bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth performance and carcass traits of Large White, Mukota and Large White ✕ Mukota F1crosses given graded levels of maize cob meal
Authors: Kanengoni A. T. , Dzama K. , Chimonyo M. , Kusina J. , Maswaure S. M.
Published: May 2019

A study was conducted to compare the performance of Mukota, Large White (LW) and LW ✕ Mukota F1pigs given increasing levels of maize cob meal. Sixteen female weaners of each genotype were given, ad libitum, diets containing 0, 100, 200 and 300 g maize cob meal per kg of diet for 14 weeks. The diets were designed to contain similar levels of protein (ca. 160 g crude protein per kg) and energy (ca. 9 MJ metabolizable energy per kg). Average daily food intake per unit metabolic body weight (ADFI per kg M0·75), average daily gain (ADG) and food conversion ratio (FCR) were determined. The pigs were slaughtered and cold dressed mass (CDM) and backfat thickness were determined for each pig. The ADFI per kg M0·75was similar among the four diets for the three genotypes. The rate of decline in ADG was higher (P < 0·05) in the LW than in the other two genotypes. The FCR in the Mukota was poorer (P < 0·05) than that in the LW and the F1crosses. The Mukota had the highest (P < 0·05) backfat thickness (K5 and K7·5) values of the three genotypes across the four diets, followed by the F1crosses. The CDM values for the LW and the F1crosses were similar and were higher (P < 0·05) than those for the Mukota. The findings indicate that F1crosses and the Mukota were better able to utilize diets containing high levels of maize cob meal than LW pigs.
Effect of type and level of dietary fibre and starch on ileal and faecal microbial activity and short-chain fatty acid concentrations in growing pigs
Authors: Wang J. F. , Zhu Y. H. , Li D. F. , Wang M. , Jensen B. B.
Published: May 2019

A repeated 4 ✕ 4 Latin square design was conducted with eight ileal cannulated castrated pigs to investigate the effect of source of dietary fibre and starch on ileal and faecal microflora and short-chain fatty acid concentrations. Four experimental diets based on cooked rice were supplied with one of two fibre-rich sources (sugar-beet pulp, S; wheat bran, W) and another two diets were prepared with (P) or without (C) potato starch. The experimental periods were 14 days, consisting of 7 days of adaptation to each diet, followed by 4 days of collection of ileal digesta and 3 days of collection of faeces. Ileal digesta were collected daily in a randomized order 0 (just before feeding the morning meal), 2, 4, 6 and 8 h after feeding the morning meal. Fresh faecal samples were also collected. Ileal pH was lower in pigs given diet P, 2 and 4 h after feeding, respectively. For all four diets ileal pH reached a minimum 4 h after feeding. Faecal pH was higher for diets P and W compared with diets C and S. The highest density of ileal coliform bacteria was found 4 h after feeding for all diets. Compared with other diets, the inclusion of potato starch resulted in an increased density of ileal enterococci at 0 h and an increased density of ileal lactic acid bacteria and lactobacilli, 2 and 6 h after feeding, respectively. The density of ileal enterococci reached a maximum 4 h after feeding for all diets. With the exception of 8 h after feeding, when a higher density of total anaerobes was observed for diet P, no significant differences were seen in the populations of yeasts and total anaerobes between the experimental diets. The concentration of formate in the ileum was high, while low concentrations of acetate, propionate and butyrate were observed for all diets. A lowered level of acetate was found for diet S on all sampling occasions. On a dry-matter basis, the counts of various faecal bacteria were increased by the inclusion of the fibre sources, and a higher level of faecal butyrate was found with the inclusion of potato starch or the fibre sources as compared with diet C, whereas no significant effects on the counts of various bacteria were observed with potato starch supplementation. Overall, the present results indicate that the addition of dietary fibre to pig diets resulted in an enhanced microbial fermentation.
Reproductive traits of female rabbits as affected by heat stress and lighting regime under subtropical conditions of Egypt
Authors: Marai I. F. M. , Habeeb A. A. M , Gad A. E.
Published: May 2019

The present work was planned to study the effects of different lighting regimes in both mild and hot periods of the year on New Zealand White doe rabbit traits. The light regimes used were natural daylight as control, 16 h light and 8 h darkness, 12 h light and 12 h darkness, and 8 h light and 16 h darkness. The traits studied were thermoregulatory parameters (respiration rate and temperatures of ear, rectum and skin), type of mating necessary, conception rate, gestation period, fur plucking, behavioural indicators of stress, litter size, litter weight, kit body weight, kit daily gain in weight, milk yield, kit milk intake, efficiency of conversion of milk into live-weight gain and kit mortality, at weekly intervals between birth and weaning at 35 days. Estimation of temperature-humidity index indicated that the doe rabbits were exposed to very severe heat stress, during the hot period of the year. Period of the year (heat stress) affected adversely many of the doe traits studied. The effects were significant (P < 0·001, 0·01 or 0·05) on thermoregulatory parameters (respiration rate and temperatures of ear, rectum and skin), litter weight at days 21 and 28 of age, kit body weight at birth, milk yield of the doe at day 7 of suckling and milk intake per kit at 7 and 14 days of age. Exposure of doe rabbits to a long daylight regime affected adversely many of the traits studied, while the contrary occurred with short daylight. The effects were significant (P < 0·001, 0·01 or 0·05) on litter size at all ages except at birth, litter weight at 14, 21 and 28 days of age, milk yield on all days studied, efficiency of conversion of milk into live-weight gain at days 7, 21 and 28 and mortality at birth and pre-weaning. There was no significant interaction between period of the year and light regime on any of the traits examined. Therefore, only the main factors are reported.
The effects of cold exposure, food allowance and litter size on immunity of periparturient sheep toTeladorsagia circumcinctaand Trichostrongylus colubriformis
Authors: Xie H. L. , Stankiewicz M. , Huntley J. F. , Sedcole J. R. , McAnulty R. W. , Green R. S. , Sykes A. R.
Published: May 2019

