1. Nitrogen balance studies have been conducted on eight early-weaned calves receiving four diets containing, respectively, groundnut meal, groundnut+lysine, groundnut+lysine+methionine and white-fish meal as the major protein source.

2. There were no significant differences between groundnut meal diets i n any of the measurements examined. On the fish meal diet all measures of nitrogen retention tended to be higher than the corresponding values for groundnut meals.

3. Daily live-weight gains were significantly higher on the fish meal diet than on any of the groundnut diets (P<0·05).

4. It is suggested that the supplementary amino acids, being highly soluble, were rapidly deaminated by rumen micro-organisms.

Low atmospheric pressure stunning (LAPS) is a novel approach to pre-slaughter stunning of chickens using progressive hypobaric hypoxia by the application of gradual decompression (280s cycle) according to a set of prescribed pressure curves. Low atmospheric pressure stunning produces a non-recovery state. Concerns have been raised relating to the possible pathological and welfare consequences of expansion of air in the body during LAPS. In a randomised trial, we compared the gross pathology of broilers exposed to LAPS with a control group euthanised by intravenous injection of pentobarbital sodium (60 mixed sex broilers per treatment). The birds were exposed to each treatment in triplets and all birds were subject to necropsy examination to detect and score (1 to 5, minimal to severe) haemorrhagic lesions or congestion for all major organs and cavities (e.g. air sacs, joints, ears and heart) as well as external assessment for product quality (e.g. wing tips). Behavioural data (latency to loss of posture and motionless) and chamber cycle data (temperature, humidity, pressure and oxygen availability) confirmed that LAPS had been applied in a manner representative of the commercial process. All of the organs observed were structurally intact for both treatment groups. No lesions were observed in the external ears, oral cavity, tracheal lumen, crop and air sacs of birds from either treatment group. There was no difference between treatments in the wingtips, nasal turbinates, thymus, biceps femoralis and colon. Haemorrhagic lesions were observed in the calvaria, brains, hearts and lungs of both treatment groups, but lesions in these areas were more severe in the LAPS treatment group. It was not possible to distinguish between pathological changes induced by decompression or recompression. In the barbiturate group, more severe haemorrhagic lesions were observed in the superficial pectoral muscles as well as greater congestion of the infraorbital sinuses, liver, spleens, duodenum, kidneys and gonads. These findings provide evidence that LAPS did not result in distension of the intestines and air sacs sufficient to cause changes, which were grossly visible on postmortem examination. There was also no evidence of barotrauma in the ears and sinuses. The pathological changes observed in the barbiturate treatment were as expected based on barbiturate toxicity. Low atmospheric pressure stunning appears to produce pathological changes by a variety of well-established mechanisms, and while these pathological data have limited value as welfare indicators, the results confirm that organ integrity was not compromised by the process.

The Maasai of Kenya are typical of many pastoral communities in that they rely on milk as a major part of their diet. Milk production in three herds of Maasai cattle was studied from 1991 to 1996. Weekly measurements of milk extracted for human consumption were used to estimate lactation length, total offtake and mean daily production. Calf live-weight data were used to estimate total milk yield. Least-mean squares regression and analysis of variance tests were adopted to assess the effect of a number of variables on milk production parameters.

Data from a total of 650 lactations and 383 calvings were collected. Mean daily offtake was 891 ml. The length of lactation of frequently milked cows was 372 (s.e. 7·96) days. Total lactation offtake was estimated at 305 I. Herd, parity level and year of calving differences were observed. Multiple regression analyses indicated that some of the variation in daily offtake could be explained by stage of lactation, season of milking, herd, parity and year of calving. An average total yield of 2·73 I/day was estimated for the first 90 days of lactation. Of this, approximately 0·4 was used for human consumption. Overall, seasonality was seen as the major variable influencing production.

