Previous trials at Newcastle have shown that plane of nutrition affects the growth performance, carcass composition and eating quality of lambs (Mustafa and Webster, 1995). It has also been found that lean tissue growth rate, a characteristic it is possible to manipulate nutritionally, influences meat quality in pigs and cattle (Whipple et al., 1990; Blanchard et al., 1995), although no similar studies have been undertaken with growing lambs. This experiment was designed to study the effect of four diets with different levels of metabolizable energy (ME) but with the same crude protein and undegradeable protein (DUP) levels on growth, carcass composition, tissue growth rate and meat quality characteristics of lambs of two breeds.

In the UK there are many different breeds of sheep to suit all conditions and environments. Utilization of a breed is dependant on suitability for the environment, production system and acceptability of the carcass. This experiment was therefore designed to evaluate breed and age effects on performance, carcass composition and eating quality of lambs using a systems approach.

Lambs of five breed types were used, representing the stratification within the industry: Swaledale (SWD), Scottish Blackface (SBF), Mule, (Bluefaced Leicester x SBF; MUL), Suffolk x Mule (SxM) and Suffolk x (Rouge de l' Quest x SBF) (SxR). All lambs were finished off grass which was of subjectively similar quality at ADAS Redesdale and were slaughtered at estimated fat class 2 to 3L. For each breed type, there was 2 or 3 slaughter dates with 2 or 3 breeds being represented on each occasion.

Excess fat in lamb is regarded as an important reason for less lamb meat being purchased by consumers. This has encouraged the development and use (particularly in Terminal Sire breeds) of selection indices that can identify animals that will sire leaner progeny. These indices usually include live weight and in vivo predictors of body composition, such as an ultrasonic measurement of muscle and fat depth, as selection criteria (Simm and Dingwall, 1989). But the usefulness of such in vivo measurements as predictors of carcass composition depends on the correlation between, and the variation in, live and carcass measures. The objectives of this study were to determine the strength of the relationship between ultrasound and dissection measures of carcass composition, and the degree of genetic variation in these measures, in crossbred progeny of Suffolk rams.

Conformation is often given high priority as a selection objective by pedigree breeders who consider this trait to be related to lean yield and distribution, despite experimental evidence to the contrary. The Texel crossbred lamb is known to have a high lean yield at a given liveweight and in considering the results of breed comparison trials Croston et al (1987) speculated that there may be variation between strains for this trait, possibly associated with differences in conformation. Support for this suggestion comes from the work of Leroy (1989) who reported that the Belgian Texel with a heavily muscled conformation (“double muscled”) had a higher killing-out proportion and lean yield than sheep with conventional shape. The aim of this trial was to investigate potential differences in the carcass traits of pure-bred Texel lambs of extreme versus conventional conformation

In 1989, ten Suffolk breeders co-operated to establish a nucleus flock at Wye College. The group is known as the Wye Suffolk Improvement Group (WSIG). The members each contributed 5-10 pedigree ewes to use as the initial nucleus flock. Eighty-nine ewes were delivered to the College by the various participants. The objective of this study was to obtain estimates of the heritabilities of live animal traits, used to improve carcass traits, and phenotypic and genotypic correlation estimates between them in the Suffolk lambs in the south of England.

The difficulty in designing an optimal breeding programme arises from a conflict between improvement in genetic gain and increase in inbreeding since selection procedures which increase genetic progress are usually associated with increased rates of inbreeding. Best linear unbiased prediction (BLUP) has optimal properties regarding the expected genetic gain after one generation of selection. However, since full genetic relationships are accounted for, selected animals are likely to be more related, leading to a higher rate of inbreeding and a larger decrease in genetic variance than less accurate methods.