Sixty twin- and 60 single-bearing ewes were used in a 2 ✕ 2 ✕ 2 factorial design incorporating nutritional and shearing-cold exposure treatment (no. = 15 per subgroup) to study the effects on periparturient immunity against nematode infection. From week –8 to week –4 relative to parturition, animals grazed ryegrass-white clover pastures at allowances designed to provide either 0·8 (low allowance) or 1·2 (high allowance) of estimated metabolizable energy requirement for a ewe carrying 1·5 lambs. During week –4, half the sheep from each reproductive effort and nutritional group were shorn and exposed to artificial wind and rain for 4 h on each of 4 days consecutively. During the same week, all animals were challenged twice with 1·5 ✕ 104Teladorsagia circumcincta and 1·5 ✕ 104Trichostrongylus colubriformis infective third stage larvae to supplement the natural infection from pasture. From week –3 to week + 5 relative to parturition the sheep were run together and offered pasture at rates estimated to enable them to meet their nutrient requirement.

Shearing and cold stress reduced ewe body weight (by up to 4·66 kg per sheep), and temporarily reduced the levels of IgA against T. circumcincta (by proportionately 0·24) and T. colubriformis (0·34), and raised faecal egg count (1·6 to 4·4 fold) but did not affect the parasite-specific total antibody levels in the serum. The low allowance during pregnancy was associated with a 6·09-kg decrease in ewe body weight, decrease in the levels of total antibody and of IgA against both T. circumcincta and T. colubriformis, and increased faecal egg count (by 1·5 to 10·6 fold) during pregnancy and lactation. Faecal egg count was consistently higher (up to 8·8 fold) in twin-bearing and rearing ewes than in single-bearing and rearing ewes except during the first 4 weeks of the experiment. A significant effect of litter size on antibody levels was relatively small when compared with short-term changes (reductions) in antibody levels immediately around parturition. There were significant negative correlations between faecal egg count during late pregnancy and ewe body weight in lactation and significant negative correlations between the levels of total antibody against T. colubriformis and faecal egg counts near the end of the experiment. We conclude that litter size is likely to have greater influence on the resistance of ewes to nematode infections in the periparturient period than either pasture allowance or cold stress within the range of parameters used in this work.
The effect of zeolite on digestibility and feedlot performance of Mehraban male lambs given a diet containing urea-treated maize silage
Authors: Forouzani R. , Rowghani E. , Zamiri M. J.
Published: May 2019

A naturally occurring zeolite (Anzymite™) was added to a diet containing 350 g maize silage per kg (which was treated with 10 g urea per kg (fresh weight)), 375 g barley and 275 g alfalfa hay per kg. Effect of inclusion of zeolite (0, 30 and 60 g/kg diet) on diet digestibility, ruminal fluid acidity and ammonia concentration, blood urea nitrogen level, and feedlot performance was studied in Mehraban ram lambs. The diets were given ad libitum. Digestibility coefficients of dietary dry matter and crude protein were significantly increased by zeolite (P < 0·05). The diet containing 30 g zeolite per kg had higher neutral-detergent fibre digestibility compared with the control (P < 0·05). Over all sampling times, the ruminal fluid of the sheep given the 30-g/kg zeolite diet had the highest and those given the 60-g/kg zeolite diet had the lowest pH values (P = 0·03). Before feeding, ruminal ammonia concentration was low for all treatments (4 to 8 mg/dl). At 4 h after feeding, the control diet had the lowest ruminal ammonia concentration (5·5 mg/dl) which was significantly lower than the values for zeolite diets (35 to 39 mg/dl). Blood urea nitrogen (BUN) level increased post feeding for all diets. At 4 h post feeding, the level for the control diet was significantly higher than for the zeolite diets, but at 6 h post feeding, the level of BUN was higher with 60 g zeolite per kg diet. Daily dry-matter intake for the 60 g zeolite per kg diet was significantly higher than for the control. Backfat depth in the 60 g zeolite group was significantly less than the control group. Pelvic and pericardial fats were significantly higher for the zeolite groups. Fat-tail weight in the 60 g/kg of zeolite group was significantly higher than in the 30 g zeolite and control groups. The findings indicated that, in spite of some improvements in digestibility and rumen fermentation pattern, addition of zeolite to the diet of feedlot Mehraban lambs, under the conditions of this experiment, was not advantageous.
Genetic parameters for resistance to nematode infections in Texel lambs and their utility in breeding programmes
Authors: Bishop S. C. , Jackson F. , Coop R. L. , Stear M. J.
Published: May 2019