Eighty-nine crossbred gilts were used in an experiment to assess the effects of age at puberty on growth and their carcass characteristics at market weight. From 100 days of age each gilt was exposed daily to a boar and observed for standing heat. The gilts were slaughtered in a commercial abattoir as they reached market weight (approximately 109 kg live weight). Thirty-two gilts (36%) reached puberty before slaughter. These 32 earlier-maturing gilts grew more slowly than the other 57 (P<0·001) yet, paradoxically, within the group of 32 which had reached puberty, there was a significant negative correlation between age at puberty and average daily gain (r=−0·565; P<0·001). Of the 32, the date at first oestrus was known in 30 cases. Among these 30, 10 had ovulated more than once (early-maturing) and 20 had ovulated once (intermediate maturing). Consistent with the paradox there was a significant negative correlation between age at puberty and rate of gain within each group but the regression line for the early-maturing gilts had a significantly lower intercept, on the gain axis, than that for the intermediate group (P<0·01). There were no significant differences between sexual maturity groups for any of the large number of physical and chemical carcass characteristics studied.

Twenty-four Hereford × Angus × Shorthorn steers, which were 18 months old, were divided at random into four groups of six. There were four treatments, two involving the feeding of supplementary protein and two involving implantation of the steers with hexoestrol, thus:

(1) basic ration, no hexoestrol;

(2) supplementary protein, no hexoestrol;

(3) basic ration, hexoestrol implant;

(4) supplementary protein, hexoestrol implant.

While the hexoestrol implantation produced a significantly higher growth rate, the addition of protein, above the level in the basic ration, had no effect.

Haemoglobin types in three breeds of sheep were investigated. All three haemoglobin types—A, B and AB—were found to be present in the animals in two of the breeds examined, namely Bikaneri and Corriedale × Bikaneri (F1 generation). Mandia sheep had only Hb B and Hb AB types. Haemoglobin JB animals predominated in all the three breeds, the Mandia breed having the highest percentage of these animals. The possible significance of these findings is discussed.

Fibre is essential to maintain healthy gut; however, energy demands of performance horses can be too high to be met by forages alone. Yeast may support the function of cellulolytic bacteria to digest fibre. The aim of this work was to determine the effect of an oral supplement (VistaEQ) containing 4% live yeast on the in vitro and in vivo digestibility of high-starch (HS) and high-fibre diets (HF). Eight ponies were used in a 4 × 4 Latin square design consisting of 4- × 19-day periods and four diets: HF, HF + yeast (HFY), HS and HS + yeast (HSY). In vivo apparent digestibility (AD) was estimated using total collection technique, and faecal particle size was measured using NASCO digestive analyser. Faeces from the ponies were subsequently used as an inoculum in ANKOM RF gas production system to assess fermentation kinetics in vitro. Each module contained 1 g of feed substrate DM in the following combinations: 50% grass hay and 50% alfalfa (HF_50 : 50) or concentrate (HS_50 : 50), and 75% grass hay and 25% alfalfa (HF_75 : 25) or concentrate (HS_75 : 25) with or without yeast. Yeast was able to induce more gas production from HF_75 : 25, HS_75 : 25 and HF_50 : 50 feed substrates incubated with respective faecal inoculum base. Yeast did not affect pH in vitro when the substrates were incubated in 50 : 50 ratio, while the pH was higher for HF_75 : 25 incubated with correspondent faecal inoculum compared to HS_75 : 25 and HSY_75 : 25. Yeast had no effects on ADF and CP AD of either diet. Yeast addition increased DM (HF: 0.2%, HS: 0.4%), organic matter (HF: 0.7%, HS: 1.3%), NDF (HF: 0.5%, HS: 1.5%), total detergent fibre (HF: 0.7%; HS: 0.4%) (P < 0.05) and also tended to increase hemicellulose AD (HF: 0.9%, HS: 1.2%) (P < 0.10). Faecal pH in vivo was higher for both HF diets compared to HS diet without yeast supplementation (P < 0.001, HF and HFY: 6.8; HS: 6.6, HSY: 6.7). However, no difference was observed in faecal pH when HSY was compared to both HF diets. Yeast had no effect on the size of the faecal particles (P > 0.05). Yeast increased in vitro gas production, suggesting more energy could be extracted from the feed, and the in vivo AD of some of the nutrients when HF and HS diets were fed.

