Animal Science, Volume 82 - December 2006
- This volume was published under a former title. See this journal's title history.
Research Article
Responses to supplementation by dairy cows given low pasture allowances in different seasons 1. Pasture intake and substitution
- J. W. Penno, K. A. Macdonald, C. W. Holmes, S. R. Davis, G. F. Wilson, I. M. Brookes, E. R. Thom
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- Published online by Cambridge University Press:
- 09 March 2007, pp. 661-670
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Two factorial experiments were designed to determine the effects of stage of lactation, and season of the year, on cow responses to supplementary feeding. These experiments were conducted over consecutive years with 128 high genetic merit multiparous Holstein-Friesian cows in early, mid and late lactation in spring, summer, autumn and winter. At each stage of lactation, and in each season of the year, cows were offered a restricted pasture allowance (25 to 35 kg dry matter (DM) per cow per day), either unsupplemented (control) or supplemented with 50 MJ metabolizable energy (ME) per cow per day in experiment 1 and 80 MJ ME per cow per day in experiment 2. Two different supplements were offered, namely, rolled maize grain (MG) and a mixture of foods (BR) formulated to nutritionally balance the diet. In experiment 2, a fourth treatment consisting solely of a generous pasture allowance (60 to 75 kg DM per cow per day, AP) was introduced. Offering MG and BR increased DM intake (DMI). At the restricted pasture allowance, increasing total ME allowance (MEA) by offering supplementary foods increased ME intake (MEI) by 0·68 (s.e. 0·047) MJ per extra MJ ME offered. This highly significant (P<0·001) linear relationship was consistent across seasons, and did not diminish at higher MEA. In experiment 2, cows in early lactation had lower substitution rates than mid and late lactation cows irrespective of season. Substitution rate was higher when higher pasture allowance or quality of pasture on offer enabled the unsupplemented cows to achieve higher DMI from pasture than at other times of the year. These results suggest that one of the key factors determining the intake response to supplementary foods is pasture allowance. Within spring calving dairying systems, the largest increases in total DMI per kg of supplement offered is likely when offering supplements to early lactation cows grazing restricted allowances of high quality pasture.
Allometric association between in vivo estimation of body composition during growth using deuterium dilution technique and chemical analysis of serial slaughtered pigs
- S. Landgraf, A. Susenbeth, P. W. Knap, H. Looft, G. S. Plastow, E. Kalm, R. Roehe
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- Published online by Cambridge University Press:
- 09 March 2007, pp. 223-231
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The objective of this study was to develop accurate mathematical-statistical functions to estimate body composition of live pigs between 20 and 140 kg weight from total body water (TBWA) determined by the deuterium dilution technique. Chemical body compositions during the growth period are essential input parameters for biological pig growth models, which are used to estimated the nutrient requirements, improve the entire production system, determine optimal slaughter weight, optimize selection for food intake, etc. In the present study, 48 pigs (17 female and 31 castrated males) were used in an experimental station to obtain protein, lipid, ash and water content at 20, 30, 60, 90, 120 and 140 kg live weight. At each target weight, body water of the animals was determined by the deuterium dilution technique. Eight pigs of each live-weight group were slaughtered and chemically analysed. Water content of the empty body decreased from 74 to 53%, whereas lipid content rose from 7 to 30%. Between 20 and 30 kg body weight, protein content increased from 16 to 17% and thereafter decreased to 16%. Ash content was constant at 3%. To estimate body composition of the remaining animals from TBWA (%) determined by deuterium dilution technique, two sets of exponential prediction functions were used to describe the relationship between chemically analysed body components and TBWA (%). The first set of prediction functions fitted one intercept for the entire growth period and the second set of prediction functions fitted a different intercept for each weight class. Correlation coefficients between estimated and chemically determined empty body water, lipid, protein and ash for the first set of functions were 0·93, 0·86, 0·83 and 0·65, respectively. The second set of prediction functions showed higher accuracy (2 to 10%), but had the disadvantage of non-continuous estimates over the entire growth period. In contrast, by using the first set of prediction functions, a continuous accurate estimation of body composition of live pigs was obtained over a large range of growth (20 to 140 kg) based on deuterium dilution space.
