It is necessary to quantify the effects of road transport on farmed livestock in order to provide a sound basis for legislation required to protect the animals. At present there is much interest in the transport of slaughter lambs as these animals tend to be transported for further, longer and in greater numbers than other, similar farmed species within the UK (Warriss et al 1990) and also because of the large numbers which are now exported. In 1993 approximately 2 million live lambs were exported from the UK, 8 per cent of UK production.

There is general agreement that transport is a stressful procedure. There are a variety of parameters which can be measured to give an indication of how well the animals are coping with the process. One measure which most would agree is indicative of failure to cope is mortality. When there is an increase in mortality it is not just those which have died which are likely to have suffered, those that survive have probably had more difficulty coping. In a survey of lambs arriving for slaughter in the south of England the overall mortality rate of lambs dead on arrival or dying in the lairage before slaughter was very low, at 0.018 per cent, when compared with figures for pigs (0.07 per cent) or broilers (0.19 per cent) (Knowles et al 1994a). This, despite a generally more protracted marketing process. However, the type of marketing process was important, as those animals which were brought direct from the farm for slaughter suffered a mortality rate of 0.007 per cent whilst those which were bought from a live auction market suffered a rate of 0.03 per cent.

Recent estimates of the genetic parameters of the traits used in the MLC Lean Index (Simm and Dingwall, 1989) have suggested that the rate of genetic progress in carcase quality could be improved by using alternative indexes (Pollott, 1994). This study was carried out to investigate the changes in a range of carcase components using these alternative selection indexes. Interest is particularly focused on changes in fat depots and bone weight under selection, as well as that of the primary trait of interest, lean weight.

The most important consideration in quality lamb production is the breed genotype used. Much work has examined a selection of terminal sire breeds, but less emphasis has been placed on assessing the influence of the female genotype on carcass quality. The benefits of the Texel breed in terms of higher carcass lean content has been highlighted (More O’Ferrall and Timon, 1977; Kempster et al 1987), but it has been suggested that Texel lambs are penalised under current MLC grading guidelines. Leymaster and Jenkins (1993) reinforced this suggestion by indicating that Texel sired lambs deposited proportionally more subcutaneous and less intermuscular fat than Suffolk sired lambs.

This study was carried out to compare the Dutch Texel (DT) and Suffolk (S) breeds as terminal sires and crossed with Greyface (GF) and Suffolk Cheviot (SC) dams. The effect of the proportion of DT blood in lambs on carcass quality was also examined. For this purpose GF, DT x GF and pure DT lambs were compared.

An experimental programme was initiated in 1990 to investigate the consequences of selection for reduced fatness in hill sheep. Lambs from some hill breeds tend to fall at the poorer end of the carcass quality scale, and achieve low carcass weights due to their small mature size. The aim of this paper is to compare carcass characteristics of lambs sired by two lines of Scottish Blackface rams selected for divergent subcutaneous backfat, and to estimate heritabilities at three ‘end ’ points: 1) at a constant subcutaneous backfat level, 2) at a constant age and 3) at a constant cold carcass weight.

The presence of a major gene influencing prolificacy has been proposed for the Cambridge breed. Cambridge ewes of extreme phenotype were identified by ovulation rate (OR) and litter size (LS) recorded in a single flock from 1976-1994. Means (sd) for all observations for OR (n=2062) and LS (n=2480) were 3.0 (1.69) and 2.5 (1.02). Extreme ewes were identified by three criteria: (a) High prolificacy had at least one OR observation ≥6; (b) Low prolificacy had records in at least three years with no OR or LS record >3; (c) Ewes had progeny with records in at least three years. On the basis of these criteria 27 High and 67 Low ewes were identified with 1.6 and 1.5 progeny per ewe, 2.1 and 2.5 OR records per progeny, and 3.7 and 1.7 LS records per progeny. The OR and LS results for ewes and their progeny are shown in Table 1. The maximum observed OR of High ewes ranged from 6-13 and both the OR and LS of Low ewes had a mean of 2.2 and ranged from 1-3. Means (se) of the progeny of the High and Low groups (determined in a model that included dam group, progeny within group, year and progeny age) were 3.9 (0.19) and 3.0 (0.13) for OR (P=0.003), and 2.6 (0.12) and 2.4 (0.11) for LS (P=0.055).

