Breeding and genetics
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Analysis of body measurements of newborn purebred Belgian Blue calves
- I. Kolkman, G. Opsomer, S. Aerts, G. Hoflack, H. Laevens, D. Lips
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- Published online by Cambridge University Press:
- 22 December 2009, pp. 661-671
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At calving, purebred animals of the Belgian Blue (BB) breed are compromised by the incompatibility in size and shape of the dam and her calf, resulting in a very high incidence of dystocia problems. To clarify which body parts of the calf are of decisive importance to allow natural delivery and to investigate both the mean value as well as the variation among these body sizes within this breed (variation being an important condition for selection), measurements of nine body parts (body weight at birth (BW), body length (BL), length of the head (LH), shoulder width (SW), hip width (HW), heart girth (HG), withers height (WH) and the circumference of the fetlock of both the front (CFF) and the hind leg (CFH)) were assessed in 147 newborn purebred BB calves on 17 farms. Simple and partial correlations were assessed and we examined whether environmental factors (gender of the calf, parity of the cow, type of calving, season of birth and time of measurement after birth) were significantly associated with these specific calf measurements. The mean BW was 49.2 ± 7.1 kg. The average BL was 56.4 ± 4.5 cm and the mean LH was 24.4 ± 2.3 cm. Measurements obtained for SW and HW were 22.4 ± 2.2 and 22.9 ± 2.1 cm, respectively, whereas the mean WH was 71.1 ± 4.7 cm. Measurements of circumferences revealed a CFF of 17.9 ± 1.1 cm, a CFH of 18.0 ± 1.0 cm and a mean HG of 78.0 ± 5.4 cm. Partial correlations of the BW with eight body measurements were significant (P < 0.01) and ranged between 0.17 and 0.85; 0.42 and 0.88; and 0.24 and 0.88 when corrected for gender, parity and type of calving, respectively. BL (P < 0.01) and the CFF and CFH (P < 0.001) are larger in bull calves than in heifer calves. Calves born through caesarean section had broader SW (P < 0.01) and HW (P < 0.01) when compared with calves born after natural calving (defined as born per vaginam without assistance or with slight traction). Sizes of calves born out of multiparous cows were generally larger than of calves born out of heifers (SW: P < 0.001; HW: P < 0.05). As SW and HW are the broadest points of a BB calf, they are both candidates for being the limiting measures for calving ease, but the difference between HW and SW for the total data set was not different from zero (P > 0.05). In contrast to male calves in which no significant difference (between HW and SW) could be found, female calves show the difference between HW and SW that was significantly different from zero (P < 0.001); thus, in female calves, the HW is the most limiting factor of the calf’s body. The significant variation in some body measures between the calves and the strong correlation within these sizes raises the possibility of selection towards smaller calves aiming to limit the dystocia problem in the BB breed. Furthermore, on the basis of our results, we were able to build equations for the farmer to use at the moment of calving containing the LH, the CF and the calf’s gender to estimate SW and HW, the limiting body parts of the calf to be born naturally. Together with the knowledge of the pelvic size of the dam, this information gives the obstetrician or the farmer a more accurate prediction of the probability of natural calving at parturition.
Parent-of-origin effects cause genetic variation in pig performance traits
- N. Neugebauer, H. Luther, N. Reinsch
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- 08 January 2010, pp. 672-681
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In order to assess the relative importance of genomic imprinting for the genetic variation of traits economically relevant for pork production, a data set containing 21 209 records from Large White pigs was analysed. A total of 33 traits for growth, carcass composition and meat quality were investigated. All traits were recorded between 1997 and 2006 at a test station in Switzerland and the pedigree included 15 747 ancestors. A model with two genetic effects for each animal was applied: the first corresponds to a paternal and the second to a maternal expression pattern of imprinted genes. The imprinting variance was estimated as the sum of both corresponding genetic variances per animal minus twice the covariance. The null hypothesis of no imprinting was tested by a restricted maximum likelihood ratio test with two degrees of freedom. Genomic imprinting significantly contributed to the genetic variance of 19 traits. The proportion of the total additive genetic variance that could be attributed to genomic imprinting was of the order between 5% and 19%.
