Terminal Sire breeds have a considerable impact on lamb production in Britain’s stratified cross-breeding sheep industry. MLC (1988) estimated that 69% of lambs used for meat production are sired by the Terminal Sire breeds. The predominant Terminal Sire breed is the Suffolk, comprising 46% of the ram population in Britain. The genetic improvement of meat production characters has, traditionally, been difficult in this breed due to the large number of small flocks making up the breed, the restriction on AI use and the lack of a cost/effective central testing facility. However, the formation of the Suffolk Sire-Referencing Scheme Ltd (SSRS), in 1989, has provided a vehicle for faster genetic progress in the breed.

Whilst our previous work (Hou et al, 1991) has shown that sheep will make structured selections amongst pairs of feeds offered as a choice, we have not been able to relate these selections to the animals requirements as estimated by relative performance as single feeds. Also the nature of crude protein in diets offered as a choice has not been used as a variable.

The objective of the experiment was to develop the proposition that growing sheep, when given a choice between a suitable pair of foods, will select a diet that meets their protein requirements by using pairs of foods to be given as a choice and also offering each food singly to sheep, in order to quantify the effects of the foods on performance. In order to address an aspect of the extent to which sheep may make selections between diets to satisfy digestive (rumen) function rather than metabolic needs we have also included urea supplementation of an otherwise low CP diet amongst the foods offered as a choice.

The Scotch whisky industry produces 220,000 tonnes/annum of malt distillers wet grains or draff (D) used mainly as a component of cattle diets, its use in lamb finishing diets has not been widely investigated. Owing to the high level of unsaturated fat in draff there exists a possibility that unsaturated fatty acids may escape rumen biohydrogeneration and have effects on tissue fatty acid composition with important implications for human health.

The purpose of this experiment was to determine the optimum level of supplementary barley to feed with ad libitum draff by comparing diets based on ad lib mineralised draff (D), ad lib draff + 0.3 kg/day barley (DB1) and ad lib draff + 0.6 kg/day barley (DB2). The effect of replacing concentrates in a silage based diet with draff was examined by comparing a diet of ad lib silage + 0.6 kg/day compound (SC) with ad lib silage + 2.1 kg/day draff (0.57 kg dry matter) (SD).

Concentrates for pregnant ewes are often increased incrementally during the last 6-8 weeks to as much as 50% of dry matter intake. Commonly, they are given as a single daily feed. Increasing the number of meals in which a concentrate allowance is given to cattle minimises diurnal fluctuation in ruminal activity with beneficial effects on dry matter intake (DMI).

The current study was undertaken to determine if more frequent feeding of concentrates to ewes in late pregnancy affects levels of nutritionally-dependent serum IGF-1 and serum metabolites and to associate these with changes in ewe DMI and performance.

Litter size and body composition are two of the major factors affecting the efficiency of production systems under grazing conditions. The objective of this study was to evaluate breed and litter size effects on herbage intake by ewes and lambs using breeds of similar mature size but different carcass composition (viz. Suffolk and Texel; Texel leaner than Suffolk). A secondary objective was to evaluate associated effects on blood metabolites proposed as indicators of carcass composition (viz. urea, creatinine).

A divergent selection experiment in a terminal sire breed of sheep was started in 1985 to examine the differences between genetically lean and fat animals, which were derived from the same population. Responses in performance and physiological traits measured on the selection lines were reported at the BSAP 1991 Winter Meeting. Responses In slaughter and carcass traits, measured on crossbred progeny of the terminal sires, are presented in this study.

The ram selection index was -0.995 FATD + 0.206 WT20, where FATD and WT20 are the ultrasonic backfat depth and liveweight at 20 weeks of age, with both traits standardised to have zero mean and unit phenotyplc variance. A total of 32 and 34 rams from the high (lean) and low (fat) selection lines were performance tested in 1988, and 11 rams were selected from the high line and 12 rams from the low line for mating to crossbred ewes for the progeny test, with a selection differential of 0.85 Index units. There were 8 and 11 rams from the high and low lines with progeny slaughtered at fixed weight, such that the selection differential was 1.0 Index units. A total of 329 crossbred lambs were slaughtered at 16 weeks of age and 250 lambs were slaughtered at fixed weight, 39±1 kg for castrates and 37±1 kg for ewe lambs.

Pig production is responsible for 65 per cent of all odour complaints and 10 per cent of water pollution incidents. In addition, the disposal of pig slurry effluent may create major difficulties in nitrate sensitive areas either from run off or leaching of liquids. In situ composting of pig manure has the potential to eliminate these problems whilst encouraging pig producers to use welfare positive, bedded systems. In situ composting is a system of housing in which pigs are contained on a deep bed of sawdust. The bed is actively managed by aeration and the use of commercial additives to encourage composting of excreta as it is produced. The system appears to give an odour and liquid free environment. Such systems cannot be encouraged however until it is clearly established that there are no environmental or health disadvantages.

