The recently sequenced cattle (Bos taurus) genome unraveled the unique genomic features of the species and provided the molecular basis for applying a systemic approach to systematically link genomic information to metabolic traits. Comparative analysis has identified a variety of evolutionary adaptive features in the cattle genome, such as an expansion of the gene families related to the rumen function, large number of chromosomal rearrangements affecting regulation of genes for lactation, and chromosomal rearrangements that are associated with segmental duplications and copy number variations. Metabolic reconstruction of the cattle genome has revealed that core metabolic pathways are highly conserved among mammals although five metabolic genes are deleted or highly diverged and seven metabolic genes are present in duplicate in the cattle genome compared to their human counter parts. The evolutionary loss and gain of metabolic genes in the cattle genome may reflect metabolic adaptations of cattle. Metabolic reconstruction also provides a platform for better understanding of metabolic regulation in cattle and ruminants. A substantial body of transcriptomics data from dairy and beef cattle under different nutritional management and across different stages of growth and lactation are already available and will aid in linking the genome with metabolism and nutritional physiology of cattle. Application of cattle genomics has great potential for future development of nutritional strategies to improve efficiency and sustainability of beef and milk production. One of the biggest challenges is to integrate genomic and phenotypic data and interpret them in a biological and practical platform. Systems biology, a holistic and systemic approach, will be very useful in overcoming this challenge.

Experiments were carried out in Nepal and Costa Rica to compare voluntary dry-matter intake (DMI) by oxen of diets based on poor quality hay (Costa Rica) and rice straw (Nepal) supplemented with different levels of concentrate foods when the animals were working and not working. Values for the apparent digestibility of the diets, rates of passage of solid and liquid phases ofdigesta and nitrogen balance are also reported.

Amounts of work calculated to raise daily energy expenditure to 1·3 to 1·6 × maintenance were associated with the following effects. (1) A depression of proportionately 0·11 and 0·14 in the DMI of oxen given a diet based on rice straw plus 18 and 27 g/kg live weight of concentrate respectively during work. No depression of DMI was seen with the hay diets which had slightly higher metabolizable energy but less nitrogen than the rice straw diets. (2) An increase in intake in the weeks following work on both the hay and rice straw diets. (3) Variable effects on apparent digestibility of food probably related more to the changes in DMI. (4) A tendency for gastro-intestinal mean retention time to be increased in working weeks particularly on the more fibrous diets.

An experiment involving 320 gilts was conducted to investigate the effects of age and growth traits on puberty attainment and reproductive performance in gilts given boar stimulation with or without exogenous gonadotropins. Following ad libitum feeding during rearing, groups of gilts were stimulated for puberty at one of four ages, namely 130, 150, 170 or 190 days. Within each age group, gilts were selected to maximize the variation in live weight, relocated, mixed and allocated to two treatments in a randomized-block design: (a) mature boar contact (boars only) and (b) boar contact plus an intramuscular injection of 400 i.u. pregnant mare's serum gonadotropin + 200 i.u. human chorionic gonadotropin (boars + PG600). Gilts were mated at puberty and slaughtered at 35 days post coitum.

For the gilts on the boars-only treatment, the interval from stimulation to puberty decreased significantly (P < 0·05) and became less variable with ascending age at stimulation. Increasing live weight at a given age also reduced the interval from stimulation to puberty. Multiple regression equations involving age, live weight and backfat thickness at stimulation and growth rate from birth to stimulation were calculated to obtain a prediction equation for the interval from stimulation to puberty. The effects of age and live weight at mating on ovulation rate, embryo survival and number of live embryos 35 days post coitum were not significant.

For the gilts on the boars + PG600 treatment, 92% attained puberty within 6 days of treatment, with a non-significant trend to improve with increasing age. Mating rates were similar to those on the boars-only treatment (90%). Ovulation rates were higher (P < 0·001) but embryo survival rates were lower (P < 0·001) in the boars + PG600 group, resulting in similar litter size at 35 days post coitum in the boars-only and boars + PG600 treatments. There was a non-significant trend for litter size to increase with age in the boars + PG600 treatment. Thirty-eight of the gilts treated with hormones failed to conceive and 53% were found by ovarian morphology at slaughter to be cycling normally with a tendency for this proportion to increase with age.

