The data relating to twenty single location trials, involving the progeny of seven sires from one variety mated with random females from another, have been analysed to obtain estimates of sire × location (genotype–environment) interaction for egg production, 23- and 64-week body weights and 32-and 45-week egg weights. In no case was a significant interaction found, indicating genetic correlations not significantly different from unity.

The between- and within-sire components of variance have been calculated for each trait on each location separately. The regressions of these components on the mean levels at the locations have been obtained. Though low and non-significant, they tend to support the use of those locations giving maximum expression of a trait for comparisons involving that trait.

Low levels of antibiotics have been used in animal diets since the 1950’s to improve growth rates by stabilising the gut flora. At higher levels antibiotics have also been used as prophylactics against enteric diseases.

As a result of growing public concern of the the indiscriminate use of antibiotics in the animal industry there are now strict controls on their use. An alternative approach to the use of antibiotics in the control of the gut flora is the use of what have become known as probiotics. Probiotics include viable lactobacillus bacteria cultures and fermentation products which actively colonise the gut wall, and suppress further colonisation by potential pathogens such as virulent E. coli organisms. At times of stress in an animal’s life, such as weaning or re-grouping, the oral application of probiotic agents could be beneficial by both preventing disease and minimising the clinical use of antibiotics.

Early-weaned artificially-reared piglets are particularly at risk to enteric disease and therefore the purpose of the present study was to assess the efficacy of a probiotic agent in pigs weaned at 6 hours of age.

Experiments were conducted to observe the taste responses of male and female calves to various levels of sodium salts, chloride solutions, and trace minerals. Animals were penned individually and given a completely pelleted ration ad libitum. Trace mineralized salt was freely available.

Using water as a basis for determination, a non-discrimination zone was established. This zone represented an intake ranging from 63 to 37%. Preference threshold was set at 80% of intake, while the rejection threshold was set at 20% of intake. Responses were determined by expressing the intake of the test solution as a percentage of the total intake during the test period. Responses at a given chemical concentration were measured during two 8-hr periods.

Taste response observations were made on the following: 0·02, 0·08, 0·32 or 1·25% sodium chloride (NaCl), sodium sulphate (Na2SO4), sodium bicarbonate (NaHCO3), sodium carbonate, monobasic sodium phosphate (NaH2PO4), dibasic sodium phosphate (Na2HPO4), ammonium chloride, potassium chloride, calcium chloride, magnesium chloride, and manganese chloride. In addition, observations were made when 0·02, 0·08, 0·32 or 1·25% NaHCO3, Na2SO4, or Na2HPO4 were offered in opposition to equal concentrations of NaCl. The responses to 5, 10, 20, 40 and 60 p.p.m. concentrations of cupric chloride, zinc chloride, molybdenum trioxide and cobaltous chloride were observed also.

With the increasing interest in the use of fibrous feeds as energy sources for pigs, it is important to establish appropriate methods for determining the digestibility of such feedstuffs. In pig nutrient balance studies, a seven-day adaptation period to a new diet is frequently used. However one week may be insufficient for stability of measurements of non-starch polysaccharide (NSP) digestibility to be achieved, for Giusi-Perrier et al (1989) found that fermentation of high-cellulose diets by pigs increased up to 4 weeks after initial exposure to the diet. The aim of this experiment was to measure the development of NSP, nitrogen and energy balance in growing pigs fed contrasting types of NSP at two levels of inclusion over a period of 6 weeks. The two NSP sources chosen for study were wood cellulose (Solka floC) and plain sugar beet pulp (SBP), which are known to be poorly and highly fermentable respectively (Longland and Low 1988).

Leg disorders in male turkey breeding stock are associated with pain during locomotion (Duncan et al 1990). Musculo-skeletal diseases are prevalent in broiler breeder males and the experiment was designed to evaluate birds of two ages for evidence of pain during movement. Two experiments were conducted, the first examined differences in sexual motivation and the second the rate of walking towards a food reward. At the end of the experiment the birds were killed and the legs dissected to establish the presence of musculoskeletal disease.