Genetic variation in competition traits at different ages and time periods and correlations with traits at field tests of 4-year-old Swedish Warmblood horses
- Å. Viklund, Å. Braam, A. Näsholm, E. Strandberg, J. Philipsson
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- Published online by Cambridge University Press:
- 19 January 2010, pp. 682-691
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For many years, the breeding value estimation for Swedish riding horses has been based on results from Riding Horse Quality Tests (RHQTs) of 4-year-olds only. Traits tested are conformation, gaits and jumping ability. An integrated index including competition results is under development to both get as reliable proofs as possible and increases the credibility of the indexes among breeders, trainers and riders. The objectives of this study were to investigate the suitability of competition data for use in genetic evaluations of horses and to examine how well young horse performance agrees with performance later in life. Competition results in dressage and show jumping for almost 40 000 horses from the beginning of the 1960s until 2006 were available. For RHQT data of 14 000 horses judged between 1988 and 2007 were used. Genetic parameters were estimated for accumulated competition results defined for different age groups (4 to 6 years of age, 4 to 9 years of age and lifetime), and for different birth year groups. Genetic correlations were estimated between results at RHQT and competitions with a multi-trait animal model. Heritabilities were higher for show jumping than dressage and increased with increasing age of the horse and amount of information. For dressage, heritabilities increased from 0.11 for the youngest group to 0.16 for lifetime results. For show jumping corresponding values increased from 0.24 to 0.28. Genetic correlations between competition results for the different age groups were highly positive (0.84 to 1.00), as were those between jumping traits at RHQT and competition results in show jumping (0.87 to 0.89). For dressage-related traits as 4-year-old and dressage competition results the estimated genetic correlations were between 0.47 and 0.77. We suggest that lifetime results from competitions should be integrated into the genetic evaluation system. However, genetic parameters showed that traits had changed during the over 35-year period covered due to the development of the sport, which needs to be considered in future genetic evaluations.
Nutrition
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Assessing feed efficiency in beef steers through feeding behavior, infrared thermography and glucocorticoids*
- Y. R. Montanholi, K. C. Swanson, R. Palme, F. S. Schenkel, B. W. McBride, D. Lu, S. P. Miller
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- 16 December 2009, pp. 692-701
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A better understanding of the factors regulating feed efficiency and their potential as predictors of feed efficiency in cattle is needed. Therefore, the potential of three classes of traits, namely, feeding behavior characteristics: daily time at feeder (TF; min/day), time per meal (TM; min), meal size (MS; g DM), eating rate (ER; g DM/min), number of daily meals (NM) and daily visits to the feeder (VF); infrared (IR) thermography traits (°C): eye (EY), cheek (CK), snout (SN), ribs (RB) and hind area (HA); and glucocorticoid levels: fecal cortisol metabolites (FCM; ng/g) and plasma cortisol (PC; ng/ml) as predictors of efficiency were evaluated in 91 steers (436 ± 37 kg) over 2 years (Y1 = 46; Y2 = 45). Additionally, the individual traits of each of these three classes were combined to define three single traits. Individual daily feed intake of a corn silage and high-moisture corn-based diet was measured using an automated feeding system. Body weight and thermographs were taken every 28 days over a period of 140 days. Four productive performance traits were calculated: daily dry matter intake (DMI), average daily gain (ADG), feed to gain ratio (F : G) and residual feed intake (RFI). Steers were also classified into three RFI categories (low-, medium- and high-RFI). Among the feeding behavior characteristics, MS and ER were correlated with all efficiency traits (range: 0.26 to 0.75). Low-RFI (more efficient steers) had smaller MS, lower ER and fewer VF in comparison to high-RFI steers. Less efficient steers (high-RFI) performed more VF during the nocturnal period than more efficient steers. More efficient steers had lower CK and SN temperatures than less efficient steers (28.1°C v. 29.2°C and 30.0°C v. 31.2°C), indicating greater energetic efficiency for low-RFI steers. In terms of glucocorticoids, PC was not correlated with efficiency traits. In contrast, more efficient steers had higher FCM in comparison to less efficient steers (51.1 v. 31.2 ng/g), indicating that a higher cortisol baseline is related to better feed efficiency. The overall evaluation of the three classes of traits revealed that feeding behavior, IR thermography and glucocorticoids accounted for 18%, 59% and 7% of the total variation associated with RFI, respectively. These classes of traits have usefulness in the indirect assessment of feed efficiency in cattle. Among them, IR thermography was the most promising alternative to screen cattle for this feed efficiency. These findings might have application in selection programs and in the better understanding of the biological basis associated with productive performance.
