A substantial proportion of the protein needs of highly productive ruminants in the UK is met by imported protein sources notably soya bean meal (SBM). New determinate varieties of sweet lupin (DSL) (Lupinus albus) low in alkaloids offer the potential to be a useful source of protein as agronomic conditions favour their cultivation in temperate climates where other proteinaceous legumes fail. There are at present no data on the new determinate varieties developed and under agronomic test in the UK. The objective of the work was to determine the chemical composition and the rumen degradability of nitrogen (N) of two UK varieties of lupins and to determine the digestibility and energy value of one of these varieties.

The digestibility and metabolisable energy content of one new variety (CH304/70) of UK grown DSL was determined in a hay based diet using wether sheep (n = 5). The diets were offered in a 4 x 4 latin square design at foragexoncentrate ratios of 1.0, 0.9, 0.8 and 0.6 (dry matter (DM) basis) at near to the maintenance level of feeding.

The in vitro gas production technique aims to characterise feeds in terms of both the amount and rate of supply of fermentable carbohydrate. Models are used to interpret the data collected and typically assume that there is one pool of fermentable carbohydrate which is used at a fractional rate although it has been shown that inclusion of a modifying rate improves the fit of the model to the data (France et al., 1993). Since forage carbohydrate is not homogenous and can, at the simplest level, be divided into soluble (sugars) and insoluble (fibre) components, the aim of the experiment was to determine the influence of soluble material on the parameters obtained using this technique.

Gas production from glucose: 12.5, 25 and 50 mg; cellulose: 50, 100, 150 and 200 mg; glucose/cellulose mixtures: 10/190, 20/180, 30/170, 40/160 and 50/150 mg and Brachiaria decumbens (Brach.), Cynodon nlenfluensis (Star) and Pennisetum clandestinum (Kikuyu) grasses: 200 mg, was measured in prewarmed 100 ml glass syringes using standard techniques with four or six replicates per sample.

There is a need to be able to measure the methane producing potential of a range of feedstuffs under different rumen conditions in order to predict more accurately the amount of methane produced per animal. In vitro techniques using rumen fluid as an innoculum can be considered as models of in vivo rumen digestion and have been applied to estimate digestibility of feedstuffs. The in vitro gas production technique (Menke et. al., 1979) can be used successfully to estimate this but there has been limited attempts to use it to estimate the methane producing potential of feedstuffs. The objective was to assess the potential of the technique to do this.

Three pure substrates, glucose (G), pectin (P) and cellulose (C) (lg) were pre-wetted in 94ml of medium D (Theodorou et. al., 1994). inoculated with strained rumen fluid (from wether sheep. 10ml) and incubated without agitation for 72h at 39°C.

Low intensity systems of animal production on the hills and uplands of the UK involve mainly the production of meat and animal fibre from ruminant species. Beef cattle and sheep are the predominant species but diversification opportunities exist with species such as goats, red deer and pigs. The future role of diversification depends upon the extent to which EU and UK government support is restricted to beef cattle and sheep. An increasing proportion of beef cattle and sheep systems are found within Environmentally Sensitive Areas or are associated with environmental management schemes such that they require to have a multi-objective function, not only producing animal products but also providing environmental and social benefits. The extent to which environmental benefits can be provided by systems of animal production in die uplands of the UK is the subject of this paper.

The financial contribution made by Government to the agricultural industry results in the views of the general public on farming practices being of major importance. Environmental issues remain high upon the public agenda and have recently been re-emphasised by two Government publications “People Prosperity and Partnership” and Biodiversity: The UK Steering Group Report”. It remains important therefore that the design of any animal production system should take account of environmental effects and seek to achieve an acceptable balance between financial returns and environmental costs. The development of such a strategy requires information on: - the main environmental characteristics which are influenced by animal production - the extent to which environmental impact might be modified by change in fanning practice - the probable changes in farming systems over the foreseeable future which are likely to influence the environment. Assessments of these factors will require information at both detailed and systems level. These issues are discussed using information from a number of systems trials.

Pork has always been blamed to be too rich in (saturated) fat and consequently as being an unhealthy food. However, pork contains actually lesser fat, a considerable amount of cardiovasculary neutral monosaturated fatty acids and the level of polyunsaturated (possibly omega-3) fatty acids (PUFA) can be easily increased by the feed (Koch et al. 1968). The question raises what will happen with the (sensory) quality of pork rich in polyunsaturated fatty acids as these may induce poor consistency of backfat, yellow discolorations of the fat and off-flavours in meat (products) due to rancidity. Hence the objective of this study was to investigate the PUFA threshold for PUFA incorporations in pig tissue. According to Fischer et al. (1991) PUFA may vary from 15 to 21 g PUFA/kg feed, depending on the use of the pork (resp. cured and fresh meat). Houben and Krol (1983) and Wood (1983) recommend max. 15% PUFA in backfat.

