1. Weanling male rats were used in three experiments to evaluate the sequence of limiting amino acids for maximum growth with diets based on wheats containing 10, 13 or 17% crude protein (N×5·71).

2. Lysine was the first-limiting, threonine the second-limiting, and valine or methionine the third- or fourth-limiting amino acid for growth rate and feed-conversion ratio of rats offered the diet based on wheat containing 10% crude protein. A further four amino acids (isoleucine, histidine, tryptophan and tyrosine) were limiting for feed-conversion ratio only.

3. For the diet based on wheat containing 13% crude protein the sequence of limiting amino acids was lysine, threonine and methionine.

4. Only lysine was limiting in the diet based on wheat containing 17% crude protein.

5. Plasma-free amino-acid concentrations were found to be a valuable criterion for prediction of the first-limiting amino acid in diets.

6. Improvement of growth and feed-conversion ratio was observed with diets based on wheat containing 17 or 13% crude protein when the limiting amino acids were supplemented to provide the recommended allowance. Further improvement in feed-conversion ratio was obtained when lysine and threonine were provided in excess of the recommended allowances.

7. There was a lysine-threonine interaction affecting growth rate and feed-conversion ratio, and a lysine-me.thionine interaction affecting feed-conversion ratio.

1. For ten years purebred Blackface and Swaledale ewes have been kept on a small hill grazing together with first crosses and backcrosses to the Swaledale. The total flock of about 120 ewes was mated and lambed on sown pastures where ewes with twins remained from lambing until weaning. Four new rams (two of each breed) were used each year.

2. It is concluded that the Swaledales produced fewer lambs than the other ewes, but these were of greater birth weight (5 %) and cannon bone length (2 %); moreoever, they were better mothers than Blackface (4 %) when rearing singles on hill grazing but not if rearing twins on sown grass.

3. Blackface sheep showed greater weights at weaning (5%), at mating (5%), and of fleece (15%) than did pure Swaledales.

4. First cross sheep were equal to or slightly superior to the parental mean in birth weight, weaning weight and cannon-bone length. They exceeded the better parent in ewe weight, first fleece weight, and weight of weaned lambs.

5. Backcross sheep although not always statistically distinguishable from Swaledale in cannon-bone length and fleece weight or from first cross sheep in reproductive characters tend to confirm the interpretations placed on the relations between the purebred and first cross sheep.

6. Heterosis estimated as a superiority of first cross sheep over the mean of the two parental breeds varied from 0% for cannon-bone length to 9·5% for prolificacy of 4-year-old ewes.

To optimize performance and carcass quality of Belgian Blue double-muscled bulls four phased feeding regimens were evaluated. All diets were offered ad libitum and consisted of 650 g concentrates and 350 g maize silage per kg dry matter (DM). Total period was divided into three phases (ca. 360 to 460, 460 to 570 and 570 to 680 kg). All four groups received the same maize silage but the different energy and protein densities were applied using different concentrates. During the three phases, the negative control (NC) group constantly received a diet with a low protein and a moderate energy density; the second group (DP) received with each phase diets with decreasing protein density while the energy density remained moderate; the third group (IE) received diets with increasing energy density at a constantly high protein density and the last group (DPIE) received diets which decreased in protein and increased in energy density.

The NC group grew significantly slower during the first interval (1·37 v. 1·62 kg/day for the other groups), resulting in a significantly longer total finishing period. During the third period IE had the slowest growth. The NC group needed 21 and 20 days more than the DP and DPIE groups, respectively, to reach the same slaughter weight. The NC group had the lowest DM intake during the first interval, the IE group during the third interval. No significant differences (P > 0·05) were found for food conversion, when expressed as DM or NEF (net energy for fattening). IE had the worst protein conversion while NC had the best, with the two other groups being intermediate.

The only important significant difference concerning carcass quality was the improved dressing proportion of the IE and DP groups. Although significant, differences in the fat content of the m. longissimus thoracis are of minor importance. These results proved that for Belgian Blue double-muscled bulls, protein density of the diet can be decreased with increasing live weight, while energy should be increased to give optimal performance.

