables and plasma leptin concentrations in dairy cows exhibiting reproductive cycle abnormalities identified through milk progesterone monitoring during the post partum period. Animal Reproduction Science 88, 191202.
Margetic S, Gazzola C, Pegg GG, Hill RA 2002a. Leptin: a review of its peripheral actions and interactions. International Journal of Obesity and Related Metabolic Disorders 26, 14071433.
Margetic S, Gazzola C, Pegg GG, Hill RA 2002b. Characterisation of leptin binding in bovine kidney membranes. Domestic Animal Endocrinology 23, 411424.
Matarese G 2000. Leptin and the immune system: how nutritional status influences the immune response. European Cytokine Network 11, 714.
Meyer MJ, Capuco AV, Ross DA, Lintault LM, Van Amburgh ME 2006. Developmental and nutritional regulation of the prepubertal bovine mammary gland. ll. Epithelial cell proliferation, parenchymal accretion rate and allometric growth. Journal of Dairy Science 89, 42984304.
Miner JL 2004. The adipocyte as an endocrine cell. Journal of Animal Science 82, 935941.
Minton JE, Bindel DJ, Drouillard JS, Titgemeyer EC, Grieger DM, Hill CM 1998. Serum leptin is associated with carcass traits in finishing cattle. Journal of Animal Science 76 (Suppl. 1), 231.
Mitchell J, DeVuyst EA, Bauer ML, Larson DL 2009. Cow-calf profitability and leptin genotyping. Agricultural Economics 40, 113118.
Montague CT, Prins JB, Sanders L, Zhang J, Sewter CP, Digby J, Byrne CD, O’Rahilly S 1998. Depot-related gene expression in human subcutaneous and omental adipocytes. Diabetes 47, 13841391.
Montague CT, Farooqi IS, Whitehead JP, Soos MA, Rau H, Wareham NJ, Sewter CP, Digby JE, Mohammed SN, Hurst JA, Cheetham CH, Earley AR, Barnett AH, Prins JB, O’Rahilly S 1997. Congenital leptin deficiency is associated with severe early-onset obesity in humans. Nature 387, 903908.
Morise A, Louveau I, Le Huërou-Luron I 2008. Growth and development of adipose tissue and gut and related endocrine status during early growth in the pig: impact of low birth weight. Animal 2, 7383.
Morrison CD, Daniel JA, Holmberg BJ, Djiane J, Raver N, Gertler A, Keisler DH 2001. Central infusion of leptin into well-fed and undernourished ewe lambs: effects on feed intake and serum concentrations of growth hormone and luteinizing hormone. Journal of Endocrinology 168, 317324.
Mounzih K, Qiu J, Ewart-Toland A, Chehab FF 1998. Leptin is not necessary for gestation and parturition but regulates maternal nutrition via a leptin resistance state. Endocrinology 139, 52595262.
Muñoz C, Carson AF, McCoy MA, Dawson LER, Wylie ARG, Gordon AW 2009a. Effects of plane of nutrition of ewes in early and mid-pregnancy on performance of the offspring: female reproduction and male carcass characteristics. Journal of Animal Science 87, 36473655.
Muñoz G, Alves E, Fernández A, Óvilo C, Barragán C, Estellé J, Quintanilla R, Folch JM, Silió L, Rodríguez MC, Fernández AI 2009b. QTL detection on porcine chromosome 12 for fatty-acid composition and association analyses of the fatty acid synthase, gastric inhibitory polypeptide and acetyl-coenzyme A carboxylase alpha genes. Animal Genetics 38, 639646.
Neglia S, Arcamone N, Gargiulo G, de Girolamo P 2008. Immunocytochemical detection of leptin-like immuno-reactivity in the chicken gastroenteric tract. General and Comparative Endocrinology 151, 432437.
Ninov K, Ledur MC, Alves HJ, Fernandes do Rosário M, Nones K, Coutinho LL 2008. Investigation of leptin gene in broiler and layer chicken lines. Scientia Agricola 65, 214219.
