Vitamin E is an important nutrient for lambs and low levels in tissues as a result of either low intake, poor absorption or excessive utilisation results in myopathy (pale muscle). The causes of deficiency are incompletely understood, especially as it can occur when lambs are consuming good quality grass containing high levels of vitamin E. We now report an occurrence of low tissue levels of vitamin E in lambs of two breeds raised on complete dry pelleted rations and its effect on meat quality and fatty acid composition.

96 male lambs, half Suffolk x Lleyn and half Scottish Blackface, with average live weights of 24 kg and 18kg respectively were individually penned and randomly allocated to one of 6 isoenergetic isonitrogenous diets based on dried grass, molassed sugar beet pulp, soya bean meal and molasses and containing two levels of vitamin E, 100 (low) and 500 (high) g/kg DM.

With the proposed ban on antibiotic growth promoters it is becoming increasingly important to provide diets to young pigs which enhance the long term health. Alternative strategies to promote health include organic acids, herbal products and natural antioxidants. These products have various proposed modes of action including improved liver function, removal of reactive oxygen species and the enhancement of the immune function. The objective of this experiment was to measure the effect of a commercial herbal mixture and Lycopene on the performance and immune function of weaned pigs.

Soyabean meal (SBM) is used extensively in poultry rations. As the cultivation of soya bean is limited in Iran, annually a large amounts of SBM is imported. In recent years cultivation of some oil seed such as sunflower seed (Heliantus annus) is undertaken in some provinces of Iran. This plant will grow in cooler and dried climates than the soya bean or cotton plants. It contains 45 percent oil and a good source of protein and B-group vitamins. Due to high fibre content and low lysine content, use of sunflower meal (SSM) is limited in poultry feeds, but dehulled SSM is suitable for broiler feeds (Church, 1988 and Scott et al., 1982). The objective of the present study was to investigate the effect of SSM on performance of broiler chicken.

Nematode parasite infections are now being recognised as possibly the greatest disease problem of grazing livestock industries, worldwide. Often parasites were considered to be of greatest concern in countries of the tropics and subtropics. This is based on the perception that parasites are either not as pathogenic, or are better controlled, in grazing livestock industries in the temperate regions of the world. Unfortunately this is not the case. The hidden costs of nematode parasite infection, particularly in young ruminants, are substantial even in Europe. This is now especially so, when one considers that maintaining livestock for longer periods on pasture is becoming and economic, environmental and animal welfare necessity.

Supplementation with legume fodder during the dry season is a strategy to improve animal performance. The results obtained in silvopastoral systems has been explained either by their ingestion of a higher quality grass (Hernandez et al., 2001, Iglesias, 1998) resulting from the inclusion of a legume in the system which provide N for grass growth or due to the intake of the legume itself, which in turn is also of higher quality than grass (Kakengi et al., 2001), and provides a higher microbial-N supply (Karda and Dryden, 2001). The objective of the present work was to discriminate, in a silvopastoral system, the effect of improved grass quality and legume intake (L. leucocephala) on rumen fermentation, microbial N supply, milk yield and composition of dual purpose lactating cows.

In one in vitro study Ashes et al. (1992) reported that C20 and C22 fatty acids (FA) from fish oil were not hydrogenated to any significant extent by rumen microorganisms. However, to our knowledge, no measurement on hydrogenation has been performed on fishmeal (FM) FA. The aim of this experiment was to study the in vivo and in situ rumen hydrogenation of long-chain FA of two different FM: FMl (60 g FA/g DM) and FM2 (85 g FA/g DM).

Six sheep fitted with rumen cannulae and single duodenal cannulae were fed every 2 hours, receiving 1 kg/d of a 60:40 hay:concentrate diet, either alone (Control; C) or supplemented with 40 g FM/d (FMl and FM2). The experiment was carried out over four periods (two sheep received one of the diets in each period) and Cr-NDF was used as a marker to estimate duodenal flow. Data were subjected to analysis of variance using the ANOVA procedure of the Statistical Analysis Systems (SAS, 1994).

Knowledge of the nutrition of free-ranging herbivores and the impact on their environment is often limited by lack of information concerning the botanical composition of their diets. For herbivores grazing heterogeneous vegetation environments, current methods for estimating the botanical composition of their diets are limited in their scope and accuracy. The purpose of this study was to establish whether urinary metabolites, occurring as a result of ingestion of different individual plant species, have the potential to be used as markers to estimate diet composition.