Cattle’s relationship with humans is a crucial factor regarding their welfare. In dairy cows, interactions with humans occur regularly during milking. We tested the effect of gentle interactions (stroking, talking in a gentle voice) during milking on avoidance distance and milk composition, yield and flow characteristics as well as behaviour during milking. Over the course of 15 days, an experimenter interacted gently with 14 German Holstein cows for 2 min during morning and evening milkings, totalling 60 min; the experimenter stayed at a similar distance to 12 control cows of the same breed for the same amount of time. There were no significant differences between the groups in behaviour during milking. Over the course of the experimental phase, avoidance distance at the feeding rack decreased significantly in stroked but not in control cows. The treatment did not improve any of the measures of milk composition, yield or flow; on the 1st day of the treatment, milk ejection was impaired in stroked cows, which points towards an effect of the novelty of the treatment. We conclude that gentle interactions during milking improve the relationship between cows and a human. Possible reasons for the absence of an effect on milk characteristics are that cows may not have perceived the interactions as positive or that a ceiling effect occurred due to otherwise optimal milking routines.

Previously, the single nucleotide polymorphism in alcohol dehydrogenase (ADH1C c.-64T>C) was shown to have an association with intramuscular fat (IMF) in the longissimus thoracis (LT) muscle when vitamin A was limited in finishing rations of beef steers. The purpose of this study was to determine the optimum vitamin A supplementation level, in combination with ADH1C genotype, to increase IMF of the LT muscle. In total, 45 TT genotype, 45 CT and 27 CC Black Angus crossbred steers were backgrounded on a commercial ration containing 3360 IU vitamin A/kg dry matter (DM). During finishing, the steers were randomly assigned to one of three vitamin A treatments at 25%, 50% and 75% of the National Research Council recommendation of 2200 IU/kg DM. Treatments were administered via an oral bolus. Carcass quality was evaluated and a sample from the LT muscle was collected for analysis of IMF. A treatment×genotype interaction (P=0.04) was observed for IMF; TT steers on the 75% treatment had higher IMF relative to CT and CC steers on the same treatment. Western blot analysis showed that TT steers had higher (P=0.02) ADH1C protein expression in hepatic tissue. Previously, TT steers exhibited increased IMF when fed limited vitamin A. In the current study, the lack of variation in IMF between treatments and genotypes at the lower vitamin A treatment levels was likely due to the majority of the steers grading Canada AAA (USDA Choice). However, the western blot data supports that TT steers are expected to have higher IMF deposition, due to an increased production of ADH1C. The interaction between ADH1C genotype and vitamin A supplementation level has the potential for use in marker-assisted management programs to target niche markets based on increased marbling.

Multi-tier aviary systems are becoming more common in organic egg production. The area on the tiers can be included in the net area available to the hens (also referred to as usable area) when calculating maximum indoor stocking densities in organic systems within the EU. In this article, results on egg production, laying behaviour and use of veranda and outdoor area are reported for organic laying hens housed in a multi-tier system with permanent access to a veranda and kept at stocking densities (D) of 6, 9 and 12 hens/m2 available floor area, with concomitant increases in the number of hens per trough, drinker, perch and nest space. In a fourth treatment, access to the top tier was blocked reducing vertical, trough and perch access at the lowest stocking density (treatment D6x). In all other aspects than stocking density, the experiment followed the EU regulations on the keeping of organic laying hens. Laying percentage was significantly lower (P<0.05) in D12 compared with the other stocking densities (90.6% v. 94.3% (±0.7)), most likely due to the concomitant reduction in nest space and drinker availability per hen. No systematic effects of density were found on other laying variables (egg weight, eggs laid outside nests, aviary side preferences). Number of hens using the veranda increased with stocking density. Hens primarily used the range near the house (within 50 m) and hens kept at the lowest stocking density and the smallest group size appeared to use the outdoor area more extensively, based on an assessment of vegetation cover (P<0.05). For the measures reported here, the welfare consequences of increased stocking density were assessed to be minor; additional results are reported in the associated article (Steenfeldt and Nielsen, 2015).