Domestication of animals has resulted in phenotypic changes by means of natural and human-directed selection. Body composition is important for farm animals because it reflects the status of energy reserves. Thus, there is the possibility that farm animals as providers of food have been more affected by human-directed selection for body composition than laboratory animals. In this study, an analysis was conducted to determine what similarities and differences in body composition occur between farm and laboratory animals using literature data obtained from seven comparative slaughter studies (n = 136 observations). Farm animals from four species (cattle, goats, pigs and sheep) were all castrated males, whereas laboratory animals from three species (dogs, mice and rats) comprised males and/or females. All animals were fed ad libitum. The allometric equation, Y = aXb, was used to determine the influence of species on the accretion rates of chemical components (Y, kg) relative to the growth of the empty body, fat-free empty body or protein weights (X, kg). There were differences between farm and laboratory animals in terms of the allometric growth coefficients for chemical components relative to the empty BW and fat-free empty BW (P < 0.01); farm animals had more rapid accretion rates of fat (P < 0.01) but laboratory animals had more rapid accretion rates of protein, water and ash (P < 0.01). In contrast, there was no difference in terms of the allometric growth coefficients for protein and water within farm animals (P > 0.2). The allometric growth coefficients for ash weight relative to protein weight for six species except sheep were not different from a value of 1 (P > 0.1), whereas that of sheep was smaller than 1 (P < 0.01). When compared at the same fat content of the empty body, the rate of change in water content (%) per unit change in fat content (%) was not different (P > 0.05) across farm animal species and similar ash-to-protein ratios were obtained except for dogs. The fraction of empty body energy gain retained as fat increased in a curvilinear manner, and there was little variation among farm animals at the same fat content of the empty body. These findings may provide the opportunity to develop a general model to predict empty body composition across farm animal species. In contrast, there were considerable differences of chemical body composition between farm and laboratory animals.

1. Data from the first 3 litters of each of 21 Wessex Saddleback sows were analysed on within-Utter, between-litter/within-sow and between-litter/ between-sow bases.

2. There were highly significant differences between sows in the mean weight of their pigs at birth, 3 and 8 weeks of age; between litters of the same sow there were no significant differences at birth or 8 weeks but pigs in third litters were significantly lighter than those of the first and second Utters at 3 weeks of age. There was a significant increase in number born but not in number weaned from first to third litters.

3. Within litters, the variation in 3-week weight accounted for by variation in birth weight was 30% in first litters, 48% in second litters and 45% in third; respective relationships between birth weight and 8-week weight were 14, 27 and 26%. Between litters of the same sow, differences in mean birth weight accounted for 50 % of the difference which occurred in 3-week weight and for 26 % of the difference in 8-week weight. Differences in mean creep-feed consumption accounted for 18% and differences in mean 3-week weight for 44% of the differences which occurred in weight at weaning. Between litters of different sows, the variation in birth weight accounted for 48% of the variation in 3-week weight, and 8% of the variation in 8-week weight. Differences in creep-feed consumption accounted for 36% and differences in 3-week weight accounted for 26 % of the difference in weight at weaning.

4. Season of birth had some effect on weaning weight due in part to an effect on creep-feed consumption. There was a negative correlation between birth weight and mortality and a positive correlation between mortality and Utter size.