Correlations between sport performance and different radiographic findings in the limbs of Hanoverian Warmblood horses
- K. F. Stock, O. Distl
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- 09 March 2007, pp. 83-93
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The purpose of this work was to quantify the additive genetic correlations between prevalent radiographic findings in the limbs of Warmblood riding horses and performance parameters. Data on 3725 Hanoverian Warmblood horses selected for sale at auctions in the period 1991 to 1998 were used. The numbers of annual entries (TE) and placings (TP) in tournament competitions in the period 1991 to 2002 served as measures of performance in riding sports. Multivariate genetic analyses were performed in linear animal models using restricted maximum likelihood (REML). The four most prevalent radiographic findings, i.e. osseous fragments in fetlock (OFF) and hock joints (OFH), deforming arthropathy in hock joints (DAH) and pathologic changes in navicular bones (PCN) were analysed jointly with the performance parameters, i.e. TE and TP. Additive genetic correlations between the radiographic findings and the performance in sports were in many cases close to zero. There were some indications for significantly negative, but few indications for significantly positive additive genetic correlations between radiological conditions in the equine limbs and the performance of Warmblood riding horses in dressage, show-jumping and basic build-up competitions. Breeding measures that allow for orthopaedic health traits could therefore contribute to maximize the breeding progress in terms of sport performance.
Differential control of lipogenesis and lipolysis during development of ovine preadipocytes in vitro
- B. Soret, S. E. Melrose, E. Finley, R. G. Vernon
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- 09 March 2007, pp. 517-525
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The stromovascular fraction of adipose tissue from sheep, like that of other species, contains preadipocytes which can be induced to differentiate in culture, providing a potentially useful system for studying adipocyte development. Differentiation of ruminant preadipocytes has only been partly characterized previously so we have investigated the factors regulating the development of lipogenesis and lipolysis in sheep cells. Insulin, rosiglitazone (a peroxisome proliferation activated receptor-γ agonist) and either dexamethasone or a lipid suplement are required during differentiation for maximum rates of lipogenesis, whereas all four components are required to achieve maximum rates of catecholamine-stimulated lipolysis. Tri-iodothyronine had no effect on the development of lipogenesis but resulted in a reduced rate of catecholamine-stimulated lipolysis. Lipogenesis and lipolysis also differed in that the rate of lipogenesis increased to a maximum at about 10 days of differentiation and then fell, whereas the rate of lipolysis reached a plateau at about 10 days. By contrast to catecholamine-stimulated lipolysis, there is little or no evidence for development of the adenosine-based antilipolytic system; this may be because response to adenosine develops very late during preadipocyte differentiation or additional, unidentified factors are required to induce this antilipolytic system. Lipogenesis in differentiated preadipocytes responded to both insulin and growth hormone. These studies show that the development of lipogenesis and lipolysis are under distinct control systems. Furthermore, while preadipocytes differentiated in vitro show many of the characteristics of adipocytes differentiated in vivo, there are still significant differences.
Influence of chicory roots (Cichorium intybus L) on boar taint in entire male and female pigs
- L. L. Hansen, H. Mejer, S. M. Thamsborg, D. V. Byrne, A. Roepstorff, A. H. Karlsson, J. Hansen-Møller, M. T. Jensen, M. Tuomola
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- 09 March 2007, pp. 359-368
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Boar taint is an off-flavour of pork caused primarily by a microbial breakdown product, skatole and a testicular steroid, androstenone. As skatole is produced in the large intestine from tryptophan, it is possible that some ‘bioactive’ ingredients could modify protein fermentation and, in the process, diminish boar taint. The aim of this study was to examine the effect of inulin-rich chicory roots (Cichorium intybus L.) on boar taint. In the first of three trials individually penned, entire males and females were given an organic concentrate in which 0·25 of the daily energy intake was replaced with crude chicory roots for 9 or 4 weeks prior to slaughter. In the second trial, entire male pigs were given diets that included, either crude chicory roots, dried chicory roots, or inulin (extracted from chicory roots) for 6 weeks pre-slaughter. In the third trial, intact male pigs were given the dried chicory diet for either 2 or 1 week before slaughter. In all trials the chicory diets were offered on a scale at 0·95 of the Danish recommendation for energy intake, and pig performance was compared with a control group given the organic concentrate at 0·95 of recommended energy intake plus silage ad libitum. In trial 1 an additional control group was offered the organic concentrate at a daily energy intake level of 1·0 of Danish recommendations. The pigs in trials 1, 2, and 3 were slaughtered at an average live weight of 118, 124, and 110 kg, respectively, in order to ensure that they had achieved sexual maturity. Overall, skatole concentrations in blood plasma and backfat at slaughter were reduced to almost zero levels by including crude or dried chicory or inulin in the diet. This occurred irrespective of sex and length of feeding period (1 to 9 weeks). In trial 3 a significant effect on blood plasma concentration was observed after 3 days of feeding a diet containing dried chicory. The only significant reduction in plasma androstenone levels was detected in pigs given the crude chicory for a 9 week duration in trial 1. The production and proportion of lean was generally not affected by the addition of either form of chicory to the diets in trials 1 and 2. Therefore, dried chicory may be the most suitable form for commercial use because it: had no initial adverse effects on food intake, consistently reduced skatole without reducing performance, was easy to handle throughout the entire year and is relatively inexpensive.
