A wide range of roughage foodstuffs is available for feeding to horses. Considerable variation exists in the quality of these feeds in terms of nutrient composition and freedom from dust, fungal and bacterial contamination and infestation by mites. Many horse-owners are now feeding forages such as haylage and baled silage to horses as opposed to hay. However, limited information is available regarding the effect of chop length on digestibility and thus the feeding value of chopped or long-cut silage to horses. More information on fodder type and preparation could help to provide the basis for improvements in the practical guidelines and recommendations for those involved with the production and feeding of forages to horses.

Methane (CH4) is a greenhouse gas of which the release into the atmosphere is directly linked with animal agriculture, particularly ruminant production. CH4 emissions from ruminant also represent a loss in productive energy for the animal. Development of effective strategies to mitigate these methane emissions will have not only environmental benefits for the planet but also nutritional benefits for the animal. It has been shown that concentrate-rich diets result in a decrease in methanogenesis per unit of animal product (milk, meat). However, some of these diets may have adverse effects on the efficiency of production, e.g. due to risk of acidosis. Our study focused on measuring methane emissions on young bulls fed three contrasting finishing diets characteristics of three intensive levels of production in France.

Mycotoxins are secondary metabolites produced by fungi under certain stress periods (Smith and Seddon 1998). When ingested, mycotoxins cause insidious losses, ill thrift and reduced disease resistance. Zearalenone is known to cause hyperestrogesium in pigs and hence a reduction in fertility in both sows and boars can occur (Binder 2004). Certain mycotoxins such as zearalenone (ZEA) and deoxinivalenol (DON) are produced by fungi of the fusarium species on crops in the field. Fusarium pseudograminearum (Crown Rot) produces both DON and ZEA in decreasing levels up the tiller of winter cereals (Blaney et al. 1987). Most studies carried out so far analysed the occurrence of mycotoxins in the grain and less is known about the prevalence of mycotoxins in the straw of the crop. Housing of sows during gestation on straw is becoming a favoured production system due to environmental and public perception pressures. The intake of straw by weaners on straw based systems has been found to account for 11.5% of total feed intake (Barneveld et al. 2004), such that there could be a considerable risk for increased ingestion of mycotoxins in animals on straw based systems. The objective of this study was to investigate the occurrence of mycotoxins in straw used for deep litter in Australian deep litter pig production systems.

Beef production is the most important farm enterprise on Northern Ireland farms, accounting for 32.5% of Gross Agricultural Output. In beef production the end saleable product is carcass rather than live weight. When undertaking nutrition studies with beef cattle, it is essential to evaluate effects on carcass characteristics, as improvement in live weight may not transfer to improvements in carcass weight and characteristics due to change in gut fill effects. Undertaking carcass assessments in beef production studies increases experimental costs. To determine carcass gains it is essential to slaughter a representative batch of cattle pre-experimentally in order to develop a relationship between initial live weight and initial carcass weight. Slaughtering store cattle further adds to the costs of beef experimentation. The present study was undertaken to develop a relationship between live weight and carcass weight of beef cattle offered grass silage-based diets to facilitate the determination of initial carcass weight of store beef cattle at the point of initiation of nutritional studies.

Pre-weaning mortality is a major source of economic loss to the pig industry which despite improvements in husbandry and farrowing crate design remains about 10% of piglets borne alive. The causes of death are multi-factorial (Varley, 1995) but a large proportion may be due to low neonatal vigor. Commercial pig diets do not normally contain long chain n-3 fatty acids, a deficiency of which has been implicated in reduced visual and neural development in premature human babies and in experimental animals. The objectives of the present experiment were to quantify the causes of piglet mortality in sows of modern genotype and to determine the effects of salmon oil supplementation of the diet of the sow, providing long-chain n-3 fatty acids, on this mortality.

Up to now, genetic selection in cattle has been directed in favour of muscle growth, which changes muscle characteristics, and hence meat quality. One key concern, that now needs examination, is to understand the relationships between muscle growth and muscle characteristics related to meat quality. To achieve such a goal, muscles of divergently selected animals were analysed by three complementary approaches: (i) determination of muscle biochemical characteristics, (ii) identification of differentially expressed genes using transcriptomic and proteomic tools, (iii) identification of Single Nucleotide Polymorphisms (SNP) within candidate genes.