This paper addresses the inheritance of host resistance to gastro-intestinal nematode parasite infections in commercial Texel lambs, and the rôle of resistance to parasites in breeding programmes. In two flocks of Texel sheep, faecal egg counts following natural parasite challenge were measured on up to three occasions post weaning per lamb over a 4-year period, with 1385 and 287 lambs measured on the two farms. Live weight, and ultrasonically measured fat and muscle depth at weaning were available for each lamb, as were deep pedigrees. Egg counts were moderately to strongly heritable on all occasions, with Nematodirus egg counts more heritable than the Strongyle egg counts. Weighted average heritabilities for Strongyle and Nematodirus egg counts were 0.26 and 0.38, respectively. Within the same category of parasite, genetic correlations across time were positive and strong but somewhat less than unity, as were the correlations between Strongyle and Nematodirus egg counts measured at the same time. Genetic correlations between performance traits and Strongyle egg counts were usually favourable (i.e. negative) but weak, whereas those with Nematodirus egg counts were generally neutral or slightly positive. Whilst Nematodirus resistance may not necessarily be included in a breeding goal, the results suggest that Nematodirus egg counts can be used as an additional genetic indicator of Strongyle egg counts, at little extra cost. Including the epidemiological consequences of decreasing Strongyle egg counts in benefits of increasing parasite resistance, it is suggested that under UK conditions selection goals that place equal emphasis on live weight and log-transformed egg counts will be a robust means of improving growth rate and decreasing parasite larval challenge.
Effect of dietary probiotic on the pH and colour characteristics of carcasses, breast fillets and drumsticks of broilers
Authors: Karaoglu M. , Aksu M.I. , Esenbuga N. , Kaya M. , Macit M. , Durdag H.
Published: May 2019

This research was carried out to determine the effects of commercial probiotic (115-Biogallinox) on the colour properties of carcasses and dissected products in broilers. Ross-308 male chicks were given probiotic (P0:0 g/kg, P1:1 g/kg and P2:2 g/kg) containing Saccharomyces cerevisiae for 49 days. At the end of the trial all birds were slaughtered, and pH and skin colour of the carcasses were determined at various times during the first 24 h (1, 3, 7, 12, 17 and 24 h). After dissection, breasts and drumsticks were divided into two groups for vacuum packaging and aerobic packaging. Packaged breasts and drumsticks were stored at 3 ± 0.5°C for 12 days. During the storage period, the colours of breast meat, drumstick meat and drumstick skin were determined.

pH values of carcasses decreased (P < 0.01) over the 24-h period post mortem. The pH values of the P1 group were lower than the P0 and P2 groups (P < 0.01). L*, a* and b* values increased during the 24-h period and the P0 group had lower a* values than the P1 and P2 groups (P < 0.05). The use of probiotic in the broiler diet had no effect on L*, a* and b* values of breast and drumstick muscle. The L* and a* values of breast muscles were lower than drumstick muscles (P < 0.05). The values of b* in aerobic packaged breasts and drumsticks were higher than when vacuum packaged (P < 0.01). L* and b* values were also affected by storage period. While the L* and b* values of drumstick skin were higher than of drumstick meat, a* values in drumstick meat were higher (P < 0.05). The packaging had no effect on drumstick colour values (drumstick meat and drumstick skin) and L* and b* values decreased during the storage period.
Effect of finishing system (feedlot or pasture), high-oil maize, and copper on conjugated linoleic acid and other fatty acids in muscle of finishing steers
Authors: Engle T. E. , Spears J. W.
Published: May 2019

Sixty Angus steers (413 ± 8.0 kg) were used to determine the effects of copper (Cu), maize type, and finishing system (confinement v. pasture) on performance, carcass characteristics, and fatty acid composition of longissimus muscle in steers. Steers in confinement were given individually high concentrate diets containing either typical or high-oil maize, using Calan gate feeders. Steers grazing pasture (tall fescue) were maintained in four pastures with each pasture containing five steers. Salt was used to limit concentrate intake in pasture steers to approximately 0.6 of that observed in confinement steers. One half of the steers in each treatment received a CuO needle bolus at the initiation of the study while the remaining steers received no supplemental Cu. Equal numbers of steers per treatment were harvested after 91, 112 or 133 days on food. Rate of gain was lower (P < 0.01; 1.2 v. 1.6 kg/day) for pasture-fed steers compared with steers receiving typical maize. Cu supplementation increased (P < 0.05) ADG in steers given typical maize (1.8 v. 1.5 kg/day) and those on pasture (1.3 v. 1.1 kg/day) but not in steers given high-oil maize diets (1.5 v. 1.5 kg/day). Gain, dry-matter intake and gain/food did not differ between steers given typical or high-oil maize. Plasma cholesterol concentrations were lower (P < 0.01) in steers given typical maize relative to steers given high-oil maize. Steers receiving a Cu bolus had higher plasma (P < 0.05) and liver (P < 0.01) Cu concentrations than steers not receiving a Cu bolus. Steers receiving typical maize had lower (P < 0.05) liver Cu concentrations than steers receiving high-oil maize. Steers finished on pasture with limited concentrate had conjugated linoleic acid (CLA) concentrations in longissimus muscle that were approximately three times higher (P < 0.01) than steers given typical maize. Cu supplementation tended (P < 0.10) to increase muscle CLA. Longissimus muscle from pasture-fed steers was lower (P < 0.01) in C16: 0 and higher (P < 0.05) in C10: 0, C17: 0, C18: 3, C20: 3 and total polyunsaturated fatty acids than steers given typical maize. Muscle C18: 1 trans and C17: 0 tended to be reduced (P < 0.10) by Cu supplementation. These results indicate that finishing cattle on pasture with limited grain increases CLA in longissimus muscle and that Cu supplementation also alters the fatty acid composition of muscle.
Acute and long term effects of chronic intermittent noise stress on hypothalamic-pituitary-adrenocortical and sympatho-adrenomedullary axis in pigs
Authors: Otten W. , Kanitz E. , Puppe B. , Tuchscherer M. , Brüssow K.P. , Nürnberg G. , Stabenow B.
Published: May 2019