Tear staining (TS) in the pig has been related to different stressors and may be a useful tool for assessing animal welfare on farm. The aim of the current study was to investigate TS across the finisher period and its possible relation to age, growth, sex and experimentally induced stressors. The study included 80 finisher pens divided between three batches. Within each batch, the pens either included pigs with docked or undocked tails, had straw provided (150 g/pig/day) or not and had a low (1.21 m2/pig, 11 pigs) or high stocking density (0.73 m2/pig, 18 pigs). Tear staining (scores 1 to 4; from smaller to larger tear stain area, respectively) and tail damage were scored on each individual pig three times per week over the 9-week study period, and the individual maximum TS score within each week was chosen for further analysis. Data were analysed using logistic regression separately for each of the four possible TS score levels. The TS scores 1 and 2 decreased with weeks into the study period and were negatively related to the average daily gain (ADG) of the pigs, whereas the TS score 4 increased with weeks into the study period and was positively related to ADG. None of the TS scores differed between females and castrated males, and neither straw provision nor lowering the stocking density affected the TS scores. However, the TS score 1 decreased the last week before an event of tail damage (at least one pig in the pen with a bleeding tail wound), whereas the TS score 4 increased. The results of the current study advocates for a relation between TS and the factors such as age, growth and stress in the pig, while no relation was found between TS and the environmental factors straw provision and lowered stocking density. The relations to age and growth are important to take into consideration if using TS as a welfare assessment measure in the pig in the future.

The performance of 32 Cambridge (C) and Suffolk × Cambridge (S × C) twin and triplet rearing ewes and their progeny was investigated from lambing until the lambs reached slaughter weight. The ewes and lambs were housed and penned in individual family groups until 35 days after lambing. From 7 to 35 days the effect of rearing type was studied in combination with feeding the ewes a complete diet containing either 250 (diet 250) or 400 (diet 400) g milled hay per kg. After 35 days ewes and lambs grazed pasture. Ewes suckling triplets produced slightly more milk at 20 days 4·3 v. 4·1 (s.e.d. 0·20) kg/day and significantly more at 30 days 4·1 v. 3·7 (s.e.d. 0·18) kg/day, but consumed similar amounts of dry matter (3·9 kg/day) and so tended to lose more body condition. The latter was also a feature of ewes given diet 400 which produced similar milk yields but had lower complete diet intakes than those on diet 250. S × C had higher yields than C ewes.

Triplet lambs grew faster than twins 361 v. 290 (s.e.d. 9·0) g/day to 35 days but during the outdoor period triplet males but not females grew as fast as their twin counterparts 337 v. 317 for males and 269 v. 302 for females (s.e.d. 12·7) g/day. A selection of male twin and triplet lambs was slaughtered within the range 39 to 42 kg when 102 and 105 days old respectively. Triplet lambs had a lower killing-out proportion 0·458 v. 0·477 (s.e.d. 0·0085) and hence carcass weight but all carcasses qualified for Meat and Livestock Commission certification.

A method was suggested that attempts to distinguish between the underlying lactation curve, the effect of season of production, and the effect of time after conception. The composite function was shown to give a better fit than an incomplete gamma function. The estimated parameters of the underlying lactation curve were unaffected by season of calving whereas the parameters of the gamma function were not. Pregnancy started to affect yield 160 days after conception by -0·1 kg/day. The difference between the best season of production (May) and the worst (November) was around 5 kg.

Several researchers have developed prediction equations to estimate the metabolisable energy (ME) of energetic and protein concentrate feedstuffs used in diets for broilers. The ME is estimated by considering CP, ether extract, ash and fibre contents. However, the results obtained using traditional regression analysis methods have been inconsistent and new techniques can be used to obtain better estimate of the feedstuffs’ energy value. The objective of this paper was to implement a multilayer perceptron network to estimate the nitrogen-corrected metabolisable energy (AMEn) values of the energetic and protein concentrate feeds, generally used by the poultry feed industry. The concentrate feeds were from plant origin. The dataset contains 568 experimental results, all from Brazil. This dataset was separated into two parts: one part with 454 data, which was used to train, and the other one with 114 data, which was used to evaluate the accuracy of each implemented network. The accuracy of the models was evaluated on the basis of their values of mean squared error, R2, mean absolute deviation, mean absolute percentage error and bias. The 7-5-3-1 model presented the highest accuracy of prediction. It was developed an Excel® AMEn calculator by using the best model, which provides a rapid and efficient way to predict the AMEn values of concentrate feedstuffs for broilers.

1. Hereford × British Friesian castrate male cattle, growing from about 80 to 500 kg, were given equal amounts of metabolizable energy (ME) from dried grass pellets or from a pelleted diet of barley and a protein supplement. Two animals on each diet were fed close to appetite (High) and two at a level mid-way between maintenance and appetite (Medium). The rations for all animals were reduced to approximately maintenance for 4 weeks on three occasions equally spaced throughout the experiment. Measurements of energy and nitrogen balance were made for each animal at intervals of 6 to 8 weeks. Total body-water content was estimated from D20 dilution at intervals of 110 kg live weight.