Effect of subacute dietary nitrate on production traits and plasma analytes in Suffolk ewes
- R. R. Cockrum, K. J. Austin, P. A. Ludden, K. M. Cammack
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- 16 December 2009, pp. 702-708
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Elevated dietary nitrate (NO3−) is associated with production losses in ruminant livestock, resulting in substantial economic losses incurred by producers. Severe drought, fertilization practices and poorly maintained pastures increase the risk of elevated NO3− intake among cattle and sheep. Nitrate is metabolized to nitrite (NO2−) in the rumen and further reduced to ammonia. Ruminants consuming high dietary NO3− vary in ability to efficiently reduce excess NO2− to ammonia. This leads to methemoglobin formation and ultimately NO3− toxicity signs. Variation in individual tolerance to elevated dietary NO3− can be partially attributed to rate and duration of exposure, rate of elimination, metabolism, species and dose. Our objectives were to confirm and quantify variation in individual tolerance to subacute levels of dietary NO3−, and determine if individuals could be identified as highly or lowly tolerant to elevated dietary NO3− based on production traits, plasma analytes and(or) signs of subacute NO3− toxicity. Purebred Suffolk ewes were administered supplement mixed with tap water (control; n = 8) or potassium nitrate (NO3− treated; 300 mg NO3−/kg BW daily; n = 47) for 8 days. Coefficients of variation (CV) indicated that supplement intake was more variable in NO3− treated ewes (CV = 59.3%) than in control ewes (CV = 13.6%). Among NO3− treated ewes, six ewes highly tolerant and six ewes lowly tolerant to elevated dietary NO3− were identified based on individual performance, NO3− treated supplement intake, and signs of toxicity. Supplement intake was lower (P < 0.0001) in NO3− treated ewes than in control ewes, indicating elevated dietary NO3− influences feed intake. Supplement intake differed (P < 0.0001) between control, highly tolerant and lowly tolerant ewes. Supplement intake of highly and lowly tolerant ewes was 82% and 23%, respectively, of the control ewes’ intake. Weight change and plasma concentrations of NO2−, cortisol, glucose and retinol were not different (P ⩾ 0.38) among control, highly tolerant and lowly tolerant ewes. Plasma urea nitrogen (PUN) levels were not different (P = 0.25) between control and lowly tolerant ewes, but were lower (P = 0.02) in highly tolerant ewes than in control ewes. Furthermore, PUN and NO3− treated supplement intake were highly correlated (0.71; P < 0.0001) in lowly tolerant ewes. These results confirm and quantify variation in response to subacute levels of dietary NO3− and indicate that individuals can be identified as highly or lowly tolerant to elevated dietary NO3− based on their performance and NO3− toxicity signs.
Fasting and sampling time affect liver gene expression of high-fat diet-fed mice
- C. Y. Lee
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- 16 December 2009, pp. 709-713
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Several physiological and biological variables are known to affect peroxisome proliferator-activated receptor (PPAR)-α-dependent signaling pathway and plasma biochemical profiles. However, less is known about the effect of these variables on high-fat diet-fed mice. In a 5-week study, C57BL/6 mice were divided into control (C) and high-fat diet-fed (H) groups, whereby before dissection, each group was subdivided into non-fasted (nC and nH) and a 15-h fasted mice (fC and fH) killed in the early light cycle, and a 15-h fasted mice (eC and eH) killed in the late phase of the light cycle. Liver and blood from the vena cava were collected. Non-fasted nC and nH mice have a marginal difference in their body weight gain, whereas significant differences were found for fasted mice. In nH mice, PPAR-α, acyl-CoA oxidase and insulin-like growth factor-binding protein expressions were significantly elevated, in contrast to fatty acid synthase (Fasn), stearoyl CoA-desaturase (SCD)-1, and elongase (ELOVL)-6 expressions. Fasn was profoundly induced in fH mice, while decreased sterol regulatory-binding protein-1 and SCD-1 were found only in eH mice. Different from the gene expression profiles, plasma total cholesterol level of the eH mice was higher than controls, whereas nH mice have increased plasma non-esterified fatty acids. Only glucose level of the fH mice was higher than that observed for controls. Results showed that fasting and sampling time have significantly affected liver gene expression and plasma biochemical indices of the high-fat diet-treated mice. An overlook in these aspects can cause serious discrepancies in the experimental data and their interpretations.
Systematic comparison of the empirical and factorial methods used to estimate the nutrient requirements of growing pigs
- L. Hauschild, C. Pomar, P. A. Lovatto
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- 18 December 2009, pp. 714-723
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Empirical and factorial methods are currently used to estimate nutrient requirements for domestic animals. The purpose of this study was to estimate the nutrient requirements of a given pig population using the empirical and factorial methods; to establish the relationship between the requirements estimated with these two methods; and to study the limitations of the methods when used to determine the level of a nutrient needed to optimize individual and population responses of growing pigs. A systematic analysis was carried out on optimal lysine-to-net-energy (Lys : NE) ratios estimated by the empirical and factorial methods using a modified InraPorc® growth model. Sixty-eight pigs were individually simulated based on detailed experimental data. In the empirical method, population responses were estimated by feeding pigs with 11 diets of different Lys : NE ratios. Average daily gain and feed conversion ratio were the chosen performance criteria. These variables were combined with economic information to estimate the economic responses. In the factorial method, the Lys : NE ratio for each animal was estimated by model inversion. Optimal Lys : NE ratios estimated for growing pigs (25 to 105 kg) differed between the empirical and the factorial method. When the average pig is taken to represent a population, the factorial method does not permit estimation of the Lys : NE ratio that maximizes the response of heterogeneous populations in a given time or weight interval. Although optimal population responses are obtained by the empirical method, the estimated requirements are fixed and cannot be used for other growth periods or populations. This study demonstrates that the two methods commonly used to estimate nutrient requirements provide different nutrient recommendations and have important limitations that should be considered when the goal is to optimize the response of individuals or pig populations.