Dose effect of live yeasts on rumen microbial communities and fermentations during butyric latent acidosis in sheep: new type of interaction
- L. Brossard, F. Chaucheyras-Durand, B. Michalet-Doreau, C. Martin
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- 13 March 2007, pp. 829-836
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Six ruminal cannulated Texel sheep were used to assess the dose response and the effect of live yeasts (Levucell® SC, Saccharomyces cerevisiae CNCM I-1077) on the prevention of induced ruminal latent acidosis. The sheep received, in a replicated 3×3 Latin-square design, an acidotic diet (wheat +lucerne hay, 60:40 (dry matter (DM) basis); starch: 410 g/kg DM) without yeast (control group; L0 treatment), supplemented with 0·2 g/day yeast (4×109 colony-forming units (c.f.u.) per day corresponding to producer recommendations; L1 treatment) or with 2 g/day yeast (4×1010 c.f.u. per day; L10 treatment). The following measurements were carried out: food intake, ruminal pH, ruminal volatile fatty acids (VFA), lactate and ammonia (NH3) concentrations, protozoal and lactate-utilizing bacterial counts, relative proportions of two main bacteria implicated in lactate metabolism (a lactate-producing species, Streptococcus bovis, and a lactate-utilizing species, Megasphaera elsdenii) using specific 16S-rRNA-targeting oligonucleotide probes, activities of lactate dehydrogenase (LDH) and of polysaccharidases involved in plant cell wall (xylanase, carboxymethylcellulase) and starch (amylase) degradation. The acidotic diet (L0) induced a butyric (12 mol per 100 mol total VFA) rather than lactic (<4 mmol/l) ruminal latent acidosis. Ruminal pH, fermentative patterns, lactate-metabolizing bacteria (concentration, LDH activity) and polysaccharidase activities were similar between treatments (P>0·1). Yeast supplementation tended to increase ruminal protozoal population (P<0·1) and intake of animals (P<0·1). The recommended yeast concentration (L1) was sufficient to ensure these effects. The yeast's action may differ according to the nature and function of the micro-organisms involved and the type of fermentative pattern favoured (protozoa/butyrate v. lactate-metabolizing bacteria/lactate and propionate) during ruminal acidosis in sheep.
Feeding with chicory roots reduces the amount of odorous compounds in colon and rectal contents of pigs
- M. T. Jensen, L. L. Hansen
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- 09 March 2007, pp. 369-376
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Sixteen pigs (eight entire males and eight females) were given individually two diets, control and control added 25% chopped chicory roots for 2 months before slaughter. Samples were taken from the contents in colon and rectum and subjected to GC-MS analysis for amount of odour impact compounds. The compounds 2-pentanone, ethylbutyrate, propylpropionate, butyric acid, ethyl-2-methylbutyrate, p-cresol, indole and skatole showed a significant difference between the two treatments. The esters, which have relatively pleasant, often fruity odours, increased in the chicory treatment, whereas the malodorous compounds, p-cresol, indole and skatole decreased in the chicory treatment. The measured amounts of compounds were corrected for their odour thresholds as different compounds can have widely different odour thresholds. Principal components analysis was then used to analyse the raw and corrected data results. p-Cresol was the most malodorous compound and together with skatole and indole count as the most malodorous compounds in the colon and rectum cotents. However, butyric acid also had some minor influence. Feeding chicory roots decreased significantly the concentrations of these malodorous compounds, especially if the lowest odour threshold values are used as correction factors.
