It is difficult to separate an age-dependent fall in nitrogen use efficiency (NUE; N balance/N intake) in growing ruminants from a progressively decrease in animal protein requirements over time. This study examined the effect of dietary protein content on N partitioning, digestibility and N isotopic discrimination between the animal and its diet (Δ15Nanimal-diet) evaluated at two different fattening periods (early v. late). Twenty-four male Romane lambs (age: 19 ± 4.0 days; BW: 8.3 ± 1.39 kg) were equally allocated to three dietary CP treatments (15%, 17% and 20% CP on a DM basis). Lambs were reared with their mothers until weaning, thereafter housed in individual pens until slaughter (45 kg BW). During the post-weaning period, lambs were allocated twice (early fattening (30 days post-weaning) and late fattening (60 days post-weaning)) to metabolic cages for digestibility and N balance study. When diet CP content increased, the average daily gain of lambs increased (P < 0.05) while the age at slaughter decreased (P = 0.01), but no effect was observed on feed efficiency (P > 0.10). Diet CP content had limited effect on lamb carcass traits. Higher fibre digestibility was observed at the early v. late fattening period (P < 0.001). The N intake and the urinary N excretion increased when diet CP content increased (P < 0.001) and when shifting from early to late fattening period (P < 0.001). Faecal N excretion (P = 0.14) and N balance (P > 0.10) were not affected by diet CP content. Nitrogen digestibility increased (P < 0.001) as the diet CP content increased and on average it was greater at late v. early fattening period (P = 0.02). The NUE decreased (P = 0.001) as the diet CP content increased and as the lamb became older (P < 0.001). However, the age-dependent fall in NUE observed was lower at high v. low dietary CP content (CP × age interaction; P = 0.04). The Δ15Nanimal-diet was positively correlated (P < 0.05) with N intake (r = 0.59), excretion of faecal N (r = 0.41), urinary N (r = 0.69) and total manure N (r = 0.64), while negatively correlated with NUE (r = −0.57). Overall, the experiment showed NUE was lower in older lambs and when lambs were fed high diet CP content, and that Δ15Nanimal-diet was a useful indicator not only for NUE but also for urinary N excretion, which is a major environmental pollution factor on farm.

Submerging in water is used by many species as a behavioral mechanism to reduce body temperature, and farmed mink have been shown to increase their swimming activity during summer months. Therefore we investigated whether a maintained, seasonally independent, high ambient temperature would lead to more swimming in farmed mink. Twelve mink were housed in a temperature controlled room and subjected to two periods of four different temperatures (8, 16, 24 and 32 °C) with each temperature lasting 4 days. Although some types of activities changed with changes in temperature, the total level of activity was not affected. At high temperatures, the mink did not show any increase in either swimming or stereotyped behavior. It is concluded that within the limits of the experiment, mink will not use submerging in water as a thermoregulatory mechanism.

To investigate possible pre-test environmental effects on testing station performance, pigs from a total of 107 litters from two breed types were weaned on one of three treatments: weaning at 3, 5 or 8 weeks of age, with a different creep-feeding regime on each. At 8 to 10 weeks of age, litter groups (usually consisting of two boars, one male castrate and one gilt) were sent to a Meat and Livestock Commission testing station and performance-tested from 27 to 85 kg live weight on twice daily to-appetite feeding.

Weaning treatment significantly affected live weight at 50 days and boar growth rate and feed efficiency on test, but carcass traits were largely unaffected. Boars weaned on the 8-week treatment showed a significant advantage in index score of two-thirds of a standard deviation over those weaned at 3 weeks. A smaller number on the 5-week treatment were intermediate but did not differ significantly from those on the other two. It is concluded that wide variation in the weaning methods of herds sending pigs to a testing station could affect selection decisions. Ways of removing any bias by standardizing weaning methods or by statistical adjustment are discussed.