Noise is a potential environmental stressor and has also been identified as an aversive stimulus during animal housing. The impact of a 4-week chronic intermittent noise exposure on plasma adrenaline, noradrenaline, ACTH, cortisol and behaviour was studied in 24 male castrated German Landrace pigs. Three treatment groups were formed: N1 animals were subjected to a daily stimulation with broad-band noise (2 h, 90 dB(Lin)), N2 animals were subjected to the same stimulus three times a week and control animals were equally handled but experienced no noise exposure. Blood was serially sampled once a week via jugular vein catheters before, during and after a noise session. Behavioural observations of focal animals were performed by video technique. The first noise exposure of the animals caused no significant changes of stress hormone levels compared with the controls despite indices for more locomotion and less lying at the beginning of the noise stimulation, indicating that this noise stimulus is a rather mild stressor compared with other stimuli. The chronic intermittent noise stimulation, however, caused an increase of plasma ACTH and cortisol concentrations in the N1 animals after 4 days. The cortisol response of the N2 animals was unchanged compared to the controls at day 4, increased thereafter and at day 11 and 18 these animals tended to have higher cortisol levels compared with the controls. The noradrenaline/adrenaline ratio was significantly increased in N1 animals after 11 days and thereafter, whereas this ratio was unchanged in N2 animals until day 18, but also increased at day 25. In tendency, chronic intermittent noise exposure tended to reduce social behaviour and increase lying behaviour in both noise groups. In addition, the growth performance of pigs was negatively affected by the daily noise stimulation. In a second experiment with 16 male castrated German Landrace pigs, the impact of the daily intermittent noise exposure (N1) on the endocrine response to an acute stressor (restraint) and on the adrenocortical sensitivity to an ACTH challenge was studied. The time course of cortisol levels during the ACTH test indicated alterations in the time dynamics of the adrenocortical response with a more rapid response in the N1 animals. The results show that chronic intermittent noise exposure causes time-dependent alterations of the adrenocortical and sympathetic neural systems and may lead to behavioural suppression and growth retardation in pigs. Thus, repeated exposure of animals to noise levels over 90 dB should be avoided in pig husbandry to sustain productivity and animal welfare.
Effects of season and stocking density during transport on live weight and biochemical measurements of stress, dehydration and injury of rabbits at time of slaughter
Authors: de la Fuente J. , Salazar M. I. , Ibáñez M. , González de Chavarri E.
Published: May 2019

The effects on rabbit welfare of transport in two seasons (summer and winter) and at two stocking densities (high stocking density: 12 rabbits per cage; low stocking density: 8 rabbits per cage) were studied. The loss of live weight during transport was calculated. At slaughter, blood samples were obtained and some physiological parameters related to stress were analysed: cortisol, creatine kinase (CK), lactate dehydrogenase (LDH), lactate, glucose, packed cell volume (PCV), osmolarity, and albumin and globulin concentrations. In addition, liver and muscle samples were taken and immediately frozen in liquid nitrogen for subsequent glycogen measurements.

Season significantly affected the live-weight losses and plasma concentrations of cortisol (P< 0.01), CK, LDH, lactate (P< 0.001) and glucose (P< 0.01), as well as osmolarity (P< 0.001). Liver and muscle glycogen concentration were also affected by the season (P< 0.001). The loss of live weight was higher in rabbits transported in winter than in summer. The plasma concentrations of cortisol, lactate and glucose, CK and LDH activity, and osmolarity, as well as liver and muscle glycogen concentrations were higher in rabbits transported in summer than in winter. Stocking density had no effect on the analysed parameters. The high levels of the analysed blood parameters, which are related to stress, lead to the conclusion that the welfare of the rabbits transported in summer was more affected than those transported in winter.
Estimation of colostrum intake in the neonatal pig
Authors: Devillers N. , van Milgen J. , Prunier A. , Le Dividich J.
Published: May 2019

Three trials were performed in order to establish a method of estimation of colostrum intake based on weight gain in newborn pigs. The first trial involved 33 piglets, bottle-fed with sow colostrum and weighed regularly for 25 h. A regression equation relating colostrum intake (CI in g) to birth weight (BWB in kg), weight at CI estimation (BW in kg), age at first suck (tFS in min) and duration of colostrum intake (t in min and with 17 h < t < 25 h) was established with a root mean-square error equal to 33 g. This equation was evaluated with a second data set using 15 further bottle-fed piglets (trial 2). Measured and predicted values were very close (R2 = 0.90). The third trial compared colostrum intake estimated either with the previous equation or with the deuterium oxide dilution method in catheterized sow-reared or bottle-fed piglets (no. = 12 per group). The equation underestimated colostrum intake of those piglets, probably due to prior surgery. However, the feeding method (bottle-feeding v. sow-rearing) had no effect on the relationship between weight gain and colostrum intake. Therefore, the equation established in bottle-fed piglets may be applied to sow-reared piglets.
Effects on inbreeding of different strategies aimed at eliminating scrapie sensitivity alleles in rare sheep breeds in The Netherlands
Authors: Windig J. J. , Eding H. , Moll L. , Kaal L.
Published: May 2019