Polyamines in sow colostrum and milk at different stages of lactation
- Z. B. Cheng, D. F. Li, C. R. Ge, J. J. Xing
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- 09 March 2007, pp. 95-99
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The objective of this study was to determine the effect of stage of lactation on the concentration of polyamines (spermine, spermidine, and putrescine) in sow colostrum and milk. Ten, third parity sows (Landrace×Yorkshire) were sampled throughout a 28-day lactation. Litter size for all sows was standardized at 10 sucking piglets immediately after farrowing. Colostrum collection began at the birth of the first piglet (0 h), and colostrum was subsequently collected 6, 12, 18, and 24 h after farrowing. Sow milk was sampled on days 3, 7, 10, 14, 17, 21, 24 and 28 of lactation. Spermine concentration in sow colostrum was relatively constant for the first 12 h after farrowing and then rapidly increased to 10·26 μmol/l 24 h after farrowing (linear and quadratic effect; P<0·01). In contrast, the concentrations of spermidine and putrescine showed little change during the first 24 h with spermidine concentration in colostrum ranging from 3·76 to 4·54 μmol/l, and putrescine concentration ranging from 1·15 to 1·52 μmol/l. The highest concentration of spermine in sow milk was 18·82 μmol/l, observed on day 7, with levels gradually declining to 4·28 μmol/l by day 28 of lactation (linear and quadratic effect; P<0·01). In contrast, the concentration of spermidine increased during lactation ranging from a low of 4·32 μmol/l on day 7 to a high of 9·01 μmol/l on day 28 of lactation (linear effect P<0·01; quadratic effect P=0·03). Putrescine concentration ranged from 1·53 μmol/l on day 3 to 1·84 μmol/l on day 28 (linear effect P=0·07; quadratic effect P>0·05). The results of this study show sow colostrum and milk provide polyamines for sucking piglets before weaning, which could potentially modulate intestinal maturation.
Comparison of models using different censoring scenarios for days open in Spanish Holstein cows
- O. González-Recio, Y.M. Chang, D. Gianola, K. A. Weigel
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- 09 March 2007, pp. 233-239
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Days open data from 113 569 lactation records in 774 Spanish Holstein herds were analysed using standard linear models under two different editing procedures, and with two alternative methodologies that account for censoring: a censored linear model (CLM) and a Weibull survival analysis (SA) model. The first editing procedure excluded from the linear model all censored records for days open (LMnc), and the second defined days open as days from calving to the last known insemination or culling date, treating censored records as complete (LM). Sire variance estimates for days open were 61, 70 and 139 for LMnc, LM and CLM, respectively, and 0·026 for SA on a logarithmic scale. Heritability estimates were 0·05, 0·06 and 0·08 with LMnc, LM and CLM, respectively. Rankings of sires varied between methodologies: sire evaluations from LMnc and LM had rank correlations with evaluations from SA equal to −0·65 and −0·82, respectively, and of 0·71 and 0·87 with evaluations from CLM. The rank correlation between evaluations from SA and CLM was −0·98, suggesting stronger agreement of sire rankings between models that take censoring into account.The SA model had a better predictive ability of daughter fertility at early stages of lactation than the other methods, as measured by chi-squared statistics for predicted pregnancy status at 75, 103, 140, or 200 days post partum in a split data set. The CLM also predicted daughter fertility more accurately than any of the two standard linear models.
Responses to supplementation by dairy cows given low pasture allowances in different seasons 2. Milk production
- J. W. Penno, K. A. Macdonald, C. W. Holmes, S. R. Davis, G. F. Wilson, I. M. Brookes, E. R. Thom
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- Published online by Cambridge University Press:
- 09 March 2007, pp. 671-681
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Two factorial experiments were designed to determine the effects of stage of lactation, and season of the year, on cow responses to supplementary feeding. These experiments were conducted over consecutive years with 128 high genetic merit multiparous Holstein-Friesian cows in early, mid and late lactation in spring, summer, autumn and winter. At each stage of lactation, and in each season of the year, cows were offered a restricted pasture allowance (25 to 35 kg dry matter (DM) per cow per day), either unsupplemented (control) or with supplement at 50 MJ metabolizable energy (ME) per cow per day in experiment 1 and 80 MJ ME per cow per day in experiment 2. The two supplements given in both years were rolled maize grain (MG) and a mixture of foods formulated to nutritionally balance the diet (BR). In experiment 2, another treatment, of a generous pasture allowance (60 to 75 kg DM per cow per day) (AP), was imposed on an additional group of early lactation cows during each season. Direct milk solids (MS) (milk fat plus milk protein) responses in experiment 1 to MG were 169, 279, 195 and 251 g MS per cow per day in spring, summer, autumn and winter, respectively, while those to BR were 107, 250, 192, 289 g MS per cow per day. In experiment 2, however, milk solids responses to both supplements during spring were slightly below the control treatment, with values similar to those in experiment 1 in summer and autumn for cows on the BR but not the MG supplement. Milk solids responses to supplementary foods were largest during seasons of the year when the quantity and quality of pasture on offer resulted in the lowest milk solids yield from unsupplemented cows. When carry-over effects of feeding MG and BR on milk solids production were detected, they were only about half the magnitude of the direct effects. Serum urea concentrations were higher in control cows than those offered MG with a similar effect for BR in all but summer in experiment 1, while serum glucose concentrations were highest in winter and lowest in summer. The most important factor influencing milk solids responses was the relative food deficit (RFD) represented by the decline in milk solids yield of the respective control groups after changing from a generous pasture allowance to restricted allowance when the feeding treatments were imposed. Total milk solids responses (direct and carry-over) to supplements were greatest when severe food restrictions, relative to the cows' current food demand, resulted in large reductions in milk solids yield of the control groups. The RFD was the best predictor of milk solids response to supplementary foods. Therefore, it is likely that cows are most responsive to supplementary foods during or immediately after the imposition of a severe food restriction.