A Method of estimating grazing intake is essential for studies of feed utilisation in ewes under natural conditions. Since the ewe is a close and selective grazer, methods involving the cutting of comparable grazed and ungrazed areas of the pasture are unlikely to allow reliable estimation of pasture intake. It seems likely that only by a study of the faeces produced can reasonable estimation of individual intakes be made. The first requisite for such estimations is an accurate method of estimating faeces output. Sheep, with their relatively lower and drier faeces output, present fewer problems in total faeces collection than do cattle, which produce large quantities of faeces of a low dry-matter content. The collection of faeces, free from urine, presents a special difficulty in female animals.

Sixteen first lactation dairy cows were used in a 2 × 2 × 2 × 2 factorial design experiment. Two silages, an extensively fermented inoculant-treated silage or a restricted fermented, mixed aliphatic carboxylic acid-treated silage were offered with two concentrate types (starch- or fibre-based) and supplementary lactic acid (LA, 0·4 kg/day) or soya oil (SO, 0·41 kg/day). Concentrates containing 180 g crude protein per kg were offered at 6 kg/day. Silage dry-matter intake tended to be higher (P = 0·07) with restricted fermented silage compared with the inoculant silage. Milk fat or protein concentrations were not significantly affected (P > 0·05) by silage fermentation type. LA inclusion had no significant effect (P > 0·05) on animal performance. SO inclusion significantly increased (P < 0-05) milk yield (+ 0·8 kg/day), decreased milk fat concentration and yield (40·2, 32·9 g/kg and 779, 667 g/dayfor - and + SO respectively, P< 0·001) and decreased milk protein concentration (-0·81 g/kg, P < 0·01). A significant concentrate × soya-oil interaction (P<0·01) suggested a greater reduction in milk fat concentration with the SO, starch compared with the SO, fibre combination. Modified acid-detergent fibre (P < 0·01) and neutraldetergent fibre (P < 0·001) apparent digestibility coefficients were significantly lower with starch- compared with fibre-based concentrates. Results suggest that milk production responses to changes in concentrate composition were not influenced by the extent of restriction of the silage fermentation process.

The main objective of the experiment was to investigate the conditioned responses of sheep towards food flavours associated with the administration of ruminally degradable protein (RDP) and ruminally undegradable, but readily digestible protein (DUP) sources given either alone or in combination. The experiment consisted of three consecutive periods during which sheep were conditioned to associate a flavoured food with a nutritive stimulus (or water, W). Two foods (basal and novel test) with different crude protein (CP; 92 and 64 g/kg dry matter (DM) respectively) and similar metabolizable energy (≊ 9 MJ/kg DM) contents were used on a total of 48 Texel ✕ Greyface female sheep. The basal food was offered during non-experimental (rest) days whereas the test food was used in combination with two flavours, orange and aniseed, during experimental days. Food was presented for 8 h (09:00 to 17:00 h) daily throughout the experiment. Two nutritive stimuli (casein, C, and formaldehyde treated casein, FC) were chosen such as to provide major contrasts in their RDP and DUP contents, on an isonitrogenous basis. Each dose (50 g) of a particular nutritive stimulus was administered by gavage through a stomach tube twice daily (at 10:00 and 14:00 h). Sheep were randomly assigned to one of four (C v . W, FC v . W , C v . FC, C v . FC + C) treatments (no. = 12 per treatment). For the first 2 days (days 1 + 2) of each conditioning period half of the sheep within each treatment were offered one flavoured food paired with the administration of C (treatments C v . W , C v . FC and C v. FC + C) or FC (treatment FC v. W). The other half were offered the opposite flavoured food paired with the administration of water (treatments C v . W and FC v . W), FC (treatment C v . FC) or C + FC (treatment C v . FC + C). There followed 2 days (days 3 + 4) of rest and for the 2 days subsequently (days 5 and 6) received the opposite flavoured food and the opposite stimuli to that received earlier. In the morning of day 7 sheep were offered a choice between the two flavoured foods for 20 min. After the completion of the preference test sheep were offered the basal food. The same procedure was followed for each of three conditioning periods (i.e. each animal followed the same flavour/stimulus association throughout the experiment). The design was balanced for order of flavour and stimulus presentation. Sheep preferred the flavoured food associated with C (P < 0·05) or FC (P < 0·01) over the opposite flavoured food associated with water in C v . W and FC v . W treatments respectively. In the C v . FC treatment sheep showed a strong preference for food flavours associated with the administration of FC to those associated with C (P < 0·05). In the C v. FC + C treatment sheep showed equal preference towards the food flavours associated with either stimuli. These results: (i) support the view that sheep are able to form learned preferences for food flavours associated with the administration of protein, and (ii) suggest that sheep are able to distinguish between food flavours associated with the administration of both RDP and DUP sources. Sheep preferred flavours associated with DUP administration only over flavours associated with RDP administration only; however, such preferences did not develop when DUP was administered concurrently with RDP. Given the learned responses of sheep towards flavours associated with RDP and DUP the expectation is that they may be able to select their diet on the basis of these qualities when they are offered a choice.

