The aim of this experiment was to study the effect of stimulation of pre-mating energy intake on reproductive performance at the subsequent mating or parturition of rabbit does during four successive cycles. In the C (control, no. = 59) and R (restricted, no. = 67) groups, females had free access to the M diet (9·92 MJ/kg dry matter (DM)), except from 18 to 31 days of gestation when R females were given 150 glday. In the E group (high energy diet, no. = 64), females were given ad libitum the H diet (12·19 MJ/kg DM) from 1 to 14 days of lactation, with the M diet for the rest of the time. Females were presented to the male 10 toll days after parturition during four cycles. For primiparous does, the experimental design had no effect on pre-mating energy intake, acceptance or conception rate and litter size or weight. However, for multiparous does, pre-mating energy intake was higher for the E and the R group females than for the C group females (+0·08 and +0·04; P < 0·01). Acceptance rate of the male (47·1% v. 69·0%) and weight of the young rabbits at birth (-0·09) were lower in the R group than in the other groups (P < 0·001). The mortality of sucking rabbits was lower (6·5% v. 24·7%) and conception rate for the fourth litter was higher (97·1% v. 78·4%) in the E group than in the other groups (P < 0·05).

These results suggested that increased pre-mating energy intake could have a positive effect on conception rate. However, inadequate pre-partum energy intake (food restriction) has a detrimental effect on receptivity and litter weight.

The protein sources in feed have a huge impact on good-quality and -quantity meat traits. Yellow lupin (YL) seeds have a similar level of protein as soybean meal (SBM). The most popular is SBM that is genetically modified (GMO). During this age, the consumer market requires non-GMO products. Yellow lupin used as a high-protein substitute for SBM in feed has an effect on the quality of meat from broiler ducks. The aim of the study was to analyse and compare meat quality traits in breast and leg muscles as well as fatty acid (FA) composition in breast muscles from ducks fed mixtures containing YL as an alternative to SBM. Two hundred 1-day-old Cherry Valley ducks were kept in pens on litter in two equal dietary groups, four replications with 25 birds per group. The control group (1) received balanced feed containing SBM. The treatment group (2) received balanced feed containing YL. The feed provided to both groups contained 55% of concentrate and 45% of wheat. Birds received feed and water ad libitum and were reared for 8 weeks. After that, 16 ducks (eight from each group) of BW close to the mean for the whole group were slaughtered. Plucked and gutted carcasses were analysed in a laboratory for quality parameters. Meat was analysed for pH, colour, water-holding capacity and drip loss. Samples of breast muscles were analysed for the content of cholesterol, collagen, intramuscular fat and FA composition. The proposed feed mixture containing YL had no impact on meat traits, content of muscles or fat in duck carcasses (P > 0.05). The values of lightness (L*) and yellowness (b*) and collagen content in breast muscles were significantly higher (P < 0.05) in group 2 (YL). A lower ability to retain water, that is, higher water-holding capacity (percentage of water lost from meat) (P < 0.05), was found for leg muscles from group 2 (YL). The content of C16:0, C18:0, C20:4 n-6, C22:4 n-6, C22:5 n-3, total content of saturated fatty acids (SFA), values of atherogenic index and thrombogenic index were significantly lower (P < 0.05) in group 2 (YL) than in group 1 (SBM). The content of C18:2 n-6 and the polyunsaturated fatty acids-to-SFA ratio (P/S) were significantly higher (P < 0.05) in ducks fed the diet with the inclusion of YL. Diets with YL could be proposed as a partial substitute for SBM in duck-rearing.

