Previous work (McIntyre and Edwards, 2001) revealed a significant correlation between plasma tryptophan (TRP) concentration and blood preference scores when pigs were fed a low CP diet. Increasing dietary TRP in rats causes increases in plasma and brain TRP, and brain serotonin concentration (Fernstrom and Wurtman, 1971), which appear to be highly localised to serotonin-containing neurones that may monitor the metabolic state and control behaviour. Uptake of TRP at the blood-brain barrier and serotonin level may also be increased by a higher TRP: LNAA (large neutral amino acids) ratio and level of dietary carbohydrate. This study aimed to determine if pigs fed diets differing in TRP and TRP: LNAA ratios differed in their behaviour or in their preference for blood during a model tail test.

Genetic selection has dramatically increased the potential for growth, feed efficiency and yield in meat type broilers. It is a widely held belief that these improvements in genetic potential have produced a broiler that is lower in fat content. However, some recent work has implied that the Modern broiler is actually fatter than its counterpart of 30 years ago (Wang et al., 2004). The objective of this study was to explore the impact that selection for growth rate and yield has had on broiler body composition.

In ruminants plasma leptin is increased with increasing body fatness. Leptin acts on hypothalamus to decrease food intake and increase energy expenditure. It is possible that leptin has a key role in transition from pregnancy to lactation of dairy cows. The objective of the present work was to investigate the pattern of plasma leptin concentration, as well as its relationship with other hormones and metabolites and dairy cow performance.

During the last decade, many of the developed countries have seen a rapid move toward explicit farm animal welfare standards. Three historical developments during the last half century have contributed to this move: (1) the emergence of intensive animal production systems developed on the principle of maximizing production efficiency, (2) the perception (sometimes justified, sometimes not) that animal production is becoming an industrial, technological activity substantially controlled by corporate owners, and (3) a rapid increase in humanitarian attitudes toward animals.

Ultrasound imaging has proved a very useful tool for the modern animal breeder wishing to improve carcass composition. However, more accurate imaging technologies, such as X-ray Computer Tomography (CT), could accelerate genetic improvement of carcass composition, and widen the range of traits assessed (e.g. by considering deeper tissues). Carcass quality is assuming more importance for breeders but quality traits are difficult to assess objectively and accurately in live sheep. The present study was designed to identify a few CT scan positions from which accurate prediction of dissected tissue weights could be made in meat sheep.

One hundred Suffolk lambs (50 of each sex) were CT scanned and slaughtered at 14, 18, 22 or 26 weeks of age (59±16kg LW, range 20-96kg). Each animal was scanned at seven sites; three in the gigot (ISC, caudal ischium; FEM, mid-shaft of femur; HIP, hip joint), two in the loin (LV5 and LV2, 5th and 2nd lumbar vertebrae) and two in the chest/ shoulder (TV8 and TV6, 8th and 6th thoracic vertebrae).

Pistachio (pistachio vera) is from Anacardiaceae family. According to the FAO (2003) report, Iran is the largest pistachio producer in the world (more than 310,000 tons). The most three important exported pistachio nuts of Iran are Ohadi, Akbari and Kaleghuchi (Mohammadi, 2005). About 150,000 tons in DM of pistachio by-product (PB) is produced from dehulling process in Iran, annually. This by-product is mainly consisted of pistachio hulls (PH), and then peduncles, leaves and a little amount of mesocarp and kernels. In this experiment the chemical composition, Total Phenolic Content (TPC) and tannin amount of PB and PH of Ohadi, Kaleghuchi and white varieties were determined; also, In Vitro Dry Matter and Organic Matter Digestibility (IVDMD and IVOMD) were measured.

In the ewe maternal care begins at parturition with grooming of the neonate and cooperation with early sucking attempts (e.g. Shillito-Walser 1978). Subsequently maternal care is expressed through sucking interactions, a close ewe-lamb association and a tendency to seek absent lambs (e.g. Hinch et al 1987). The ewe increasingly controls sucking interactions using a ‘head-up’ posture to signal when the lamb may approach and suck (Lawrence 1984).