The objectives of this study were to compare the effects of post-ruminal and intravenous infusions of wheat starch or glucose (CHO) or a mixture of amino acids (AA) on milk protein yield, nitrogen (N) utilisation, plasma metabolites and mammary extraction rate of dairy cows in late lactation. Eight cow, ruminally fistulated, was assigned to two 4 × 4 Latin squares during 14-day periods, where the last 7 days were for infusions. Infusions were: (1) starch in the abomasum (SP), (2) glucose in the blood (GB), (3) AA in the abomasum (AP), and (4) AA in the blood (AB). The experiment started 165 ± 4 days (mean ± s.e.) post partum (milk yield 22.5 ± 1.1 kg) Daily amounts of nutrients infused were 257, 283, 233, and 260 g for SP, GB, AP and AB, respectively. The cows were fed a basal diet consisting of a concentrate mixture and grass silage (55:45 on a dry-matter (DM) basis), where total dry-matter intake (DMI) was 13.3 kg/day. Milk production was affected by site of infusion within substrate, whereas infusion substrates within infusion site (CHO or AA) were of minor importance. Responses to intravenous infusions (GB or AB) were similar to those in early lactation, but more pronounced. Compared with SP infusion, GB infusion increased ( P < 0.05) milk yield, energy-corrected milk (ECM), protein and lactose yield by 1.4 and 0.9 kg, 38 and 59 g, respectively. The AB infusion had 1.4 and 1.3 kg, 51, 52 and 50 g higher ( P < 0.05) milk yield, ECM, protein, fat and lactose yields than the AP infusion, respectively. N balance data indicated higher losses of metabolic faecal nitrogen (MFN) by abomasal than by intravenous infusions, but the catabolism of AA was lower than in early lactation indicated by no difference ( P < 0.05) in urinary N excretion between treatments. Intravenous AA infusion increased plasma glucose and insulin above that of intravenous glucose infusion. The treatment effects on plasma insulin concentrations were higher in late than in early lactation, suggesting a higher sensitivity in late lactation even at similar negative energy balance. Compared with the SP infusion, GB infusion showed lower ( P < 0.05) concentrations of essential AA (EAA) and branched-chain AA (BCAA) resulting in a higher AA utilisation because of a higher milk protein production. AP infusion increased ( P < 0.05) plasma non-essential AA concentration compared with AB infusion, but infusion site of AA had no effect ( P>0.05) on plasma EAA or BCAA. It is concluded that it is the nutrient supply and not the lactation stage per se that is important for the response in milk production. Nevertheless, stage of lactation affects the N metabolism and the response in plasma hormone concentrations even when cows are in negative energy balance in both lactation stages.

The objective of this study was to assess the effect of dietary saponins, extracted from the plant Quillaja saponaria, on the concentrations of immunoglobulins in sow colostrum and milk, and additionally to observe any effect on piglet performance. Twenty-two sows were allocated to each of two dietary treatments on day 72 of gestation, balancing for parity, fatness and past reproductive performance. Treatments were : control (C) and supplemented (Q; 2.5 g saponin per day as a top-dressing). Sows received 2.5 kg food once per day throughout gestation. Between days 72 and 93 of gestation Q sows received a saponin top-dressing as described. After day 93, all sows were given the same diet and managed in an identical manner. Colostrum samples were taken from all sows at farrowing on delivery of the first piglet then 4, 8, 24 and 72 h later and again on day 21 of lactation. A group of eight sows from each treatment were also blood sampled at farrowing, day 3 and day 21 of lactation. Concentrations of immunoglobulins IgG and IgA in the colostrum, milk and blood were not affected by sow treatment during gestation at any sampling point. Fat, lactose and cell counts were also similar across treatments in colostrum and milk. Protein tended to be higher in milk on day 3 but lower on day 21 (P < 0.1) in Q sows. Piglet performance was not affected by sow treatment during week 1 of lactation. However pigs suckling Q sows grew more slowly between days 8 to 14 (P < 0.05) and days 15 to 21 (P < 0.1). Q sows also had fewer stillborn piglets in their litters at farrowing (7.67 v. 13.25%, P < 0.05, s.e. = 1.93). It is concluded that dietary quillaja saponin given during this time period has no influence on sow lacteal immunoglobulin secretions. However an adverse effect on performance of the sucking piglet was observed, the reasons for which are unclear, but may be related to reduced milk protein concentrations. Dietary quillaja saponin during gestation does however appear to reduce the incidence of stillborn piglets.