Oestrus detection remains a problem in the dairy cattle industry. Therefore, automatic detection systems have been developed to detect specific behavioural changes at oestrus. Vocal behaviour has not been considered in such automatic oestrus detection systems in cattle, though the vocalisation rate is known to increase during oestrus. The main challenge in using vocalisation to detect oestrus is correctly identifying the calling individual when animals are moving freely in large groups, as oestrus needs to be detected at an individual level. Therefore, we aimed to automate vocalisation recording and caller identification in group-housed dairy cows. This paper first presents the details of such a system and then presents the results of a pilot study validating its functionality, in which the automatic detection of calls from individual heifers was compared to video-based assessment of these calls by a trained human observer, a technique that has, until now, been considered the ‘gold standard’. We developed a collar-based cattle call monitor (CCM) with structure-borne and airborne sound microphones and a recording unit and developed a postprocessing algorithm to identify the caller by matching the information from both microphones. Five group-housed heifers, each in the perioestrus or oestrus period, were equipped with a CCM prototype for 5 days. The recorded audio data were subsequently analysed and compared with audiovisual recordings. Overall, 1404 vocalisations from the focus heifers and 721 vocalisations from group mates were obtained. Vocalisations during collar changes or malfunctions of the CCM were omitted from the evaluation. The results showed that the CCM had a sensitivity of 87% and a specificity of 94%. The negative and positive predictive values were 80% and 96%, respectively. These results show that the detection of individual vocalisations and the correct identification of callers are possible, even in freely moving group-housed cattle. The results are promising for the future use of vocalisation in automatic oestrus detection systems.

Fifty male Merino lambs (6 to 8 weeks, 14.1 kg; n=10 per group) were used to study the effect of feeding system: barley straw in long form and concentrate pellets in separate troughs (Control), ad libitum alfalfa supplemented with concentrate in separate troughs (Alfalfa) or including various levels of ground barley straw in concentrate pellets (B05, B15 and B25 for 50, 150 and 250 g barley straw/kg), on rumen characteristics, acid-base status, blood cell counts and lymphocyte stimulation. Alfalfa lambs had the heaviest digestive tract contents, highest rumen pH values, lowest volatile fatty acid concentration, highest papillae counts and best mucosa colour and the greatest blood pCO2 values, lowest sodium and chloride and highest potassium concentrations (P<0.05). Including ground barley straw in the concentrate pellet or providing straw in long form separately from the concentrate reduces rumen pH and darkens ruminal mucosa as compared with alfalfa-fed lambs, thus affecting acid-base status.

Although food from grazed animals is increasingly sought by consumers because of perceived animal welfare advantages, grazing systems provide the farmer and the animal with unique challenges. The system is dependent almost daily on the climate for feed supply, with the importation of large amounts of feed from off farm, and associated labour and mechanisation costs, sometimes reducing economic viability. Furthermore, the cow may have to walk long distances and be able to harvest feed efficiently in a highly competitive environment because of the need for high levels of pasture utilisation. She must, also, be: (1) highly fertile, with a requirement for pregnancy within ~80 days post-calving; (2) ‘easy care’, because of the need for the management of large herds with limited labour; (3) able to walk long distances; and (4) robust to changes in feed supply and quality, so that short-term nutritional insults do not unduly influence her production and reproduction cycles. These are very different and are in addition to demands placed on cows in housed systems offered pre-made mixed rations. Furthermore, additional demands in environmental sustainability and animal welfare, in conjunction with the need for greater system-level biological efficiency (i.e. ‘sustainable intensification’), will add to the ‘robustness’ requirements of cows in the future. Increasingly, there is evidence that certain genotypes of cows perform better or worse in grazing systems, indicating a genotype×environment interaction. This has led to the development of tailored breeding objectives within countries for important heritable traits to maximise the profitability and sustainability of their production system. To date, these breeding objectives have focussed on the more easily measured traits and those of highest relative economic importance. In the future, there will be greater emphasis on more difficult to measure traits that are important to the quality of life of the animal in each production system and to reduce the system’s environmental footprint.

The objective of this research was to evaluate the survival rate of primiparous heifers within a large sample of herds across the United Kingdom and specifically to assess the association between age at first calving (AFC) on their survival. Data from 437 herds were re-structured for analysis. Descriptive statistics were calculated, and a multilevel logistic regression model was used to explore factors associated with the risk of first lactation culling. Potential explanatory variables included AFC, herd size, culling rate within the whole herd, calving season, herd mean 305-day yield and herd mean calving interval. The mean within-herd culling rate for the primiparous heifers was 15.9%. The mean within-herd AFC was 29.6 months, with 35.9% of heifers having an AFC >30 months of age. Multivariable analysis revealed a negative association between survival rate of primiparous heifers and increasing AFC, and also associations with herd culling rate in older cows and calving season. This study highlights the importance of AFC for survival of primiparous heifers, as well as the need to address heifer wastage in herds with high culling rates.