Recently, in Iran, increasing surplus of whey, a by-product of cheese producing plants are becoming an environmental problem and this is due to dairy development programs. Whey dumped into the plant disposal systems insert a high pollution load to the environment. Whey is a valuable source of carbohydrates, a good supply of energy and contains high quality protein and minerals. Options such as condensation and/ or fractionation also dehydration are too costly, and requires high technology. Finding an alternative method for preserving and using of whey could reduce the environmental risks, cost and associated difficulties. The use of liquid whey has been used for many years as a supplemental feed for ruminants. Like molasses, liquid whey can be a carrier of non-protein nitrogen components such as urea or ammonium salts to make crude protein supplements (Khattab et al. 2000). Therefore, the objective of the present study was to find a simple method to preserve and improve the utilisation of fresh whey in animal nutrition as well as a desirable way to reduce environmental pollution.

Assessing the availability of a feed in the rumen is an important element of its characterisation. In the Metabolisable Protein system, it is assumed that all starch is available in the rumen, although clearly this is not the case. However, estimating the amount of starch that is apparently fermented in the rumen is difficult, expensive and cannot be routinely undertaken. The objective of this experiment was to determine whether the in vitro gas production technique could be used as a means of predicting the amount of starch that apparently disappears in the rumen (STA ADR).

Four Holstein cows, each fitted with a rumen and duodenal cannula, were used. They were fed one of four diets in a 4x4 latin square design. The diets consisted of grass silage (GS), molassed sugarbeet feed (MSBF), fishmeal (FM) and minerals (MIN). They were also supplemented with either wheat (WHT) or maize (MZE).

Fat is often fed to lactating dairy cows to provide supplemental metabolizable energy and increase milk yield. Commercial fat sources are typically processed to render them more inert in the rumen, but whole oil seeds also represent an effective fat source for lactation rations. In a previous study (Reynolds et al., 1998), we fed lactating dairy cows a commercial rumen-inert fat, cotton seed or crushed rapeseed at 25 g added fat/kg ration DM in a grass silage-based total mixed ration (TMR). All 3 fat supplements increased milk yield to a similar extent, whilst the commercial fat source, but not the whole oil seeds, reduced milk protein concentration. As a UK grown source of supplemental fat and protein, crushed rapeseed offers an attractive alternative to commercial fat supplements for dairy rations. Therefore, our objective was to determine the incremental effects of supplemental ground rapeseed on intake and milk production response of dairy cows fed rations containing maize silage.

Straw based production systems are common in the UK compared to European, Asian and American competitors. The effects of mycotoxins in cereal feed on livestock performance are relatively well documented with pigs being particularly sensitive to mycotoxicosis. The European Commission has recently set guideline limits for fusarium mycotoxins in animal feedstuffs (Anon, 2006). Guidance limits for feedstuffs for young pigs is 900 ppb deoxynivalenol and 100 ppb zearalenone. However, any possible effects of ingestion of fusarium mycotoxins from bedding have not been enumerated. This project was designed to evaluate the potential risk of mycotoxin challenge from straw bedding in the UK.

The reaction of thermal oxidation products of phospholipid fatty acids with other meat components is an important source of cooked meat flavour and odour (Mottram and Edwards, 1983) and preferences for meat from forage or concentrate finished beef have been attributed to differences in the feed fatty acids (Melton, 1990). Therefore modifying lipids to meet human dietary recommendations to raise the P:S and n-3:n-6 ratios of dietary polyunsaturated fatty acids (PUFA) is likely to affect meat quality. We have investigated the effect on eating quality, flavour volatiles and phospholipid fatty acid composition of feeding steers linseed, which is high in α-linolenic acid (18:3 n-3), and fish oil containing EPA (20:5 n-3) and DHA (22:6 n-3).

Good quality maize silage with a high starch content and DM digestibility when fed to dairy cows increased forage intake, milk production and milk protein concentration compared with grass silage or low starch maize silage (Fitzgerald, 1997). Due to the low crude protein (CP) content of maize silage compared with grass silage, additional protein supplementation is required in the concentrate. The optimum level of protein in the concentrate for maize silage based forages differing in starch content was investigated in this study.

Three forages consisting of either all grass silage (GS) or mixed forages of grass silage and maize silage (40:60 DM mix) which contained either a low (LSM) or a high (HSM) starch content were offered ad libitum to individually fed dairy cows in early lactation (12 cows/forage). Each forage was supplemented with concentrates (6 kg/day) containing 180, 230 or 280 g CP/kg according to a change over design (3 periods of 3 weeks/period).

Bioactive forages such as chicory (Cichorium intybus) or tanniferous legume sulla (Hedysarum coronarium), have been reported to lower the parasite intensities or faecal egg counts (FEC) of parasitised ruminants (Waller and Thamsborg, 2004). To our knowledge, there is no report studying the effects of these forages on established worm populations when grazed in combination. This knowledge could guide us towards optimum grazing management using special forage species as de-worming paddocks. The aim of the present study was to use the bioactive forages alone or in combination for a short period to test their effects on established T. circumcincta adult population in sheep. The tested bioactive forages were chicory and sulla, with grass/clover (Lolium perenne/Trifolium repens) providing the control forage.