Dietary carbohydrates with different rates of fermentation affect fermentation end-product profiles in different sites of gastro-intestinal tract of weaning piglet
- A. Awati, B. A. Williams, M.W. Bosch, M.W.A. Verstegen
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- Published online by Cambridge University Press:
- 13 March 2007, pp. 837-843
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An in vivo experiment was conducted to examine changes in fermentation end-products in the gastro-intestinal tract (GIT) of weaning piglets by the inclusion of fermentable carbohydrates in the diet. The experiment was repeated in three replicates of 36 piglets. Piglets were raised free of antibiotics and creep feeding prior to weaning at 4 weeks of age. Each replicate was conducted over a period of 10 days. The piglets were offered one of two dietary treatments: control diet (CON), and fermentable carbohydrate enriched diet (CHO); and were subjected to one of the two fasting treatments (i) fasting for 2 days in the beginning of the experimental period and (ii) non-fasting. Piglets were slaughtered on the 1st, 4th and 10th day of each period. Digesta samples were collected from: first half of small intestine, second half of small intestine, caecum, and colon. The dry matter, volatile fatty acid (VFA) profile, and ammonia concentrations were analysed. Food intake, growth and food conversion ratio were also recorded. There were no differences in production performances such as growth and food conversion ratio (FCR) between the treatment groups. Concentrations of VFA were significantly higher, while ammonia concentration was significantly lower in the CHO group compared to the CON group in different fermentation sites within the GIT (P<0·001), and on different slaughtering days (P<0·05). Fasting had no effect on fermentation end-products. This study concludes that the addition of fermentable carbohydrates of varying fermentabilities stimulated carbohydrate fermentation, with reduction in protein fermentation along the different parts of GIT studied, in weaning piglets.
Pro-inflammatory cytokine and acute phase protein responses to low-dose lipopolysaccharide (LPS) challenge in pigs
- S. Llamas Moya, L. Boyle, P. B. Lynch, S. Arkins
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- Published online by Cambridge University Press:
- 09 March 2007, pp. 527-534
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The objective of this study was to establish the pro-inflammatory cytokine and acute phase protein responses to low-dose lipopolysaccharide (LPS) challenge in pigs and to determine whether these immune parameters could also be measured in saliva. Possible gender differences in the acute phase reaction were also assessed. At 6 weeks of age, 24 male and 24 female pigs were injected intraperitoneally with a single dose of 0 or 5 μg/kg live weight (LW) of LPS from Escherichia coli (treatment). Matched saliva and blood samples were taken at 0, 2, 4, 8, 12 or 24 h after treatment administration. Samples were analysed for concentrations of the pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α) and interleukin-1beta (IL-1β), the acute phase proteins C-reactive protein (CRP), serum amyloid A (SAA), haptoglobin (Hp), and cortisol. Low-dose LPS administration increased plasma levels of TNF-α (P<0·001), CRP (P<0·05) and SAA (P<0·05) but did not affect plasma concentrations of IL-1β or Hp (P>0·1). Treatment by time interactions showed that plasma levels of TNF-α and CRP in LPS-treated pigs peaked at 2 h (P<0·001) and 12 h (P<0·01), respectively. Low-dose LPS injection tended to increase plasma concentrations of cortisol (P=0·056) and the response to LPS differed between genders (P<0·05), with females showing higher cortisol responsiveness to the challenge (P<0·01). Males showed higher levels of both cytokines regardless of the treatment (P<0·05), probably due to the inhibition of cytokine synthesis by cortisol. Concentrations of both pro-inflammatory cytokines were consistently detectable in saliva and were present in higher concentrations than in plasma (P<0·001). Hence, plasma TNF-α, CRP and SAA are useful indicators of sub-acute inflammation/infection in pigs as simulated by a low-dose LPS challenge and gender differences exist in the pro-inflammatory cytokine response after a low dose of LPS.