Limiting the post-weaning intake of the young rabbit is known to improve its resistance to digestive disorders, whereas a degradation of its housing hygiene is assumed to have a negative impact on its health. This study aims at providing insights into the mechanism of digestive health preservation regarding both host (growth and immune response) and its symbiotic digestive microbiota. A 2×2 factorial design from weaning (day 28) to day 64 was set up: ad libitum intake or restricted intake at 70% of ad libitum, and high v. low hygiene of housing (n=105 per group). At day 36 and day 45, 15 animals/group were subcutaneously immunized with ovalbumin (OVA) to assess their specific immune response. Blood was sampled at 36, 45, 57 and 64 days of age to determine total and anti-OVA immunoglobulin type G (IgG) and haptoglobin levels. The cecal bacterial community was explored (18 per group) by 454 pyrosequencing of genes coding for the 16S ribosomal RNA, whereas cecal pH, NH3 and volatile fatty acid (VFA) concentrations were measured to characterize fermentative activity. A 30% reduction in feed intake reduced the growth by only 17% (P<0.001), and improved the feed conversion ratio by 15% (P<0.001), whereas the degradation of hygiene conditions slightly decreased the feed intake in ad libitum fed rabbits (−3.5%, P<0.02). As poor hygiene conditions did not affect weight gain, feed conversion was improved from day 42 (P<0.05). Restricted feeding led to a lower mortality between day 28 and day 40 (P=0.047), whereas degraded hygiene conditions decreased overall morbidity (7.8% v. 16.6%; P<0.01). Both a reduced intake and low hygiene conditions of housing affected microbiota composition and especially dominant genera belonging to the Ruminococcaceae family (P<0.01). Moreover, low hygiene was associated with a higher Ruminococcaceae/Lachnospiraceae ratio (3.7 v. 2.4; P<0.05). Cecal total VFA and pH were increased (+19%; P<0.001) and decreased (−0.1 pH unit; P<0.05), respectively, in feed-restricted rabbits. Neither specific anti-OVA IgG nor haptoglobin was affected by treatments. Total IgG concentrations were the highest in animals raised in poor hygiene conditions after 8 days of restriction, but decreased after 19 days of restriction in high hygiene conditions (−2.15%; P<0.05). In conclusion, the degradation of hygiene conditions failed to induce a systematic specific and inflammatory response in rabbit, but reduced morbidity instead. Our results suggest that the microbiota composition would be a helpful source of biomarkers of digestive health.

Three sheep with permanent fistulas of the rumen were each given dried grass and two hays, each in three different amounts, and the apparent digesti-bility of the roughages in the rumen and distal to the rumen was determined. A lignin ratio method was used to measure digestibility.

With increase in the amount of the poorest hay given, the proportion digested in the rumen fell and that distal to the rumen increased. With the second hay this effect was also noted but was not statistically significant. The voluntary intakes ofdry matter varied from 1·94 kg/day for the dried grass to 1·28 for the poorest hay. The volumes of distribution of polyethylene glycol in the rumen when feed was offered ad libitum, however, were the same, irrespective of the type of feed, at between 14·1 and 15·2 litres. These observations were confirmed at slaughter. The results support the hypothesis that sheep voluntarily consume roughages of different qualities to achieve constant fill of their rumens, and that little regulation of voluntary intake can be attributed to distension of the hind gut.

Energy expenditure, food intake and some physiological reactions of Brahman and Brahman × British Friesian cattle working on an inclined treadmill at 33°C were studied. The effect of work at a lower ambient temperature (15°C) and local cooling of the head region while at 33°C were also investigated. Whilst walking up a 6° gradient at 1 m/s, animals expended about four times as much energy as when standing. Heat production during work (W/kgM0·75) was similar in both breeds and was not influenced by the treatments imposed. Crossbred animals showed significantly higher respiration rates and sweating rates than the Brahmans immediately after working for 30 min at 33°C. Food intake and body-weight changes in the crossbreds at 33°C compared with Brahmans provided further evidence that these animals were less tolerant of the conditions. Head cooling during work appeared to reduce depression in food intake associated with work at 33°C in both breeds although it had no effect on physiological changes.