Nkrumah JD, Keisler DH, Crews DH Jr, Basarab JA, Wang Z, Li C, Price MA, Okine EK, Moore SS 2007. Genetic and phenotypic relationships of serum leptin concentration with performance, feed efficiency, and carcass merit of feedlot cattle. Journal of Animal Science 85, 21472155.
Nkrumah JD, Li C, Yu J, Hansen C, Keisler DH, Moore SS 2005. Polymorphisms in the bovine leptin promoter associated with serum leptin concentration, growth, feed intake, feeding behavior, and measures of carcass merit. Journal of Animal Science 83, 2028.
Nonaka S, Hashizume T, Yamashita T 2006. Effects of leptin and leptin peptide amide on the release of luteinising hormone, growth hormone and prolactin from cultured porcine anterior pituitary cells. Animal Science Journal 77, 4752.
Norgaard JV, Nielsen MO, Theil PK, Sorensen MT, Safayi S, Sejrsen K 2008. Development of mammary glands of fat sheep submitted to restricted feeding during late pregnancy. Small Ruminant Research 76, 155165.
Ogasawara H, Ohwada S, Nagai Y, Taketa Y, Matsuzaki M, Tanaka S, Watanabe K, Aso H, Yamaguchi T 2008. Localisation of leptin and leptin receptor in the bovine adenohypophysis. Domestic Animal Endocrinology 35, 815.
Ohkubo T, Nishio M, Tsurudome M, Ito M, Ito Y 2007. Existence of leptin receptor protein in chicken tissues: isolation of a monoclonal antibody against chicken leptin receptor. General and Comparative Endocrinology 151, 269273.
Oikonomou G, Angelopoulou K, Arsenos G, Zygoyiannis D, Banos G 2009. The effects of polymorphisms in the DGAT1, leptin and growth hormone receptor gene loci on body energy, blood metabolic and reproductive traits of Holstein cows. Animal Genetics 40, 1017.
Oka A, Maruo Y, Miki T, Yamasaki T, Saito T 1998. Influence of vitamin A on the quality of beef from the Tajima strain of Japanese Black cattle. Meat Science 48, 159167.
Ortiz RM, Houser DS, Wade CE, Ortiz CL 2003. Hormonal changes associated with the transition between nursing and natural fasting in northern elephant seals (Mirounga angustirostris). General and Comparative Endocrinology 130, 7883.
Ovilo C, Fernandez A, Noguera JL, Barragan C, Leton R, Rodriguez C, Mercade A, Alves E, Folch JM, Varona L, Toro M 2005. Fine mapping of porcine chromosome 6 QTL and LEPR effects on body composition in multiple generations of an Iberian by Landrace intercross. Genetics Research 85, 5767.
Paczoska-Eliasiewicz HE, Proszkowiec-Weglarz M, Proudman J, Jacek T, Mika M, Sechman A, Rzasa J, Gertler A 2006. Exogenous leptin advances puberty in domestic hen. Domestic Animal Endocrinology 31, 211226.
Paczoska-Eliasiewicz HE, Gertler A, Proszkowiec M, Proudman J, Hrabia A, Sechman A, Mika M, Jacek T, Cassy S, Raver N, Rzasa J 2003. Attenuation by leptin of the effects of fasting on ovarian function in hens (Gallus domesticus). Reproduction 126, 739751.
Pan W, Hsuchou H, Hong T, Kastin A 2008. Developmental changes of leptin receptors in cerebral microvessels: unexpected relation to leptin transport. Endocrinology 149, 877885.
Pannier L, Sweeney T, Hamill RM, Ipek F, Stapleton PC, Mullen AM 2009. Lack of an association between single nucleotide polymorphisms in the bovine leptin gene and intramuscular fat in Bos taurus cattle. Meat Science 81, 731737.
Peixoto J de O, Guimarães SEF, Lopes PS, Soares MAM, Pires AV, Barbosa MVG, Torres R de A, e Silva M de A 2006. Associations of leptin gene polymorphisms with production traits in pigs. Journal of Animal Breeding and Genetics 123, 378383.