Barley and oat cultivars with diverse carbohydrate composition alter ileal and total tract nutrient digestibility and fermentation metabolites in weaned piglets
- R. Jha, B. Rossnagel, R. Pieper, A. Van Kessel, P. Leterme
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- 18 December 2009, pp. 724-731
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An experiment was conducted to evaluate the effects of cereal carbohydrate form (isolated v. cereal matrix) and level, especially mixed-linked β-glucan (hereafter referred to as β-glucan) and starch amylase/amylopectin ratio on nutrient digestibility and fermentation parameters in the intestines of weaned pigs. Four hulless barley cultivars containing varying β-glucan levels (41 to 84 g/kg) were compared with hulled barley, supplemented or not with a β-glucan concentrate (BBG; 270 g/kg β-glucan) and two oat cultivars for digestibility and fermentation metabolites. Seventy-two weaned piglets (BW = 12.8 ± 1.9 kg) were assigned to one of nine diets composed of 815 g/kg cereal, 60 g/kg whey, 90 g/kg soy protein isolate and 35 g/kg minerals. After 15 days, the pigs were killed, and digesta collected from ileum and colon were analyzed for proximate nutrients, short-chain fatty acids (SCFAs), lactic acid (LA) and ammonia. Ileal and total tract digestibility of proximate nutrients and non-starch polysaccharides (NSPs) were determined using HCl-insoluble ash as a marker. Organic matter (OM) ileal digestibility was greater (P < 0.05) for diets based on hulless barley (77% ± 1.1% on average), as compared with hulled barley (64% ± 1.4%) and oat (58% ± 1.5%). Similar trends were found for total tract OM digestibility, varying from 90% ± 0.3% for hulless barley to 67% ± 0.4% for oat, on average. NSP digestibility differed (P < 0.05) within and between cereal types, ranging from 20% (hulled barley plus 163 g/kg BBG or ∼40 g/kg β-glucan) to 51% (SB94893 hulless barley cultivar with high β-glucan and high amylose ratio) at the ileum and from 44% (hulled barley) to 84% (SB94893 cultivar) at the total tract level. No dietary effect (P > 0.05) was found for SCFA concentration in ileal contents, whereas in colonic contents, SCFA was lower in pigs fed oat (P < 0.001). LA concentration was greater (P < 0.001) in the colon of pigs fed hulless barley than in pigs fed hulled barley and oat. Expressed per kg carbohydrate (NSP + starch) fermented, the ammonia concentration at the colon was lowest for hulled barley diets (supplemented with β-glucan) and the highest for oat diets. In conclusion, the interaction of both form and level of β-glucan impacted nutrient digestibility and fermentation. Hulless barleys with high soluble NSP such as β-glucan and resistant starch yielded, in general higher SCFA and LA and lower ammonia. Hulless barleys may, therefore, have potential for use in feeding strategies designed to improve gut health in pigs.
Effects of mixtures of red clover and maize silages on the partitioning of dietary nitrogen between milk and urine by dairy cows
- R. J. Dewhurst, L. J. Davies, E. J. Kim
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- Published online by Cambridge University Press:
- 07 January 2010, pp. 732-738
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Eight multiparous lactating Holstein–Friesian cows were used to evaluate the partitioning of dietary nitrogen (N) from diets based on mixtures of red clover and maize silages in comparison with diets based on ryegrass silage. All cows received 4 kg/day of a standard dairy concentrate with one of four forage treatments in an incomplete changeover design with three 4-week periods. Three treatments were based on mixtures of red clover and maize silage. N intake was altered both by varying the ratio of these silages (40/60 and 25/75 on a dry matter (DM) basis) and by an additional treatment for which the DM intake of the 40/60 mixture was restricted to the level achieved with grass silage. Rumen passage rates were estimated from faecal excretion curves following a pulse oral dose of Dysprosium-labeled silage and urinary excretion of purine derivatives (PD) was used as an index of rumen microbial protein synthesis. Red clover silage mixtures led to significantly increased feed intake (21.5, 20.7 and 15.2 kg DM/day for 40/60 and 25/75 red clover/maize silage mixtures and grass silage, respectively), milk production (25.8, 27.8 and 20.0 kg/day for the same treatments, respectively) and milk component yields, but were without effect on milk fat and protein concentrations. The large increase in the yield of milk (24.5 kg/day) and milk components for the restricted red clover/maize silage treatment, in comparison with the grass silage treatment, was proportionately greater than the increase in DM intake (16.6 kg DM/day). There were no significant treatment effects on diet digestibility, while the higher intakes of red clover silage mixtures were associated with higher rumen passage rates (5.82%, 6.24% and 4.55%/h, respectively). There were significant effects of both N intake and forage source on the partitioning of dietary N between milk and urine. When dietary protein was diluted by the inclusion of maize silage, red clover silage led to increased milk N and reduced urinary N in comparison with grass silage. Improvements in N utilisation may be related to increased dietary starch and/or rumen passage rates leading to increased microbial protein synthesis for these treatments. Urinary excretion of PD was significantly higher for all diets based on mixtures of red clover and maize silages, in comparison with grass silage. Urinary N output was close to literature predictions based on N intake for the diet based on ryegrass silage, but 40 to 80 g/day (25% to 30%) less than predicted for the diets based on the mixtures of red clover and maize silages.