Reproduction of wild Mongolian gerbils bred in the laboratory with respect to generation and season 1. Morphological changes and fertility lifespan
- I. W. Stuermer, C. Tittmann, C. Schilling, S. Blottner
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- 09 March 2007, pp. 377-387
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A new strain of wild Meriones unguiculatus (strain Ugoe:MU95, named WILD) with high genetic variability was recently established in Germany. A previous study showed that offspring (F-1) of WILD founders (F-0) showed reduced spermatogenesis and testosterone compared to domesticated gerbils (LAB) maintained under similar conditions. We investigated F-0 and subsequent generations in respect to sexual maturation, duration of fertility and gonadal weights of different seasons. Body and reproductive organ weights showed negligible seasonal fluctuations in both strains. Testis and epididymis weights in WILD covered a wide range, which indicates a high reproductive variability. Reproductive organ weights increased in F-3. Less variable and high reproductive organ weights (testis >900 mg, epididymis >200 mg) in almost all LAB illustrate their readiness to reproduce, even in small individuals. Prominent testis (T+) was found in 71% of adult males (F-1, F-2) reflecting the natural portion of T+(63%) found in wild gerbils investigated in Mongolia in 1995 and 2002. Testicular descent was accelerated and pronounced in WILD F-3 (T+, 88%) and LAB (T+, 91%). Time between mating and the first litter was significantly longer in wild F-0 than in their offspring or LAB. The average age in wild F-0 when the last litter was born was 27 months. Breeding went on for 2 to 32 months and was mostly terminated by the death of the females. Relative testis and epididymis weights correspond in young adults and in old males up to 6 years, the total life span of male wild Mongolian gerbils. In summary, the results suggest that laboratory conditions improve the reproductive fitness of wild gerbils.
Chemical composition and fermentation characteristics of grain and different parts of the stover from maize land races harvested at different growing periods in two zones of central Mexico
- J. G. Estrada-Flores, M. González-Ronquillo, F.L. Mould, C. M. Arriaga-Jordán, O. A. Castelán-Ortega
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- Published online by Cambridge University Press:
- 13 March 2007, pp. 845-852
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The objective of this work was to determine the rumen fermentation characteristics of maize land races used as forage in central Mexico. In vitro gas production (ml per 200 mg dry matter (DM)) incubations were carried out, and cumulative gas volumes were fitted to the Krishnamoorthy et al. (1991) model. The trial used a split-plot design with cultivation practices associated with maize colour (COL) as the main plot with three levels: white, yellow and black maize; growing periods (PER) were the split plots where PER1, PER2 and PER3 represented the first, second and third periods, respectively and two contrasting zones (Z1=valley and Z2=mountain) were used as blocking factors. The principal effects observed were associated with the maturity of the plants and potential gas production increased ( P<0·05) in stems (PER1=51·8, PER2=56·3, PER3=58·4 ml per 200 mg DM) and in whole plant (PER1=60·9, PER2=60·8, PER3=70·9 ml per 200 mg DM). An inverse effect was observed with fermentation rates in leaves ( P<0·01) with 0·061, 0·053 and 0·0509 (per h) and in whole plant ( P<0·05) with 0·068, 0·057, 0·050 (per h) in PER1, PER2 and PER3 respectively. The digestibility of the neutral-detergent fibre (NDF) decreased with maturity especially in leaves ( P<0·05) with values of 0·71, 0·67 and 0·66 g/kg; in rachis ( P<0·01) 0·75, 0·72, and 0·65 in PER1, PER2 and PER3 respectively. The NDF content in leaves in leaves (668, 705 and 713 g/kg DM for PER1, PER2 and PER3, respectively), stems (580, 594 and 644 g/kg DM) and, husk (663, 774 and, 808 g/kg DM) increased ( P<0·05) with increasing plant maturity, rachis were significantly different between periods ( P<0·01). The structure with the best nutritive characteristics was the husk, because it had the lowest fibre contents, especially in acid-detergent lignin, with values of 22·6, 28·6 and 37·6 g/kg DM in PER1, PER2 and PER3, respectively.
The efficiency of utilization of metabolizable energy for milk production: a comparison of Holstein with F1 Montbeliarde × Holstein cows
- Y. Aharoni, A. Brosh, E. Kafchuk
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- 09 March 2007, pp. 101-109
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The objectives were to demonstrate the potential of heat production measurements to characterize the gross and net efficiencies of dairy cows under commercial conditions and to compare the efficiencies of purebred Holstein and Montbeliarde × Holstein F1 dairy cows. The heat productions of seven Holstein (H) and seven Montbeliarde × Holstein (MH) cows were measured over two 10-day periods separated by a 75-day interval, during the summer of 2004, in a commercial high-yielding dairy herd in Israel. Energy expenditure was measured by monitoring heart rates and oxygen consumption per heart beat. Milk yield and composition were recorded for these cows and their investment of energy in the milk was calculated from the milk yield and composition. Live weight and body condition score were also recorded in parallel with these measurements. Metabolizable energy (ME) intake was estimated as the sum of heat production, energy in milk and body energy balance. The MH cows were heavier by 90 kg, had higher body condition scores by 0·9 units and secreted proportionately 0·19 and 0·38 less energy in their milk than H cows in the first and second periods, respectively. The gross energy efficiencies, expressed as the percentage of milk production plus body retention in ME intake were 48·3 and 43·4% in the first period and 45·6 and 32·8% in the second period, for H and MH cows, respectively. The milk production of MH cows in this study was lower than the potential of this cross, however, MH cows that expressed this potential would still be expected to require proportionately 0·10 greater intake of ME than H cows, per unit of energy in milk.