Commercial broiler breeder males were housed singly with 15 females in 4 rooms each containing 12 floor pens measuring 1.5 x 2.4 m. There were 24 males in each of two age groups (40 and 60 weeks at the start of the experiments). To determine sexual motivation, males were removed to an empty pen in a spare room. They were returned after 3-5 h and observed for 15 min. The time to make a sexual approach (AP) and to mount a female (MT), and the number of copulations were recorded on three different days. Subsequently, males were trained to walk through a 20 m long alley constructed of hardboard to receive their daily food allocation. During testing, the time taken to reach the food was recorded 3 times before the male was returned to its pen. The males in two rooms were used in a 2-period crossover experiment to evaluate the effects of naloxone (an opiate receptor antagonist) and three analgesics on walking speed (Table 1). All measurements of time were transformed to natural logarithms for analysis. A censored analysis was used for AP and MT. The total number of copulations observed (COP) was modelled using Poisson errors. The models included effects for age and day (where appropriate). The data were reanalysed with the lesion score as a fixed effect. The initial model for walking speed included period and carry over effects. Mixed model methods (REML) were used to assess the final model with birds as blocks and treatment and lesion as main effects.

Much of the early studies investigating the water consumption of pigs have measured water use rather than actual water intake. Water use includes an unknown component of waste from the drinking utensil used.

WATER USE = WATER INTAKE + WATER WASTAGE

One of the objectives of this study was to measure actual total water Intake of growing pigs and to calculate actual total water to feed ratio.

Recommendations of water feed ratio for liquid feed systems have been commonly made from experimentation with non wet fed pigs. The Code of Recommendations for the Welfare of Livestock : Pigs (1985) state that where water is not freely available, for example by means of bowls or drinkers, at least 2 litres of water should be added to each kg of meal. Water to feed ratios calculated in this way may be over estimated as they include an element of waste from drinking utensils which does not occur with wet fed pigs. Also recommendations of this nature make no allowance for the amount of water a pig may choose to consume with its feed. The second objective of this study was to investigate how much water pigs choose to drunk with their feed and how much is drink interprandially.

Energy intake and nitrogen balance studies have been conducted on 12 lambs fed ad libitum on four all-concentrate diets of equal crude-protein content in an experiment of latin square design. Each diet contained one cereal, either barley or oats and one protein supplement, either white-fish meal or soya bean meal.

Protein supplements had no influence on energy intake, but intake was significantly higher when the lambs were given barley rather than oat diets.

There were highly significant differences in the degree of utilization of digested nitrogen between diets containing fish meal and soya bean meal, and between diets containing barley and oats.

The energy: nitrogen ratio of urine was inversely related to the proportion of urinary nitrogen present as urea and directly related to the degree of utilization of digested nitrogen.

In each of 4 years, 24 autumn-calving, single-suckling Aberdeen Angus × Friesian cows with Charolais cross calves were subjected to different winter feeding regimes and to a range of weaning dates, and the effect on cow and calf food intake and performance was measured. Giving 257 kg concentrate dry matter to cows on an ad libitum silage diet over winter increased calf and cow weights in the following September by 17·8 and 11·7 kg respectively. Weaning after 4 months of lactation resulted in a net saving in winter forage requirements when compared with weaning in March/April but a high input of concentrate was necessary to achieve satisfactory calf performance. Weaning in July increased calf weights in August/September by 22·1 kg and reduced cow weights by 22·3 kg compared with weaning in March/April. Later weaning at pasture might be preferable, producing heavier calves, provided that cow weights can be restored at pasture.

Milk output has been manipulated by dietary methods for many years, however the underlying mechanisms for changes in milk composition are as yet unclear. In an attempt to further understand these mechanisms we have compared the mammary uptake of metabolites on two isoenergetic diets with different protein levels expected to provide different amounts of amino acid to the mammary gland.

