An experiment was conducted using medium-sized crossbred beef heifers to study how manipulation of weight gain in late gestation affected production. Forty heifers were fed individually to gain according to one of three regimens for an approximate 90 day period prior to parturition: (1) 1·2 kg gain per head per day for 45 days followed by no gains for 45 days; (2) 0·6 kg gain per head per day for the entire period; (3) no gain for the first 45 days followed by 1·2 kg gain per head per day for the last 45 days. Milk production was measured by weighing of calves before and after suckling at 30, 60, and 150 days post partum. Heifers were weighed, measured for heart girth and hip weight, and visually scored for condition at the start, middle and end of the feeding period to quantify growth and condition changes. Heifers that had a high rate of gain for a short time produced more milk in early lactation than heifers that gained at a slower rate for a longer time pre-partum (P < 0·05). Calf weaning weights and dam reproductive performance were unaffected (P < 0·05) by pre-partum weight gain. It is concluded from these results, that as long as the recommended weight gain is achieved during late gestation, the timing of the weight gain is not critical to sustain productivity.

The objective of the present study was to investigate the intestinal development of newborn intrauterine growth-restricted (IUGR) piglets subjected to normal nutrient intake (NNI) or restricted nutrient intake (RNI). Newborn normal birth weight (NBW) and IUGR piglets were allotted to NNI or RNI levels for 4 weeks from day 8 postnatal. IUGR piglets receiving NNI had similar growth performance compared with that of NBW piglets. Small intestine length and villous height were greater in IUGR piglets fed the NNI than that of piglets fed the RNI. Lactase activity was increased in piglets fed the NNI compared with piglets fed the RNI. Absorptive function, represented by active glucose transport by the Ussing chamber method and messenger RNA (mRNA) expressions of two main intestinal glucose transporters, Na+-dependent glucose transporter 1 (SGLT1) and glucose transporter 2 (GLUT2), were greater in IUGR piglets fed the NNI compared with piglets fed the RNI regimen. The apoptotic process, characterized by caspase-3 activity (a sign of activated apoptotic cells) and mRNA expressions of p53 (pro-apoptotic), bcl-2-like protein 4 (Bax) (pro-apoptotic) and B-cell lymphoma-2 (Bcl-2) (anti-apoptotic), were improved in IUGR piglets fed the NNI regimen. To test the hypothesis that improvements in intestinal development of IUGR piglets fed NNI might be mediated through circulating glucagon-like peptide-2 (GLP-2), GLP-2 was injected subcutaneously to IUGR piglets fed the RNI from day 8 to day 15 postnatal. Although the intestinal development of IUGR piglets fed the RNI regimen was suppressed compared with those fed the NNI regimen, an exogenous injection of GLP-2 was able to bring intestinal development to similar levels as NNI-fed IUGR piglets. Collectively, our results demonstrate that IUGR neonates that have NNI levels could improve intestinal function via the regulation of GLP-2.

Sixty entire male pigs between 7 and 28 days and 60 entire male pigs between 28 and 56 days of age were given ad libitum basal diets using peanut meal and wheat gluten with or without dried milk as the protein supplements. The diets contained between 7·0 and 10·7 g lysine per kg. These diets were supplemented with graded additions of synthetic L-lysine hydrochloride.

It was found that the lysine required for maximum performance and nitrogen retention was at least 12·7 g/kg dry matter (DM) between 7 and 28 days of age and not greater than 12 g/kg DM between 28 and 56 days of age. These values are 4·7 and 5·3 g/kg dietary crude protein for the two ages or 0·81 and 0·79 g/MJ digestible energy.

A method is discussed for the calculation of the most economical level of lysine supplementation. This is dependent on the cost of the basal diet and lysine, and the value of the weight gain.

The concentration of free lysine in the blood plasma did not give a clear indication of lysine requirement of the pigs.