The periparturient relaxation (PPR) in acquired immunity in ewes has been ascribed to various factors, including poor nutrition (Barger, 1993). Clinically, the faecal egg count (FEC) may increase during PPR when the ewe is continuously infected with gastrointestinal parasites. As such, the periparturient ewe plays an important role in the epidemiology of parasitic infections. The nutritional basis of PPR probably includes metabolizable protein (MP), since host's responses, in terms of immunity and resilience, are highly proteinaceous by nature. We propose that the PPR directly results from less MP being available to maintain acquired immunity and resilience, since an increasing amount of MP is directed to bodily functions with higher priority (reproduction). It is hypothesized that the increased FEC in the parasitized periparturient ewe reduces if her MP-intake exceeds her assumed MP-requirement (AFRC, 1993).

Embryo mortality is a major cause of reproductive loss in all the farm species (Bolet, 1986). Losses of a total litter by embryo mortality account for about 15% of all services but may be substantially higher in the summer months, particularly in outdoor systems (Love et al., 1993). There has been interest in the use of gonadotrophin releasing hormone (GnRH) in cows and sheep, both on the day of service and 12 days after, to improve pregnancy rates (see review by Peters 1996) with 10 -12% improvements being reported. The mechanisms of maternal recognition of pregnancy are different between pigs and ruminants, however, a pilot study was carried out to determine whether GnRH might have similar effects in the pig.

The aquaporins (AQPs) are a family of small integral membrane proteins 28-35kDa in size, sub classified into 2 groups; those selectively permeated by water (the aquaporins; AQP0, AQP1, AQP2, AQP4, AQP5, AQP6 and AQP8) or by water and small organic osmolytes such as glycerol and urea (the aquaglyceroporins; AQP3, AQP7, AQP9 and AQP10). AQPs are expressed in a variety of epithelial tissues where they are responsible for rapid water movement driven by osmotic gradients. The mammary gland produces and secretes milk which consists of water, lipids, electrolytes, vitamins, sugars and specific milk proteins. However, little is known about AQP expression, distribution and function in mammary tissue or about the process of water transport across the mammary epithelium. The only information available relates to the identification of AQP1 and AQP3 in capillary endothelia and epithelial cells of mouse mammary glands respectively (Matsuzaki et al., 2005). Since water delivery to the mammary gland is critical for milk production, which is of major economic importance to the dairy industry, it is necessary to understand the underlying physiology involved. The aim of this study was to determine the expression and distribution of AQPs within the bovine mammary gland.

The high yields obtained in agriculture rely heavily on the use of domesticated and genetically improved breeds and varieties. Until quite recently this has not been the case for most farmed aquaculture species that, in the genetic sense, are still much closer to the wild state than are the major terrestrial animals and food crops. Less than 10 % of the total world aquaculture production is based on improved strains. Due to a growing human population and a decline in production from capture fisheries, there is therefore a great disparity between the need for increased aquaculture production and the genetic quality of the strains available to meet that need. Moreover, full benefits of investments in management improvements (feed and feeding practices, control of diseases, etc.) can only be obtained through the use of genetically improved animals.

Genetic selection has greatly improved individual cow productivity. A high genetic merit Holstein Friesian cow will produce 10,000 of litres of milk in a 305 day lactation, those of lower genetic merit half this amount. Despite major research effort in generating these differences, quantitative biological description of what has been achieved is lacking. The aim of this study was to compare biological variables of relevance to milk synthesis in well defined high genetic merit and lower genetic merit dairy cows.

12 cows of high genetic merit (HGM: top 5% of UK national herd) and 12 of lower genetic merit (LGM: close to UK average) were purchased from the Blythbank and Langhill herds; the ontogeny of these selection lines has been described elsewhere (Woolliams et al, 1993). Mean parity was 3.7±0.3 and was balanced between HGM and LGM. Management of the two groups was identical. Measurements were made over a period of two weeks close to peak lactation. Milk yield was recorded at each milking. Plasma samples were collected and analysed for a variety of hormones by radioimmunoassay and metabolites by established spectrophotometric assays. Udder size was determined by a casting technique (Dewhurst et al., 1993) and mammary biopsies for key enzyme activities were obtained as described by Knight et. al. (1992). Differences between lines were analysed by analysis of variance (ANOVA).

This review surveys the nutritional and veterinary effects of tannins on ruminants and provides comparisons with non-ruminants. Tannins are a diverse group of naturally occurring compounds with useful biological effects. However, currently there are difficulties in predicting which tannins produce what effects.