There is a considerable current interest in the feeding of high fibre diets to pregnant sows, with a view to gaining both economic and welfare advantages. The potential use of these diets will depend on the extent to which the fibrous materials are fermened in the hindgut, and the subsequent capacity of the products of the fermentation, that is VFAs, to meet the energy needs of the animal. Sugar beet pulp and wheat straw are two ingredients that have considerable potential as feed ingredients for sows. The present experiment was designed to study the extent to which diets containing high level of non-starch polysaccharides (NSP), largely from plain sugar beet pulp (SBP) or wheat straw (WS), influenced nutrient partition and the efficiency of ntrient utilisation in pregnant sows.

Greater demands have been Imposed by present-day management practices on the modern dam with gilts being bred at younger ages and lower levels of back fat. This has raised questions over whether current rearing feeding practices and low pregnancy feeding regimes may have adverse Influences on lifetime reproductive performance. The objectives of this experiment were to compare the reproductive performance of sows given different feeding regimes during rearing and pregnancy. Data previously reported from the experiment have shown that the weight and back fat depth of the gilt and sow can be manipulated by feeding regime over the first four parities (Simmins et al. 1989, 1991). Sows reared on the lower feed levels were more prolific 1n their first two Utters, but also had longer, farrowing Intervals (Edwards et al. 1989). These sows remained more prolific by weaning of the fourth Utter (Simmins et al. 1991). Performance over eight litters is described below.

There has been much interest in the possible use of the Duroc breed. Several reports have indicated improved meat quality traits and advantages for Duroc cross females in sow productivity (D. E. Steane, 1986). An evaluation of productivity, carcase and meat quality traits of Duroc crosses was carried out in the second trial at the Stotfold Pig Development Unit.

Vitamin E functions as an antioxidant in animal tissues. Deficiency has been associated with sudden deaths in suckling and growing pigs as well as impaired immune function and reduced fertility. Of the tocopherols and tocotrienols present in nature, only a-tocopherol (a-T) appears in appreciable amounts in pig blood and tissues. A previous trial (Monahan et al., 1990) had shown that feeding a diet containing a high level of a-tocopherol to sows from day 3 of lactation resulted in a significant increase in sow plasma, sow milk and piglet plasma a-T levels. The present trial was designed to study the effect of feeding high a-T from late pregnancy or from farrowing on milk a-T levels.

With the exception of the immediate family, many humans interact more with domesticated animals than they do with other humans. These interactions are often frequent and intense and consequently complex and strong social relationships can be formed between humans and domesticated animals. Results of recent research on the interactions between humans and farm animals indicate some surprising and substantial consequences for the animals and the objective of this paper is to review some of this recent research, particularly that concerned with the biological basis of the response of farm animals to humans. The results of recent research by my colleagues and I, particularly on commercial pigs, will be utilized heavily in this paper.

In intensive animal production the animal frequently has to respond to the presence of humans and to handling by humans. One of the main motivations of the animal which will determine the animal's response to humans is fear. Although there is debate concerning the concept and measurement of fear, we have adopted a functional approach in studying the behavioural responses of farm animals to humans.

The paper outlines the major problems in scientifically assessing the nature and quality of the man-animal interface and the difficulties in isolating its effects on animal production. Research epistemologies in this area are thwart with difficulties as it is virtually impossible to isolate individual factors. For example, while it is possible to devise ‘pleasant’ and ‘unpleasant’ handling treatments; as defined by level and nature of the physical interaction of the human body with that of the animal; it is not possible to separate physical handling from aspects such as voice tones, gestures, smell, sound of foot movements, or other ‘vibes’ transmitted in the experiment. Thus, any changes in ‘production’ may arise from a number of inter-woven components. It is also of relevance that the quality of the man-animal interface is a perceived construct and that the animal may perceive both applied ‘pleasant’ and ‘unpleasant’ stimuli as undesirable. Limitations of research paradigms are raised, for example, in experimental situations the environment may well be ‘richer', and with more humans present, than in commercial situations. The nature of the interface may thus be somewhat different.

A new age of mechanisation of animal agriculture is dawning following advances in robotic engineering, coupled with current knowledge of animal physiology, behaviour and disease. The advent of automated machines equipped with novel sensors and controlled by cheap microprocessors will eliminate many of the hazardous, tedious or unpleasant chores currently undertaken by farmers. Automatic attachment of teat cups to dairy cows, robotic sheep shearing and mechanical harvesting of broilers are now feasible and commercial exploitation is likely within a decade. Machines may tackle some tasks which are too difficult, dangerous or costly for man, who may be better employed elsewhere. Paradoxically, replacement of man by robotics designed according to animal needs may improve not only production efficiency but also welfare. Utilisation of robotics in animal agriculture requires research in sensing techniques, data interpretation, design of end effectors, machine control, and animal perception and response. Animal applications provide a particularly intriguing challenge to robotics engineers because animals are (relatively) fragile, and mobile. The dynamic interaction of animals with machines presents novel opportunities for animals to control their own environment as well as difficulties in machine design. Potential applications of robotics in animal husbandry are legion and include many husbandry tasks involving inspection, monitoring, handling, manipulation, treatment and caretaking.