The effects of milking on the overall productivity of N'Dama cattle kept under village conditions were studied using three groups of cows during a 27-month period. One group of 46 cows in 16 herds in Nioro Jattaba village was not milked for human consumption and their calves had access to all of their milk (group 1). Another group of 46 cows in the same herds was partially milked for human use once a day while the calves had access to the residual milk (group 2), the normal husbandry practice in this village. A third group of 70 cows in six herds, managed similarly in a similar production environment in the nearby village of Keneba, was milked twice daily with the residual milk for their calves, the normal husbandry in this village. A mean extraction of 296 (s.d. 110·7) kg milk per cow occurred in group 2 during a lactation period of 517 days while the figure for group 3 was 450 (s.d. 177·7) kg per cow over 430 days. At the end of the observation period, calf mortality to 12 months averaged 6% and was similar in all groups. Calf weights at 12 months in group 1 (98·1 kg) exceeded that of groups 2 and 3 by proportionately 0·26 and 0·38 (P < 0·001) respectively. Mean calving rate was 53% in groups 1 and 2, and 72% in group 3. Post-partum body-weight losses were most severe in group 1, followed in order by groups 2 and 3. A herd productivity index (incorporating calf weight, live weight equivalent of milk extracted for human use, cow and calf viability and calving rate) was 100·7 kg calf weight per 100 kg metabolic weight of cow per year for group 1, 110·2 for group 2 and 166·1 kg for group 3. These values suggest that recommendations to small-holder farmers for enhancing livestock productivity should include strategies to improve milk yields in general rather than advocating no milk extraction or changing the milking regime currently practised.

The effects of the proportion of hay in the diet (18 or 40%), implantation of diethylstilboestrol and the type of housing on the performance of male calves was examined over the growth period from 250 to 500 kg live weight in a 2×2×2 factorial experiment. The dry-matter consumption per 100 kg of live weight was lower and the live-weight gain and efficiency of conversion of crude metabolizable energy was higher with the diet containing 18% of hay than with that containing 40%. Diethylstilboestrol implantation had only a small effect on performance. Animals that were allowed yard space in addition to pens gained less rapidly, were less efficient in the conversion of energy into live weight, and were somewhat leaner, than those restricted to pens.

Housed pigs are often exposed to elevated concentrations of atmospheric ammonia. This aerial pollutant is widely considered to be an environmental stressor that also predisposes to reduced growth rates and poor health, although evidence to support this view is limited. Hepatic gene expression is very responsive to stress and metabolic effects. Two batches of growing pigs were therefore exposed to a nominal concentration of atmospheric ammonia of either 5 ppm (low) or 20 ppm (high) from 4 weeks of age for 15 weeks. Growth rates were monitored. Samples of liver were taken after slaughter (at ∼19 weeks of age). Samples from the second batch were analysed for global gene expression using 23 K Affymetrix GeneChip porcine genome arrays. Samples from both batches were subsequently tested for five candidate genes using quantitative real-time PCR (qPCR). The array analysis failed to detect any significant changes in hepatic gene expression following chronic exposure to atmospheric ammonia. Animals clustered into two main groups but this was not related to the experimental treatment. There was also no difference in growth rates between groups. The qPCR analyses validated the array results by showing similar fold changes in gene expression to the arrays. They revealed a significant batch effect in expression of lipin 1 (LPIN1), Chemokine (C-X-C motif) ligand 14 (CXCL14), serine dehydratase (SDS) and hepcidin antimicrobial peptide (HAMP). Only CXCL14, a chemotactic cytokine for monocytes, was significantly down-regulated in response to ammonia. As chronic exposure to atmospheric ammonia did not have a clear influence on hepatic gene expression, this finding implies that 20 ppm of atmospheric ammonia did not pose a significant material risk to the health or metabolism of housed pigs.

