Non-starch polysaccharides (NSP) in cereals which have been linked to antinutritional activity through elevated viscosity of intestinal contents, vary in concentration in different regions of the grain, but are particularly rich in the endosperm cell wall (Forrest & Wainwright 1977; Mulder, Hotten et al 1991). The current trial investigated the degree to which increasing inclusion levels of an exogenous β-glucanase with different barley fractions, from either a hulled or known high viscosity producing hulless variety, would influence the viscosity of broiler digesta and if, as in rye (Bedford & Classen 1991), reductions in carbohydrate molecular weight were obtained.

Milk fat conjugated linoleic acid (CLA) concentrations are higher for milk produced from cows grazing fresh pastures than for milk when conserved forages are fed (Jahreis et al., 1997). This experiment investigated the hypothesis that this increased CLA production results from the action of volatile compounds (hydroperoxides, alcohols, aldehydes and ketones) released during the cutting of grass (De Gouw et al., 1999).These compounds have antimicrobial activities (Kubo et al., 1995) and may have an effect on rumen microbial populations.

Nutritional approaches are the most important strategy for altering the fatty acid composition of muscle lipids (Scollan et al., 2006). Grass relative to concentrate feeding increases the content of n-3 polyunsaturated fatty acids (PUFA) resulting in a low n-6:n-3 PUFA ratio. Ruminally protected plant lipids enhance PUFA content very significantly resulting in beneficial P:S and n-6:n-3 ratios (Scollan et al., 2006). This study considered the effects of finishing steers (1) outdoors on grass ± concentrate versus (2) indoors on straw/concentrate ± a protected lipid supplement with one of two levels of vitamin E on the fatty acid composition of the m. longissimus thoracis et lumborum.

Anthropogenic lead is the most common cause of poisoning in ruminants. Vehicular lead emissions pollute herbage by the road, which may pose a risk to grazing ruminants. A series of experiments was conducted first to determine whether livestock could detect lead in herbage, and if so at what levels, and second whether they avoided lead contaminated herbage. The effects on grazing behaviour were recorded to investigate whether cattle could alter their grazing strategy to reduce their intake of lead from contaminated pasture.

It has been suggested that periparturient breakdown of immunity to parasites (BIP) has a nutritional basis (Coop and Kyriazakis, 1999). In support of this hypothesis, recent studies have shown that an increased supply of metabolizable protein (MP) reduces the magnitude of periparturient BIP in sheep (Houdijk et al., 2001). Improved MP supply to ewes, infected with gastrointestinal nematodes, has been associated with reduced nematode egg excretion and smaller worm burdens. These immunity indicators may differ in their sensitivity to changes in MP supply. This hypothesis has been addressed in the current doses-response experiment, which also allowed us to estimate the MP requirements of parasitized, lactating, twin-rearing ewes. The latter can be expected to be larger than those of non-parasitized ewes, due to MP requirements for mounting an immune response and for replenishing protein losses.

Livestock are one of the largest single sources of methane emission, equivalent to 15-20 % of total anthropogenic methane. Selective suppression of the rumen protozoa has been suggested to be promising approach to reduce methane release (Moss et al., 2000) as up to 25 % of the methanogens in the rumen are associated with protozoa (Newbold et al., 1995). However, contradictory results have been reported between in vitro and in vivo data and short and long term defaunation experiments (Ranilla et al., 2003). This study was carried out to investigate the effect of the absence of protozoa in the rumen on enteric methane production by lambs.

One of the major limiting factors in practical exploitation of embryo transfer is the lack of a predictable and reliable supply of embryos on a regular basis. Superovulation requires the stimulation of significantly increased numbers of pre-ovulatory follicles by the administration of gonadotrophins mimicking the effect of follicle stimulating hormone (FSH). Ewes can be effectively superovulated using gonadotrophins given towards the end of a 12 to 14-day progestagen treatment, initiated without reference to the stage of the oestrous cycle (Boland et al., 1983). However, as in cattle (Goulding et al., 1991) there is a large variation in the follicular and ovulatory response in sheep. Although crude horse pituitary extracts will induce superovulation effectively in sheep, the lack of availability means that they are rarely used. The LH content in commercial FSH preparations has been indicated as contributing to some of the variation in the yield of transferable embryos in cattle following superovulation (Murphy et al., 1984). Recent preliminary data from this laboratory indicates that pFSH with a high LH:FSH ratio will induce superovulation in cattle and sheep. However, pFSH is normally given in multiple injections over 3 to 4 days which makes administration difficult. Therefore, an experiment was designed to assess the efficacy of a pFSH preparation with a high LH:FSH ratio to induce superovulation in sheep when given in either 4 or 6 injections. A second experiment compared the use of an ovine and porcine FSH preparation during superovulation in ewes.