2. Values for the metabolizability of the gross energy of the dried grass and barley/protein diets were 0·55 and 0·67.

3. Metabolic heat production during growth was closely related to body weight to the power 0·75. Predicted basal metabolism was 395 kJ/kg 0·75 per 24 hr.

4. Estimates of the net efficiency of utilization of ME for growth were unaffected by small variations in the exponent of W used to describe the effect of body size on heat production. Both diets were utilized above maintenance with a net efficiency close to 0·62.

5. Nitrogen balance trials seriously overestimated nitrogen retention. Gains in fat-free body mass estimated from D2O dilution were combined with calorimetric measurements of energy retention to predict the relationship between energy retention and weight gain. The agreement between observed and predicted live-weight gain was good at the lower body weights and on the lower ration. For fatter animals eating the high ration at higher body weights, live-weight gains were less than predicted.

Recurrence relationships are used to relate breeding values of age-sex classes from different time periods. Their application to single-stage (progeny) and multi-stage (parent) selection is demonstrated. These relationships enable definition of the effect of age structure, initial genetic differences between age groups, and the extent to which allowances are made for these or later genetic differences between age groups. The expressions derived show that, given initial genetic differences between age groups, subsequent progeny means will fluctuate even under completely random selection. Using these means as a basis for measuring responses to selection, it is shown that there can be selective effects where selection is at random within parental age classes. A careful definition of the alternative programme is therefore important in interpreting results of selection experiments and in investment appraisal of selection programmes.

These models were then used to describe economic returns from parent and progeny selection programmes and from programmes in which returns are realized in more than one age group. A further extension of the model accommodates the effects of finite population size on returns through its effects on genetic variance.

By separating the (constant) within- and (fluctuating) between-group components of the selection differential within the recurrence relationships a number of computational problems are overcome.

Twenty-two triplet or small twin lambs were reared in two ways. One group received cow's milk and the other a synthetic milk designed to approximate in composition to ewe's milk.

The group fed synthetic milk made significantly better live-weight gains to weaning. This difference was not maintained after weaning. Possible reasons for this are discussed.

Two experiments were made to study the effects of a mist or large-droplet water spray for different lengths of time, on pig behaviour in lairage prior to slaughter and on subsequent carcass Quality. Water spraying caused more pigs to stand, chew the pen walls and root around the pen floor compared with unsprayed controls, and they also tended to fight more. The sprayed pigs produced meat of superior quality in terms of m. longissimus dorsi rate of acidification and colour. It is suggested that these benefits were due to the effects of evaporative cooling and increased water intake.

In the accompanying paper, specific genetic factors for body weight and food intake were identified in non-reproductive male and female mice of a line selected for high litter size at birth (average of 22 born per litter) and a non-selected control line (average of 10 born per litter). The existence of these factors are indicated by variation in efficiency parameters such as growth efficiency and maintenance requirements. Residual food intake (RFI) and Parks’ estimates of growth efficiency (AB) and maintenance requirements (MEm) were used to quantify these factors. In the growing period, females had a higher RFI (are less efficient) than males. At maturity, selected mice had higher RFI than control mice and selected females had higher RFI than selected males. AB was higher in selected-line mice than in control-line mice, and higher in males than in females. MEm was higher in selected-line mice than in control-line mice, and higher in females than in males. The results indicate the existence of specific genetic factors for both growth efficiency and maintenance requirements. Selected females may increase RFI in the adult state to anticipate the metabolically stressful periods of pregnancy and lactation, to support a genetically highly increased litter size.

The Creole goat is a local meat breed well adapted to the tropical environment of Guadeloupe, a French island in the Caribbean. A survey of 47 goat farmers was conducted in May 2008 to describe the Guadeloupean goat farming systems. It was the preliminary step for the implementation of a breeding programme for Creole goats. Farmers had 31 does on average. A small number (4%) kept only Creole goats. Most of them (62%) had a mixed herd of Creole and crossbreds. One-third of them (34%) reared only crossbred goats. Farmers appreciate the rusticity and resistance of the Creole goat but consider its growth as too slow. The most desired traits for goat selection were conformation and growth for males (77% of the answers). These traits were also important for females (30% of the answers). Maternal qualities were also frequently cited (maternal behaviour 23%, reproduction 20% and milk production 17%). Disease resistance was not seen as an important trait (10% and 7% of the answers for bucks and does, respectively). A typology constituted of five groups of farmers was also created. Farmers of three groups were retained to participate at a selection programme. They kept Creole goats and have expressed a strong willingness to join a selection programme. The results of the survey suggest that a breeding programme should mostly focus on the Creole goat as a maternal breed. Real consideration should be given to disease resistance. The Creole goat has indeed a key role to play in the sustainability of local farming systems.