A total of 16 multiparous (range 2nd to 9th parity) Camborough sows were housed over parturition and during lactation in a group farrowing system. Two replicates of four sows were studied in the large pen (L) and two further replicates studied in the small pen (S) configuration, providing 13•4 m2 and 8•6 m2 per sow, respectively. A lactation diet providing 14 MJ/kg digestible energy (DE) and 180 g/kg crude protein was supplied ad libitum via a sow-operated feeder, adapted to facilitate the calculation of individual food intakes. The influence of environmental, physical, and production factors upon food intakes and feeding strategies was investigated. Daily food intakes of 7•69 (s.e. 0•31) kg and 7•72 (s.e. 0•35) kg were achieved during lactation by sows in the L and S pen configurations, respectively, accomplished by sows taking a series of small meals throughout the day. Sows in the S pen area made fewer visits to the feeder and spent less time per day feeding than sows in the L pen area. However, more food was consumed per visit by the S sows, resulting in similar daily food intakes in both treatment groups. There was a depression in lactation food intakes of sows housed at a mean daily ambient temperature of 17•5ºC compared with the other sow groups. The majority of sows consumed energy well in excess of their predicted requirements during lactation, whilst one sow in the L and two in the S pen areas had intakes within ±3•4 MJ DE of predictions. Only two of the L sows had food intakes that produced an energy deficit. In the L pen area, two distinct peaks of feeding activity occurred from 09:00 to 13:00 h and from 15:00 to 23:00 h that accounted for 0•77 of the total feeding time. In contrast, in the S pen configuration, one prolonged period of feeding occurred from 09:00 to 22:00 h accounting for 0•88 of total feeding time. The results show that S sows adapted their feeding patterns to maintain similar daily intakes to those of L sows, thus demonstrating that an ad libitum food supply enabled sows to obtain individual nutritional requirements in a communal farrowing system.

Current rates of inbreeding due to A.I. and natural service are estimated in Pedigree Welsh Black cattle.

Since 1948, 27 sires have been used in A.I., 16 of which have a common male ancestor. Four sire-son pairs and two pairs and one trio of half-brothers have been in recent use. Two-thirds of the bulls and heifers bred by A.I. and registered in 1960 were sired by 4 bulls. Since 1954 progeny of two A.I. sires who are father and son, were preferred for registration.

Pedigree analysis of a sample of 128 bulls showed that those bred by A.I. were, on average, 2·80% inbred, compared with 2·32% for those from natural matings. In a sample of 166 heifers corresponding values were 0·82% and 1·17%.

One herd, through natural service, contributed 12% of the genes of a sample of bulls and heifers. Four other herds were outstanding for the number of males they provided. The average inbreeding of their young, registered bulls was estimated to be 7·04%.

The widespread use of the descendents of one bull, both in A.I. and natural service, led to 94 cases of inbreeding in the third and fourth ancestral generations of the pedigrees of animals in the sample.

It is concluded that the short term consequences of using a small number of bulls in A.I. measured in terms of inbreeding, are no different from those in natural service and that inbreeding depression in traits of commercial importance would be undetectable.