Early- to mid-lactation Friesian cows were used to examine the effect of increased dietary protein supply on the supply of metabolites to and uptake by the mammary gland in relation to milk protein synthesis. Two barley based concentrates were formulated to contain 20.8 (Cl) or 29.1 (C2) g N/kg DM, using fishmeal (Provimi 66, high UDP) as the supplementary protein and fed with grass silage (28.3 g N/kg DM) at a total dry matter intake of 17 kg/day. In Experiment 1 these diets were fed at 50:50 (concentrate:silage) to four lactating cows fitted with rumen and duodenal cannulae in a simple crossover design.

The progeny test is generally regarded as an important aid to selection in livestock improvement. It is by no means a new method, but it seems to be in the limelight today. The usual methods of selection have brought us to a certain standard of performance, and apparently any further imporvement can only result through the application of the progeny test.

It is worth pointing out that cattle, especially dairy cattle, pigs and poultry have received more attention by the scientist than sheep. This may be due to the fact that these animals are more under the direct control of the breeder than sheep. They require daily attention whereas a hill flock of sheep may not be seen for weeks or months by the breeder. Again one has definite objectives in view when breeding dairy cows or hens; one can weigh the milk and count the eggs but the task of the hill sheep worker is considerably more complicated.

In some grazing experiments stocking rates are adjusted during the experiment. For these and other experiments in which the initial number of animals per treatment is subsequently reduced a more powerful statistical analysis than the normal analysis of variance may be possible. The methodology of the analysis is presented in this paper and applied to an example.

The efficiency of part lactation test day (TD) records in first parity for the genetic evaluation of bulls and cows using a random regression model (RRM) and a fixed regression model (FRM) was studied, modelling the random and fixed lactation curves by Legendre polynomials. The data set consisted of 9 242 783 TD records for first lactation milk yield of 1 134 042 Holstein Friesian heifers. The efficiency of both models with part lactation TD records was examined by comparing predicted transmitting abilities (PTAs) for 305-day milk yield for 114 bulls and their 4697 daughters, from analyses where the maximum number of TD records of these daughters was restricted to the initial 2, 4 or 6 TDs with those estimated from 10 TDs. The correlations of PTAs estimated from 2, 4 or 6 TDs with those from 10 TDs computed for cows and bulls within each model were very similar. A rank correlation of 0·91 (0·92 FRM) was obtained for cows between PTAs based on 2 TDs and those from 10 TDs. The correlation increased to 0·96 with 4 TDs and 0·98 with 6 TDs. For bulls, correlations between PTAs estimated from 4 or 6 TDs with those estimated from 10 TDs were high at 0·98 and 0·99 respectively. With 2 TDs, the correlation was 0·95. The average under-prediction of PTAs with 2, 4 or 6 TDs relative to 10 TDs was generally higher and more variable with a FRM compared with a RRM for highly persistent cows and bulls. A similar trend was observed for mean over-prediction of PTAs, except for the initial predictions based on 2 TDs when the RRM gave a higher mean over-prediction for bulls and their daughters with low persistency but high initial TD records. The range of over and under-predictions were large (up to 200 kg milk) for some bulls when only 2 TDs were included in both models. A moderate correlation of 0·64 was obtained between persistency evaluations estimated from 10 TDs with those estimated from 2 TDs. The correlation increased to 0·71 with 4 TDs included and 0·85 with 6 TDs. The moderately high correlation between 6 TDs and 10 TDs of 0·85 was unexpected given the high correlation of 0·99 between PTAs for yield estimated from 6TDs with those estimated from 10 TDs.

Two experiments have compared the effects of forages or concentrates offered to dairy cows, continuously stocked in late Summer at a low stocking rate in Experiment 1 or a higher stocking rate in Experiment 2.

In Experiment 1 (July - October 1984) 20 Spring calving British Friesian cows were allocated to a Latin square design with four, three week periods and four treatments, a control group, grazing only (TO), grazing with 5 kg dry matter fresh lucerne per day (TL), grazing with 5 kg dry matter hay per day (TH) and grazing with 4 kg DM concentrate per day (TC). In Experiment 2 (August -October 1985) 24 cows of similar calving dates were used in an incomplete Latin square design lasting eight weeks to compare treatments TO, TL, TS and TC where silage (TS) replaced hay. All supplements were offered for 1 hour after each of two milkings per day.