The concept of long term contributions was devised by Wray and Thompson (1990) to describe the accumulation of inbreeding in a population under selection, and further developed by Woolliams and Thompson (1994) to describe genetic progress. This study describes a method to utilise these relationships for optimising schemes where the breeding objective is cumulative net response with restrictions on inbreeding. The selection decisions at a given generation can be obtained from maximising the function f(x) of accumulated gain corrected for squared contributions: f(x) = xTg-λTAx, where x is the vector of long term contributions, g is the vector of estimated breeding values, A is the matrix of genetic relationships which has not been corrected for reduced Mendelian variance with inbreeding (unlike the method of Wray and Goddard, 1994), and λ is a constant taking positive values.

Mastitis is one of the most costly health problems of dairy cattle. Herd average somatic cell counts (SCC) have been measured and used since 1977 as a means of identifying high levels of mastitis in herds. Although good management is an effective means of reducing mastitis the costs and penalties introduced in payment schemes, for high cell counts, has focused attention on breeding to reduce the incidence of mastitis through indirect selection for lower SCC. Optional, individual cow SCC recording commenced in 1991 and approximately 0.80 of all cows are now recorded. This paper presents the results of SCC evaluations for three dairy breeds.

The use of genetic selection as a means of reducing the welfare and production losses caused by gastrointestinal parasites has hitherto been ignored by the UK sheep industry. The aim of this study is to assess the potential for selection for reduced faecal egg count, as an indicator of parasitism, and to establish relationships with live weight.

Faecal egg counts and live weights were measured on approximately 200 predominantly twin born Scottish Blackface lambs each year for three years following natural, predominantly Ostertagia circumcincta , infection on pasture. Measurements were made from one to six months of age, at four week intervals, following anthelmintic treatment. Heritabilities, maternal common environment effects, genetic and phenotypic correlations were calculated using Residual Maximum Likelihood techniques.

Recent work on the agronomy and the genetic make-up of a new strain of lupin, which could be grown on almost half the agricultural land in England and Wales, has resulted in improvements in the yield and protein content of lupins. The protein content of lupins, at 37 % of the dry matter, is higher than that of either peas or beans and therefore lupins could be an important source of home-grown protein. There is little information available on the potential of new strains of lupins as a protein source in the feed of ruminants, particularly in conjunction with forage maize.

There is ample evidence to show that the intake characteristics of silages harvested from the same sward can differ due to variations in digestibility and fermentation characteristics as influenced by additive treatment. In these studies animals were allocated to specific silages and had no choice of diets. More recently, Keady and Murphy (1994) have reported that cows have the ability to select their preferred silage within minutes, by either sight or smell, when offered access to a range of contrasting grass silages ad libitum and unsupplemented. The present study was designed to evaluate cows preferences for silages differing in fermentation and intake characteristics when offered concentrates varying in energy source.

Vitamin E is the major lipid soluble antioxidant in animals and post mortem it continues to inhibit the oxidation of lipids, which causes rancidity, and the oxidation of myoglobin to metmyoglobin which results in a brown discoloration of the meat. Feeding vitamin E in amounts greater than those needed for normal growth and reproduction of the animal raises the vitamin levels of the tissues and increases the shelf life of meat by delaying the onset of oxidative deterioration (Schaefer et al., 1995). We have investigated the effectiveness of supplemental vitamin E given to beef cattle fed grass silage, since grass and conserved grass contain relatively high levels of endogenous vitamin E. Meat quality was assessed not only by physical and chemical methods but also by taste panel to determine whether high levels of vitamin E affected cooked meat flavour which requires limited lipid oxidation for its development.

In Belgium, beef meat is traditionally produced with growing fattening bulls kept indoors and fed concentrate. Alternatives exist to this technic. Dufirasne et al. (1995) showed that young bulls may spend one season on pasture before a finishing period indoors. It has been reported recently that the finishing of young Belgian Blue bulls at grass did not provide carcasses with the required qualities (Hornick at al., 1995). The supplementation at grass has been suggested as an alternative. The aim of the present experiment was to study the effects of supplementation of bulls finished at grass on animal performance, carcass and meat characteristics.

In forage-based intensive beef production systems supplementary feedingstuffs are generally required to optimise live-weight gain and to ensure adequate finish. Information on the feeding of molasses alone or molasses in conjunction with supplementary protein, in grass silage-based beef cattle diets is limited.