A total of 120 Duroc×(Large White×Landrace) pigs, 50% barrows and 50% gilts, with 54.1±0.14 kg BW and 103±3 days of age, were used to study the effect of advancing the shift to a standard finisher feed from 100 to 90 and 80 kg BW on production performances and carcass and pork quality. Each of the six treatments (two sexes×three BWs at time of feeding shift) was replicated four times and the experimental unit was the pen (with five pigs for growth performance and carcass variables and three pigs for pork and fat traits). The grower (163 g CP and 9.5 g total Lys/kg) and the finisher diets (152 g CP and 7.9 g total Lys/kg) were based on maize, barley and vegetal protein concentrates, contained 13.39 MJ metabolizable energy/kg and were offered ad libitum through the trial. Pigs intended for dry-cured product elaboration were slaughtered at 170±3 days of age as average (124 and 115 kg BW for barrows and gilts, respectively). For the overall period, barrows ate more feed (P<0.001) and grew faster (P=0.03) than gilts. No effect of feed shift was observed on growth performances, although the average daily CP intake (P=0.01) and feeding costs (P=0.04) were reduced by advancing the transition to the finisher feed. Carcasses from barrows were heavier (P<0.001) and had wider backfat depth (P<0.001) than those from gilts but no significant differences were observed in the meat chemical composition. The feed change schedule did not modify carcass or meat traits. It is concluded that an early shift to the finisher feed (at 80 kg BW instead of 100 kg BW) might be an interesting strategy in pigs intended for dry-cured products because, although it neither increased body fatness nor improved pork quality, CP intake and feeding costs were reduced without impairment of growth performances. Results were similar for barrows and gilts.

Adipocyte size and number are correlated with fat deposition, which is of major concern to human health and pork producers. To identify quantitative trait loci (QTL) for adipocyte size and number in pigs, a total of 341 F2 animals at 240 days in a White Duroc × Erhualian cross were measured for the area, perimeters, volume and number of adipocyte in abdominal fat. A genome scan was performed on these animals and their parents and grandparents with 183 microsatellite markers spanning the pig genome. Five chromosomal regions showed effects on the traits measured, predominantly on adipocyte size, on pig chromosome (SSC) 1, 4, 7 and 9. Neither of these QTL has been reported before this study. The QTL for adipocyte size detected in this study perfectly correspond to the previously reported QTL for fatness traits on SSC1, 4 and 7. The most significant association was evidenced at 58 cM on SSC7. At the locus, the favorable allele decreasing adipocyte size was unusually originated from the obese Erhualian breed. Only a suggestive QTL was detected for adipocyte number on SSC9. The results shed new lights on the understanding of the genetic basis of fatness traits in pigs.

Dried grass pellets of high density (1·3 g/ml) were fed ad libitum to British Friesian male calves 5 to 7 mo old (Experiment 1) or 2 to 5 mo old (Experiment 2). All eight animals in Experiment 1 and eight out of 12 in Experiment 2 were fitted with rumen fistulae. In some subperiods of both experiments, pellets were broken down in water and administered as a slurry directly into the rumen at a level equivalent to approximately one-third that of voluntary intake. Intake per os was significantly reduced by this treatment but total intake (per os+per rumen) was not affected.

In Experiment 3 pellets of high (1·24 g/ml) or medium (1·14 g/ml) density were fed ad libitum to 40 9-mo-old Suffolk × Scottish Halfbred wether sheep, either alone or with access limited to 3 hr a day, in which case chopped hay was always available. Pellet density did not affect total intake, but when offered as supplements to hay the consumption of medium-density pellets was higher than that of high-density pellets. In all three experiments animals required 2 or 3 weeks to reach maximum intake of pellets. Over the 42 days of Experiment 3 the proportion of pellets in the feed consumed by animals given pellets as supplements to hay increased from 60 to 80%.

When different protein sources are infused direct into the abomasum of the dairy cow, the pattern of utilization of the amino acid-N supplied might be expected to be influenced by the amino acid composition of the infused protein. This suggestion was examined in a nitrogen-balance study with lactating cows.