1. The ability to resist hypothermia was measured in 265 lambs of 10 breeds immersed in a progressively cooling water bath.

2. Cold resistance varied significantly between breeds, with hill lambs showing the highest resistance. Hill breeds and feral breeds together had the highest weight-specific cold resistance.

3. Cold resistance was positively correlated with birth weight and skinfold thickness.

4. Age at test varying from 1 to 60 h did not significantly affect cold resistance.

5. Rate of recovery from hypothermia varied slightly between breeds. The feral lambs tended to recover fastest.

In the domestic environment, horses are often presented with foods to which they are not evolutionarily adapted, such as low fibre pellets. Horses may not have the ability to learn the consequences of consuming unnatural foodstuffs and adapt their selection accordingly. This study aimed to investigate the horse’s feeding preferences when presented with concentrate pellets differing in nutrient content. Using a choice test, the relative preferences of 12 horses for mint and garlic, in iso-caloric diets, was first assessed over 29 meals. A mint preference, calculated as the proportion of mint in the total food intake, was shown by 11 horses. The horses were then divided into two groups, approximately balanced on the basis of mint preference. Group A was exposed to a choice of a mint-flavoured lower energy food or a garlic-flavoured higher energy food, while group B was exposed to mint-flavoured higher energy food and garlic-flavoured lower energy food for 29 meals. Next the flavours were presented in iso-caloric foods, initially for 10 meals, then a further 40, before the flavour-energy pairings were reversed for 30 meals. A final iso-caloric test was carried out for 30 meals. Both groups showed a preference for mint in the initial iso-caloric choice test but no such preference was shown in later iso-caloric tests. Both groups showed a higher preference for mint when paired with higher energy (proportion of mint intake to total intake was 0·75 (s.e.0·02) and 0·73 (s.e.0·02) for A and B respectively). Group B also showed a preference for garlic when paired with higher energy (proportion of mint intake: 0·32, s.e. 0·02) whilst group A showed a significant decrease in preference for mint when paired with lower energy (by 0·21 (s.e. 0·03), T = 6·88, P 0·01). The results suggest that horses can select a higher energy diet over a lower energy one and that horses can form associations between foods and their nutritional composition, even if they do not resemble those found in their natural environment.

Fifty-five calves aged 105 days of age, of both sexes, belonging to two genetic groups (H, high or L, low) differing in their predicted breeding value (PBV) by 78 kg for fat plus protein yield, were individually penned for 3 weeks with the final 2 weeks on a diet designed to provide energy close to their maintenance requirements. The calves were then cannulated in the jugular vein and blood was sampled every 15 min for 25 h. Following this a growth hormone releasing factor (GRF) preparation was administered on up to four occasions, being one of (per kg live weight) either 0·2 or 0·4 μg GRF (treatments SGRF or DGRF respectively) or 0·2 μg thyrotropin releasing hormone (TRH). On each occasion blood samples were taken at −15, 4, 8,12,16, 20 and 45 min relative to the time of administration and up to four further occasions, one prior to and three within 32 min of administration. Samples were assayed for growth hormone (GH).

GH concentration of troughs prior to an episode of GH release was 1·19-fold greater in H compared with L calves with concentrations decreasing to 0·9 of their previous values each h. Trough and peak concentrations had repeatabilities of 0·21 and 0·26 respectively (both P < 0·05). There was no association between PBV and either peak concentrations, number of pulses (4·84 per 25 h) or mean GH concentration (13·3 μg/l).

GH released was only 1·11-fold greater after DGRF than SGRF. The difference in the regression coefficients for PBV between SGRF and DGRF was small, as it was for the difference between coefficients for the two sexes. The pooled coefficient was 0·00342 loge units per kg (s.e. 0·00157; P< 0·05) indicating a 1·31-fold greater response in H than in L calves. The correlation between responses to SGRF and DGRF was 0·482 and the repeatability of SGRF was 0·338; a pooled repeatability was estimated as 0·362(P < 0·01). The regression of GH release on PBV for TRH was 0·00345 (s.e. 0·00330). For all secretagogues, response depended on prior concentrations.

It was concluded that GH release following GRF administration was positively related to PBV in dairy calves and response was moderately repeatable; furthermore, although aspects of endogenous secretion may be related to PBV they suffer from measurement difficulties.