Changes in live weight, body condition, milk production and composition were monitored for single- and twinsuckling cows in two experiments. In experiment 1, all cows were managed for 3 months before calving to achieve condition scores at calving 2·1 (low) and 3·1 (moderate). Subsequently, these animals were placed on a fixed level of energy intake (80 MJ metabolizable energy (ME) per day) for 16 weeks. Post-partum diets contained differing amounts of digestible undegradable protein (DUP), but similar amounts of effective rumen degradable protein (ERDP). In experiment 2, single- and twin-suckling cows were fed to achieve a condition score at calving of around 2·75. These animals were subsequently placed on two levels of energy intake (80 MJ and 130 MJ ME per day) during the first 16 weeks of lactation. The diets providing these energy intakes also contained differing amounts of DUP. Neither the level of DUP in the diet nor the level of feeding significantly altered the digestibility of the dry matter or organic matter in the dry matter of the experimental diets.

Body condition at calving had little effect on daily milk yield (9·5 kg) and composition (33·5 g/kg fat; 30-0 g/kg protein) in experiment 1. Cows with higher body condition scores at calving lost 13·5 kg more live weight and 0·26 units more body condition (P < 0·05) during the 1st month post partum but remained in better condition throughout the trial period than cows with lower body condition scores. Cows on 130 MJ ME per day produced higher (P < 0·001) daily yields of milk, milk fat and protein (+2·0 kg; +151 g; +85 g) and lost 57 kg less live weight and 0·52 units less body condition (P < 0·001) than cows on 80 MJ ME per day. Elevated dietary levels of DUP promoted (P < 0·05) daily milk yields (by 1·25 kg) and reduced live-weight and body condition-score loss during the 1st month post partum in both experiments. Twin-suckling cows produced the highest average daily yields of milk throughout the 16-week trial period in both experiments but yields were not significantly higher after early lactation in experiment 1. Cow body condition score at calving and the level of DUP in the post-partum diet of cows had no effect on the post-partum performance of calves. Twin calves had slower growth rates (P < 0·001) than single calves (0·65 and 1·07 kg/day respectively) in experiment 1. However, twin calves sucking cows on 130 MJ ME per day in experiment 2 grew similarly to single sucking calves from week 8 of lactation (0·8 kg/day).