Pelleymounter MA, Cullen MJ, Baker MB, Hecht R, Winters D, Boone T, Collins F 1995. Effects of the obese gene product on body weight regulation in ob/ob mice. Science 269, 540543.
Pinotti L, Rosi F 2006. Leptin in bovine colostrum and milk. Hormone and Metabolism Research 38, 8993.
Pittroff W, Dahm F, Blanc F, Keisler D, Cartwright TC 2008. Onset of puberty and the inflection point of the growth curve in sheep – Brody’s Law revisited. Journal of Agricultural Science 146, 239250.
Rago V, Aquila S, Guido C, Carpino A 2009. Leptin and its receptor are expressed in the testis and in the epididymis of young and adult pigs. The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology 292, 736745.
Ramsay TG, Richards MP 2005. Leptin and leptin receptor expression in skeletal muscle and adipose tissue in response to in vivo porcine somatotropin treatment. Journal of Animal Science 83, 25012508.
Ramsay TG, Yan X, Morrison C 1998. The obesity gene in swine: sequence and expression of porcine leptin. Journal of Animal Science 76, 484490.
Ramsay TG, Stoll MJ, Caperna TJ 2010. Adipokine gene transcription level in adipose tissue of runt piglets. Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology 155, 97105.
Reist M, Erdin D, von Euw D, Tschuemperlin K, Leuenberger H, Chilliard Y, Hammon HM, Morel C, Philipona C, Zbinden Y, Kuenzi N, Blum JW 2002. Estimation of energy balance at the individual and herd level using blood and milk traits in high-yielding dairy cows. Journal of Dairy Science 85, 33143327.
Ren MQ, Wegner J, Bellmann O, Brockmann GA, Schneider F, Teuscher F, Ender K 2002. Comparing mRNA levels of genes encoding leptin, leptin receptor, and lipoprotein lipase between dairy and beef cattle. Domestic Animal Endocrinology 23, 371381.
Richards MP 2003. Genetic regulation of feed intake and energy balance in poultry. Poultry Science 82, 907916.
Richards MP, Poch SM 2003. Molecular cloning and expression of the turkey leptin receptor gene. Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology 136, 833846.
Richards MP, Caperna TJ, Elsasser TH, Ashwell MC, McMurtry JP 2000. Design and application of a polyclonal peptide antiserum for the universal detection of leptin protein. Journal of Biochemical and Biophysical Methods 45, 147156.
Robert C, Palin MF, Coulombe N, Roberge C, Silversides FG, Benkel BF, McKay RM, Pelletier G 1998. Backfat thickness in pigs is positively associated with leptin mRNA levels. Canadian Journal of Animal Science 78, 473482.
Rock FL, Altmann SW, van Heek M, Kastelein RA, Bazan JF 1996. The leptin haemopoietic cytokine fold is stabilized by an intrachain disulfide bond. Hormones and Metabolic Research 28, 649652.
Rosenbaum M, Pietrobelli A, Vasselli JR, Heymsfield SB, Leibel RL 2001. Sexual dimorphism in circulating leptin concentrations is not accounted for by differences in adipose tissue distribution. International Journal of Obesity 25, 13651371.
Rothschild MF, Hu ZL, Jiang Z 2007. Advances in QTL mapping in pigs. International Journal of Biological Science 3, 192197.
Ruf T, Heldmaier G 1992. Reduced locomotor activity following daily torpor in the Djungarian hamsters: recovery from hypothermia? Naturwissenschaften 79, 574575.
Saad MF, Damani S, Gingerich RL, Riad-Gabriel MG, Khan A, Boyadjian R, Jinagouda SD, El-Tawil K, Rude RK, Kamdar V 1997. Sexual dimorphism in plasma leptin concentration. Journal of Clinical Endocrinology and Metabolism 82, 579584.
Sandberg FB, Emmans GC, Kyriazakis I 2006. A model for predicting feed intake of growing animals during exposure to pathogens. Journal of Animal Science 84, 15521566.
Sasaki S, Clutter AC, Pomp D 1996. Assignment of the porcine obese (leptin) gene to chromosome 18 by linkage analysis of a new PCR-based polymorphism. Mammalian Genome 7, 471472.