The Dutch scrapie eradication programme aims at the exclusive use of homozygous ARR/ARR breeding rams by the end of 2004. As a consequence, breeds with a small population size and a low frequency of the ARR allele may suffer unacceptable losses of genetic diversity and high inbreeding levels. We simulated three breeding strategies to assess their efficacy in eliminating scrapie sensitive alleles and their effect on inbreeding levels. Under mild selection, both homozygous and heterozygous ARR rams were used indiscriminately. Under moderate selection, homozygous ARR rams were used preferably but they were supplemented with heterozygous rams when necessary. Under severe selection, only homozygous rams were used. Severe selection mimics then the proposed eradication programme. Simulations were carried out with allelic frequencies and population parameters of existent rare breeds in The Netherlands. With severe selection all simulated breeds showed unacceptably high inbreeding rates (> 0·5% per year). For some breeds, moderate selection resulted in acceptable inbreeding rates, while for other breeds only mild selection resulted in acceptable rates. The frequency of the ARR allele after 5 years of selection was only slightly lower with moderate selection than with severe selection (0·8% lower on average), but it was clearly lower with mild selection. Based on these simulations, we propose a selection programme where with low frequencies of the ARR allele, mild selection is used initially. Once the ARR frequencies rise to a particular value, the switch can be made to moderate selection. The population size (e.g. below 750, 750 to 3750 and above 3750 ewes) determines the frequency of the ARR allele at which the switch can be made (33%, 25% and 10%, respectively). With even higher ARR frequencies (above 70%, 50% and 33%, respectively) the regime can be changed to severe selection.
Genetic relationships between faecal egg count and production traits in commercial Merino sheep flocks
Authors: Pollott G. E. , Greeff J. C.
Published: May 2019

In several countries the gastro-intestinal parasites of sheep show evidence of resistance to the commonly used anthelmintic treatments. The use of animals with genetic resistance to such parasites has been shown to be a viable alternative in a number of resource flocks. However, the genetics of host resistance to parasites in industry flocks and the effects on production traits of using resistant sheep is relatively unknown. This study addresses these questions using data from 55 commercial Merino flocks in Australia. The heritability and genetic correlations were estimated for faecal egg count (FEC), an indicator of host resistance, and eleven fleece and body production traits. The heritability of FEC (0·26 (s.e. 0·018)), using a sire model, was found to be similar to other estimates reported in the literature from resource flocks. The heritabilities of production traits were also consistent with published reports from resource flocks. The genetic correlations between FEC and the 11 production traits, calculated using a sire model, were mostly zero, except for staple strength (-0·17 (s.e. 0·096)), fat depth (-0·26 (s.e. 0·088)) and eye-muscle depth (-0·18 (s.e. 0·091)). Animal model estimates of heritability and the genetic correlations between the traits were largely similar to the sire model estimates. Correlated responses to selection for reduced FEC based on the sire model genetic parameters were calculated to be less than 0·15% of the trait mean per generation for all traits except staple strength, fat depth, muscle depth and live weight. These were expected to increase slightly under selection for reduced FEC. Thus industry-based selection programmes to increase host resistance to parasites should be effective and have no detrimental effect on production characteristics of Merino sheep in Australia. The full benefit of such industry-based schemes could be improved by a better level of recording in the flocks studied.
Genetic parameters for growth, reproductive performance, calving ease and suckling performance in beef cattle heifers
Authors: Phocast F. , Sapa J.
Published: May 2019

There is considerable concern about the consequences on fitness-related traits of using narrow breeding objectives for production traits. The aim of this study was to assess the potential consequences of selection for growth in French beef cattle breeds by estimating genetic correlations between growth, reproduction, calving and suckling traits of Charolais, Limousin and Blonde d’Aquitaine heifers. Data consisted of the records collected from 1985 to 2002 in progeny test stations that were used in the genetic evaluation of 284 Charolais, 125 Limousin and 118 Blonde d’Aquitaine AI sires. Seven traits were considered simultaneously in the analysis: weights at 18 months and after calving (for measuring heifer growth), sexual precocity and fertility (for measuring heifer reproductive performance), calving difficulty score and pelvic opening (for measuring calving ease) and milk yield (for measuring the suckling ability of the primiparous cow). REML (co)variance estimates were derived using linear multitrait sire models. Estimates of heritability were in the range of values given in the literature. They were very similar in the Charolais and Blonde d’Aquitaine breeds, and rather different for reproductive and suckling performance in the Limousin breed. Estimates were about 0·35 for heifer growth traits and about 0·15 for calving difficulty score in the three breeds. In the Charolais and Blonde d’Aquitaine breeds, estimates of heritability were 0·15 for sexual precocity and 0·05 for heifer fertility. These estimates were close to zero in the Limousin breed. Heritabilities of pelvic opening and milk yield were, respectively, 0·2 and 0·6 in the Limousin breed and around 0·3 in the other two breeds. Genetic correlations between traits concerning the same ability (as, for instance, weight at 18 months and weight at calving) were high and, in general, similar among breeds. Genetic correlations between heifer growth, reproductive traits, calving ease and suckling performance were nil or slightly favourable in the three breeds. Consequently, past selection mainly directed towards increasing growth seems not to have adversely affected the efficiency of female reproduction and the maternal abilities of French specialized beef cattle breeds.
Muscle-specific metabolic, histochemical and biochemical responses to a nutritionally induced discontinuous growth path
Authors: Cassar-Malek I. , Hocquette J. F. , Jurie C. , Listrat A. , Jailler R. , Bauchart D. , Briand Y. , Picard B.
Published: May 2019