Effects of inulin and lactulose on the intestinal morphology of calves
- S. Masanetz, N. Wimmer, C. Plitzner, E. Limbeck, W. Preißinger, M. W. Pfaffl
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- 13 January 2010, pp. 739-744
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For some time now prebiotics have been proposed to improve health by stimulation of beneficial bacteria in the intestine of humans and animals. The current study is aiming to show effects of feeding of either 2% inulin or 2% lactulose in milk replacer on performance and intestinal morphology of male Holstein–Friesian calves. After 20 weeks of feeding inulin led to significantly higher daily weight gains than lactulose while control animals ranged between the experimental feedings. Ingestion of milk replacer was reduced in lactulose treated animals. Additionally differences of villus height in jejunum (P = 0.07) and ileum (P = 0.03) could be found with an increase for lactulose treated animals and a decrease for inulin treated animals. In ileum the density of proliferative epithelial cells tended to be lower in inulin treated and higher in lactulose treated animals (P = 0.08). Both inulin and lactulose tended to decrease the quantity of goblet cells in the tips of ileal villi (P = 0.07). Both prebiotics can affect performance and intestinal morphology of calves and may as such affect animal health. But effects differ between substances.
Nutritional values of sugarcane products in local Caribbean growing pigs
- X. Xandé, C. Régnier, H. Archimède, B. Bocage, J. Noblet, D. Renaudeau
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- 13 January 2010, pp. 745-754
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A total of 24 castrated male Creole were used for digestibility studies on three sugarcane (SC) products: final molasses, SC juice and ground SC. Digestibility of macronutrients were determined in three consecutive experimental trials between 35 and 60 kg BW. The first trial measured the effect of a constant rate of incorporation of those SC products in a control diet (23% on a dry matter (DM) basis) on digestibility of energy and nutrients. The second and the third trials were designed to determine the effects of increasing rates of inclusion of SC juice and ground SC in the control diet on the digestibility of nutrients and energy. The DM content of molasses, SC juice and ground SC were 74.3%, 19.3% and 25.8%, respectively. Free sugar contents were 73.8%, 81.6% and 51.5% of DM for molasses, SC juice and ground SC, respectively. In contrast with molasses and SC juice, NDF content of ground SC was very high (40.3% DM). Energy digestibility coefficients (DC) were 99.0% and 83.6% for SC juice and molasses, respectively. For ground SC, amounts and composition of intakes differed from feed allowance as a consequence of chewing-then-spitting out most of the fibrous contents of ground SC. Expressed as a percentage of energy intake and energy allowance, DC of energy for ground SC were 68.6% and 31.9%, respectively. On an intake basis, digestible energy (DE) and metabolisable energy (ME) values were higher for SC juice (17.3 and 17.2 MJ/kg DM, respectively) than for molasses (13.1 and 12.6 MJ/kg DM, respectively) or ground SC (12.3 and 11.8 MJ/kg DM, respectively). On an allowance basis, the corresponding values for ground SC were only 5.7 and 5.6 MJ/kg DM, respectively. The gradual inclusion rate of SC juice in the diet up to 66% resulted in a linear increase of the DC of the diet organic matter and energy (P < 0.001) by 0.10% per 1% in SC juice DM. On the other hand, the partial substitution of the control diet by ground SC up to 74% resulted in a linear (P < 0.05) reduction of digestibility of nutrients and energy. Each 1% increase of ground SC incorporation rate resulted in a 0.13% and 0.61% linear decrease of DC of the energy, expressed as a percentage of energy intake or energy allowance, respectively. In conclusion, our study provides updated energy values of SC products usable as energy sources for feeding pigs.