In order to evaluate genetic gain in populations under selection it is necessary to be able to partition the observed response into genetic and environmental components. This requires estimates of the appropriate genetic and environmental (co)variances unless appropriate genetic controls are available. Growth rate is an important component of the breeding objective for sheep breeds used as terminal sires and, whereas older estimates of the contribution of genetic variation to differences in preweaning growth indicated heritabilities of the order of 0.1, more recent studies have indicated considerably higher values. The present report concerns analyses of preweaning growth data on purebred Suffolk and Texel sheep to estimate genetic parameters for preweaning growth traits and genetic trend in growth rate from birth to weaning.

It was investigated in a small-scale study using a climate-controlled room at IAPGR, Roslin, that the effects of feeding a high level of supplemental vitamin E (500 mg/kg) on egg production and plasma concentrations of egg-associated metabolites in laying hens subjected to a short exposure (7 days) to a moderate heat stress (temperature of 32°C). The study showed, on small group sizes (12 birds / group), that in control birds (fed 30 mg supplemental vitamin E/kg), this degree of heat stress depressed egg production by about 30%. In the birds receiving the high level of vitamin E, egg production was maintained at levels very close to those prior to the heat stress. The objective of this experiment was to confirm in a larger scale the effects of high levels of dietary vitamin E on egg production of hens exposed to a chronic heat stress and during a period of recovery at thermoneutral temperatures.

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.

Recent developments in computing technology have seen the widespread implementation of animal models for parameter estimation and breeding value prediction in both experimental and commercial breeding programs. These techniques have several benefits over traditional least squares and index methods, including the ability to monitor genetic trends in die absence of an unselected control population. This paper reports heritabilities and genetic trends estimated from a large poultry data set for three broiler traits.

Selection in a commercial sire line is primarily based on improvement of broiler traits and those reproductive traits affected by the breeding male i.e. fertility, hatchability and chick quality. However some consideration in the selection programme must be given to die egg production and quality traits as the pure line must be maintained and parent sires produced. Dam lines are also selected for broiler and reproductive traits with more selection pressure being brought to bear on the egg related traits than in the sire lines. Consequently, the cross-bred progeny of these lines, which are sold as commercial breeding stock, exhibit a high performance in both egg production and meat deposition. As the primary basis of selection is to effect development of the pure-bred lines the assessment of the relationships between broiler and reproductive traits will facilitate in the advancement of the selection programme.

This trial sought to increase the knowledge of the changes in the endocrine status of male sheep as they mature and to link this with their sexual and agonistic behaviour when reared in the presence or absence of females; the influence of female lambs could significantly alter the behaviour, growth, performance, carcass composition and meat quality of entire and castrated male lambs. Therefore, this project could lead to improvements in the efficiency of sheep production by providing the background physiology necessary to understand sexual behaviour. This may lead to improved practices for the management of growing sheep, which may reduce the necessity to routinely castrate all male lambs.

Embryo survival rate is a major factor determining litter size and overall reproductive efficiency in sheep. In sheep, as ovulation rate increases the proportion of embryos surviving decreases. There is evidence, from cattle, that feeding a rumen-undegradable protein supplement enhances embryo survival rate. The objective of this experiment was to determine the effect on embryo survival rate in high prolific ewes of feeding an energy or protein supplement.

Insulin-like growth factor-1 (IGF-1) is one of the potential autocrine/paracrine regulators of ovarian function. Not only do relationships exist between follicular fluid concentrations of IGF-1 and various biochemical markers of follicular differentiation, but IGF-1 has also been shown to stimulate both proliferation and steroidogenesis in ovarian cells in vitro (Adashi et al., 1985). The actions of IGF-1 are thought to be modulated by IGF-binding proteins (IGFBPs). Indeed, follicular growth and atresia in the ewe have been reported to be determined more by changes in IGFBPs than by changes in IGF-1 (Monget et al., 1993). However, in mat particular study, stage of follicular development was determined by follicle size and by microscopic examination of the granulosa cells of individual follicles rather than by biochemical markers of follicle status. The objective of the present study was, therefore, to investigate changes in IGF-1 and IGFBPs levels in follicular fluid and to relate these to the physiological status as determined by steroidogenic content of follicular fluid.