Cloning, expression and tissue distribution of IGF-1 from giant panda (Ailuropoda melanoleuca)
- X. -L. Hu, M. -Y. Zhu, Z. -H. Zhang, R. Hou, F. -J. Shen, A. -J. Zhang
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- Published online by Cambridge University Press:
- 09 March 2007, pp. 535-543
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Insulin-like growth factor-1 (IGF-1) is a polypeptide that regulate growth, differentiation and muscle regeneration in several species. This study was designed to analyse the cDNA sequence of IGF-1 in giant panda, its gene expression and tissue distributions in relation to growth, development and reproduction of captive giant pandas. A cDNA encoding IGF-1 was cloned by reverse transcriptase-PCR from a male giant panda cub liver tissue. Sequence alignment analysis showed the cysteine residues and other amino acid residues of the mature IGF-1 peptide of giant panda are highly conserved in mammalian species. DNA encoding the mature IGF-1 peptide of the giant panda was ligated with pET-DsbA expression vector and expressed in E. coli BL21. Western blot confirmed the IGF-1 antigen activity of the recombinant protein. By in situ hybridization and immunohistochemistry analysis it is demonstrated that the IGF-1 mRNA distribution abundance were significantly higher in the liver, muscles and heart than those in the other tissues studied. However, the IGF-1 peptide distribution abundances in all the tissues studied did not show any significant differences. The localization of the IGF-1 peptide was in accordance with that of mRNA for each tissue. These results may suggest that IGF-1 play an autocrine or paracrine rôle in regulation of the giant panda growth and development.
Holo-analysis of the efficacy of Bio-Mos® in pig nutrition
- G. D. Rosen
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- Published online by Cambridge University Press:
- 09 March 2007, pp. 683-689
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This exploratory holo-analysis of the efficacy of Bio-Mos®, (BM), an outer cell wall derivative of a strain of Saccharomyces cerevisiae, is part of an empirical modelling research programme comparing the efficacies of potential replacements for veterinary prescription-free pronutrient antibiotics in pig production. The data resource was mined from 128 saccharide publications of which 31/97 on BM (1997 to 2003) provided 69 negatively controlled start-to-finish tests from 10 countries (USA 71%) using 3778 pigs(30·5 per treatment). Respective food intake, live-weight gain and food conversion responses of 0·0075 kg/day (0·99%), 0·0145 kg/day (3·58%) and −0·0526 (3·07%) have coefficients of variation of 511, 163 and 229% and beneficial gain and conversion frequencies of 73 and 68%, 54% jointly. Holo-analytical multiple regression models of BM food intake, live-weight gain and food conversion effects using conventional and less stringent probabilities contain significant independent variables for negative control performances, dosage, discontinuous dosage, test duration, year of test, non-USA test, male, grower-finisher, slatted floor, processed food, antibacterial foods, animal protein food, main vegetable protein not soya bean, added oil/fat food and factorial data, which account for 11 to 68% of variations in response. The models quantify differences in research and praxis and indicate areas for future modelling research on BM dose-response relations, effects of ration ingredient and nutrient contents, other saccharide efficacy comparisons, including lactose, and BM comparisons and interactions with other proposed antibiotic replacements.