The tissues of animals for food use have come to be associated with a predominance of saturated and monounsaturated fatty acids, the result of which has been to contribute to the perceived human dietary imbalance of fatty acids. The fact that porcine tissues assume a fatty acid composition similar to that of the respective diet has enabled the composition to be altered with respect to human dietary needs (Morgan et al, 1992). The fatty acid compositions of rapeseed and fish oils are characterised by a number of factors of relevance to human health recommendations (BNF, 1992). Thus, rapeseed oil contains a low content of saturates, a moderate content of linoleic acid and a high content of α-linolenic acid whilst fish oil contains high levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Although benefiting the nutritional value of meat/fat, the feeding of increased levels of highly polyunsaturated fatty acids has the potential, in theory at least, of adversely affecting organoleptic and various physical properties. Such adverse effects could be manifested during and/or after the preparation and cooking of the meat or meat products at which times the oxidative degradation of fatty acids is maximised. The inclusion of dietary vitamin E has a range of beneficial effects on meat quality principally due to its antioxidant effects. The present experiment was an attempt to optimise the fatty acid composition of pork and pork products for human health purposes whilst not adversely affecting factors controlling consumer acceptability.

The recent increase in slaughter weights and a wider range of genotypes in the UK might be increasing the risk of abnormal odours and flavours due to taints. This study investigated the role of skatole in the control of pigmeat odour characteristics and examined differences between genotypes based on the Large White - Landrace type or including some Meishan genes.

Twenty-four pigs were slaughtered at each of 100,110, 120 and 130 kg live weight comprising 6 entire male and 6 female progeny from Manor Hybrid (MH) or Manor Meishan (MM) gilts, both crossed with Large White boars. The animals were grouped together in a straw yard at 39 kg live weight and given a diet containing 13.8 MJDE and 11g lysine per kg.

Endogenous opioids are known to inhibit oxytocin release from the neurohypopysis (Bicknell et al, 1982). This mechanism has been suggested to be involved in the timing of parturition and delivery of young (Leng et al, 1985). Environmental disturbance in the rat (Leng et al, 1988) and pig (Lawrence et al, 1992) during parturition resulted in a naloxone reversible increase in birth interval, and an increase in plasma oxytocin concentration after naloxone treatment suggesting stress-induced opioid inhibition of oxytocin. Pain, which is associated with parturition, results in increased opioid activity and may be involved in the inhibition of oxytocin. Pregnancy-induced analgesia has been shown in the human (Whipple et al, 1990) and the rat (Gintzler, 1980), with the latter suggesting involvement of an opioid mechanism. This study aimed to determine whether an increase in pain threshold occurred over pregnancy and parturition in the pig and whether this was opioid-mediated.

Previous work has shown that an acute mid-partum can inhibit oxytocin secretion and prolong delivery in the pig, an effect that is opioid-mediated (Lawrence et al., 1992). However, where gilts were given 5 days to adapt to the farrowing crate, there was little indication that the crate interfered with oxytocin secretion or the progress of parturition relative to gilts farrowing in pens with straw bedding (Lawrence et al., 1995). This experiment aimed to directly assess the extent to which crates or pens affect opioid-control of oxytocin (OT) secretion as a means of measuring stress in the parturient gilt.

Maternal oestrogen and progesterone have been shown to be important in the initiation of maternal behaviour (e.g. Shipka and Ford, 1991). It has also been suggested by Csermely and Nicosia (1991) that there is an association between social rank and the performance of maternal behaviour. This study investigated the relationships between social behaviour during pregnancy, levels of sex steroids around parturition and the level of maternal care shown by gilts. Sows and gilts are generally housed in farrowing crates during parturition and lactation. This study also ascertained whether or not the farrowing environment affected sex steroid concentrations.

Previous work has suggested that gilts housed in a crated environment, without bedding, are more physiologically stressed over the pre-parturient period as characterised by elevated cortisol levels (Lawrence et al, 1994) compared to those housed in a straw bedded pen. β-endorphin and Adrenocorticotropic Hormone (ACTH) are released concomitantly from the adenohypophysis (Guillemin et al, 1977) and have been shown to increase during parturition in humans (Fajardo et al, 1994), with ACTH being involved in the stress response, and β-endorphin possibly playing a role in an endogenous defence against the pain of parturition. This study aimed to demonstrate the pre-parturient changes in these plasma hormonal concentrations and activity levels in relation to two different farrowing environments.