It is well established that the subcutaneous administration of bovine somatotropin (bst) to dairy cows results in an increased level of milk production. This effect occurs irrespective of the method of application, the duration of the treatment or the time after calving after which it commences. However, the reported extent of this galactopoietic effect in the published literature has been highly variable, with one long term study reporting an increase of over 11.5 kg/day (Bauman et al. 1985), whilst other long term studies have reported relatively small increases or no significant increase at all (Hof et al. 1991, Morbeck et al. 1991). As yet it is unknown what factors control the milk yield response to bst, though there is a clear effect of dose of the hormone and possibly of energy and protein balance. There are also confusing reports on the effect of the previous milk yield and genetic potential of the animal on the observed increase.

Recently there has been increased interest in the effects of changing the milking frequency of dairy cows because of the possibilities of either increased milking frequency, through the use of robot-milkers or of once-daily milking as a part of a programme of extensification. Archer (1983), reviewing the literature and data from herds monitored by Farm Management Services, found milk yield responses on changing from twice- to thrice-daily milking from -0.14 to +0.49. These differences represent large between-animal differences in responses to thrice-daily milking and there is a need to identify sources of this variation.

Milk is stored in the udder in both the cistern and the secretory alveolar tissue itself. Since milk contains a protein which is inhibitory to secretion, storage within the secretory tissue is disadvantageous and reduces the efficiency of secretory tissue. Work at the Hannah Research Institute has shown that the effect of the inhibitor can be overcome by milking more frequently and that the response to thrice-daily milking of goats was greater with animals having smaller cisterns.

In a previous study at this Institute, significant increases in total dry matter intake were obtained with first lactation animals offered grass silage and concentrates as a complete diet rather than in separate feeds. However, the increased DM intake associated with complete diet feeding was not reflected in improved animal performance. Similar results have also been reported by Phipps, Bines, Fulford and Weller (1984) and Cassel, Merrill, Milligan and Guest (1984).

The aim of this experiment was to investigate the effect on animal performance of offering two types of concentrate in addition to grass silage, with concentrates offered either as a complete diet or in three feeds per day.

Studies reported by Mayne (1990) and Slater (1989) have shown that the yield of milk achieved by feeding a low level of a high protein concentrate with a good quality silage fed to appetite was comparable to that obtained by feeding higher levels of a conventional concentrate containing a normal level of protein (160-180g CP/kg). These results would indicate that there is considerable scope to reduce concentrate feeding levels and reduce feed costs when good quality grass silage is available. However, in previous studies at this centre (Murphy, 1987) very low levels (2.4 kg/d) of high protein concentrates (400-450 g CP/kg) fed with a good quality grass silage reduced milk production compared with a moderate level (6 kg/d) of a normal protein concentrate (160-180 g CP/kg).

The present study was carried out to clarify the position and to establish the benefit of including a source of undegradable protein, e.g. maize distillers grains or fishmcal in place of soyabcanmeal in the prolein concentrate.

Previous studies at this Institute have shown a marked interaction between level of supplementary feeding and protein content in the supplement with dairy cows offered high quality grass silage-based diets. For example, a given milk yield or yield of milk constituents can be obtained by offering supplements of high crude protein (CP) content, eg 340 g CP/kg fresh weight, at much lower levels than would be required with conventional supplements with a CP content of 180 g/kg fresh weight. The aim of the present study was to quantify if. the interrelationships established with high digestibility silages also applied with lower digestibility silage.

The experiment was carried out with 60 autumn-calving British Friesian dairy cows. Twenty eight animals were offered early cut silage (E), harvested between 17-19 May, with the remaining thirty two animals offered late cut silage (L) harvested between 2-12 June. Both E and L silages were produced from the same swards and in both cases grass was direct harvested and treated with an inoculant of Lactobacillus plantarum, at the rate of 3.0 litres/t fresh herbage.

There have been many recent reports of the successful production of large numbers of in vitro matured (IVM) and in vitro fertilised (IVF) cow ova. While a high proportion (80-90%) of oocytes undergo apparently normal maturation and fertilisation in vitro, only 15-20% develop in vitro to the morulae and blastocyst stages. Early cleavage stage in vivo matured and fertilised cow ova also encounter a developmental “block” at the 8-16-cell stage during in vitro culture in conventional culture media. However, this block has been readily overcome by co-culture involving the use of bovine oviducal cells, with up to 80% of 1-4-cell ova developing to morulae and blastocysts: The present study examined the development of IVM-IVF cattle ova removed at 24 or 48 hours from the insemination medium and cultured on cattle oviducal cells and also compared the development of IVM-IVF and in vivo produced ova in the same oviducal cell co-culture system.