Sato K, Nishida M, Akiba Y 2003. Nutritional modulation of leptin receptor messenger RNA in broiler chickens. Journal of Poultry Science 40, 1320.
Schaeffer LR 2006. Strategy for applying genome-wide selection in dairy cattle. Journal of Animal Breeding and Genetics 123, 218223.
Schenkel FS, Miller SP, Ye X, Moore SS, Li C, Yu J, Lobo S, Mandell IB, Wilton JW 2006. Association of SNPs in the leptin and leptin receptor genes with different fat depots in beef cattle. Proceedings of the 8th World Congress on Genetics Applied to Livestock Production, 13th–18th August 2006. Instituto Prociência, Belo Horizonte, Minas Gerais, Brazil.
Schenkel FS, Miller SP, Ye X, Moore SS, Nkrumah JD, Li C, Yu J, Mandell IB, Wilton JW, Williams JL 2005. Association of single nucleotide polymorphisms in the leptin gene with carcass and meat quality traits of beef cattle. Journal of Animal Science 83, 20092020.
Shan TZ, Wang YZ, Guo J, Chu X, Liu JX, Xu ZR 2008. The body weight-related differences of leptin and neuropeptide Y (NPY) gene expression in pigs. Asian-Australasian Journal of Animal Sciences 21, 161166.
Shi ZD, Shao XB, Chen N, Yu YC, Bi YZ, Liang SD, Williams JB, Taouis M 2006. Effects of immunisation against leptin on feed intake, weight gain, fat deposition and laying performance in chickens. British Poultry Science 47, 8894.
Shimizu H, Shimomura Y, Nakanishi Y, Futawateri T, Ohtani K, Sato N, Mori M 1997. Estrogen increases in vivo leptin production in rats and human subjects. Journal of Endocrinology 154, 285292.
Shin SC, Chung ER 2007. Association of SNP marker in the leptin gene with carcass and meat quality traits in korean cattle. Asian-Australasian Journal of Animal Sciences 20, 16.
Silva LFP, VandeHaar MJ, Nielsen MSW, Smith GW 2002. Evidence for a local effect of leptin in bovine mammary gland. Journal of Dairy Science 85, 32773286.
Silva LF, Liesman JS, Etchebarne BE, Nielsen MS, Vandehaar MJ 2005. Short communication: intramammary infusion of IGF-I increases bromodeoxyuridine labeling in mammary epithelial cells of prepubertal heifers. Journal of Dairy Science 88, 27712773.
Silva LFP, Etchebarne BE, Nielsen MSW, Liesman JS, Kiupel M, VandeHaar MJ 2008. Intramammary infusion of leptin decreases proliferation of mammary epithelial cells in prepubertal heifers. Journal of Dairy Science 91, 30343044.
Sirotkin A, Rafay J, Kotwica J 2009. Leptin controls rabbit ovarian function in vivo and in vitro: possible interrelationships with ghrelin. Theriogenology 72, 765772.
Smith JL, Sheffield LG 2002. Production and regulation of leptin in bovine mammary epithelial cells. Domestic Animal Endocrinology 22, 145154.
Smith-Kirwin SM, O’Connor DM, Johnston J, De Lancey E, Hassink SG, Funanage VL 1998. Leptin expression in human mammary epithelial cells and breast milk. Journal of Clinical Endocrinology and Metabolism 83, 18101813.
Solberg R, Aas V, Thoresen GH, Kase ET, Drevon CA, Rustan AC, Reseland JE 2005. Leptin expression in human primary skeletal muscle cells is reduced during differentiation. Journal of Cellular Biochemistry 96, 8996.
Stachowiak M, Mackowski M, Madeja Z, Szydlowski M, Buszka A, Kaczmarek P, Rubis B, Mackowiak P, Nowak KW, Switonski M 2007. Polymorphism of the porcine leptin gene promoter and analysis of its association with gene expression and fatness traits. Biochemical Genetics 45, 245253.
Stone RT, Kappes SM, Beattie CW 1996. The bovine homolog of the obese gene maps to chromosome 4. Mammalian Genome 7, 399400.