An experiment has been carried out to examine the effects of implantation with hormonal growth promoters on the response in the performance of castrated male cattle (steers) to protein supplementation of a silage-based diet. The treatments consisted of grass silage offered ad libitum and supplemented with 2·7 kg per head daily of either a low protein (LP, 114 g crude protein per kg dry matter (DM)) or a high protein (HP, 206 g crude protein per kg DM) concentrate. Half of the animals, given each of the two concentrates were implanted with 20 mg oestradiol plus 200 mg progesterone and 300 mg trenbolone acetate at the beginning of the experiment and after 77 days, while the remainder of the animals received no implant, giving four treatments in a 2 × 2 factorial design. Sixty-four British Friesian and Simmental cross steers which were initially 426 (s.e. 3·5) kg live weight were used. The treatments were imposed for 157 days. The silage used was well preserved and of high digestibility. For LP and HP concentrates given to non-implanted animals and LP and HP given to implanted animals respectively silage DM intakes were 5·7, 5·8, 6·3 and 6·6 (s.e. 0·18) kg/day; live-weight gains 0·96, 0·92, 1·22 and 1·33 (s.e. 0·045) kg/day; carcass gains 0·58, 0·53, 0·78 and 0·81 (s.e. 0·024) kg/day; carcass subcutaneous fat depth 6·0, 6·5, 5·8 and 5·5 (s.e. 0·35) mm; areas of m. longissimus dorsi 69·1, 58·5, 69·6 and 74·7 (s.e. 1·91) cm2 and marbling scores 3·0, 3·6, 3·3 and 3·1 (s.e. 0·25). It is concluded that protein supplementation of well preserved grass silage produced a marginal increase in the performance of implanted finishing steers but did not affect carcass fatness. With non-implanted steers protein supplementation produced a marginal depression in performance and increased carcass fatness.

Pigmented egg yolks are more attractive. Popular culture treats annatto as a powerful anticholesterolemic agent, besides being widely used in the form of industry pigment. This work evaluated the effects of the addition of annatto (Bixa orellana L.) in the feed of hens, verifying a possible alteration of cholesterol in the yolks, content of carotenes, and iron and available iron, over time. One hundred and twenty-five hens divided in control (0% - T1) and four annatto-added treatments (0.5% - T2; 1.0% - T3; 1.5% - T4, and 2.0% - T5) were used. Eggs were collected at 23, 25, 27, 29 and 30 weeks. The animals were randomly separated into five groups of five animals each. The cholesterol was measured by the colorimetric method, vitamin A (β and α carotene) by spectrophotometry, total iron by atomic absorption spectrophotometry, and dialysable iron by dialysis. Tukey's test was used at the 5% level for comparison of the averages. Regarding cholesterol, treatments T2 and T3 did not differ significantly. However, other treatments differed ( P ≤ 0.05) from the control, decreasing the cholesterol level as the percentage of annatto in the feed increased. In time, there was a significant increase ( P ≤ 0.05). For β and α carotene, T5 presented statistically higher values than the others ( P ≤ 0.05). With regard to total iron, T5 had higher values than the others. Dialysable iron was also higher, probably due to the increase in carotenes. Thus, we can conclude that the use of annatto in the feed of layer hens is useful, as it provokes the reduction of cholesterol and promotes an increase in the content of iron and carotenes in eggs.

A trial compared the voluntary water intake of 72 purchased British Friesian bull calves fed at different nutrient intake levels by varying the type and strength of the milk replacer given to 5 weeks of age. There was no control group without water on offer. Water was offered from the 1st day the animals entered the unit. All calves received 4 1/day of either cows' milk (12 calves), milk replacer with 100 g fat per kg (24 calves), milk replacer with 170 g fat per kg (24 calves) or milk replacer with 200 g fat per kg (12 calves). Standard early-weaning pellets containing 190 g crude protein per kg and hay ad libitum were on offer from the 2nd day on the unit. Results indicated that voluntary intakes of water were highest with calves fed on cows' milk and lowest on the milk replacer with 100 g fat per kg given at the lowest mixing strength, although differences were only significant in week 5 (P ≤ 0·05). By covariance analysis, the effects of water intakes on live-weight gain and on pellet intake were examined. The regression coefficient of live-weight gain (weeks 0 to 5) (kg) on water intake (weeks 1 to 5) (1) was b= 0·056 (s.e. 0·021, P ≤ 0·01). The regression coefficient of pellet intake (weeks 0 to 5) (kg) on water consumption was: b= 0·082 (s.e. 0·031, P ≤ 0·01). There was thus a significant correlation of both live-weight gain and pellet intake with water intake. For each extra litre of water consumed per day, there was an extra pellet intake of 0·082 kg and an increase in live-weight gain of 0·056 kg. There was a significant difference in total water intake according to the initial live weight of the calf.