To evaluate the effect of replacing barley with molasses and/or mineralised fishmeal when fed with ad libitum grass silage to finishing beef cattle.

Daily supplements of 2.0 kg of rolled barley + 50 g minerals (B), 0.5 kg mineralised fishmeal (F), 2.0 kg cane molasses + 0.5 kg mineralised fishmeal (MF) or 2.5 kg cane molasses + 50 g minerals (M).

In early weaning calf rearing systems, intake and nutritive value of the concentrate are the main determinants of performance. A possible way of increasing the nutritive value of concentrates is to increase the oil level, either by adding oil/fat or full fat oilseeds. An experiment was carried out to evaluate the effect on calf intake and performance of the addition of full fat rapeseed or full fat soyabean to a calf starter concentrate.

Use of high levels of fertiliser N on pasture and silage making can cause environmental pollution through nitrate leaching to ground water and accidental seepage of silage effluent to water courses. The reformed Common Agricultural Policy of the European Union promotes more extensive beef production on grassland to reduce these risks. The objective of the present study was to ascertain the consequences for animal performance and carcass traits of reducing fertiliser N and eliminating silage making in beef production.

Forty eight Charolais x Friesian yearling steers (initial liveweight 358 kg) were allocated to 4 treatments in a 2 × 2 factorial experiment at turn-out to pasture in April. The two factors were fertiliser N level (215 (Normal) and 57 (Low) kg/ha) over two consecutive grazing seasons and type of feed (grass silage or by-products) during the intervening winter.

Simplifying rations and using home grown ingredients can reduce costs of production and, provided productivity is maintained, increase profit. The objective of this experiment was to determine the performance of weaned suckled bull calves on a ration containing field beans (vicia faba), rolled barley, molasses and vitamins and minerals; the ad libitum straw intake was also examined.

Twelve Limousin x (Hereford x Friesian) bull calves, 9 months old, were individually fed through two Callan-Broadbent doors, one for the concentrate ration and the other for chopped straw. Wood shavings were used for bedding. The two treatments, fed ad libitumfor 63 days were, barley/ rapeseed meal (B/RSM) and barley/ beans (B/E) and contained 153 ± 5.0 and 166 ± 8.4 g/kg DM CP and 12.6 ± 0.16 and 12.9 ± 0.17 MJ ME/ kg DM respectively.

Calves are often offered the same starter feed both before and after weaning. Starters which promote high rates of intake facilitate earlier weaning (thus reducing milk replacer usage) but can impair feed conversion efficiency (FCE) after weaning (Newbold et al., unpublished).

The objective of this experiment was to compare a combination of an optimal pre-weaning diet and an optimal post-weaning diet with a conventional starter fed both before and after weaning. 'Optimal' diets had previously been identified as superior to the conventional starter in terms of either feed intake (pre-weaning) or FCE (post-weaning).

Artificial rearing necessitates stressful cow-calf separation (Lefcourt and Elsasser, 1995; Hopster et al, 1995) and precipitates cross-suckling (Lidfors, 1993). Thus, suckling systems may improve the welfare of cows and calves, by alleviating 'stressful' cows-calf separation and satiating suckling motivation. The aim of this experiment was to compare behaviour in cows and calves in restricted suckling and non-suckling systems.

Thirty six multiparous dairy cows and calves were divided at 4 days postpartum into three groups. The treatment groups were; non-suckled (NS) cows with calves artificially reared (AR), cows suckled by their own calf (RSM) and cows suckled by a foster calf (RSF). Suckling took place for 15 minutes following mechanical milking only.

The export of live calves to be reared for veal in Continental Europe has raised animal welfare issues for calves transported over long distances for finishing in continental production systems which use veal-crates. Veal production systems which are designed to be welfare-friendly, and do not involve the live export of calves from the UK could help to resolve current consumer objections, and also stimulate an increase in domestic veal production and consumption.

To compare the performance and suitability for veal production of three breeds of heifer calves, when reared in the UK on a welfare-friendly veal system.