Estimation of whole body lipid mass in finishing pigs
- M. Kloareg, J. Noblet, J. Van Milgen
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- Published online by Cambridge University Press:
- 09 March 2007, pp. 241-251
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Most nutritional pig growth models are based on the deposition of whole body protein (P) and lipid (L) mass. Chemical analysis of the whole animal is the best method to determine body composition. However, this method is expensive, time consuming and the carcass is lost. Alternatively, P and L may be estimated using simple indicators that should be precise and easily accessible. Although empty body weight (EBW) is a good indicator for P (through the strong relation between water and P), L is more difficult to estimate. This study was carried out to evaluate the relationship between simple carcass measurements and L. Measurements included backfat thickness in vivo and at slaughter in the hot and cold carcass and the weight of carcass, organs and primal cuts. To maximize variations in adiposity a total of 30 females and barrows from two genotypes (Piétrain×(Landrace×Large White) and Large White) were slaughtered at body weights typically used in Europe (i.e. 90 to 150 kg) and ground for chemical analysis. Backfat mass (in combination with EBW) was the best indicator for L (L (kg)=0·0590×EBW (kg)+2·99×backfat mass (kg), R2=0·96). Different backfat thickness measurements were highly correlated and appeared reasonable indicators for total backfat mass. Backfat thickness measured in the hot carcass between 3rd and 4th last lumbar vertebra at 8 cm from the mid line was the second best indicator for L (L=(0·0855+0·0073×backfat thickness)×EBW, R2=0·94). On average, 18% of total body lipids were located in the backfat. Although these equations can be used to obtain a reasonable estimate of whole body lipid mass, a significant genotype effect remained. Differences between genotypes in the partitioning of lipids between different tissues suggest that the quantification of an external lipid depot alone is insufficient to precisely estimate whole-body lipid mass across genotypes.
Predicting intramuscular fat, moisture and Warner-Bratzler shear force in pork muscle using near infrared reflectance spectroscopy
- N. Barlocco, A. Vadell, F. Ballesteros, G. Galietta, D. Cozzolino
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- Published online by Cambridge University Press:
- 09 March 2007, pp. 111-116
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Partial least-squares (PLS) models based on visible (Vis) and near infrared reflectance (NIR) spectroscopy data were explored to predict intramuscular fat (IMF), moisture and Warner Bratzler shear force (WBSF) in pork muscles (m. longissimus thoracis) using two sample presentations, namely intact and homogenized. Samples were scanned using a NIR monochromator instrument (NIRSystems 6500, 400 to 2500 nm). Due to the limited number of samples available, calibration models were developed and evaluated using full cross validation. The PLS calibration models developed using homogenized samples and raw spectra yielded a coefficient of determination in calibration (R2) and standard error of cross validation (SECV) for IMF (R2=0·87; SECV=1·8 g/kg), for moisture (R2=0·90; SECV=1·1 g/kg) and for WBSF (R2=0·38; SECV=9·0 N/cm). Intact muscle presentation gave poorer PLS calibration models for IMF and moisture (R2<0·70), however moderate good correlation was found for WBSF (R2=0·64; SECV=8·5 N/cm). Although few samples were used, the results showed the potential of Vis-NIR to predict moisture and IMF using homogenized pork muscles and WBSF in intact samples.
Variations in liver and blood copper concentrations in young beef cattle raised in north-west Spain: associations with breed, sex, age and season
- M. Miranda, J. M. Cruz, M. López-Alonso, J. L. Benedito
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- Published online by Cambridge University Press:
- 09 March 2007, pp. 253-258
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The aim of the present study was to evaluate the influence of breed and other factors (age, sex and season) on copper (Cu) accumulation by calves reared in a region in north-west Spain where pig slurry is widely used for slurry fertilization, and where cattle typically have hepatic Cu concentrations above the generally accepted safe-adequate levels. In December 2000 and August 2001, paired liver and blood samples were obtained at slaughter from 532 male and female Galician Blond, Holstein-Friesian and Galician Blond×Holstein-Friesian calves, aged between 6 and 10 months, from 434 different farms. Samples were acid-digested and Cu concentrations determined by ICP-OES. Holstein-Friesian calves showed significantly higher mean Cu concentrations both in the liver (80·6 mg/kg fresh weight) and blood (0·891 mg/l) than Galician Blond calves (50·4 mg/kg and 0·748 mg/l respectively) and crosses between the two breeds (61·3 mg/kg and 0·829 mg/l respectively). Holstein-Friesian was the breed with the highest percentage (42%) of calves with hepatic Cu concentrations above safe-adequate levels (25 to 100 mg/kg fresh weight) and Galician Blond the breed with the highest proportion (29%) of hypocupraemia during the winter sampling. Considering all breeds, hepatic Cu levels were higher in males (63·8 mg/kg) than in females (53·5 mg/kg) and significantly increased with age in summer. A significant three-way breed×sex×age interaction was observed for liver Cu but this may be attributable to the small number of animals in some groups, having a confounding effect on the analysis. A significant sex×age×season interaction was also observed which could indicate greater male dominance in summer, so that they consume more forage (and thus more Cu) than females. Calves slaughtered in winter showed significantly lower mean blood Cu concentration (0·703 mg/l) than calves slaughtered in summer (0·940 mg/l).