Mycotoxins are a major contaminant of pig feed and have negative effects on health and performance. The present study investigated the impact of single or repeated acute challenges with a diet naturally contaminated with deoxynivalenol (DON) and zearalenone (ZEN) on growth performances of finishing pigs and their fecal microbiota composition. A total of 160 pigs (castrated males and females) in two successive batches were randomly divided into four experimental groups of 40 pigs each. The control group received a control finisher diet from 99 to 154 days of age. Challenged groups were subjected to a 7-day acute challenge by being fed a DON- and ZEN-contaminated diet (3.02 mg DON/kg feed and 0.76 mg ZEN/kg feed) at 113 days (group DC), 134 days (group CD) or both 113 and 134 days (group DD). Microbiota composition was analyzed via 16S rRNA sequencing from fecal samples collected from the 80 females at 99, 119, 140 and 154 days. Challenged pigs (i.e. groups DC, CD and DD) reduced their average daily feed intake by 25% and 27% (P < 0.001) and feed efficiency by 34% and 28% (P < 0.05) during the first and second mycotoxin exposure, respectively. Microbiota composition was affected by mycotoxin exposure (P = 0.07 during the first exposure and P = 0.01 during the second exposure). At the family level, mycotoxin exposure significantly (P < 0.05) decreased the relative abundances of Ruminococcaceae, Streptococcaceae and Veillonellaceae and increased that of Erysipelotrichaceae at both 119 and 140 days of age. After the 7-day DON/ZEN challenge, the relative abundance of 6 to 148 operational taxonomic units (OTUs) differed among the treatment groups. However, none of these OTUs changed in all treatment groups. Using 27 functional pathways, pigs exposed to DON/ZEN challenges could be distinguished from control pigs using sparse partial least squares discriminant analysis, with a 15% misclassification rate. Regarding the functionality of these predictors, two pathways were involved in detoxifying mycotoxins: drug metabolism and xenobiotic metabolism by cytochrome P450. In challenged pigs, microbiota composition returned to the initial state within 3 weeks after the end of a single or repeated DON/ZEN challenge, highlighting the resilience of the gut microbiome. The feeding and growth performances of the pigs during challenge periods were significantly correlated with biological pathways related to health problems and modifications in host metabolism. To conclude, short-term DON/ZEN challenges resulted in transient modifications in the composition and functions of fecal microbiota.

Several studies have reported data on comparisons between two methods: the total collection of feces and the internal markers method. The aim of this study was to assess the apparent digestibility of two concentrates and to compare the apparent digestion coefficients using the total collection of feces and acid-insoluble ash (AIA) as the internal marker method. In 2009, six adult geldings aged between 3 and 11 years, with an average weight per trial of 543, 540 and 542 kg, respectively, were used to determine the apparent digestibility by means of three in vivo digestibility trials on hay, hay plus wheat bran (60 : 40) and hay plus extruded flax (80 : 20). Feces were collected over a 6-day period with a previous 14-day adaptation period. The three digestibility trials were carried out to determine the digestion coefficients of the three diets and, indirectly, of the two concentrates. The digestion coefficients of the diets were determined for the dry matter, organic matter, crude protein and gross energy, whereas the apparent digestion coefficients of the same parameters were calculated for wheat bran and extruded flax, by calculating the difference from the previous results. The data were analyzed using the Student t-test for paired samples. The digestion coefficients obtained were similar when the total collection of feces and the AIA method were used. Higher data variability, confirmed by a greater standard deviation, was observed using the AIA method to estimate the apparent digestion coefficients. It can be concluded that the use of AIA as an internal marker in digestibility trials on average leads to values similar to those obtained with the total collection of feces and can therefore be considered a less-expensive method to determine apparent digestion coefficients. Nevertheless, the total collection of feces should still be considered the best choice to determine the digestibility of some specific feedstuffs.

A deterministic bio-economic model was developed to evaluate the effects of changes in breeds and mating systems in a beef enterprise whilst keeping management constant. The model simulates all aspects of beef production including the transition of the breed composition, the biological performance and the overall economic performance of animals within the herd, over time. Breed performance parameters are based on a synthesis of results from published beef breed comparison experiments. In order to illustrate how the model is implemented an example is given based on UK economic information. The model predicts physical and financial performance over a planning horizon of 20 years. For a hypothetical enterprise, changing from buying in surplus dairy cross heifers to a situation of self-replacing beef cows, the model demonstrated a financial advantage, due largely to a reduction in production costs.