A proline-free, chemically defined amino acid basal diet was compared with this same diet fortified with 4g L-proline per kg when given to 5-kg pigs. During a 28-day feeding period, daily gain, food intake, and gain: food ratio of pigs given the proline-free diet were not different (P > 0·05) from those of pigs given the proline-supplemented diet. Young pigs can apparently synthesize adequate quantities of proline endogenously to meet their needs for both growth and maintenance.

Dairy ewes (Prealpes breed) were subjected to differential photoperiod treatments: either long (15·5 light (L): 8·5 dark (D) or short (8·5 L: 15·5 D). Treatments started 15 days before lambing and continued until the 5th week of lactation. After lambing the 22 ewes of each photoperiodic treatment were divided in two groups and fed on either a high or low plane (19 v. 10·5 MJ/day and 370 v. 237 g crude protein per day). Milk yield was not affected by photoperiod but significantly modified by feeding levels (1154 v. 789 ml/day). Protein content of the milk was reduced under long days (—4·9 g/1) compared with short days, while no effect was observed for fat content. Body chemical composition changes, estimated by the deuterium oxide (heavy water) dilution technique between weeks 1 and 4, were affected by both treatments, with a significant interaction between photoperiod and diet for body protein changes: under short days lipid and protein changes were closely related while under long days they were independent.

Blood samples were taken on day 23 of lactation from six ewes per group, every 30 min from 07.30 to 15.30 h for growth hormone (GH) and prolactin (PRL) measurements. The timing of GH and PRL pulses were different, but there was evidence that secretory patterns of each hormone were synchronized across ewes within the four treatments. Long photoperiod increased plasma PRL baseline rather than pulse amplitude, with no effect of diet. Undernutrition mainly increased GH pulse amplitude rather than baseline concentration, with no significant effects of photoperiod.

High spontaneous concentrations of GH were associated with body lipid mobilization (R2 = 0·51) and were also involved in the control of protein changes (R2 = 0·71). These results indicate that GH (and PRL) are involved in nutrient partitioning in the lactating ewe.

The red deer (Cervus elaphus) is a seasonal breeder, mating mainly in October and calving in June. This timing is advantageous to wild deer on the hill in that the relatively high nutritional demands of lactation may be met from the abundance of summer vegetation. On low-ground pastures, however, there is an earlier start to the grazing season and the deer farmer may benefit from being able to advance calving dates. Recent research work has shown that exogenous hormone therapy can advance the breeding season in female red deer (Adam and Atkinson, 1984; Adam, Moir and Atkinson, 1985; Nowak, Elmhirst Webster and Barrell, conception and hence and Rodway, 1985; Webster; and Barrell, 1985) and that conception and hence calving dates can indeed also be advanced (Adam, 1985; Adam, Moir and Atkinson, 1986). This paper reports the effects of birth date on the performance of suckled calves and their dams under farm conditions.

Blood samples were taken from three Brahman × Friesian cattle while they walked for 1 h daily on a treadmill pulling 20 or 25 kg weights suspended in a cage. Heart rate and energy expenditure during work were closely correlated. The work had no significant effect on blood levels of red cells, haemoglobin, packed cell volume, total protein, albumin, glycerol, urea, Mg, Ca, Na, K and chloride. White blood cells, glucose, lactate, free fatty acids, P-hydroxybutyrate and inorganic phosphate were affected by work although the changes were shortlived and values had returned to resting levels 75 min after work finished. The changes were similar in each animal and indicated work done by draught cattle is largely at a submaximal level. Apart from lactate no blood parameters were identified that could be usefully used to compare performance.