Stone RT, Casas E, Smith TPL, Keele JW, Harhay G, Bennett GL, Koohmaraie M, Wheeler TL, Shackelford SD, Snelling WM 2005. Identification of genetic markers for fat deposition and meat tenderness on bovine chromosome 5: development of a low-density single nucleotide polymorphism map. Journal of Animal Science 83, 22802288.
Strat AL, Kokta TA, Dodson MV, Gertler A, Wu Z, Hill RA 2005. Early signaling interactions between the insulin and leptin pathways in bovine myogenic cells. Biochimica et Biophysica Acta 1744, 164175.
Summer A, Saleri R, Malacarne M, Bussolati S, Beretti V, Sabbioni A, Superchi P 2009. Leptin in sow: influence on the resumption of cycle activity after weaning and on the piglet gain. Livestock Science 124, 107111.
Sun C, Wang L, Jiang DF, Zhang B 2009. Missense mutations in exon 2 of the porcine leptin receptor gene and their associations with litter size and body weight. Czech Journal of Animal Science 54, 210216.
Suzuki K, Inomata K, Katoh K, Kadowaki H, Shibata T 2009. Genetic correlations among carcass cross-sectional fat area ratios, production traits, intramuscular fat, and serum leptin concentration in Duroc pigs. Journal of Animal Science 87, 22092215.
Taouis M, Chen JW, Davidaud C, Dupont J, Derouet M, Simon J 1998. Cloning the chicken leptin gene. Gene 208, 239242.
Tartaglia LA 1997. The leptin receptor. Journal of Biological Chemistry 272, 60936096.
Tartaglia LA, Dembski M, Weng X, Deng N, Culpepper J, Devos R, Richards GJ, Campfield LA, Clark FT, Deeds J, Muir C, Sanker S, Moriarty A, Moore KJ, Smutko JS, Mays GG, Woolf EA, Monroe CA, Tepper RI 1995. Identification and expression cloning of a leptin receptor, OB-R. Cell 83, 12631271.
Thomas L, Wallace JM, Aitken RP, Mercer JG, Trayhurn P, Hoggard N 2001. Circulating leptin during ovine pregnancy in relation to maternal nutrition, body composition and pregnancy outcome. Journal of Endocrinology 169, 465476.
Thorn SR, Meyer MJ, Van Amburgh ME, Boisclair YR 2007. Effect of estrogen on leptin and expression of leptin receptor transcripts in prepubertal dairy heifers. Journal of Dairy Science 90, 37423750.
Thorn SR, Purup S, Cohick WS, Vestergaard M, Sejrsen K, Boisclair YR 2006. Leptin does not act directly on mammary epithelial cells in prepubertal dairy heifers. Journal of Dairy Science 89, 14671477.
Tokuda T, Matsui T, Yano H 2000. Effects of light and food on plasma leptin concentrations in ewes. Animal Science 71, 235242.
Tokuda T, Kono S, Fujihara T 2001. The relationships between leptin and vitamin A levels in plasma of fattening cattle supplemented with vitamin A. Animal Science 73, 433441.
Tokuda T, Delavaud C, Chilliard Y 2003. Plasma leptin concentration in pre-and post-weaning lambs. Animal Science 76, 221227.
Treacher RJ, Reid IM, Roberts CJ 1986. Effect of body condition at calving on the health and performance of dairy cows. Animal Production 43, 16.
Tu H, Kastin AJ, Hsuchou H, Pan W 2008. Soluble receptor Inhibits leptin transport. Journal of Cell Physiology 9999, 15.
Uotani S, Bjørbaek C, Tornøe J, Flier JS 1999. Functional properties of leptin receptor isoforms: internalization and degradation of leptin and ligand-induced receptor downregulation. Diabetes 48, 279286.
Valderrabano J, Gomez-Rincon C, Uriarte J 2006. Effect of nutritional status and fat reserves on the periparturient immune response to Haemonchus contortus infection in sheep. Veterinary Parasitology 141, 122131.