Physiology and functional biology of systems
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Effect of dietary fatty acids on expression of lipogenic enzymes and fatty acid profile in tissues of bulls
- A. Herdmann, K. Nuernberg, J. Martin, G. Nuernberg, O. Doran
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- Published online by Cambridge University Press:
- 15 March 2010, pp. 755-762
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This study investigated the effects of dietary linolenic acid (C18:3n-3) v. linoleic acid (C18:2n-6) on fatty acid composition and protein expression of key lipogenic enzymes, acetyl-CoA carboxylase (ACC), stearoyl-CoA desaturase (SCD) and delta 6 desaturase (Δ6d) in longissimus muscle and subcutaneous adipose tissue of bulls. Supplementation of the diet with C18:3n-3 was accompanied by an increased level of n-3 fatty acids in muscle which resulted in decrease of n-6/n-3 ratio. The diet enriched with n-3 polyunsaturated fatty acids (PUFAs) significantly inhibited SCD protein expression in muscle and subcutaneous adipose tissue, and reduced the Δ6d expression in muscle. There was no significant effect of the diet on ACC protein expression. Inhibition of the Δ6d expression was associated with a decrease in n-6 PUFA level in muscles, whereas repression of SCD protein was related to a lower oleic acid (C18:1 cis-9) content in the adipose tissue. Expression of ACC, SCD and Δ6d proteins was found to be relatively higher in subcutaneous adipose tissue when compared with longissimus muscle. It is suggested that dietary manipulation of fatty acid composition in ruminants is mediated, at least partially, through the regulation of lipogenic enzymes expression and that regulation of the bovine lipogenic enzymes expression is tissue specific.
Effect of n-3 and n-6 polyunsaturated fatty acids on hare reproductive performances
- V. Tufarelli, L. Valentini, M. Dario, V. Laudadio
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- Published online by Cambridge University Press:
- 07 January 2010, pp. 763-766
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The study was carried out on 42 breeder couples (42 males and 42 females) of European brown hare (Lepus europaeus), divided into three groups fed three different experimental diets (14 couples/treatment). Two diets were supplemented with n-3 and n-6 polyunsaturated fatty acids (PUFAs; 2% of linseed oil and soybean oil, respectively) and were compared with a control diet supplemented with a monounsaturated fatty acids (2% of olive oil). During the experimental period (from 15 April to 30 September), the following parameters were recorded: days from the beginning of trial to the first parturition, parturition interval, number of parturitions, number of leverets born (alive and dead), dead during suckling, the total number of leverets weaned and feed intake per cage (of males, females and leverets until weaning). Feed intake was not influenced by treatments. In hares fed n-3 and n-6 diets, the days from the beginning of the trial to the first parturition and the parturition interval were similar and were lower compared with control group (63.1 v. 70.6 days, and 37.8 v. 40.9 days, respectively; P < 0.05). Hares from n-6 group had a higher (P < 0.05) number of parturitions per cage during the experimental period than the n-3 and control group that showed a similar value (3.00 v. 2.36, respectively). The total number of leverets born per cage and parturition in n-6 and n-3 groups increased with respect to those fed control diet (P < 0.05). The leverets’ mortality rate at birth was higher in n-6 than in n-3 and control group (3.50 v. 2.17, respectively; P < 0.05). In control group, leverets’ mortality rate during suckling was lower with respect to n-3 (P < 0.05) and n-6 (P < 0.05), showing the highest value for the latter (P < 0.05). In spite of this higher mortality, the number of leverets weaned per cage and parturition was higher (P < 0.05) in n-6 compared with n-3 group, being the latter higher than the control group (3.12, 2.79 and 2.43, respectively). Our results show that the dietary PUFAs, particularly n-6 supplementation, have a positive influence on the reproductive performances of the European brown hare.
Construction of transgenic swine with induced expression of Cre recombinase
- L. Chen, L. Li, D. Pang, Z. Li, T. Wang, M. Zhang, N. Song, S. Yan, L. X. Lai, H. Ouyang
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- Published online by Cambridge University Press:
- 07 January 2010, pp. 767-771
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Miniature pigs have been recognized as valuable experimental animals in medical research. However, porcine models related to gene knockout of human diseases are not widely available. The objective of this study was to establish Mx1-Cre pigs using somatic cell nuclear transfer. In this study, we created transgenic pigs using somatic cell nuclear transfer (SCNT). Transfer of 210, 230, 250 and 215 zygotes to four surrogates produced 10 piglets. The Cre recombinase expression in transgenic pigs was studied using reverse transcriptase (RT)-PCR and immunohistochemistry. Mx1-Cre swine were shown to harbor the Cre gene in their genomic DNA using the PCR. In conclusion, Mx1-Cre transgenic piglets were successfully produced by SCNT. These transgenic swine, in conjunction with inducible systems for controlling Cre expression and function, are likely to have a profound impact on the study of human diseases.