Growing pigs were given diets based on barley (whole or milled), which was either untreated or sprayed with an aqueous solution of sodium hydroxide (270 g sodium hydroxide per kg water) to give 33·8 g sodium hydroxide per kg dry matter. The barley grain was treated with sodium hydroxide while in the whole state. A total of 48 pigs penned individually were given the diets on a restricted scale of feeding from an initial weight of 31·6 kg until slaughter at 81·7 kg live weight. In a metabolism study, eight boars were subjected to the same experimental treatments in two identical 4 × 4 balanced change-over experiments.

The diet containing untreated milled barley gave significantly faster live-weight gain and lower food conversion ratio than the other three diets (P < 0·001). Food conversion ratios were similar for untreated whole barley and sodium hydroxide-treated barley, whether this was whole or milled. Killingout proportion was similar for untreated and treated milled barley but was significantly lower when the diet contained untreated or treated whole barley.

Milling significantly increased the digestibility of energy and nitrogen. Treatment with sodium hydroxide improved the digestibility of energy in the diet with whole barley but not in the diet with milled barley. With both whole and milled barley, treatment with sodium hydroxide increased the digestibility of crude fibre (P < 0·05) but with ground barley the digestibility and retention of nitrogen were reduced considerably by treatment with sodium hydroxide.

It is concluded that treatment of barley with sodium hydroxide did not improve the nutritive value of either milled or whole grain, that it reduced the digestibility of nitrogen and that it severely depressed the utilization of digested energy for growth.

An experiment was carried out to determine which feeding method maximised feed intake of growing pigs and to record growth rates, feed conversion efficiency and backfat measurements. There is an increasing tendency for dry fed pigs to be fed ad libitum or to appetite in order to increase growth rates and throughput of building.

Limited information is available on how the modern genetically improved pig will respond to high levels of feeding and whether ad libitum feeding will encourage higher feed intake than feeding to appetite either wet or dry.

The growth of pigs kept continuously or intermittently in metabolism cages was compared with that of animals penned in groups. The ten continuously caged grew more slowly and contained more fat at slaughter than their penned littermates.

Sibs of five to 11 twin pairs each of five breeds were either slaughtered as veal or as yearling bulls. Highly significant breed differences were evident in the carcass tissue proportions which could be explained on the basis of differences in the physiology of dairy and dual-purpose animals, the former depositing more fat and more bone than dual-purpose breeds. Among the dual-purpose breeds the carcasses of the Pinzgauer (Pi) tended to rank between the carcasses of the Fleckvieh (FV), Braunvieh (BV), Grauvieh (GV) and those of the Friesian (Fr).

The dual-purpose breeds FV, BV, GV had more meat in the hindquarter and in the shoulder than the FR while these in turn had more meat in the brisket and in the flank and shank muscles. Again the Pi group tended to rank between the aforementioned groups.

Within breeds, large differences between twin pairs indicated high heritabilities for carcass tissue proportions and ratios. The heritability of commercial cut proportions was fairly high but the genetic variance was small, the genetic coefficient of variation being less than 0-02. The different degrees of sexual maturity and of carcass maturity also caused differences in the distribution of meat in the carcasses of young male animals.

Significant mean squares for interactions between treatments and breeds, and genetic correlations of less than unity between performance of twin genotypes in veal and in bulls, indicated age and/or rearing system by genotype interactions between and within breeds for various slaughter traits.

Phenotypic correlations between various slaughter traits were low except where part-whole relationships were involved. It is suggested that slaughter at comparable maturity in the respective treatments was the cause of the weak connection between the traits.