An acutely stressful stimulus such as relocation from a familiar strawed pen to an unfamiliar farrowing crate during birth has been shown to interrupt the birth process and inhibit oxytocin secretion (Lawrence et al, 1992). Both of these departures from normal parturition could be prevented by administration of the μ opioid antagonist naloxone. A likely site of action for this effect is presynaptic μ receptors on noradrenergic nerve terminals in the hypothalamus (Onaka et al, 1995). Such a neuro-endocrine control system, if active in the day prior to birth, might influence the timing of the onset of parturition and its subsequent efficiency even in the absence of a stressful stimulus. This experiment tested this hypothesis.

The need to continuously re-establish the social structure in dynamic groups of sows gives rise to higher levels of aggression compared to stable groups. Previous familiarity of animals could shorten the time it takes to reorganise the social structure, but relies on the animal's social memory.

Most suckled calf producers depend on various CAP premium schemes to achieve profitability. Some must continue to look at ways of improving the performance of our suckler herds. One area that has been neglected and under-researched is suckler cow type and breeds. The Holstein has had an influence on suckler cow conformation particularly when they are sired by Aberdeen Angus or Hereford bulls. Both these breeds go for size using poorly fleshed Canadian bloodlines.

There is debate on whether suckler producers should breed their own replacements. In fact many are doing just that, but how successful is it? Is reproductive and whole herd performance suffering? Many farmers will have 'gut' feelings but we really do not know the answers. This massive gap in our knowledge deserves serious research.

A feature of EU beef production following the introduction of milk quotas in 1984 has been the decrease in calf supplies from the dairy herd and increased supplies from the suckler herd. As a result, suckler cows have increased from 20% of the cow herd in 1984 to 32% in 1993. Corresponding increases for Ireland were 21 to 42% and for the UK 29% to 39%.

A major concern has been the decline in beef consumption in recent years (Food and Drink Information Service 1994). Although total meat consumption per capita in the EU 12 increased from 80.2 kg in 1987 to 82.6 kg in 1993 beef consumption declined from 17.0 to 15.1 kg over the same period. While price may have been a contributing factor to the decline, other factors are also involved. These factors can collectively be described as meat quality. Quality factors which are measurable include leaness, tenderness, flavour and colour.

The profitability of suckled calf production is closely linked to the number and value of calves weaned. Hence, herd fertility is a crucial measure of efficiency. For the commercial suckled calf producer fertility can be defined as the production of a viable, quality calf when required. While there are many factors influencing herd/individual conception rates, three of the most important are time, nutrition and calving difficulties.

Conception rates to first oestrus post-partum are low, particularly where post-partum anoestrus periods are short. This effect can be clearly seen in trials monitoring over 1500 suckler cows where fertility was depressed if the interval between calving and mating was less than 30 days, ie the calving period extended over 50 days. Where however the post-partum anoestrus period is extended the depression in conception rate to first oestrus is less marked.

Estimates of the metabolisable energy (ME) content of whole crop wheat (WCW) derived using measured energy losses as methane (ELMm) are lacking due to the cost of measuring ELMm. Published ME values of WCW are largely calculated using predicted energy losses as methane (ELMp, Blaxter and Clapperton, 1965) or digestible organic matter content (DOMD) in vivo. However, there appears to be no published information about the accuracy with which DOMD in vivo or ELMp predicts the ME content of WCW. Therefore, this study assessed the validity of such ME predictions by comparing them with ME contents calculated using ELMm.

Forage mixtures containing urea-treated whole crop wheat (WCW) have been shown to be used less efficiently than expected by dairy cows due to low digestibility, particularly of the starch. The purpose of the present experiment was to measure the contribution of the rumen to the digestibility of diets based on grass silage or mixtures of grass silage and urea-treated WCW.

Synchronising the availability of energy and nitrogen to the rumen microbes is considered to be important for enhancing output of microbial protein from the rumen. This is particularly relevant to diets based on grass silage (Chamberlain and Choung, 1995). In the rumen ammonia, is rapidly released from the substantial content of non-protein nitrogen compounds in grass silage and this requires a similarly rapid release of energy in the rumen to ensure efficient capture of ammonia. Different sources of carbohydrate may enhance rumen function to varying degrees. The aim of this study was to examine the effects of various carbohydrate sources on intake, rumen fermentation characteristics and digestibility in steers fed on grass silage.