Two breeds of sheep, Suffolk and Scottish Blackface, are known to differ in their initial maternal behaviour. Blackface ewes spend longer grooming their lambs, show more cooperation with sucking attempts and less negative behaviour such as aggression and rejection, when compared to Suffolk ewes (Dwyer & Lawrence 1998). The aim of this study was to examine whether these breed differences in the expression of maternal care persist throughout the lactation period.

At a time of high public awareness of food safety issues, particularly with respect to transmissable encephalopathies, and a government policy to eradicate scrapie, there is increasing pressure for breeders to select for scrapie resistance in sheep. Genetic variation has been identified at the PrP locus that confers differing degrees of susceptibility to scrapie. In the Suffolk breed this variation is confined to amino acid variations at codon 171, resulting in two alleles R and Q. Animals with the genotype RR and RQ show a greater degree of resistance to scrapie than animals with genotype QQ (Hunter, Moore, Hosie, Dingwall and Greig, 1997).

Genotyping of pedigree animals has now become routine for many breeders and RR animals are favoured. It is, however, unknown whether there is a relationship between PrP genotype and performance traits. The objective of this study was to analyse the relationship between PrP genotype at codon 171 and the performance traits included in the Lean Index (Simm and Dingwall, 1989), which is used for selection in the Suffolk breed.

Identification of genetically unique populations is a key aim in the study of livestock breed diversity (Hall and Bradley, 1995). In this study random sampling techniques were used to test the significance of genetic distances between European cattle breeds, and to analyse the stability of breed relationships.

Under Northern Ireland conditions, until recently, it was difficult to achieve high starch maize (greater than 200 g/kg DM) more often than one year in fifteen. However, recent developments in maize breeding and in agronomic practices, particularly the development of degradable full cover plastic mulch, have resulted in the possibility of consistently producing high starch maize. As there is considerable variability in the quality of grass silage produced on Northern Ireland dairy farms, the objective of the present study was to examine the effects of maturity of maize silage at harvest on the performance of lactating dairy cattle offered two contrasting feed value grass silages. The potential concentrate sparing effect of contrasting maize silages was also examined.

The mixing of unfamiliar sows usually results in fighting which determines relative social rank. In some situations aggression can be perpetuated and subordinate animals can suffer as a result of competition for resources such as feed and space. Although Moore et al (1993) suggested that newly introduced group members become fully integrated after 21 days there have been few studies which have examined the development of social interactions over the longer term. The aim of the experiment was to determine how social behaviour changed over time and the affects that this may have on the welfare of group-housed sows.

Breeding goals differ for different breeds of dairy cattle. For example the breeding programmes for Holstein-Friesian (HF) animals have been based primarily on improved milk production with little emphasis on functional traits such as fertility. In contrast, Norwegian (NC) dairy cattle have been bred using a multi-trait selection procedure for 25 years. These differences in selection procedures for the two breeds may have major effects on overall herd output and profitability with the forage-based systems of milk production employed in Northern Ireland. The objective of the present paper is to present the effects of two levels of nutrient input on food intake and utilisation, and animal performance of the two breeds, with diets based on grass silage during the first and second lactation.

The mixing of unfamiliar sows at weaning leads to aggression whilst dominance hierarchies within the group are established (Kay et al, 1999). The objective of this study was to determine whether the presence of a boar would reduce the incidence of aggression and level of skin damage of newly mixed sows. The overall aim of the project was to improve welfare by designing a suitable strategy for mixing groups of newly-weaned sows

As more farmers try to improve the efficiency of their production systems by sourcing safer and cheaper dietary energy and protein from home grown feeds, the importance of cereal-legume bi-crops for winter-feeding of UK livestock may increase. However, little is known about the production, conservation, feeding value and animal performance from such bi-crops in the UK. This study measured the feed intake and milk production from dairy cows fed pea-wheat bi-crop silages.