Effect of Bromocryptine on hormones and milk secretion in Murrah buffaloes (Bubalus bubalis)
- J. Prasad, M. Singh
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- Published online by Cambridge University Press:
- 02 February 2010, pp. 772-776
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An experiment was carried out on 10 advance pregnant Murrah buffaloes to determine the role of hormones in milk secretion around parturition. Experimental animals were administered with a single injection of bromocryptine, @ 100 μg/kg BW, for 5 days before expected calving, whereas control group buffaloes were injected with placebo injections. Blood samples collected before parturition (−5,−4,−3,−2,−1 days), on day of parturition (day-0) and on day 1, 2, 3, 4, 5, 10 and 15 post partum were analyzed for growth hormone (GH), insulin like growth factor-I (IGF-I) and prolactin (PRL) by radioimmunassay methods. Milk samples were collected daily for 5 days and on day 10 and 15 after parturition. Milk fat, protein, lactose, citric acid, non-esterified fatty acids (NEFAs) and somatic cell counts (SCCs) were determined in milk samples. Bromocryptine treatment significantly (P < 0.01) decreased pre partum PRL and increased GH levels (P < 0.01) on day of parturition in experimental buffaloes without influencing plasma IGF-I level. Milk yield was significantly lower (P < 0.01) in experimental than in control group. Further, effect of bromocryptine on milk yield was only for a week. Milk yield increased (P < 0.01) gradually and was similar to control group on day 15 post partum. Bromocryptine treatment significantly increased milk SCC (P < 0.01) and protein content (P < 0.01) but there was no effect of treatment on fat, lactose, citric acid, glucose, milk and plasma NEFA concentration. It was concluded that prepartum suppression of PRL by bromocryptine impairs milk secretion temporarily in ensuing lactation. The significant rise in GH level before parturition and on day of parturition suggests a role of it in milk secretion of buffaloes.
Behaviour, welfare and health
Full Paper
Quantitative assessment of the effects of space allowance, group size and floor characteristics on the lying behaviour of growing-finishing pigs
- X. Averós, L. Brossard, J. Y. Dourmad, K. H. de Greef, H. L. Edge, S. A. Edwards, M. C. Meunier-Salaün
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- Published online by Cambridge University Press:
- 18 December 2009, pp. 777-783
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To obtain quantitative information that can be later used in animal welfare modelling, the relationship between the lying behaviour of growing-finishing pigs (initial body weight (BW) between 19 and 87 kg) and different factors related to the housing conditions, with a potential negative effect on their welfare, was studied by means of a meta-analytical approach. Data from 22 experiments reported in 21 scientific publications were collected. The space allowance, expressed on an allometric basis by means of a k-value (m2/BW0.667), the group size (n) and the floor characteristics (fully and partly slatted v. non-slatted floor), as well as their significant two-way interactions were used as fixed effects, and the experiment was used as a random factor to take into account the interexperiment effect. Further regression analyses were performed on the predicted values of observations in order to improve the adjustment of data. A significant quadratic relationship was established between space allowance (k-value, P < 0.05; squared k-value, P < 0.01) and the percentage of time spent lying. A significant interaction between the k-value and the floor type was also found (P < 0.05), showing that the relationship between space allowance and lying behaviour is affected by the presence or absence of slats. Threshold k-values were obtained using broken-line analyses, being about 0.039 for slatted floors and almost double for non-slatted floors. Compared to other studies, these values suggest that the ability to rest as space availability decreases may be compromised before a reduced performance becomes apparent. Group size did not show a significant effect. Additional information should be added to the model, as further data become available, to adjust the proposed parameters as well as to try to include the effect of other important aspects such as that of ambient temperature.
Role of early experience in the development of preference for low-quality food in sheep
- F. Catanese, R. A. Distel, R. M. Rodríguez Iglesias, J. J. Villalba
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- Published online by Cambridge University Press:
- 07 January 2010, pp. 784-791
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Domestic ruminant selectivity induces floristic changes in pasturelands, risking sustainability and limiting the subsequent availability of susceptible plant species. Development of preferences for species of lower nutritional quality may help to overcome those problems. In this study, we tested the hypothesis that early experience of sheep with a low-quality food (LQF) in a nutritional enriched context increases preference for LQF in adulthood. We predicted a higher proportional consumption of LQF in experienced lambs (EL) than in inexperienced lambs (IL) in choice situations involving LQF and alternative foods. Additionally, we determined intake of LQF by EL and IL at different levels of high-quality food (HQF) availability. From 60 to 210 days of age, EL were fed in separated feed bunks mature oat hay (LQF) simultaneously with sunflower meal (SM) and corn grain (CG), whereas IL were fed alfalfa hay (HQF) simultaneously with SM and CG. After exposure, EL and IL were offered LQF in free choice situations involving alternative foods, and also at five levels of HQF availability (100%, 75%, 50%, 25% and 0% of ad libitum intake). Proportional consumption of LQF was lower or similar in EL than IL. Intake of LQF was also lower or similar in EL than IL at all levels of HQF availability, except when the LQF was the only food available. Our results did not support the hypothesis that early experience with a LQF in a nutritional enriched context increases preference for LQF in adulthood. On the contrary, experience with LQF diminished subsequent preference for LQF in adulthood. It is proposed that, in the conditions of our study, continuous comparison between the LQF and the high-quality supplements (CG and SM) during the early exposure period lead to devaluation of LQF by EL through a simultaneous negative contrast effect.