An experiment was conducted with 42 Montbéliard steers to determine if nutritionally induced interrupted growth could influence muscle characteristics of steers and hence meat quality. A restriction/refeeding path was designed in order to induce a discontinuous growth path. At 9 months of age, 21 steers were given a restricted amount of diet for 3 months and were then slaughtered (R steers; no. = 10; intake: 5·28 kg dry matter (DM) per day) or subjected to a 4-month ad libitum refeeding period (R/F steers; no. = 11; intake: 8·99 kg DM per day) with the same diet (11·03 to 11·12 MJ metabolizable energy (ME) per kg DM) prior to slaughter. An additional 21 control steers were offered the same diet but in amounts that allowed them to gain continuously between 9 and 12 months of age, and were then slaughtered (C steers; no. = 10; intake: 7·08 kg DM per day) or maintained on a continuous feeding protocol through to 16 months of age prior to slaughter (C/C steers; no. = 11; intake: 8·07 kg DM per day). M. semitendinosus (ST), m. longisssimus thoracis and m. triceps brachii (TB) were collected for biochemical and histochemical analyses. R steers had a lower average daily gain (ADG; P 0·001), a lower final weight (P 0·01) and a leaner carcass (P 0·01) than C steers. Upon refeeding, R/F steers had a higher ADG than C/C steers (P 0·05) and underwent compensatory growth resulting in compensation of body weight and composition at 16 months. In muscles, glycolytic lactate dehydrogenase activity was lower in R steers (P 0·01) and restored in R/F steers compared with control steers. Among oxidative enzymes, cytochrome-c oxidase activity was higher in the TB of R/F compared with C/C steers (P 0·001) indicating a muscle-specific metabolic adaptation to the feeding level. There was little effect of the nutritional treatment on muscle fibre size and type except for an increase in the frequency of hybrid fibres in R and R/F groups (P 0·05). Total and insoluble collagen content were affected by restriction (P 0·001) in a muscle-specific manner: insoluble collagen content was lower in ST, but total and insoluble collagen contents were higher in TB of R compared with C animals at 12 months of age. No differences were recorded in lipid contents nor in proteasome activities. The data suggest that an alternation of relatively mild nutritional restriction and ad libitumfeeding had only a small effect on muscle characteristics. However, muscles respond differentially to changes in feeding level.
Partial and total apparent digestibility of dietary carbohydrates in horses as affected by the diet
Authors: Varloud M. , Fombelle A. de , Goachet A. G. , Drogoul C. , Julliand V.
Published: May 2019

The study reported in this paper was conducted to evaluate the digestibility of dietary carbohydrates (‘starch and sugars’ (S), neutral-detergent fibre (NDF), acid-detergent fibre (ADF)) and organic matter (OM) in the different parts of the equine digestive tract (stomach, jejuno-ileum, caecum, right ventral colon, left ventral colon, left dorsal colon, right dorsal colon, small colon and faeces). Three horses were given a standard diet (D1) based on fibrous pellets and straw and four were offered a high energy diet (D2) based on starch pellets and meadow hay. The digesta collection procedure, by total tract removal, permitted measurement of organ length, and dry matter and volume of digesta. Acid-detergent lignin (ADL) and acid insoluble ash (AIA) were used as natural digestibility markers. It was shown that AIA and ADL gave coherent data for ‘starch and sugars’ digestibility evaluation. ADL was a more relevant marker for parietal carbohydrates and OM digestibilities in horses given D1, whereas AIA have been preferred to evaluate these components digestibilities in horses offered D2. In horses given D1, precaecal OM digestibility coefficient varied from -0·04 to 0·20 whereas it varied from 0·46 to 0·62 in horses receiving D2. For both pellets, the results showed a considerable S digestibility occurring in the stomach (0·69 and 0·60 for D1 and D2 respectively) and this continued in the small intestine (0·88 and 0·89 for D1 and D2 respectively). With the exception of D2, structural carbohydrate fractions of the foods were poorly digested in the pre-caecal digestive parts. In the hindgut, OM digestibility coefficient varied from 0·47 to 0·60 for D1 and from 0·33 to 0·51 for D2. In horses given D1, highest digestibility was observed for each dietary carbohydrate in the left dorsal colon where it reached 0·99 for S; 0·45 for NDF and 0·40 for ADF. In horses receiving D2, the dietary components’ digestibilities increased regularly along the hindgut up to the faeces. The D2 structural fractions (NDF and ADF) digestibilities in the hindgut and faeces were lower than in horses given D1. These results not only confirmed that high energy diets like D2 can affect structural carbohydrate digestion in the horse hindgut but also indicated that a large amount of the energy part of the pelleted morning meal is broken down in the stomach.
Circulating levels of insulin-like growth factor-1 and associated binding proteins in plasma and mRNA expression in tissues of growing pigs on a low threonine diet
Authors: Katsumata M. , Kawakami S. , Kaji Y. , Takada§ R.
Published: May 2019