Intensively reared early weaned lambs are conventionally fed a high energy concentrate diet in order to maximise daily gain and feed conversion efficiency. This reduces both the time required to reach slaughter weight and the overhead costs. However, it is estimated that feed costs in intensive lamb systems amount to 0.24 of the total output value (MLC 1998) and that the profitability is sensitive to relatively small changes in the lamb price to feed cost ratio. The objective of the work was to investigate the effects of various alternative feeds consisting of molassed sugar beet feed (MSBF), distillers products and the whole barley or grainbeet (200 g/kg MSBF and 700 g/kg brewers grain) on the performance and profitability of intensively reared lambs.

Whole–plant maize silage dorms the basis of winter rations for the vast majority of dairy and beef cattle production in Uruguay. Microbiological examination of silage is of little value in gauging the outcome of silage, and so chemical analysis is more reliable and meaningful indicator of quality. Chemical assessments of the principal fermentation products provide an unequivocal basis on which to judge quality. Silage fermentation and chemical composition are important to preservation of forage with respect of feeding value and animal performance. Many of the important chemical components of silage must be assayed in fresh (wet presentation) or by extraction of the fresh material, since drying either by heat or lyophilisation, volatilises components such as acids or nitrogenous components, or effects conversion to other compounds (fibre and carbohydrates) (Abrams et al., 1987). Chemical and biological methods for assess maize silage quality are laborious and considered to slow to be used for routine analysis of large number of forage samples. Near infrared reflectance spectroscopy (NIRS) is increasingly used as a rapid, accurate method of evaluating chemical constituents in cereals and dried forages. The objective of this study was to determine the potential of NIRS to assess the chemical composition of dried maize silage samples for advisory purposes.

San Pietro and Rittenberg (1953) reported that urea appeared to meet all the requirements of a satisfactory tracer. Urea is non toxic, not foreign to the body and it shows an even and rapid distribution throughout the total body water without any physiological effect. For these reasons in addition to its easy and accurate measurement, urea is an ideal candidate tracer to estimate empty body water in vivo. Total body water volume (urea space) can be estimated by dividing the total amount of urea infused by the increase in plasma urea concentration from prior to infusion until 12 or 30 minutes after mean infusion time. Kock and Preston (1973) reported significant relationships between urea space measurements and percentage of empty body fat and water in cattle. However, Andrew et al. (1995) using 21 Holstein cows showed that prediction of empty body water using the urea space technique only explained 31 % of the variation. The objective of this experiment was to use the urea dilution technique to estimate the body composition of lactating dairy cows and produce relationships between urea space and body fat and protein content.

Assessment of the quality characteristics of meat is time consuming and, due to the heterogeneity of muscle tissue, is subject to considerable variability. A cheap, fast, accurate and non-destructive method of assessment of meat with the potential to predict subsequent quality, would be useful to the meat industry. Near infra red spectroscopy (NIRS) offers this potential for rapid quality assessment and has been shown to be a valuble tool in the evaluation of a variety of meats (Cozzolino et al 1996)

Twenty beef bulls were selected from a commercial herd. Ten bulls (group US) were fed a standard barley-based ration consisting of (g kg–1 DM) barley, 900; GFS Beef 34 protein pellets, 100. Ten bulls (group S) were fed an identical ration supplemented with α-tocopherol acetate (ATA). The average daily intake of these diets was 10 kg DM head-1 d-1 over 100 days prior to slaughter.

Insulin-like growth factor-1 has been positively associated components of growth in pigs, such as protein deposition. Therefore, serum insulin-like growth factor-1 concentration (IGF-1) was measured in lines of pigs divergently selected for daily food intake (DFI) or for efficient lean growth rate (LGS) to determine if there was a non-zero genetic association between IGF-1 and the selection criteria. If a genetic association did exist, then IGF-1 could be used as a physiological predictor of genetic merit in a breeding programme. The presence of a major gene effect on IGF-1 was also examined in the study.

Paratuberculosis (Johne’s disease) is a chronic invariably fatal enteritis of cattle caused by the bacterium Mycobacterium avium subspecies paratuberculosis and has recently been isolated from wild rabbits. One potential route of transmission of M.a.paratuberculosis from rabbits to cattle is the ingestion of rabbit excreta contaminating pasture. Here we (1) determine the prevalence and level of infection in rabbits and their excreta (2) quantify the level of rabbit faeces contaminating cattle pastures and (3) determine the impact of rabbit faeces on cattle grazing behaviour.