Effect of housing conditions on activity and lying behaviour of horses
- S. J. Chaplin, L. Gretgrix
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- Published online by Cambridge University Press:
- 21 January 2010, pp. 792-795
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Housing conditions for horses impose various levels of confinement, which may compromise welfare. Lying behaviour and activity can be used as welfare indicators for domestic animals and rebound behaviour suggests a build-up of motivation resulting from deprivation. The objective of this study was to determine if activity and lying behaviour of horses are affected by housing conditions and to investigate the occurrence of rebound behaviour after release from confinement. Eight horses were subjected, in pairs, to each of four experimental treatments; paddock (P), fully stabled (FS), partly stabled (PS) and yard (Y). Each horse received 6 days acclimatisation prior to the 24 h recording period. Time spent in lying and activity were electronically recorded using a tilt switch and motion sensor connected to a data logger worn on the horse’s left foreleg. Time spent active during the first 5 min of release from stable to paddock in the PS treatment (days 1 and 5) and at the same time of day in the P treatment was used as a measure of rebound behaviour. Effect of housing conditions on total time spent active was highly significant (FS = 123 s, PS = 158 s, Y = 377 s, P = 779 s, P < 0.001). Housing conditions did not significantly affect total time spent lying (P = 0.646). Horses were significantly more active, compared with baseline paddock behaviour, on release from stabling on both days 1 (P = 0.006) and 5 (P = 0.025) of PS treatment. These results suggest that activity patterns of horses, but not lying behaviour, are affected by the housing conditions tested and that rebound activity occurs in horses after a period of confinement.
Ewe and lamb contact at lambing is influenced by both shelter type and birth number
- J. C. Broster, R. L. Dehaan, D. L. Swain, M. A. Friend
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- 21 January 2010, pp. 796-803
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A significant number of lambs born each year in Australia die within 72 h of birth. Periods of high wind, combined with rain and low temperatures can lead to marked increases in the mortality level. Under these climatic conditions mortality levels may be reduced with the provision of shelter. This study used contact loggers to compare interactions between ewes with twin lambs across two shelter types (Hessian and shrubs), while also comparing ewes with single and twin lambs in a single shelter type (Hessian). The contact loggers record the time of the initial contact (within approximately 4 to 5 m) between collared animals and the duration of each contact. Contact levels between ewes immediately after lambing were only 10% of the initial levels (1 h/day). For single-born lambs, lambs averaged 11 h contact per day with their mother, while for twinborn lambs, each lamb averaged 9.25 h/day with its mother and 14.7 h/day with its sibling. The level of contact between ewes and each of their offspring in the Hessian was 24% lower (P < 0.05) for ewes with twin lambs than with singles. For ewes with twin lambs the level of contact was 17% lower (P < 0.05) in the Hessian shelter compared with shrub shelter. We conclude that shelter type and birth number can affect the level of contact between ewes and their offspring.
Repeatability of lameness, fear and slipping scores to assess animal welfare upon arrival in pig slaughterhouses
- A. Dalmau, N. A. Geverink, A. Van Nuffel, L. van Steenbergen, K. Van Reenen, V. Hautekiet, K. Vermeulen, A. Velarde, F. A. M. Tuyttens
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- Published online by Cambridge University Press:
- 02 February 2010, pp. 804-809
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The EU project Welfare Quality® proposes an overall assessment system for animal welfare based on animal outcomes. The objective of this study was to test inter-observer reliability (IOR) when assessing lameness, fear and slipping and falling scores as parameters for monitoring the welfare of killing pigs during arrival at the slaughterhouse. Two Belgian and two Spanish slaughterhouses were visited by six to seven observers. Lameness, slipping and falling were assessed twice; during unloading and in the passageway to the lairage zone (lairage). Fear, which was assessed in the unloading area, was based on four indicators: reluctance to move, retreat attempts, turning back and vocalisations. Lameness had low-to-moderate IOR when observed in the passageway to lairage (r = 0.46), but the IOR was low during unloading (r = 0.25). IOR for slipping and falling was moderate to high (r = 0.71 and r = 0.50, respectively), when assessed in the unloading area, but low for observations in the passageway (r = 0.13). Fear indicators had only moderate or low IOR. Turning back was the measure with the highest IOR (r = 0.43) and retreat attempts had the lowest IOR (r = 0.25). Based on these results, we concluded that scoring lameness could be reliable when assessed from the unloading bay to lairage, whereas slipping and falling should be scored in the unloading area of the slaughterhouse. We suggest scoring a maximum of two measures of fear on the same animals at the unloading area, with the most reliable parameters being turning back and reluctance to move. The three indicators of animal welfare (lameness, fear and slipping and falling) should be measured in a way to reduce overtax of the observers in order to achieve accurate results.