Concentrate inclusion levels in dairy cow diets are often adjusted so that the milk yield responses remain economic. While changes in concentrate level on performance is well known, their impact on other biological parameters, including immune function, is less well understood. The objective of this study was to evaluate the effect of concentrate inclusion level in a grass silage-based mixed ration on immune function. Following calving 63 (45 multiparous and 18 primiparous) Holstein Friesian dairy cows were allocated to one of three isonitrogenous diets for the first 70 days of lactation. Diets comprised of a mixture of concentrates and grass silage, with concentrates comprising either a low (30%, LC), medium (50%, MC) or high (70%, HC) proportion of the diet on a dry matter (DM) basis. Daily DM intakes, milk yields and BW were recorded, along with weekly body condition score, milk composition and vaginal mucus scores. Blood biochemistry was measured using a chemistry analyzer, neutrophil phagocytic and oxidative burst assessed using commercial kits and flow cytometry, and interferon-γ production evaluated by ELISA after whole blood stimulation. Over the study period cows on HC had a higher total DM intake, milk yield, fat yield, protein yield, fat+protein yield, protein content, mean BW and mean daily energy balance, and a lower BW loss than cows on MC, whose respective values were higher than cows on LC. Cows on HC and MC had a lower serum non-esterified fatty acid concentration than cows on LC (0.37, 0.37 and 0.50 mmol/l, respectively, P=0.005, SED=0.032), while cows on HC had a lower serum β-hydroxybutyrate concentration than cows on MC and LC (0.42, 0.55 and 0.55 mmol/l, respectively, P=0.002, SED=0.03). Concentrate inclusion level had no effect on vaginal mucus scores. At week 3 postpartum, cows on HC tended to have a higher percentage of oxidative burst positive neutrophils than cows on LC (43.2% and 35.3%, respectively, P=0.078, SED=3.11), although at all other times concentrate inclusion level in the total mixed ration had no effect on neutrophil phagocytic or oxidative burst characteristics, or on interferon-γ production by pokeweed mitogen stimulated whole blood culture. This study demonstrates that for high yielding Holstein Friesian cows managed on a grass silage-based diet, concentrate inclusion levels in early lactation affects performance but has no effect on neutrophil or lymphocyte immune parameters.

Two experiments were designed to test the efficacy of two different methods of administering prostglandin F2α-tham salt for oestrous synchronization in mature cyclic ewes maintained under normal husbandry conditions. The effect of these agents on ewe fertility and lambing performance was also assessed.

A total of 180 Clun Forest ewes were used in this investigation conducted during the 1983 and 1984 breeding seasons. In the 1983 breeding season, 80% of ewes treated with a single injection of 20 mg prostaglandin F2α-tham salt were mated by fertile rams within a 3-day period, compared with 100% of ewes treated with progestagen pessaries or 23% of ewes treated with saline. Returns to service for the three groups were 23%, 3% and 16%, respectively. In 1984, a single injection of 20 mg prostaglandin F2α-tham salt resulted in oestrus synchronization in 73% of treated ewes, compared with 27% of saline-treated controls and 97% of ewes given two injections of prostaglandin F2α-tham salt, 11 days apart. Returns to service following these treatments were 36%, 6% and 20%, respectively. There was no difference between treatments in lambing performance.

The results indicate that acceptable levels of oestrus synchronization and fertility can be obtained with a single injection of 20 mg prostaglandin F2α. Furthermore, two injections of 20 mg prostaglandin F2α given 11 days apart produce levels of synchronization of oestrus comparable to those previously obtained with commercially available progestagen pessaries.

Two studies were conducted to examine the effects of selection for milk-fat yield on pancreatic responses to exogenous glucose, as measured by circulating insulin concentrations following an intravenous glucose load, in heifer calves. The first study involved 6-month-old Friesian heifers, eight each from the Massey University high breeding index (HBI) and low breeding index (LBI) lines. Average breeding indices (BI) for milk-fat yield of the calves based on ancestry BI were 136 (s.d. 2) and 112 (s.d. 2), respectively. Oestrous cycling of the heifers was controlled by intravaginal insertion of progesterone-impregnated controlled internal drug-releasing devices (CIDRs). Challenges of glucose (0, 75, 150 and 300 mg/kg live weight) and insulin (0, 0·1, 1, and 10 fig/kg live weight) were administered via indwelling jugular cannulas and were followed by serial blood sampling to measure responses. Plasma insulin concentrations immediately following the glucose challenge were significantly (P < 0·05) greater in HBI than in LBI heifers, peak insulin concentrations (above baseline) in the HBI group being approximately twice those in the LBI group. Plasma glucose concentrations were marginally lower in HBI heifers, probably due to the secondary effect of the relatively greater hyperinsulinaemia in this group. Although the exogenous insulin challenge significantly reduced circulating glucose concentrations in all heifers, there was no difference between the lines in the magnitude of insulin-induced hypoglycaemia.