Van der Lende T, Te Pas MFW, Veerkamp RF, Liefers SC 2005. Leptin gene polymorphisms and their phenotypic associations. Vitamins and Hormones 71, 373404.
Vickers MH, Gluckman PD, Coveny AH, Hofman PL, Cutfield WS, Gertler A, Breier BH, Harris M 2005. Neonatal leptin treatment reverses developmental programming. Endocrinology 146, 42114216.
Villalba D, Tor M, Vidal O, Bosch L, Reixach J, Amills M, Sanchez A, Estany J 2009. An age-dependent association between a leptin C3469T SNP and intramuscular fat content in pigs. Livestock Science 121, 335338.
Vincent AL, Wang L, Rothschild MF 1997. Rapid communication: a restriction fragment length polymorphism in the porcine leptin receptor (LEPR) gene. Journal of Animal Science 75, 2287.
Wabitsch M, Blum WF, Muche R, Braun M, Hube F, Rascher W, Heinze E, Teller W, Hauner H 1997. Contribution of androgens to the gender difference in leptin production in obese children and adolescents. Journal of Clinical Investigation 100, 808813.
Wang Y, Li H, Zhang YD, Gu Z-L, Li ZH, Wang Q-G 2006. Analysis on association of a SNP in the chicken OBR gene with growth and body composition traits. Asian-Australasian Journal of Animal Sciences 19, 17061710.
Wegner J, Huff P, Xie CP, Schneider F, Teuscher F, Mir PS, Mir Z, Kazala EC, Weselake RJ, Ender K 2001. Relationship of plasma leptin concentration to intramuscular fat content in beef from crossbred Wagyu cattle. Canadian Journal of Animal Science 81, 451457.
Weigle DS 1994. Appetite and the regulation of body composition. FASEB Journal 8, 302310.
Whisnant CS, Harrell RJ 2002. Effect of short-term feed restriction and refeeding on serum concentrations of leptin, luteinizing hormone and insulin in ovariectomized gilts. Domestic Animal Endocrinology 22, 7380.
Whitley NC, O’Brien DJ, Quinn RW, Keisler DH, Walker EL, Brown MA 2009. Milk leptin in sows and blood leptin and growth of their offspring. Journal of Animal Science 87, 16591663.
Williams GL, Amstalden M, Garcia MR, Stanko RL, Nizielski SE, Morrison CD, Kiesler DH 2002. Leptin and its role in the central regulation of reproduction in cattle. Domestic Animal Endocrinology 23, 339349.
Wójcik-Gładysz A, Wańkowska M, Misztal T, Romanowicz K, Polkowska J 2009. Effect of intracerebroventricular infusion of leptin on the secretory activity of the GnRH/LH axis in fasted prepubertal lambs. Animal Reproduction Science 114, 370383.
Wolinski J, Biernat M, Guilloteau P, Westrom BR, Zabielski R 2003. Exogenous leptin controls the development of the small intestine in neonatal piglets. Journal of Endocrinology 177, 215222.
Wuethrich AJ, Hancock DL, Long HB, Manetta J, Roth JL, Anderson DB 1998. The effect of leptin immunization on feed intake in finishing swine. Journal of Animal Science 76 (Suppl 1), 129.
Wylie ARG 2004. Association of plasma leptin concentrations with fat depot accumulation in growing sheep. British Society of Animal Science Annual Meeting, York, UK. Abstract 129.
Wylie ARG, Devlin DJ, Bjourson AJ 2002. Profiles of leptin and IGF-1 and inter-relationships between energy-related metabolites and hormones in fed and fasted sheep. British Society of Animal Science Annual Meeting, York, UK. Abstract 87.
Wylie ARG, Mackey DR, Devlin DJ, Bjourson AJ, Diskin MG 2001. Plasma leptin in intact and ovariectomised beef heifers on low and high planes of nutrition. Proceedings of Agricultural Research Forum at Tullamore, 43pp. Teagasc, Dublin, Ireland.
Wylie ARG, Woods SM, Carson AF, McCoy MA 2008. Periprandial changes in metabolite and metabolic hormone concentrations in high genetic merit dairy heifers and their relationship to energy balance in early lactation. Journal of Dairy Science 91, 577586.