The application of ultrasonics to the evaluation of live cattle has been carried out in bull performance testing for several years. The machine used for this was the Scanogram. The fact that this machine is no longer being produced and the emergence of several new machines has prompted this trial to evaluate seven ultrasonic machines.

A total of 49 bulls, 27 Limousin x Friesian and 22 Charolais x Friesian, were evaluated and slaughtered in four batches of approximately equal size, over four weeks. Each batch was of one breed.

Age, live weight at evaluation and subjective assessments of fatness and conformation were recorded together with fat and muscle measurements by the Delphi (Delphi Instruments Ltd, New Zealand), Meritronics (Merit, Lowson and French, England), Scanogram (Ithaco Incorporated, USA), Vetscan (Company no longer in existence), Kaijo Denki (Medata Systems Ltd, England), Velocity of Sound (Prototype developed at IFR-Bristol, England) and Warren (Prototype developed by J Warren) ultrasonic machines.

The majority of lamb production in Britain is concentrated in March and April resulting in a glut of lambs during July-September when the guaranteed price is at its lowest. Trials were carried out over 3 years to assess the feasibility of lambing hill and lowground ewes in early summer when grass is at its most productive and little concentrates are necessary prior to lambing.

Trial 1 involved 20 bought-in Blackface (BF) ewes which were exposed to the tup in January/February in a sheltered field. Hay was available but no concentrates were fed. Ewes were outwintered and lambed in June/July when they were moved onto clean grazing. Concentrates were fed at the rate of 150g/d rising to 300g/d from 4 weeks pre-lambing to 10 days post-lambing. Results are shown in table 1.

Carcass quality was evaluated in 35 male and 41 female lambs, 38 expressing the callipyge phenotype (Cg) and 38 controls expressing the normal phenotype (N). Lambs were from Romanov and Suffolk × Romanov ewes mated to two rams heterozygous for the callipyge locus and slaughtered at approximately 44 kg live weight. The Cg lambs reached slaughter weight at 163 days of age, 13 days younger, and had a dressing proportion 0·524 , 0·029 points higher. Also they had more leg (341 v. 308 g/kg), less loin (315 v. 328 g/kg) and less shoulder (340 v. 360 g/kg) than the N lambs. The leg, loin and shoulder wholesale cuts and half the carcass of Cg lambs had 81, 113, 77, and 92 g/kg more lean and 52, 98, 59, and 72 g/kg less fat than N lambs, respectively. The Cg lambs also had larger loin-eye area (18·5 v.13·1 cm2), less backfat at the C (4·1 v. 6·1 mm) and at the GR locations (11·0 v. 15·2 mm) and less internal fat (202 v. 339 g) than the N lambs. Dissection of the 12th rib indicated that Cg lambs had more muscle (574 v. 462 g/kg), less fat (276 v. 358 g/kg) (both P < 0·001) and similar (V > 0·05) bone (155 v. 265 g/kg) to N lambs. Colour of the longissimus muscle was significantly paler in Cg lambs. Intramuscular fat and dry matter of longissimus muscle were significantly lower (49 v. 120 and 247 v. 253 g/kg) in Cg than in N lambs. Cg lambs were significantly different (P < 0·05) from N lambs for all traits studied except age at slaughter, tissues at the GR location, proportion of bone in the 12th rib and the L* colour of the longissimus muscle. Breed type effect was significant only for age at slaughter, whereas the effect of sex was significant for all traits except for proportion of lean in the leg, b* colour and intramuscular fat content of the longissimus muscle. No interactions were significant except phenotype × breed type on fat thickness over the longissimus muscle. Post-mortem ageing of the longissimus muscle for 9 or 15 days caused a significant reduction in muscle toughness in Cg lambs compared with those aged for 3 days (113 v. 98 Newtons) but the muscle was still tougher than that from N lambs (with a shear force of 64 and 51 Newtons at 3 and 9 or 15 days post mortem). The principle component analysis including carcass conformation and composition traits as well as meat quality traits was indicative of a distinctly different carcass ofCg compared with N lambs. The first two principal components explained 0·70 of the total variation.