The aim was to determine whether dietary threonine levels affected hepatic insulin-like growth factor-1 (IGF-1) mRNA expression as well as plasma IGF-1 concentration and IGF binding protein (IGFBP) profile in growing pigs. Two male 6-week-old pigs from each of seven litters were used. Each littermate was assigned to one of two diets, control or low threonine (LT), providing per kg 14·3 MJ digestible energy in both diets, 170 g protein in the control diet and 167 g protein in the LT diet. The control diet contained all essential amino acids in the recommended amounts, including 8·2 g threonine per kg. The LT diet was similar but contained only 5·1 g threonine per kg. Pigs were pair-fed these diets for 3 weeks. Growth rate and food efficiency of pigs given the LT diet were significantly lower than those of pigs given the control diet (P 0·001). Plasma IGF-1 concentration of pigs given the LT diet was proportionately 0·44 lower than that of pigs given the control diet (P 0·01). Plasma free threonine concentration of pigs given the LT diet was lower than that of the pigs given the control diet (P 0·001). Plasma IGFBP2 level of pigs given the LT diet was significantly higher than that of pigs given the control diet (P 0·05). Pigs given the LT diet had a significantly lower plasma IGFBP3 level compared with their littermates given the control diet (P 0·05) suggesting that clearance rate of circulating IGF-1 was higher in the LT group. Dietary threonine level did not affect IGF-1 mRNA abundance in the liver. It is concluded that lower plasma IGF-1 level caused by reduced dietary threonine level may have been partly due to increased clearance rate of circulating IGF-1 but not due to IGF-1 gene expression in the liver.
Oxidative stress in primiparous cows in relation to dietary starch and the progress of lactation
Authors: Gabai G. , Testoni S. , Piccinini R. , Marinelli L. , Howard C. M. , Stradaioli G.
Published: May 2019

Oxidative stress may be important in early lactation cows due to high metabolic demands. Modifying dietary starch may alter glucose utilization, modify oxidative metabolism and, consequently, increase oxidative stress. To test this hypothesis, early lactation primiparous cows underwent a short-term dietary starch restriction followed by realimentation. At calving, 10 Friesian primiparous cows were randomly assigned to two groups and given a basal starch diet (BSD, 249 g/kg of starch dry matter (DM)) in the form of a total mixed ration until 42 days in milk (DIM). Afterwards, five cows (CTR) continued to receive the same diet and five cows (EXP) were allotted to experimental diets: low starch diet (LSD, 210 g/kg starch DM) from 43 to 65 DIM followed by high starch diet (HSD, 283 g/kg starch DM) from 66 to 85 DIM and BSD from 86 to 94 DIM. Blood samples were collected at 37, 50, 60, 70, 80, and 94 DIM to measure total plasma glutathione (GSH), thiobarbituric acid reactive substances (TBARS), and erythrocyte glutathione peroxidase (GPx) activity as indicators of oxidative stress, N-acetyl-ß-D glucosaminidase (NAGase), lysosyme, and white blood cell counts as indicators of immune response. Metabolic adaptations were evaluated by glucose, non-esterified fatty acids (NEFA), beta-hydroxy-butyrate (BOHB), insulin, and GH concentrations, and the acid/base balance. Milk yield was not significantly different between groups throughout the experiment and was correlated with TBARS (r 0·284; P 0·05) and GSH (r = 0·294; P 0·05). Estimated energy intake was significantly higher in the EXP group at 70 DIM only (P 0·05). Plasma glucose was significantly lower in the EXP group at 50, 60 (P 0·001) and 80 DIM (P 0·05), and was correlated with GSH (r = 0·348; P 0·01) and TBARS (r = 0·367; P 0·01). Plasma NEFA decreased overall in both groups (P 0·01). EXP was lower than CTR in concentrations of plasma BOHB at 70 DIM (P 0·05) and plasma insulin at 60 (P 0·001), 80 and 94 (P 0·05) DIM. Plasma TBARS, GSH and GPx increased throughout (P 0·01) in both groups. This was delayed in the EXP group following introduction of LSD; significant differences between groups at 60 (P 0·01), 80 and 95 (P 0·05) DIM for TBARS, and at 70 (P 0·01) and 80 (P 0·05) DIM for GPx. Indicators of immune response and plasma bicarbonates did not differ between groups. Blood pH was significantly lower in the EXP group at 80 and 94 DIM (P 0·001). Blood pCO2 was significantly lower at 80 and 94 DIM (P 0·05) in the CTR group. While recovering from the negative energy balance, cellular metabolism probably shifted towards oxidative phosphorylation, with a consequent oxidative stress increase. LSD delayed this recovery in the EXP group and thus reduced GSH synthesis. In conclusion, the diet starch content may alter the control of oxidative stress and expose animals to oxidative injuries.
The effect of stocking density and social regrouping stressors on growth performance, carcass characteristics, nutrient digestibility and physiological stress responses in pigs
Authors: Leek A. B. G. , Sweeney B. T. , Duffy P. , Beattie V. E. , O’Doherty J. V.
Published: May 2019