Xu S-Y, Wu D, Guo H-Y, Zheng A-R, Zhang G 2009. The level of feed intake affects embryo survival and gene expression during early pregnancy in gilts. Reproduction in Domestic Animals 45, 685693.
Yacobovitz M, Solomon G, Gusakovsky EE, Levavi-Sivan B, Gertler A 2008. Purification and characterization of recombinant pufferfish (Takifugu rubripes) leptin. General and Comparative Endocrinology 156, 8390.
Yamada T, Kawakami S-I, Nakanishi N 2003. The relationship between plasma leptin concentrations and the distribution of body fat in crossbred steers. Animal Science Journal 74, 95100.
Yan T, Mayne CS, Keady TWJ, Agnew RE 2006. Effects of dairy cow genotype with two planes of nutrition on energy partitioning between milk and body tissue. Journal of Dairy Science 89, 10311042.
Yang SH, Kawachi H, Khan MA, Lee SY, Kim HS, Ha Jong K, Lee WS, Lee HJ, Ki KS, Kim SB, Sakaguchi S, Maruyama S, Yano H 2008. Development of bovine specific leptin radioimmunoassay and relationship of plasma leptin with vitamin A and age of Wagyu. Asian – Australasian Journal of Animal Sciences 21, 12861295.
Yonekura S, Oka A, Noda M, Uozumi N, Yonezawa T, Katoh K, Obara Y 2002. Relationship between serum leptin concentrations and the marbling scores in Japanese Black cattle. Animal Science Journal 73, 5157.
Yu WH, Kimura M, Walczewska A, Karanth S, McCann SM 1997. Role of leptin in hypothalamic-pituitary function. Proceedings of the National Academy of Sciences USA 94, 10231028.
Yu T, Luo G, Zhang L, Wu J, Zhang H, Yang G 2008. Leptin promotes proliferation and inhibits differentiation in porcine skeletal myoblasts. Bioscience, Biotechnology, and Biochemistry 72, 1321.
Zaralis K, Tolkamp BJ, Houdijk JGM, Wylie ARG, Kyriazakis I 2008. Changes in food intake and circulating leptin due to gastrointestinal parasitism in lambs of two breeds. Journal of Animal Science 86, 18911903.
Zaralis K, Tolkamp BJ, Houdijk JGM, Wylie ARG, Kyriazakis I 2009. Consequences of protein supplementation on anorexia, expression of immunity and plasma leptin concentrations in parasitised ewes of two breeds. British Journal of Nutrition 101, 499509.
Zembayashi M, Nishimura K, Lunt DK, Smith SB 1995. Effect of breed type and sex on the fatty acid composition of subcutaneous and intramuscular lipids of finishing steers and heifers. Journal of Animal Science 73, 33223325.
Zhang S, Blache D, Blackberry MA, Martin GB 2005. Body reserves affect the reproductive endocrine responses to an acute change in nutrition in mature male sheep. Animal Reproduction Science 88, 257269.
Zhang Y, Proenca R, Maffei M, Barone M, Leopold L, Friedman JM 1994. Positional cloning of the mouse obese gene and its human homologue. Nature 372, 425432.
Zhang Y, Basinski MB, Beals JM, Briggs SL, Churgay LM, Clawson DK, DiMarchi RD, Furman TC, Hale JE, Hsiung HM, Schoner BE, Smith DP, Zhang XY, Wery J-P, Schweitz RW 1997. Crystal structure of the obese protein leptin-E100. Nature 387, 206209.
Zhao FQ, Keating AF 2007. Expression and regulation of glucose transporters in the bovine mammary gland. Journal of Dairy Science 90, E76E86.
Zhou H, Hickford JGH, Gong H 2009. Identification of allelic polymorphism in the ovine leptin gene. Molecular Biotechnology 41, 2225.
Zieba DA, Amstalden M, Williams GL 2005. Regulatory roles of leptin in reproduction and metabolism: a comparative review. Domestic Animal Endocrinology 29, 166185.