Automatic technologies based on video image analysis (VIA) to assess lamb carcass value offer an accurate measure of weight of individual carcass components (Rius-Vilarrasa et al., 2008). In addition, VIA systems offer the possibility to record linear and area traits (dimensional measurements) on the carcass. Linear measurements on the body and carcass have been suggested by several authors as good indicators of live weight, conformation score and production traits in beef and sheep (Maiwashe et al., 2002; Janssens et al., 2004). Therefore, the aims of this study were (1) to estimate genetic parameters for VIA dimensional measurements (VIA-DM) and (2) to investigate the associations between VIA-DM with carcass conformation and fatness.

Mice lacking a functional leptin gene (ob/ob) are obese and sterile. Treatment with exogenous leptin will restore fertility and allow full-term pregnancy, but when leptin is withdrawn at parturition the young die, apparently as a result of total lactation failure (Chehab et al., 1996). From this one could hypothesise that leptin is an essential requirement for mammary development and/or initiation of milk secretion. Since a few of the mice used in this work were subsequently able to rear pups following a second pregnancy and parturition, we decided to re-examine this hypothesis.

Consumer purchasing decisions are, to a large part, governed by the level and consistency of meat quality and there is a need to identify systems of production that deliver consistent lamb eating quality through the winter months that will restore retailer confidence in British lamb outside the main grazing season.. The Vipond et al. (2005) report on lamb eating quality highlighted the deterioration in lamb flavour post-Christmas and recommended that dietary effects be investigated with a specifically designed experiment.

With a growing interest in less-intensive housing systems, pig breeding companies have developed genotypes which are supposedly better suited to these conditions. The aim of this experiment was to compare the performance of progeny from sows of 2 types:

1. a) ‘indoor’ - Large White x Landrace

2. b) ‘outdoor’ - 25% Meishan or 25% Duroc with 50%Large White and 25% Landrace

All sows were mated to a Large White boar and the progeny housed in one of three finishing systems - outdoor paddocks, straw yards or fully slatted pens. The systems were typical of commercial practice, with an automatically controlled natural ventilation system and 0.6 m2 of floor space per pig in fully-slatted pens. Outdoor paddocks and straw yards had minimal environmental control and space allowances of 20.0 m2 and 1.6 m2 per pig respectively. Pigs in outdoor paddocks were retained on cereal stubble with electric fencing and had free access to a bedded shelter hut.

The extent to which young sows, which still have a strong drive to continue maternal growth, partition nutrients from body reserves towards milk production, may be influenced by their genetic growth target. Modern genotype sows, with a high mature body protein mass, are thus particularly challenged. It has been suggested that to optimise their metabolic state for expressing lactational potential they will have to achieve a satisfactory proportion of their mature body protein mass before farrowing. This could be constrained by current feeding and breeding regimes. To test this hypothesis, gilts of genotypes differing in their body protein:lipid content were given the choice between a low and a high protein diet during rearing and pregnancy, and their intake, subsequent performance and metabolic state in lactation were measured.

The objective of this study, which formed part of a larger project, was to investigate the effect of feeding high levels of urea on the reproductive function of the lactating dairy cow. Increasing dietary protein intake can increase milk production, but may reduce reproductive performance (Laven and Drew 1999). McEvoy et al (1997), based on work which fed urea to sheep, suggested that this effect on fertility may be caused by ammonia. However, there is little information on the effect of feeding quickly degradable nitrogen (QDN) on the concentration of plasma ammonia in the dairy cow and the accurate measurement of plasma ammonia is difficult. The measurement of a more stable metabolite, such as urea, may be more useful, if it can be shown to be correlated with plasma ammonia.

Previous work with fermented whole crop wheat (WCW) silage has focussed on the effects of stage of maturity on nutritive value and milk production (Sinclair and Wilkinson 1998). An alternative means of manipulating nutritive value may be to alter the relative proportions of grain to straw by changing the cutting height at harvest. The objectives of the current experiment were to determine the effects of two cutting heights on the aerobic stability and whole tract digestibility of fermented WCW silage offered to sheep.

Winter wheat (variety Hunter) was grown as a conventional crop and harvested at a dry matter (DM) content of 450 g/kg and a Zadock growth stage of approximately 85 (soft dough). The crop was cut to leave a stubble length of either 17.9 cm (long straw, LS) or 38.2 cm (short straw, SS) prior to ensiling in separate ag-bags.