The objective of this study was to analyse the associations between ovine prion protein (PrP) genotypes and reproduction traits in three German meat sheep breeds. Reproduction traits were age at first early lambing, age at first late lambing, first lambing interval, second lambing interval and total number of lambs born. The data set included 595 genotyped German Texel sheep among 5225 recorded sheep, 351 genotyped German Black-Headed Mutton among 10 177 sheep and 282 genotyped Suffolk sheep among 2849 sheep. Linear animal models were employed for the analysis of the PrP-genotype effect. The PrP-genotype effect was analysed by comparing the most frequent PrP genotypes ARR/ARR, ARR/ARQ, and ARQ/ARQ. In a more general analysis three PrP genotype classes of animals with two, one or no copy of the ARR allele were compared.

In most cases, no significant associations were found between the PrP genotypes and the reproduction traits investigated. Only for the traits age at first early lambing in German Texel and second lambing interval in German Black-Headed Mutton and Suffolk could a significant association with the PrP genotype be observed.

Boar taint is a quality defect in meat, related to accumulation of skatole and androstenone in male pigs. The levels of skatole and its main metabolites in plasma and urine samples were measured with a validated liquid chromatography-MS method and related to activity of hepatic cytochrome P450 (CYP450) in order to identify ‘fast metabolizing’ pigs. Urine (n=46), blood (n=12), liver (n=25) and adipose tissue (n=46) were sampled from a total of 46 entire male pigs. Skatole levels in fat were negatively correlated to CYP2E1 activity and positively to 3-hydroxy-3-methyloxindole (HMOI), indole-3-carboxylic acid (ICA) and 2-aminoacetophenone in urine. HMOI and ICA levels in urine were the best predictors of high skatole levels in fat. In summary, the present study provided further evidence for the key role of CYP2E1 in skatole metabolism and suggested that measurement of HMOI and/or ICA in urine might provide information about skatole levels in live pigs.

Data on growth rate and carcasses of pedigree Polled Dorset Horn castrated male lambs have been collected. The lambs were the half-sib progeny of 18 rams mated to groups of 20 ewes in 1968 and 1969. The lambs were slaughtered at between 35 and 45 kg live weight and when considered ‘fit’ on the basis of a handling appraisal. The whole carcasses were classified by a retail organization as either ‘accepted’ or ‘rejected’ and subsequently all carcasses were cut into commercial joints ready for sale. Analyses indicated that classification of carcasses was largely but not solely based on backfat thickness. Accepted carcasses were from older and heavier lambs which had larger eye-muscle areas. There was no difference in value per unit weight between accepted and rejected carcasses.

Heritability for growth rate to 16 weeks of age was zero but for growth rate and age at slaughter was 0·26 ± 0·22 and 0·28 + μ 0·22 respectively. The heritability estimates for percentage best end, loin and backfat thickness were greater than 0·30. There were insufficient data to estimate genetic correlations accurately, but the estimates of pheno-typic correlations and heritabilities were very similar to those obtained in a previous study of carcasses of Down cross lambs.

It is suggested that the method of choosing lambs for slaughter accounts for the large difference in the heritabilities for growth to 16 weeks and to slaughter. Selection to change backfat thickness would be effective and would probably result in a reduction in age at slaughter and an increase in growth rate to slaughter. Selection to change proportions of the carcass is not considered to be worthwhile.

Twenty-eight Holstein/Friesian dairy cows were divided into four groups of seven. From weeks 4 to 15 of lactation they were given a basal diet consisting of 8 kg hay, 2 kg sugar-beet feed and 2 kg grass nuts, together with a concentrate allowance of 8 kg/day. Concentrates for group A were based on cereals and soya (control). Concentrate B contained 60 g protected fat supplement per kg; concentrate C contained 100 g lactose per kg; concentrate D contained 60 g fat supplement and 100 g lactose per kg. Milk yields were 24·6, 27·7, 25·6 and 26·5 kg/day and milk protein concentrations were 32·3, 30·7, 32·7 and 31·9 g/kg for groups A, B, C and D respectively. The effect of fat supplementation on milk yield and protein concentration was significant (P < 0·05) but the effect of lactose was not significant. Milk fat concentration was not significantly affected by treatment. It is concluded that lactose can partially alleviate the depression in milk protein concentration often observed when cows are given protected fat.