An exceptionally high incidence of difficult birth (29% of ewes giving birth to single lambs) in a Cheviot sub-flock in 1957 was reported by Gunn and Robinson (1963). To analyse some of the factors contributing to variation in the incidence of difficult births, observations were made on three farms over a seven-year period from 1958 to 1964. The farms are Sourhope, Roxburghshire, in the Cheviot Hills, with 1000 Cheviot and 350 Blackface ewes on predominantly Festuca-Agrostis, Nardus and Molinia pastures, with no regular provision of supplementary feed; Glensaugh in the East Grampians in Kincardineshire, with 550 Blackface ewes on predominantly heather (Calluna) pasture on free draining ground, with regular provision of supplementary feed during winter and spring; Lephinmore on Loch Fyne in Argyll, with over 600 Blackface ewes on mixed pasture mostly overlying peat, with limited provision of supplementary feed during winter and spring. Further details are given in the H.F.R.O. report (1958).

One hundred and twenty-eight Landrace and Large White pigs were allocated on the basis of sex, litter origin and initial weight to one of 16 treatments made up of four basal 16, 18, 20 and 22% protein diets, each supplemented with either 0·00,0·05,0·10 or 0·15% synthetic L-lysine; methionine was added to meet the levels earlier found to be optimal. All diets had a common energy level of 3740 kcal/kg DE and pigs were fed from 8 to 50 kg live weight.

Growth rate and feed efficiency improved as the protein levels were increased from 16 up to 20%. Only the 16 and 18% protein diets showed significant responses to additional lysine. Best overall gains and efficiency of gain was achieved on the diet with 20% protein and total dietary lysine and methionine+cystine levels of 1·17 and 0·66% respectively. Carcass leanness increased and fatness decreased as protein and lysine levels were increased, being best at the highest level (1·41%) of lysine studied.

Nitrogen retention indicated slightly lower protein and lysine requirement, efficiency of utilization being best on the 18% protein diet with added 0·15% lysine, giving a total dietary lysine level of 1·1% at the equalized methionine and cystine level of 0·66%.

It is indicated that diets providing between 18 and 20% protein in the diet, provided proper amino acid balance is maintained, would be optimal for pigs between 8 and 50 kg live weight.

A buffalo oocyte-specific subtracted cDNA library was constructed to identify exclusively or preferentially oocyte-expressed genes. The library represented an enriched population of transcripts obtained from oocytes of diverse ovarian follicular origin and at different stages of in vitro maturation. A total of 1173 high-quality sequences of oocyte-specific genes were clustered into 645 unique sequences, out of which 65.76% were represented as singlets and 34.26% as contig expressed sequence tags (ESTs; clusters). Analysis of sequences revealed that 498 of these sequences were identified as a known sequence in mammalian species including buffalo, 103 as uncharacterized ESTs and 44 unknown sequences including 1 novel EST, so far not reported in any species. Gene ontology annotation classified these sequences into functional categories of cellular events and biological processes associated with oocyte competence. Expression status of the isolated unknown ESTs confirmed that many of these are expressed in oocytes exclusively and in others preferentially, some in excess of 80-fold greater in comparison with a variety of somatic tissues. The isolated novel EST was detected to be expressed exclusively in oocytes and testicular cells only. To our knowledge, this is the first report giving a detailed transcriptome account of oocyte-expressed genes in buffalo. This study will provide important information on the physiological control of oocyte development, as well as many questions yet to be addressed on the reproductive process of buffalo.

The effect of passive immunization against testosterone on reproductive performance was investigated in 180 mature Scottish Blackface ewes in different levels of body condition at mating. Ewes were fed to achieve a wide range of condition (scores 1·5 to 3·0) by 2 weeks before a synchronized mating. During the week before mating, 90 ewes were each injected with 32 ml of a neat anti-testosterone antiserum (1: 96 000 initial titre) and 90 ewes were untreated. At about 55 days after mating, 50 immunized and 50 control ewes were slaughtered and the numbers of corpora lutea and embryos present were recorded. The proportion of immunized ewes that conceived during two periods of mating was in excess of 0·9 in all condition categories. By contrast, untreated ewes in the low condition category (score =£ 2·00) had significantly lower conception rates than ewes in higher condition categories. Immunized ewes with condition scores of 2·50 or less at mating had significantly higher ovulation rates, litter sizes and lambing rates compared with control ewes, while immunized ewes with scores of 2·75 or higher were not significantly different from control ewes in these measurements. There was no effect of immunization on embryo mortality rate, lamb sex ratio, lamb birth weight, or lamb survival rate in the 1st week after birth.