Four experiments with sheep fitted with rumen cannulae were conducted to investigate whether the rate of digestion of ammonia-treated straw, estimated as disappearance of dry matter from nylon bags in the rumen, might be increased by supplements of either soya bean meal, sucrose or sugar beet pulp at a level of 0·1, or by increasing the concentrations of dietary soluble micro and macro minerals.

There were no differences among treatments in rate and extent of digestion of straw due to supplementations.

In another experiment, the effect of increasing the proportion of molassed sugar beet pulp or rolled barley on rate of digestion of ammonia-treated straw was investigated. A greater proportion of sugar beet pulp (0·45) could be included in the diet before the rate of digestion was decreased in comparison with rolled barley (0·35).

Assuming that the digestibility of the sugar beet pulp and the rolled barley was not changed by the increasing proportion in the diet, it could be calculated that the digestibility of straw was reduced from 0·538 with straw alone to 0·403 with the sugar beet pulp and to 0·218 with the rolled barley supplement when the supplements were included at a level of 0·70.

Three experimental diets (L, M and H) containing 135, 175 and 210 g crude protein per kg dry matter respectively were given to crossbred does in two experiments. Protein quality was constant throughout.

In experiment 1 a total of 18 does (six per diet) were given the diets during two successive reproductive cycles. Losses of nitrogen in faeces and urine were estimated for four successive 7-day periods in each 28-day lactation period. Litters were culled at birth to give ‘high’ and ‘low’ lactational loads with 8 and 4 pups respectively. Total 28-day milk yields on diets L, M and H were 3·89, 4·82 and 5·27 kg respectively with eight pups sucking, and 302, 400 and 400kg respectively with four pups. These differences in milk yield were directly reflected in the weights of the pups when weaned at 28 days of age. There was no effect of diet on milk composition, pup birth weight or litter size. Does given diet L did not always consume their allotted ration and this may have affected the results.

The proportion of digested nitrogen utilized for milk protein synthesis differed significantly between diets and lactational loads, and was at its maximum (0·72) when diet L was given to does with eight pups. Does suckling eight pups retained 005 of the nitrogen they digested in their body tissues and those with four pups 0·13; there were no differences between diets in this respect.

In experiment 2 the nitrogen retention of 18 does (six per diet) was measured during pregnancy. Nitrogen retention increased as pregnancy progressed, and overall 0·20 of digested nitrogen was retained for conceptus growth and doe body tissue accretion.

The effects of the halothane gene on growth and performance were estimated from British Landrace positive and negative selection lines and crosses between the lines. A total of 214 full-sib pairs were performance tested from 25 to 85 kg live weight on either ad libitum or scale (0·69 g/g ad libitum food intake) feeding. Half-sides of 45 carcasses were fully dissected.

In the crosses, growth and performance did not depend on whether the sire or the dam was from the positive line. Carcass length, conformation score, eye muscle area and incidence of pale, soft, exudative meat (PSE) were all intermediate in the crosses. Given food ad libitum, the crosses had increased appetite and growth rates which resulted in increased backfat depths. However, in the fully dissected carcasses, the crosses were intermediate for lean proportion. Although the crosses gave a net economic advantage, the incidence of PSE may be unacceptably high for commercial exploitation.

The effect of underfeeding and ref eeding on digestion was studied in Bos taurus and Bos indicus cows. Eight nonlactating cows, four B. taurus and four B. indicus (live weight 156 kg and 207 kg respectively) were first given a forage-based diet at a level above energy maintenance requirements for 4 weeks (3·65 and 4·66 kg dry matter (DM) per day respectively for B. taurus and B. indicus). They were then restricted at a low level of intake for 2 months (1·83 and 2·33 kg DM per day respectively for B. taurus and B. indicus) and finally refed at the first level for 2 months. Digestion measurements were made before the underfeeding period, at 3 and 8 weeks of underfeeding and at 3 and 8 weeks ofref eeding. Organic matter apparent digestibility decreased with underfeeding and increased with refeeding (0·637, 0·591, 0·652, 0·692 and 0·669 in B. taurus and 0·674, 0·560, 0·580, 0·698 and 0·692 in B. indicus, respectively 1 week before, 3 and 8 weeks after underfeeding, and 3 and 8 weeks after refeeding). This lower apparent digestibility at low level of intake was not expected either by ruminal particle retention time, which increased when intake decreased, or by measurements ofmicrobial activity: DM degradability measured in situ and ruminal particle size did not vary with level of intake. An effect of the length of underfeeding and refeeding was seen: the apparent digestibility tended to increase after several weeks of undernutrition and was higher after refeeding than before underfeeding. No difference was observed between the two genotypes.