Most of silver foxes bred in captivity show predominantly defensive responses to human contact. Since early captive breeding humans have unconsciously carried out selection for tameness. Thus, artificial selection for the absence of aggressive and fearful responses to humans most likely played a key role in domestication process. To establish the genetic and physiological mechanisms of the early evolution of domestic animals, a model of silver fox domestication was developed at the Institute of Cytology and Genetics (Novosibirsk, Russia). A population of silver foxes has been produced in long-term selection for lack of aggression and fear towards humans (domestic behaviour). The method of selection and the behavioural changes in the course of selection have been described (Belyaev, 1979; Trut, 1995). Selected animals show no aggressiveness to humans and they are better adapted to captive conditions than their wild counterparts. The purpose of this study was to determine how behaviour selection influences testicular function in silver fox males. Plasma concentrations and testicular production of testosterone were determined in selected and control males in different parts of the reproductive cycle and prenatal life. In addition, reproductive behaviour and hormonal responses to opposite sex were estimated in the males of both behaviour groups. Sperm production and sexual activity were also compared between selected and control males.

Poor animal performance associated with low digestibility silages results partly from the reduced nutrient yield per unit intake, but also from the associated lower intakes which were presumed to be a consequence of rumen fill effects. Legume silages have a lower average digestibility than grass silages, and yet often have higher intake characteristics. The objective of this work was to compare rumen fill and rumen particle size distribution for animals fed grass silage or legume silage-based diets.

Previous work has indicated that unmolassed sugar beet pulp (USBP) may suppress voluntary feed intake (VFI) in ponies when offered as the major component; but not when offered as a relatively minor component of the diet (Hyslop et al, 1998, 1999). However, critical levels of USBP inclusion in equine diets remain to be established. This study examines VFI, in vivo apparent digestibilities and nutritive values in ponies offered pelleted complete diets containing USBP at inclusion levels between 0 – 800 g/kg dry matter (DM).

The long-chain polyunsaturated fatty acids (PUFA) docosahexaenoic acid (DHA) and arachidonic acid (AA) are the most abundant fatty acids in the brain and are vital for its correct development and for that of the nervous system (Huang and Craig-Schmidt, 1996). Ruminant diets are low in DHA and its precursor alpha-linolenic acid. In addition, dietary PUFAs are substantially hydrogenated in the rumen. Consequently, it may be argued that the diets of pregnant and lactating ewes may be deficient in DHA and that a response to supplementation may be observed. Studies involving the supplementation of pregnant ewes with supraoptimal levels of vitamin E have shown that lambs born to supplemented dams are more vigorous immediately after birth and have higher liveweight gains (Merrell, 1998). The objective of this experiment was to investigate the effects of dietary long-chain PUFA in combination with vitamin E supplementation of ewes on ewe and lamb performance.

Pastoralists (broadly speaking, people dependent on extensively grazed livestock for their livelihoods), are a vulnerable group of people who have been marginalised in developmental and political terms, and whose problems are very different from those of people in mainstream agricultural areas. Pastoralist Parliamentary Groups (PPGs), groupings of MPs concerned with the issue of pastoralism, have been formed since 1997 in the national parliaments of Ethiopia, Kenya and Uganda (Mohammed Mussa 2004, Livingstone forthcoming a and b). A research project investigated the context, successes and failures of the three PPGs, using interviews with their members and other stakeholders and document review.

Lower cost systems of sheep production, with reduced labour inputs, require examination for the future viability of the sheep industry. Carson and Dawson (2002) demonstrated that ewes lambing under grass-based systems had similar lamb outputs and survival rates to ewes lambing under labour intensive, indoor lambing systems. Although there is a significant amount of information is available on the effect of conserved forage on ewe performance in late pregnancy, there is a scarcity of information on the effect of grazed grass and concentrate supplementation at grass in late pregnancy on subsequent ewe performance. The aims of this study were to investigate the effects of herbage allowance and concentrate feed level during late pregnancy on ewe live weight and body condition change and lamb growth and development.