Myostatin (MSTN), a member of the transforming growth factor-β superfamily, has been shown to be a negative regulator of myogenesis. Natural mutation in beef cattle causes double-muscling phenotypes. We report an investigation designed to knockout the MSTN gene by gene targeting in ovine myoblast cells. Two promoter-trap targeting vectors MSTN-green fluorescent protein (GFP) and MSTN-neo were constructed and used to transfect foetal and neonatal ovine primary myoblast cells. Both GFP-expressing cells and drug-resistant cells were obtained. Targeted cells expressing GFP were confirmed by polymerase chain reaction (PCR) assay and drug-resistant cells were characterised by PCR and Southern blot after growing into cell clones.

Counts were made before and after fixation of the numbers of fertilised and unfertilised ova recovered from 3 mated sows, 7 unmated sows and from 34 sows inseminated at varying times before and after the onset of heat.

The percentages of fertilised ova for sows inseminated the day before heat (day — 1) on the first day of heat (day 0) the second day of heat (day 1) and the third day of heat (day 2) are respectively for unfixed and fixed ova: 7·1 and 9·8, day – 1 ; 55·9 and 68·8, day 0; 63·4 and 98·2, day 1; 20·1 and 15·2, day 2. No fertilised ova were recorded from unmated sows; the percentages for mated sows were 94·3 and 95·5.

It is concluded that failure of fertilisation is likely to be the greatest source of loss of fertility in inseminations made before heat and late in heat.

Most ova from sows inseminated on day — 1 and from sows inseminated in day 2 had no spermatozoa on the zona pellucida. A few ova from sows inseminated on day 2 had very large numbers of spermatozoa present.

It is suggested that failure of the spermatozoa to reach the site of fertilisation rather than their loss of fertilising capacity is likely to be the cause of the low fertility of early inseminations.

The objective of this study was to compare growth performance and carcass and meat quality characteristics of growing–finishing pigs fed diets containing Roundup Ready wheat (MON 71800), compared with the non-transgenic genetically similar parental control wheat (MON 71900), and four commercial varieties of non-transgenic wheat (HANK, Westbred 926, Express and Zeke). The study was carried out as a split-plot design with a 2 × 6 factorial arrangement of treatments (two genders and six wheat varieties). A three-phase dietary program was used; all diets were formulated with a fixed level of wheat inclusion (70%, 80% and 85% for the Grower, Finisher I and Finisher II phases, respectively). A total of 240 commercial hybrid pigs (equal numbers of barrows and gilts) were grown from 29.5 ± 0.29 to 114.5 ± 2.23 kg live weight in single-gender pens (barrows or gilts) of five pigs (eight pens per dietary treatment) with ad libitum access to feed and water throughout the study. At the end of each dietary phase and of the test period, ultrasound measurements were taken at the 10th rib. Animals from the transgenic (MON 71800) and non-transgenic (MON 71900) treatments were harvested at the end of the study and carcass and meat quality measurements were taken. Pigs fed the six wheat varieties had similar (P > 0.05) feed intake, live weight gain, gain : feed ratio and ultrasound measures of backfat thickness and longissimus muscle area. There was a wheat variety × gender interaction (P < 0.05) for longissimus fat content. Gilts fed the transgenic wheat had higher (P < 0.05) longissimus fat content than those fed the non-transgenic control wheat; however, for barrows there was no effect (P > 0.05) of wheat variety on longissimus fat content. However, there was no effect (P > 0.05) of wheat variety on other longissimus muscle quality or composition measures. Gilts had lower (P < 0.01) feed intake, growth rate and backfat thickness, and similar gain : feed ratio (P > 0.05) compared to barrows. This study, with growing–finishing swine, suggests that the Roundup Ready wheat (MON 71800) resulted in equivalent animal performance to conventional wheat.

In-lamb ewes were given 38, 58 and 82 g of digestible crude protein daily at a constant energy intake of 1600 kcal ME per head daily during the last 6 weeks of gestation. There were no significant differences between treatments in live-weight gain of the ewes, lamb birth weight or ewe net body-weight change (the difference between live-weight gain over the experimental period and live-weight loss at lambing).