In heifers, plasma progesterone levels were low (<0·3μg/l) from the 59th to about the 15th day before puberty (defined as the day when oestrus was first detectable by the fern pattern of dried cervical mucus). Plasma oestradiol-17β levels varied randomly within the range 1 to 4 ng/l over the same period, but then showed three peaks of about 6, 9 and 4 ng/l, respectively 8 days before puberty, on the day of puberty and 4 days later. The pre-pubertal oestradiol-17p peak was followed by a short period of elevated progesterone levels. Whether this oestradiol-17β peak induced ovulation is uncertain; it is however clear that a corpus luteum of normal life-span was not formed. The oestradiol-17β peaks on the day of puberty and 4 days later, when progesterone levels were rising rapidly, were typical both in magnitude and duration of those occurring before and after ovulation in post-pubertal oestrous cycles.

Dairy cattle were injected at intervals of 4 weeks with recombinantly derived bovine somatotropin (bST) i n a slow-release form (somidobove, Lilly Research Centre Ltd, Windlesham, Surrey), to examine the effect on milk production. In the first experiment with 38 autumn-calving animals in a randomized-block design, treatment lasted for 28 weeks and a control and three doses of bST: 320 (low), 640 (medium) and 960 (high) mg were compared. Over the 28 weeks the mean daily milk yields were: control 23·4, low 23·4, medium 25·4 and high 25·4 (s.e.d. 1·17) kg. Milk composition was not affected by bST. In experiment 2 with 40 autumn-calving animals, the medium dose of bST was used for 24 weeks in animals given two levels of concentrate in a factorial design. On average there was a non-significant increase in daily milk yield of 1·3 kg in the bST-treated cattle; there was no interaction between bST and level of concentrate. There were no effects of bST on milk composition. Changes in live weight and body condition of the cattle and their food intake were measured. It was concluded that the trends toward higher milk yields were supported initially at the expense of live weignt and possibly later by increased food intake. In a third experiment 10 grazing cows were given three consecutive doses of 640 mg bST and 10 similar cows acted as controls. There were no significant effects of bST on milk production and food intake. Reasons for the low responses in milk production compared with several recent American and European experiments may possibly be the pattern of use of the slow-release form of bST and the low content of dry matter in the maize silages which restricted forage intake and response in milk production.

The objective was to evaluate the effect of microbial phytase (1250 FTU/kg diet with 88% dry matter (DM)) on apparent total tract digestibility (ATTD) of phosphorus (P) in pigs fed a dry or soaked diet. Twenty-four pigs (65±3 kg) from six litters were used. Pigs were housed in metabolism crates and fed one of four diets for 12 days; 5 days for adaptation and 7 days for total, but separate collection of feces and urine. The basal diet was composed of wheat, barley, maize, soybean meal and no mineral phosphate. Dietary treatments were: basal dry-fed diet (BDD), BDD with microbial phytase (BDD+phy), BDD soaked for 24 h at 20°C before feeding (BDS) and BDS with microbial phytase (BDS+phy). Supplementation of microbial phytase increased ATTD of DM and crude protein (N×6.25) by 2 and 3 percentage units (P<0.0001; P<0.001), respectively. The ATTD of P was affected by the interaction between microbial phytase and soaking (P=0.02). This was due to a greater increase in ATTD of P by soaking of the diet containing solely plant phytase compared with the diet supplemented with microbial phytase: 35%, 65%, 44% and 68% for BDD, BDD+phy, BSD and BSD+phy, respectively. As such, supplementation of microbial phytase increased ATTD of P in the dry-fed diet, but not in the soaked diet. The higher ATTD of P for BDS compared with BDD resulted from the degradation of 54% of the phytate in BDS by wheat and barley phytases during soaking. On the other hand, soaking of BDS+phy did not increase ATTD of P significantly compared with BDD+phy despite that 76% of the phytate in BDS+phy was degraded before feeding. In conclusion, soaking of BDS containing solely plant phytase provided a great potential for increasing ATTD of P. However, this potential was not present when microbial phytase (1250 FTU/kg diet) was supplemented, most likely because soaking of BDS+phy for 24 h at 20°C did not result in a complete degradation of phytate before feeding.