The second study was designed to determine whether insulin responses to an exogenous glucose load were influenced by stage of the oestrous cycle in heifers of the two lines. In this study, eight yearling HBI heifers and eight LBI heifers (with BI of 135 (s.d. 4) and 111 (s.d. 1) respectively) were administered an intravenous glucose load (150 mg/kg live weight) on tivo occasions, the first being after 17 days of CIDR treatment (simulating the luteal phase of the oestrous cycle) and the second 46 h after withdrawal of the CIDRs (when the heifers were expected to be in oestrus). HBI heifers again showed significantly greater circulating insulin concentrations than LBI heifers following the glucose challenge but the magnitude of this effect was not influenced by time relative to CIDR withdrawal. It is concluded that heifers selected for high milk-fat yield have an increased pancreatic response to exogenous glucose which is apparently independent of the stage of the oestrous cycle. This difference may provide a useful means of identifying heifers of superior genetic merit for milk-fat production prior to their first lactation.

An experiment was carried out using lambs reared from 1 day to 23 days of age on milk substitute given either ad libitum or at a restricted rate of 250 g dry matter per day, in rooms maintained at three temperatures, 7, 14 and 21°C.

Lambs fed milk substitute ad libitum showed similar growth rates (about 365 g per day) at all environmental air temperatures. Total dry-matter intake of milk substitute per lamb over 22 days was slightly higher in those kept in an environmental air temperature of 7°C. The efficiency of lambs in the 7°C environment was lower than those in the 14 and 21°C environments.

When dry-matter intake was held constant, at the restricted level, growth rate increased linearly between 237 and 265 g per day as the environmental air temperature was increased.

At each of these temperature levels the restricted-rate lambs were more efficient than the respective lambs fed ad libitum.

Low winter growth is a characteristic of male red deer and is caused, in part by a combination of reduced appetite and higher energy expenditure due to cold weather. This study aimed to determine whether housing during winter would reduce energy expenditure and increase the growth rate of male red deer calves. An additional aim was to investigate whether food restriction in winter would be compensated for by increased spring growth. In each of two consecutive years, 80 calves were randomly allocated to eight groups (no. = 10) comprising two replicates of four treatments during winter. Groups were housed inside (I) or outside (O) and given food either ad libitum (AL) or restricted (R) to maintain live weight. Winter treatments (southern hemisphere) ran from 22 May to 25 August (year 1) and from 5 June to 5 September (year 2). During these periods, animals were weighed weekly and group food intake recorded daily. At the end of winter animals were moved outside onto pasture and weighed monthly until the end of spring (27 November, year 1 and 7 December, year 2). In year 2 weighing continued during summer, until 4 April. The animals were slaughtered on 28 November and 18 January (year 1) and 5 April (year 2). The effect of housing on live-weight gain (LWG) and dry-matter intake (DM1) in AL groups was not significant in either year. However in R groups, O had a higher DMI than I in both years (P < 0·05) and a higher LWG than I in year 1 (P < 0·05). LWG was loiver in R than in AL groups in winter in year 1 (P < 0·05) and year 2 (P < 0·001) and live weight was lower in R than in AL groups at the end of winter in both years. Live weight was still lower in R than in AL groups at the end of spring in both years (P < 0·01). In year 2, this live-weight difference was not significant by the end of summer. Hot carcass weight (HCW) was greater in AL animals than R animals (P < 0·05) and dressing proportion was higher in R than in AL (P < 0·05) in year 1. GR (an index of body fatness) was greater (P < 0·05) in O than I in year 1 and was greater (P < 0·05) in AL than in R animals in year 2. Differences in GR between treatments were not significant in either year, with HCW as a covariate.