A 2 ✕ 2 factorial arrangement of treatments used 280 growing pigs and 240 finishing pigs to examine the main effects and interactions between two levels of stocking density (0·75 m2 v. 0·45 m2 per growing pig and 0·88 m2 v. 0·53 m2 per finishing pig) and grouping (static groups v. regrouped) on pig growth performance, carcass characteristics, nutrient digestibility and measurements of physiological indicators of stress responses. Regrouping was achieved by moving four unfamiliar pigs between replicate groups every 14 days. Average daily gain (ADG) and average daily food intake (ADFI) were reduced by an additive interaction between high density and regrouping in growing pigs (P < 0·01). In finishing pigs, regrouping reduced ADG (P 0·05) and carcass weight (P 0·05). Regrouping reduced apparent dry matter and gross energy digestibility in finishing pigs (P 0·05). Rectal temperature increased 3 h after mixing finishing pigs (P 0·05), but not growing pigs. In growing pigs, the neutrophil: lymphocyte ratio tended to increase (P 0·1) after regrouping, although plasma cortisol concentration was unaffected. In finishing pigs, the response to a Newcastle disease virus antigen challenge tended to decrease at high stocking density (P 0·1), although total IgG concentration was unaffected. In conclusion, the growth performance of growing and finishing pigs was affected by social stressors. However, effects on the physiological measurements did not concur with effects on growth performance.
Theoretical model of heat balance in pigs
Authors: Fialho F. B. , Bucklin R. A. , Zazueta F. S. , Myer R. O.
Published: May 2019

A theoretical model was developed to predict the heat balance and body temperature of growing and finishing pigs subjected to different environments. The heat transfer modes considered in the model were convection to the surrounding air, conduction to the floor, long-wave radiation between the animal and the surrounding walls, shortwave radiation from the sun, evaporation on the skin surface, evaporation and heating of air in the respiratory tract and heating of ingested food and water. The heat balance is the net heat gain or loss from the environment due to all these processes, added to the animal's heat production. Body temperature is calculated over time using the heat balance, the animal's mass and the specific heat of the animal's body. Behavioural responses to heat and cold environments, such as vasoconstriction, vasodilatation, posture changes and huddling were expressed as changes in heat transfer coefficients and exposed surface area. The increase in evaporation under hot conditions was also considered. It was assumed that the animal's reaction to the environment may be expressed as a function of mean body temperature. The animal's heat production was considered an input to the model, which should reflect the increased metabolic rate in cold environments. Although further research is still needed to determine precisely some of the parameters, the model may be integrated with other models in order to compose a complete pig model.
An estimate of the leucine requirement for young pigs
Authors: N. R. Augspurger  , Baker D. H.
Published: May 2019

Three pig trials were done to estimate an objective requirement of young (10 to 20 kg) pigs for leucine (Leu). Within each trial, four or five replicates of five pigs were given ad libitum access to their experimental diet for a period of 21 (trial 1) or 19 days (trials 2 and 3). A Leu-deficient diet (177 g crude protein per kg) based on maize, peanut meal, lactose, sucrose, dried whey, maize starch, soya-bean meal (SBM), and gelatin was used in these trials. Trial 1 showed that the Leu-deficient diet supplemented with Leu produced responses in weight gain and gain/food ratio that were similar (P > 0·10) to that obtained from a maize-SBM-whey positive-control diet containing 213 g crude protein (CP) per kg. Trials 2 and 3 utilized graded levels of crystalline L-Leu to determine the minimal Leu requirement in young pigs. Both trials showed linear increases (P < 0·05) in weight gain and gain/food as a result of Leu supplementation. Closer examination of the data revealed no significant change in gain/food or PUN responses above 11·2 g/kg total Leu in trial 2, or in weight gain or PUN values above 11·5 g/kg total Leu in trial 3. These data indicate that the Leu requirement of young pigs is probably not greater than 11·5 g/kg (10·5 g/kg true digestible), which equates to approximately 0·72 g true digestible Leu per MJ metabolizable energy. The ideal ratio of Leu to Lys appears to be close to 1: 1 for pigs in the weight range of 10 to 20 kg.
Effect of driver behaviour, driving events and road type on the stability and resting behaviour of sheep in transit
Authors: Cockram M. S. , Baxter E. M. , Smith L. A. , Bell S. , Howard C. M. , Prescott R. J. , Mitchell M. A.
Published: May 2019

The aim of this project was to examine the relationships between driver behaviour and driving events during a journey and the behavioural responses of sheep to these events. Driving style can have a major influence on the welfare of the animals by affecting the risk of injury and by disturbing the ability of the sheep to rest. Two drivers each drove groups of 10 sheep in a 5·5-tonne, single-deck, non-articulated livestock vehicle on five 7-h road journeys consisting of minor roads, main single carriageways and a motorway. The driver, the driver’s view through the windscreen, the speedometer and the sheep were video recorded. Differences in driving style were identified as differences in vehicle speed, rapid braking and the number of corners taken with high cornering g-force. Differences in driving style had a slight effect on the frequency of losses of balance by the sheep and a more significant effect on the degree of disturbance to the sheep and on their ability to rest during the journey. Losses of balance were common, but falls were rare. About 80% of the losses of balance could have been caused by driving events, such as acceleration, braking, stopping, cornering, gear changes and uneven road surfaces. Only about 22% of driving events were followed by a loss of balance. It is likely that driving events were also responsible for many interruptions to both lying behaviour and rumination. Clear benefits of motorway driving compared with single carriageway driving were fewer losses of balance, more lying down, more rumination and fewer disturbances amongst the sheep. This study provides evidence that would be useful for driver training and education to promote careful driving as a means of ensuring the welfare of animals in-transit. The quality of the journey experienced by sheep during transport is dependent upon a number of factors that can be influenced by the driver of the vehicle.