To further understand the contribution of feedstuff ingredients to gut health in swine, gut histology and intestinal bacterial profiles associated with the use of two high-quality protein sources, microbially enhanced soybean meal (MSBM) and Menhaden fishmeal (FM) were assessed. Weaned pigs were fed one of three experimental diets: (1) basic diet containing corn and soybean meal (Negative Control (NEG)), (2) basic diet + fishmeal (FM; Positive Control (POS)) and (3) basic diet + MSBM (MSBM). Phase I POS and MSBM diets (d 0 to d 7 post-wean) included FM or MSBM at 7.5%, while Phase II POS and MSBM diets (d 8 to d 21) included FM or MSBM at 5.0%. Gastrointestinal tissue and ileal digesta were collected from euthanised pigs at d 21 (eight pigs/diet) to assess gut histology and intestinal bacterial profiles, respectively. Data were analysed using Proc Mixed in SAS, with pig as the experimental unit and pig (treatment) as the random effect. Histological and immunohistochemical analyses of stomach and small intestinal tissue using haematoxylin–eosin, Periodic Acid Schiff/Alcian blue and inflammatory cell staining did not reveal detectable differences in host response to dietary treatment. Ileal bacterial composition profiles were obtained from next-generation sequencing of PCR generated amplicons targeting the V1 to V3 regions of the 16S rRNA gene. Lactobacillus-affiliated sequences were found to be the most highly represented across treatments, with an average relative abundance of 64.0%, 59.9% and 41.80% in samples from pigs fed the NEG, POS and MSBM diets, respectively. Accordingly, the three most abundant Operational Taxonomic Units (OTUs) were affiliated to Lactobacillus, showing a distinct abundance pattern relative to dietary treatment. One OTU (SD_Ssd_00001), most closely related to Lactobacillus amylovorus, was found to be more abundant in NEG and POS samples compared to MSBM (23.5% and 35.0% v. 9.2%). Another OTU (SD_Ssd_00002), closely related to Lactobacillus johnsonii, was more highly represented in POS and MSBM samples compared to NEG (14.0% and 15.8% v. 0.1%). Finally, OTU Sd_Ssd-00011, highest sequence identity to Lactobacillus delbrueckii, was found in highest abundance in ileal samples from MSBM-fed pigs (1.9% and 3.3% v. 11.3, in POS, NEG and MSBM, respectively). There was no effect of protein source on bacterial taxa to the genus level or diversity based on principal component analysis. Dietary protein source may provide opportunity to enhance presence of specific members of Lactobacillus genus that are associated with immune-modulating properties without altering overall intestinal bacterial diversity.

Many thousands of cast-for-age Blackface ewes in Scotland and England are transferred each year to lower ground after producing four or five lamb crops on their native hill farms. It is then customary to use on them rams of another breed, often the Border Leicester, with a view to the production of more profitable lambs than can be obtained from pure-breeding (Bywater, 1945). Such is the scale on which this procedure is practised that it becomes an important consideration in any breeding plan for hill sheep that the cast ewes should be adapted to this phase of their careers as well as to that which precedes it on the hills. The outcome of selection work with Blackface sheep consequently cannot be fully assessed until the cast ewes have reared crossbred lambs, and have been finally disposed of.