Digestibility coefficients for the diet components and nitrogen balances were determined on three ewes per treatment during weeks 15-16 and 19·20 of gestation. No differences in the apparent digestibility of the diet components were observed between the two periods. The apparent digestibility of crude protein increased significantly (P > 0·001) with increase in crude protein intake. A significant linear relationship (P<0·01) was found between digestible crude protein intake and nitrogen retention; daily N retention increased by 0·19 g per kg W0·73 for every 1 g per kg W0·73 of apparent digested nitrogen intake per day.

Death of calves around parturition is a matter of concern for dairy farmers. Relatively high stillbirth rates and unfavourable trends have been reported for Holstein heifers in the Netherlands and several other countries. In our study, we investigated herd differences, genetic parameters and genotype by environment interaction for heifer calf livability. A large dataset with data from calvings between 1993 and 2012 of Dutch dairy farms was used. There were considerable differences between herds in livability of calves from heifers, with averages ranging from 74% to 95%. Both herds with relatively high and low averages showed the same negative trend between 1993 and 2012, with largest declines in herds with the lowest averages. We found that heritability and genetic variation of first parity livability were substantially larger in herd environments where the likelihood of stillbirth was high v. environments where stillbirth was at a low level. The genetic correlations between herd environment levels were all very close to unity, indicating that ranking of sires was similar for all environments. However, for herds with a relatively high stillbirth incidence selecting sires with favourable breeding values is expected to be twice as profitable as in herds with a relatively low stillbirth incidence.

Genetic parameters for test-day milk flow (TDMF) of 2175 first lactations of Holstein cows were estimated using multiple-trait and repeatability models. The models included the direct additive genetic effect as a random effect and contemporary group (defined as the year and month of test) and age of cow at calving (linear and quadratic effect) as fixed effects. For the repeatability model, in addition to the effects cited, the permanent environmental effect of the animal was also included as a random effect. Variance components were estimated using the restricted maximum likelihood method in single- and multiple-trait and repeatability analyses. The heritability estimates for TDMF ranged from 0.23 (TDMF 6) to 0.32 (TDMF 2 and TDMF 4) in single-trait analysis and from 0.28 (TDMF 7 and TDMF 10) to 0.37 (TDMF 4) in multiple-trait analysis. In general, higher heritabilities were observed at the beginning of lactation until the fourth month. Heritability estimated with the repeatability model was 0.27 and the coefficient of repeatability for first lactation TDMF was 0.66. The genetic correlations were positive and ranged from 0.72 (TDMF 1 and 10) to 0.97 (TDMF 4 and 5). The results indicate that milk flow should respond satisfactorily to selection, promoting rapid genetic gains because the estimated heritabilities were moderate to high. Higher genetic gains might be obtained if selection was performed in the TDMF 4. Both the repeatability model and the multiple-trait model are adequate for the genetic evaluation of animals in terms of milk flow, but the latter provides more accurate estimates of breeding values.

The aim of this study was to assess the effects of hop cones (Humulus lupulus L.) from two varieties Aurora and Dana, differing in their α- and β-acid contents, on rumen microbial activity measured with in vitro gas production kinetics and short-chain fatty acids (SCFA) production. Hop cones were added to the total mixed dairy cow ration (CONT) in concentrations simulating a cow’s daily intake of 50, 100 and 200 g of hop cones – the concentrations of hop cones expressed on a substrate basis were 43, 82 and 153 mg/g of substrate. Substrates were anaerobically incubated in glass syringes, and gas production kinetic parameters were determined by fitting data with the Gompertz model. Gas produced after 24 h (Gas24), maximum fermentation rate (MFR) and time of maximum fermentation rate (TMFR) were calculated from the estimated gas production kinetic parameters. After 24 h of incubation, the fermentation liquids of each substrate were taken for the determination of SCFA. Increasing the hop cone concentration decreased the total potential gas production, Gas24, MFR and shortened TMFR. The highest hop cone concentration significantly decreased acetic and butyric acid productions and total SCFA production after 24 h of incubation, but not propionic acid production, resulting in a decreased ratio between acetic acid and propionic acid.