In two experiments over 2 years, 181 Scottish Blackface ewes were differentially group-fed indoors to achieve moderately-good (score 2·5), moderate (score 2) or poor (score 1·5) body condition. Over 5 weeks prior to mating, ewes in moderately-good condition were either maintained or brought down to moderate condition by restricted feeding and ewes in moderate and poor condition were raised, respectively, to moderately-good and moderate condition by a high level of feeding. After mating, ewes were maintained in condition until slaughtered for a count of corpora lutea relating to first service. Ovulation rate was positively and significantly related to the level of pre-mating food intake at the moderate level of condition but not significantly so at the moderately-good level. It is postulated that ewes of this breed are more sensitive to the level of pre-mating food intake when in moderate condition at mating than they are when condition has risen to a moderately-good level.

Seven research and teaching centres have co-operated in an experiment involving 154 sows. The experiment compared the effect of feeding four different patterns of feed intake during pregnancy upon reproductive performance of sows. In each case approximately 220 kg of feed were given during each gestation according to four patterns of intake designated Constant (C), Low-High (L-H), High-Low (H-L) and High-Low-High (H-L-H). During lactation all animals were given a daily ration of 3·7 kg of feed for litters of five pigs or less, and 0·4 kg for each additional piglet. Wherever possible the sows remained on the same nutritional regimes for three parities.

Although the pattern of feed intake slightly affected the live-weight changes of the sows during the course of pregnancy, the treatments had no significant effects on overall change in weight of the sows in pregnancy or in lactation in any of the three parities. The live weights of the sows at the end of the third parity were very similar for all treatment groups.

The patterns of feed intake had no appreciable or significant effect on the numbers of pigs born, their average weight at birth or upon the numbers of pigs which survived to weaning at 6 weeks or their live weight. The health and breeding regularity of the sows were also unaffected by the treatments.

There were differences between the centres in many of the variables which were compared, but there was no evidence of any important centre × treatment interactions.

It is concluded that, at the levels of intake given in pregnancy and lactation in this experiment, there are no beneficial or detrimental effects of changing the pattern of intake during pregnancy.

The voluntary food intake in a limited period, 30 or 60 min after morning and afternoon feeds, and during 24 h, by lambs and calves given diets containing rapeseed meal (RSM) or soya bean meal (SBM) as the only protein supplement was determined. Four rapeseed meals were compared, one from seed of British-grown winter Brassica napus varieties (BRSM), and the others from seeds of the varieties Tower (TRSM) and Loras (LRSM), or from seeds of Canadian spring sown varieties (Canola; CRSM). The effects on food intake of treating BRSM with heat and ammonia, steam, steam and ammonia, or calcium hydroxide and ammonia were also determined.

In lambs, intakes in a limited period of BRSM and CRSM were significantly lower than that of SBM, and there were no differences between intakes of BRSM and CRSM. In calves, intake in a limited period of BRSM was significantly lower than intake of SBM, TRSM and LRSM: those of TRSM and LRSM were lower, but not significantly so, than that of SBM. Treatment of BRSM with steam, steam and ammonia or calcium hydroxide and ammonia, increased food intake significantly but by small amounts: intakes of the treated meal diets were markedly lower than that of the control SBM diet. The glucosinolate concentration of untreated RSM influenced intake in calves but not in lambs. The effects of treatment of RSM on intake were not closely related to changes in glucosinolate concentration.