In mitigating greenhouse gas (GHG) emissions and reducing the carbon footprint of dairy milk, the use of generic estimates in inventory and accounting methodology at farm level largely ignores variation of on-farm GHG emissions. The present study aimed to implement results of an extant dynamic, mechanistic Tier 3 model for enteric methane (CH4) (applied in Dutch national GHG inventory) in order to capture variation in enteric CH4 emission, and in faecal N and organic matter (OM) digestibility, ultimately required to predict manure CH4 and ammonia emission. Tier 3 model predictions were translated into calculation rules that could easily be implemented in an annual nutrient cycling assessment tool including GHG emissions, which is currently used by Dutch dairy farmers. Calculations focussed on (1) enteric CH4 emission, (2) apparent faecal OM digestibility and (3) apparent faecal N digestibility. Enteric CH4 was expressed in CH4 yield indicated with the term emission factor (EF; g CH4/kg DM) for individual dietary components and feedstuffs. Factors investigated to cover predicted variation in EF value included the level of feed intake, the type of roughage fed (proportions of grass silage and maize silage) and the quality of roughage fed. A minimum number of three classes of roughage type (i.e. 0. 40% and 80% maize silage in roughage DM) appeared necessary to obtain correspondence between interpolated EF values from EF lists and Tier 3 model predictions. A linear decline in EF value with 1% per kg increase in DM intake is adopted based on model simulations. The quality of roughage was represented by the effect of maturity of harvested grass or of the whole plant maize at cutting, based on a survey of modelling as well as experimental work. Also, predictions were assembled for apparent faecal OM digestibility which could be used in national inventory and in farm accounting. Apparent faecal N digestibility (as a major determinant of predicted urinary N excretion) was predicted, to support current Dutch national ammonia emission inventory and to correct the level of N digestibility in farm accounting. Compared to generic values or values retrieved from the Dutch feeding tables, predicted OM and N digestibility and enteric CH4 are better rooted in physiological principles and better reflect observed variation under experimental conditions. The present results apply for conditions with fairly intensive grassland management in temperate regions.

The significance of hepatocyte nuclear factors (HNFs) in β-cell development and function has been generally recognized in humans, as evidenced by their associations with cases of maturity onset diabetes of the young (MODY). Common Hepatocyte nuclear factor-1 alpha (HNF1A), Hepatocyte nuclear factor-1 beta (HNF1B) and Hepatocyte nuclear factor-4 alpha (HNF4A) mutations could lead to monogenic forms 3, 5 and 1 of diabetes mellitus, respectively, and were characterized by MODY in humans. In this study, multiple variants were discovered in the porcine HNF1A and HNF4A genes, and one single-nucleotide polymorphism (SNP) was detected in the HNF1B gene. Using the Iowa State University Berkshire × Yorkshire pig resource population, the HNF1A, HNF1B and HNF4A genes were mapped on chromosomes 14, 12 and 17, respectively. The linkage disequilibrium (LD) analyses indicated that most of the HNF1A variants were not in strong LD with each other; however, nearly all of them were highly significantly (P < 0.01) associated with loin muscle area (LMA). The SNPs c.327-19G>T and c.1768+40_23del were significantly (P < 0.05) associated with backfat and total lipid percentage, and the latter was also associated with muscle glycogen metabolism measures. Four major haplotypes were observed and the association analyses suggested that haplotype 3 (-CGCGD-, I indicates Insertion and D indicates Deletion) was favorable for reduced backfat, while haplotype 1 (-CACGI-) was unfavorably associated with backfat and LMA. There was no significant interaction effect on backfat among the SNPs c.327-19G>T, c.1768+40_23del of the HNF1A gene and c.646C>T of the transcription factor-7-like 2 (TCF7L2) gene. These findings suggest that the HNF1A gene has significant effects on both fatness- and meat production-related traits. No significant associations with production traits with the SNPs from the HNF1B and HNF4A genes were observed in the study.