Male lambs were selected annually at 18 and 24 weeks of age for high or low concentrations of copper in plasma to produce two closed lines. The difference between the high and low lines increased to approx. 0·5 mg/1 after 5 years when the experiment ended, indicating appreciable additive genetic variation for the concentration of Cu in plasma. The selection lines were derived from a population of Scottish Blackface × Welsh Mountain crosses which had been interbred for many generations. The two parental breeds contributing to the cross normally differ in a number of aspects of Cu status with that of the Welsh higher than that of the Blackface. Both pure breeds were kept as controls. In the final year, Cu concentrations of the high selection line exceeded the values of the Welsh and the low selection line had values below those of the Blackface. Differences between the selection lines persisted at all ages.

There were indications of changes in the frequency of the Hb alleles, associated with the selection for Cu concentrations, but there were no correlated changes in body weight, reproductive performance or lamb mortality during the 5-year selection period when dietary supplies of Cu were not particularly restrictive.

Responses of selection for milk production and secondary traits were predicted in open nucleus schemes using a deterministic model. Secondary traits considered were: traits recorded during lactation (e.g. mastitis resistance; calving ease); traits recorded in the nucleus only (e.g. food intake); traits recorded early in life (e.g. growth rate); and traits recorded late in life (e.g. longevity). Also, genotype × environment interactions between nucleus and commercial herds and predictors of merit in juveniles were considered.

Extension of the breeding goal to include an uncorrelated secondary trait, which was recorded at each lactation, had the same heritability as milk production (assumed throughout to be 0·25) and half its economic value, increased total economic gain by a factor of 0·12. This increase was only 0·04, if the heritability of the secondary trait was 0·1. The situation for traits of low heritability was not improved by progeny testing of young bulls due to the short optimized generation intervals. Gain increased only by a factor of 0·04, if the economic value was 0·25.

Including a secondary trait of heritability 0·25 and a genetic correlation with yield of 0·5 in the index, only increased economic response rates by a factor of 0·04. However, when the genetic correlation was –0·5 the benefits were greater with increases of 0·09, 0·10 and 0·22 for heritabilities of 0·05, 0·10 and 0·25, respectively. Hence, including traits with low heritability but with strong negative correlations with yield, which might apply to fertility and disease resistance, increased rates of gain moderately.

If an uncorrelated secondary trait was recorded in the nucleus only, e.g. food intake, and had half the economic value of milk production, total gains increased by a factor of 0·10. Hence, recording of secondary traits can be restricted to the nucleus with only minor loss of gain. The extra economic benefit was greatest from secondary traits measured early in life compared with late in life, e.g. longevity, with benefits increased by factors of 0·24 and 0·06, respectively.

Open nucleus schemes are robust in the presence of genotype × environment interactions between nucleus and commercial herds, if the breeding value estimation method accounts for these interactions, juvenile indicator traits of milk production may increase rates of gain by a factor of 0·11, if the heritability of the indicator trait is 0·25 and the correlation with milk production is 0·5.

Nutrition modulates both production and composition of milk. Milk composition was studied in rats chronically fed a diet without additional lipids, and therefore eating only traces of the recommended supply of essential polyunsaturated fatty acid. Despite a large decrease in milk-protein synthesis, only protein composition, but not protein concentration, was found to change in the milk of rats following a lipid-deprived diet. Correlatively, we observed a substantial increase in the lactose concentration of milk. Analysis of milk proteins by two-dimensional electrophoresis demonstrated that the relative proportion of the various molecular forms of κ-casein, an O-glycosylated protein, was modified in the milk of rats receiving the lipid-deprived diet. In tissues, differences in the two-dimensional pattern of κ-casein between control and lipid-deprived rats were similar, if not identical. In contrast to κ-casein, the molecular forms of α-lactalbumin, an N-glycosylated protein, were not affected by the diet. These data provide evidence that O-glycosylation of milk proteins in the secretory pathway of mammary epithelial cells is modulated by the lipid content of experimental diets.