The aim of this study was to determine how cows with different genetic merit behave and perform when grazing biodiverse and heterogeneous mountain pastures with different slopes. Three groups of 12 cows in late lactation, each composed of four Holstein, four Montbéliarde and four Valdostana Red Pied cows, breeds of increasing presumed robustness and decreasing milk yield (MY) potential. Cows grazed without concentrate either on a low-diversity flat pasture or on two species-rich mountainous pastures having slopes of either 7° or 22°. Milk yield, BW and grazing behaviour were monitored two times in the first and once in the second grazing cycle. Cows of different breeds had similar behaviour on all pastures. The Montbéliarde cows performed close to their production potential; Holstein and Valdostana cows produced less milk than anticipated. No breed difference in terms of BW loss was found. The Valdostana cows exhibited the least selective behaviour with respect to plant species and plant growth stage. Still, all cows searched for the most palatable vegetation regardless of pasture diversity. On the steep pasture, cows optimised the trade-off between ingesting and saving energy to obtain feed. They remained longer at the lowest zone and selected forbs, whereas cows on the flatter pasture went to the upper zone to select grasses. The present study gave no evidence for a superior short-term adaptation to harsh grazing conditions through an optimised feeding behaviour of the Valdostana breed compared to Montbéliarde and Holstein cows.

The aim of this study is to assess how the fat molecular structure and its glycerol-to-fatty acid ratio (G : FA) affect the fatty acid (FA) apparent absorption of palm oils in broiler chickens. The experimental diets were the result of a basal diet supplemented with 6% of different palm oils. Native palm oil (N), rich in triacylglycerols, was the positive control (T1), and acid palm oil (A), rich in free FA, was the negative control (T2). In order to improve the nutritive value of A, two different nutritional strategies were performed. The first strategy was achieved by adding increasing amounts of free glycerol (G) (4% (T3), 8% (T4) and 16% (T5)) to A, and the second one by adding increasing amounts of mono- (MAG) and diacylglycerols (DAG), coming from re-esterified palm oil (E) (40% (T6), 70% (T7), and 100% (T8)) to A. As a result, eight dietary treatments were formulated with a G : FA ratio ranging from 0.04 to 0.67. These treatments were randomly assigned to 192 one-day-old female broiler chickens (Ross 308), distributed in 48 cages. The results showed how, by keeping the G : FA ratio constant (0.33 mol/mol), the diet with a high MAG and DAG content (T7) achieved higher saturated FA apparent absorption values than did the diet with a high triacylglycerol content (T1) and this, in turn, more than did the diet with a high free FA content (T4). The behavior of oils with high or low G : FA ratio was dependent on whether G was in a free state or esterified as part of acylglycerol molecules. Thus, increasing amounts of G to A did not enhance the total FA apparent absorption, but rather quite the opposite, even impairing the absorption of mono- and polyunsaturated FA. However, increasing amounts of E (rich in MAG and DAG) to A (rich in FFA) did enhance total FA apparent absorption, primarily due to the increased absorption of saturated FA. In conclusion, the greater the G : FA ratio of a palm oil, the greater the absorption of total FA, as long as G is esterified as part of acylglycerol molecules. Thus, the re-esterification process for obtaining E makes sense in order to give added value to A, achieving even greater digestibility values than does its corresponding N.

Osteochondrosis (OC) is an inherited developmental disease in young horses most frequently observed in thoroughbreds, trotters, warmblood and coldblood horses. Quantitative trait loci (QTL) for equine OC have been identified in Hanoverian warmblood horses employing a whole genome scan with microsatellites. A QTL on ECA16 reached the genome-wide significance level for hock osteochondrosis dissecans (OCD). The aim of this study was to refine this QTL on ECA16 using an extended marker set of 34 newly developed microsatellites and 15 single nucleotide polymorphisms (SNPs). We used the same 14 paternal half-sib groups as in the above-mentioned whole genome scan. The QTL for OCD in hock joints on ECA16 could be delimited at an interval between 17.60 and 45.18 Mb using multipoint non-parametric linkage analyses. In addition, six microsatellites and one SNP were significantly associated with hock OCD in the QTL region between 24.26 and 42.41 Mb. Furthermore, our analysis revealed a second QTL for fetlock OC between 6.55 and 24.26 Mb on ECA16. This report is a further step towards unravelling the genes underlying QTL for equine OC and towards the development of a marker test for OC in Hanoverian warmblood horses.