Legumes, such as red and white clover, are potentially important constituents of low input, environmentally friendly beef production systems. However, the effects of grazing clover on the quality of beef have not been assessed fully. Important aspects of meat quality are shelf-life (colour and lipid stability), flavour and human nutritional value, all of which are affected by components of the animals diet such as antioxidants and fatty acids. Tissues from lamb finished on swards containing white clover were reported to contain more linoleic and a-linolenic acid and less eicosapentaenoic acid (EPA, 20:5 n-3) (Vipond et al., 1993) compared to animals grazing grass. The objective of this study was to determine the quality of meat from two beef breeds raised on grass or grass plus white or red clover.

One of the sources of variation in the in vitro gas production (GP) technique (Theodorou et al., 1994) is the inoculum source that is used. The time of rumen fluid collection in relation to the feeding time of the donor animals could greatly affect the microbial activity and hence fermentative capacity of the inoculum. This study was carried out to quantify both within day and between day variation in rumen fermentative capacity.

Lameness causes significant economic losses and serious welfare problems in dairy cows. Surveys carried out in the UK since 1960 have produced different results. In a recent survey (1989/1991) the annual incidence of lameness was put at 54.6 limb cases per 100 cows. The objective of the present survey was to measure the incidence of lameness, and type of lesions involved, in a group of typical UK herds using the Dairy Information System (DAISY).

A survey was carried out using computer based dairy cow records from 17 DAISY sites (veterinary practices and farms) in southern England. Lameness records from over 150 herds were examined for lameness cases (treated by the vet or farmer) recorded between July 1995 and June 1996. Data reliability was checked via personal contacts with veterinary surgeons involved with these herds. Data for the survey were finally derived from 50 Holstein/Friesian herds (average herd size 150 cows).

The spatial distribution of grazing sheep is influenced by the distribution of vegetation and by social behaviour. Where there are conflicts between grazing preferred vegetation and maintaining normal inter-individual distances, animals may have to make trade-offs based on the relative strengths of their motivation to feed or to be social. Social motivation, or sociability, has been assessed in chickens by measuring the rate at which isolated individuals move towards their companions (Suarez and Gallup, 1983) and in sheep by studying nearest neighbours (Sibbald et al, 1998). The aim of this experiment was to test whether individual differences in sociability affect the foraging behaviour of sheep, when animals have to choose between grazing or remaining close to their companions.

The ▵9-desaturase enzyme adds a cis-9 double bond to fatty acids in adipose and mammary tissue. In the mammary gland, this reaction converts C14:0 to C14:1, C16:0 to C16:1, C18:0 to cis-9 C18:1 (oleic acid), and trans- 11 C18:1(vaccenic acid) to cis-9, trans- 11 conjugated linoleic acid (CLA). Oleic acid is of interest in human nutrition as a component of the “Mediterranean diet” and CLA has been shown to have numerous health benefits. Conversion of vaccenic acid to CLA in the mammary gland accounts for 75-80% of CLA found in milk (Lock and Garnsworthy, 2002), but activity of the Δ9-desaturase enzyme varies among individual cows irrespective of dietary manipulations (Lock and Garnsworthy, 2003), suggesting that it may have a genetic component. The objective of this study was to estimate the genetic variation in Δ9-desaturase activity in dairy cows using milk fatty acid profiles.

An adequate intake of colostrum by the newborn piglet allows the piglet to acquire passive immunity and develop active immunity. Many studies have looked at the uptake of IgG by piglets in artificial situations rather than by natural suckling. Therefore we investigated the uptake of IgG by piglets whilst suckling naturally and estimated the time of gut closure.

A total of 8 multiparous sows (Newsham - Large White x Landrace) were induced to farrow on day 114 of gestation. Colostrum/milk was sampled, using oxytocin where necessary, at 0, 4, 8, 12, 16, 20, 24h and 2, 5 and 7 days after farrowing. Female piglets (average 3 per litter) were fitted with umbilical catheters to allow blood sampling at 0, 4, 8, 12, 16, 20, 24 and 48h; samples were taken at 5 and 7 days of age by venepuncture.