The use of small ruminants, such as sheep, in metabolism studies is more convenient as handling problems are reduced and their maintenance costs are lower, in comparison with cattle. However in vivo digestibility estimates obtained at maintenance are known to differ between these two species. With the increased use of in vitro gas production techniques, to evaluate ruminant feedingstuffs, it is of great importance to identify whether the species from which the rumen fluid inoculum is obtained has a significant influence on the results obtained.

Rumen fluid samples were obtained from a non-lactating Holstein cow (C) and six wether sheep (S) offered the same diet (80 % tropical grass and 20 % dairy concentrate) and prepared so as to have similar dry matter (DM) contents and therefore potentially the microbial mass. Nine substrates (two tropical grasses 1-2, tropical alfalfa 3, barley straw 4, and five temperate grasses 5-9) were examined.

Feed is the single largest cost in most animal production systems. Feed conversion ratio (FCR) is a commonly used measure of growth efficiency. Previous research has shown that FCR is moderately heritable and highly related to growth rate. While selection for FCR is beneficial to those feeding growing cattle for slaughter, any associated increase in the size of breeding females will mean this benefit will be at a cost to the calf breeder, as larger breeding cows require more feed.

Earlier work showed that red clover silage has considerable potential for milk production (e.g. Thomas et al., 1985), though low digestibility and difficulties ensiling clovers were seen as problems that needed to be addressed. Advances in legume breeding and conservation technology as well as a renewed emphasis on extensive organic production systems within Agenda 2000 meant that it was timely to reconsider the potential of legume silages for milk production.

Body fat and protein reserves at calving can affect milk production and composition (Garnsworthy, 1988; Moorby et al., 1996). Milk producers frequently feed their dry cows with a low quality diet to prevent them from becoming too fat before calving. However, the cow must nourish the foetus and develop mammary secretory tissues, which can be a problem if she is offered a low protein diet. This experiment was designed to test the interaction between energy and protein supplies during the dry period on changes in live weight (LW), condition score (CS) and muscle Longissimus dorsi depth (LD). Subsequent milk production and composition data are reported in a separate summary (Jaurena et al., 2001).

Group housing of sows is becoming a commonly used housing method in modern pig production because of welfare legislation which requires the phasing out of all stall and tether systems by 1999. Since group housing exposes sows to potential social stressors, the objective of this study was to determine whether dominance order has an effect on the behavioural expression of oestrus and mating behaviour of sows.

Replacing grass silage with maize silage in the diets of finishing beef cattle can improve DM intake and performance even when starch content of the maize silage is low (McCabe, O'Mara and Caffery, 1995). The objective of this experiment was to investigate the response of beef cattle fed diets containing different proportions of maize silage and grass silage with the same level of concentrate supplementation.

Knowledge of the genetic and phenotypic relationships for muscle fibre characteristics with meat and eating quality in pigs is required by the pig breeding industry for two reasons. Muscle fibre traits, determined from muscle biopsy, could be used as genetic predictors of meat and eating quality traits and, secondly, if responses in meat and eating quality traits are partially due to changes in muscle fibre traits, then selection criteria can be designed to compensate for such responses. The current study estimated the genetic and phenotypic relationships for muscle fibre traits with meat and eating quality traits.

The study consisted of 160 Large White pigs from lines divergently selected for lean growth rate on ad-libitum or restricted feeding regimes, lean food conversion ratio and daily food intake for seven generations in the Edinburgh lean growth selection experiment. Within each selection line, there were 10 pairs of full-sibs. Boars and gilts were tested from 30 kg, individually penned and fed a diet consisting of 224 g CP/kg DM and 15.9 MJ DE/kg DM.

Profitability of sheep production systems depends on several different animal characteristics rather than a single trait. Economic selection indexes combine information from more than one trait into an overall score, to maximise genetic gain. Economic values (EVs) are required for each trait in the breeding goal so that selection emphasis is proportional to the economic importance of each trait. Defining clear breeding goals is more complex for hill breeds than for other sectors of the sheep industry because they provide breeding females in addition to lambs for slaughter. The aims of this paper are to i) describe how EVs for breeding goal traits suitable for UK hill sheep were derived for a combination of carcass, maternal and ‘sustainability’ traits using a bio-economic model, and ii) show how these EVs vary between different production systems as a result of the differences in the physical constraints of farm size, pasture availability and the biological limits of sheep in extensive rearing environments.