In conclusion, housing calves given food ad libitum during winter did not reduce DMI or increase growth rate. When normal growth rates were prevented by restricting food intake, housing lowered DMI requirement, although such a situation is unlikely to be a useful farm management practice as recovery from the growth check was slow. Annual variations in climate may determine both the food savings made by housing and the extent of compensatory growth of food-restricted animals in spring.

Relationships play a very important role in studies on quantitative genetics. In traditional breeding, pedigree records are used to establish relationships between animals; while this kind of relationship actually represents one kind of relatedness, it cannot distinguish individual specificity, capture the variation between individuals or determine the actual genetic superiority of an animal. However, with the popularization of high-throughput genotypes, assessments of relationships among animals based on genomic information could be a better option. In this study, we compared the relationships between animals based on pedigree and genomic information from two pig breeding herds with different genetic backgrounds and a simulated dataset. Two different methods were implemented to calculate genomic relationship coefficients and genomic kinship coefficients, respectively. Our results show that, for the same kind of relative, the average genomic relationship coefficients (G matrix) were very close to the pedigree relationship coefficients (A matrix), and on average, the corresponding values were halved in genomic kinship coefficients (K matrix). However, the genomic relationship yielded a larger variation than the pedigree relationship, and the latter was similar to that expected for one relative with no or little variation. Two genomic relationship coefficients were highly correlated, for farm1, farm2 and simulated data, and the correlations for the parent-offspring, full-sib and half-sib were 0.95, 0.90 and 0.85; 0.93, 0.96 and 0.89; and 0.52, 0.85 and 0.77, respectively. When the inbreeding coefficient was measured, the genomic information also yielded a higher inbreeding coefficient and a larger variation than that yielded by the pedigree information. For the two genetically divergent Large White populations, the pedigree relationship coefficients between the individuals were 0, and 62 310 and 175 271 animal pairs in the G matrix and K matrix were greater than 0. Our results demonstrated that genomic information outperformed the pedigree information; it can more accurately reflect the relationships and capture the variation that is not detected by pedigree. This information is very helpful in the estimation of genomic breeding values or gene mapping. In addition, genomic information is useful for pedigree correction. Further, our findings also indicate that genomic information can establish the genetic connection between different groups with different genetic background. In addition, it can be used to provide a more accurate measurement of the inbreeding of an animal, which is very important for the assessment of a population structure and breeding plan. However, the approaches for measuring genomic relationships need further investigation.

Juice was extracted from a ryegrass silage after fermentation times of 0, 51 or 291 h. Three solutions of D/L lactic acid were prepared to have the same neutralizing values (NV) as the silage juices. Experiment A measured the mtakes by sheep of dried silage residues remaining after juice extraction. Experiment B measured the effect of adding each of the juices and lactic acid solutions (1·5 l/kg) on intake of unmolassed sugar-beet nuts. Intakes were measured daily and also over 3 h following an overnight fast.

Fermentation time had no effect on the composition or intake of the residues (P < 0·05). Increasing fermentation time from 0 to 51 to 291 h reduced silage juice pH (5·07, 4·96 and 4·10), increased lactic acid (gfl 6·2, 7·1, 18·7), NV (meq/l 29, 40, 157) and osmolality (mosmol/l 1000, 1010, 1390). Corresponding values for the lactic acid solutions were 2·82, 2·74, 2·41 (pH), 3·1, 4·3,18·3 (lactic), 26, 38,154 (NV) and 32, 42,176 (osmolality).

Total daily DM intake (g/kg live weight1·473) was unaffected by NV but was significantly higher overall (P < 0·05) for the silage juices (7·49) than for the lactic acid solutions (6·64) although this difference was mostly due to the extra dry matter (DM) contained in the added silage juice. Short-term DM intake (g per 3 h per kg live weight1·473) decreased with increasing NV, being significantly lower (P < 0·05) for the highest NV than for the others (3·58, 3·34 and 3·11) but lactic acid and silage juice gave similar responses (P > 0·05). Effects on short-term intake were influenced mainly by NV and suggested effects on immediate feedback mechanisms or palatability.