Thirty-two entire male and 32 female pigs were used to investigate responses to eight concentrations of dietary protein, with constant amino acid composition ranging from 90 to 248 g/kg over different live-weight stages between 20 and 90 kg.

With increasing live weight there was a continuous decline in the concentrations of dietary protein required to support maximum growth and an increasing difference between the sexes in their response to dietary protein. Between 20 and 40 kg live weight sex had no significant effect on growth performance or on the dietary protein concentration for maximum growth (P > 0·05). Over all heavier live-weight stages entire males grew faster and more efficiently than females, and between 20 and 70, 20 and 80, 20 and 90 and between 50 and 90 kg live weight they responded to higher concentrations of dietary protein than females. During the latter stages of growth, the performance of females was also depressed on the two highest-protein diets. This was associated with a significant increase in carcass fat thickness at 90 kg.

The occurrence of oestrus and ovarian function during the post-partum period was examined in 160 lactating beef cows of the Africander and Mashona breeds. Cows were fed either to gain 12 to 14% (High) or to lose 12 to 14% (Low) of their autumn peak live weight (early pregnancy) by mid-breeding season. Half the cows in each group were subjected to an increase (Low-High) or decrease (High-Low) in nutrient intake for a 25-day period starting at 25 days partum. Nursing was interrupted for an 8-day period in half of the cows at 50 days post partum by the application of nose plates to their calves.

Oestrus occurred significantly earlier in the high than the low plane cows (66 v. 75 days post partum respectively, P< 0·05), but short-term fluctuations in nutrient supply had no apparent effect on the incidence of oestrus. Temporary weaning significantly reduced the mean time from calving to first oestrus in the high-plane (P< 0·01) but not in the low-plane cows, and in Mashona (P<0·05) but not in Africander cows. There was a lower incidence of ‘silent’ oestrus and the mean occurrence of oestrus was significantly earlier (P< 0·001) in the Mashona when compared with the Africander cows.

Two trials were conducted to examine the influence of dietary oil type and rate of inclusion on fatty acid profiles of adipose tissue and eating quality of griddled pork. Trial 1 was based on three sources high in specific fatty acids: palm oil (palmitic acid), tallow (stearic acid) and linseed oil (linolenic acid) each at three rates of inclusion (palm at 44·6, 88·7 and 133·3 g/kg; tallow at 44·1, 87·6 and 131·7g/kg; linseed oil at 40·1, 79·8 and 120·0g/kg into a synthetic fat-free diet. Trial 2 was based on systematic replacement of soya-bean oil (incorporated at a rate of 0, 34, 69 and 104 g/kg diet) with olive oil (rate of 62, 46, 29 and 13 g/kg diet) to alter dietary concentrations of oleic acid. Diets were offered to pigs over the live-weight range 55 to 90 kg. Samples of subcutaneous fat were analysed for fatty acid composition and samples of loin assessed for meat quality with taste panels. There were no significant effects (P > 0·05) of treatment on daily live-weight gain, food conversion ratio or gross carcass composition, with the exception of anterior loin fat for trial 1 (P < 0·05) although not in a manner that was consistent between treatments and, in trial 2, anterior loin fat, minimum loin fat and posterior loin fat (all P < 0·05) but, again, not consistently between treatments allowing no meaningful conclusions to be drawn. Fatty acid profiles of adipose tissue reflected dietary levels to a variable degree, the more so with oleic acid and the greatest for linoleic and linolenic acids. The quality of the pig meat as measured by sensory analysis was related to the fatty acid profile in the situation where the most extreme changes in fatty acid profile occurred, as was apparent for the diets based upon linseed oil. No other major influences on meat quality were obtained.