The effects of sex (wethers v. ewes), diet (chopped lucerne hay v. lucerne-barley pellets) and cimaterol on energy utilization by Suffolk cross lambs were determined by comparative slaughter. Quadratic regression of energy retention (RE) on metabolizable energy intake (MEI) enabled estimation of maintenance energy requirements (Em), efficiencies of gain (ktotal) and maximum rates of gain (REMAX). Regressions using RE in fat and protein v. MEI yielded analogous parameters for fat and protein deposition (Em fat, kfat, REMAX fat and Emprotcin, kprolein, REMAXprotcin respectively). Em was lower in wethers than ewes (455 v. 510 kJ/kg M0·75 per day respectively), but was unaffected by diet or cimaterol. Sex and cimaterol did not affect ktotai. which was higher in lambs given pellets compared with lambs given hay (0·417 v. 0·224 respectively). Similarly, REMAX was higher in lambs given pellets than in lambs given hay (326 v. 114 kJ/kg 0·75 per day respectively). None of the groups differed significantly in the parameters of fat deposition, which averaged 480 kJ/kg 0·75 per day for Em fal, 0·224 for ktat, and 250 kJ/kg M0·75 per day for REMAX, fat- Em.protein was lower in wethers than in ewes (466 v. 569 kJ/kg 0·075 per day, respectively), and was further reduced by cimaterol (418 and 507 kJ/kg 0·75 per day for wethers and ewes respectively). Estimates of kprotcin were higher in wethers than in ewes (0·091 v. 0·064 respectively), and were increased by cimaterol (0·115 and 0·089 for wethers and ewes respectively). Similarly REMAX protein was higher in wethers than in ewes (47 v. 37 kJ/kg 0·75 per day respectively), and was increased by cimaterol (58 and 48 kJ/kg 0·75 per day for wethers and ewes respectively). The repartitioning action of cimaterol was additive with effects of diet, intake and sex.

An 18-week experiment investigated the effects of type of diet and frequency of watering on the performance of growing cattle given food at maintenance (metabolizable energy (ME) allowance (MJ) = 8·3 + 0·091 M where M = live weight of the animal). Three diets with 20: 80 (low, L), 50:50 (medium, M) and 80: 20 (high, H) roughage to concentrate ratios (10·2, 7·8 and 5·4 MJME per kg dry matter) were used in combination with free access to water for 2·5 h once daily or once every 3rd day. A completely randomized-block design with a 3 (diets) × 2 (watering frequencies) factorial arrangement of treatments was used. Five animals were allocated per treatment (average weight 245 (s.d. 21·6) kg).

Dry-matter intake increased as the roughage content of the diet increased (P < 0·05) but was not affected by the watering regime (P > 0·05). Total water intake was found to be positively correlated with dry-matter intake and increased with dietary roughage level. Animals watered daily drank more (P < 0·05) water (12·6 v. 10·0 kg/day) than those watered every 3rd day. The apparent digestibility of the diets decreased as the amount of roughage increased (diet L 734g/kg, M471 g/kg and H 433 g/kg). Similar apparent digestibilities were observed under the two watering frequencies (546 g/kg and 547 g/kg).

Type of diet significantly (P < 0·05) affected the final weights of the steers. Animals given diet H were proportionately 0·07 heavier than those offered diet L corresponding to total weight changes of −0·8 and +18·4 kg respectively. Carcass weight, backfat thickness and eye muscle area were not affected by the treatments. The chemical composition of the 9 to 11th rib joint was only affected by diet H which gave less fat (P < 0·05). Water, fat, protein and ash content averaged 607,118,190 and 84 g/kg respectively.