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.

The laparoscopic technique used for intra-uterine insemination of sheep within sire-referencing schemes involves a small degree of surgical intervention. Although current codes of practice require the use of sedation and local anaesthesia, the concept of laparoscopic procedures still raises welfare questions in the minds of some. In spite of its sensitivity, little work has yet been undertaken to objectively measure the stress responses of sheep to laparoscopic procedures, and the present studies were therefore designed to rectify this deficiency.

In Belgium, about one third of beef meat production is based on fattening of bulls from double muscle type (IEA. 1993). Young bulls are generally fattened from about 300 to 600 kg in stanchion barns, they may however spend one season on pasture before a finishing period indoor (Dufrasne et al., 1995). This technic allows a meat production which corresponds to the market demand, with low costs of production associated with grazing. Scarce data are available on carcass characteristics of Belgian bulls slaughtered after a grazing period. In the present experiment, we compared animal performances and carcass composition of bulls which completed a full fattening period either on pasture or indoors.

Suckler cows from the hills and uplands are generally of traditional type. The introduction of new continental genotypes into a hill environment could have the potential to increase output and produce carcasses of high quality. The objective of this experiment was to assess the output and reproductive performance of Simmental cross Holstein/Friesian (S) and Piemontese cross Holstein/Friesian (P) suckler cows producing three-quarter bred continental progeny from an autumn calving suckler herd. Reproductive performance and calving difficulties of the first calf crop were presented previously (Keatinge et al 1994). This paper presents the growth and finishing performance of calves from S and P dams.

In a series of production studies undertaken at this Institute with growing and finishing beef and dairy cattle an inoculant based on a single strain of Lactobacillus plantarum ,when applied to easy and difficult-to-ensile herbage, has produced considerable benefits in terms of silage intake and animal performance without any apparent improvement in silage fermentation. More recently detailed studies have shown that treatment of herbage at ensiling with the same inoculant has resulted in increased degradability of nitrogen (N) in the rumen, and total tract digestibility of dry matter (DM), organic matter (OM), N, neutral detergent fibre (NDF), and modified acid detergent fibre (MADF). Treatment with the inoculant has also altered rumen volatile fatty acid (VFA) concentrations by increasing rumen propionate and decreasing acetate concentrations.

It has been suggested that the effects of inoculant treatment on silage DM intake may be due to the presence of the applied bacteria when they reach the rumen rather than their effects in the silo.

Efficient nutrient utilization by livestock is a function of adequate intake of a given nutrient, its unimpaired release from the ingested feed and optimal availability to, absorption by, and retention in animals. Optimization of these functions to fulfil livestock physiological requirements is not often achieved under normal feeding conditions. A nutrient imbalance, especially of minerals, can initiate the onset of clinical disease such as parturient paresis and hypomagnesaemia. An additional difficulty of improper nutrient balance arises in diet formulation, since the addition of one nutrient almost invariably affects the concentration and utilization of another. The antagonism between sodium (Na) and potassium (K) and their specific involvement at the cellular level in water metabolism, nutrient uptake and transmission of nerve impulses is a firmly established example. High levels of Na ingestion such as often occurs in saline environments or when loose forms of Na are included in conserved feeds can be detrimental to animal performance. However, at levels more typical of practical livestock feeding, Na nutrition is beneficial to livestock productivity. Sodium increases the divalent cation contents of forage and depresses K (Moseley, 1980; Chiy and Phillips, 1993), improves in vivo DM and fibre digestion and the release of inorganic nutrient from fresh forage grazed by ruminants (see recent review by Chiy and Phillips, 1995).

Lambs from a Finnish Landrace flock at Moredun Research Institute are frequently affected by a diarrhoea which does not respond to anthelmintic. Three different drugs have been used (levamisole, albendazole and ivermectin) and there is no history of drug resistance at the site. By the normal rules of differential diagnosis, nematodiasis would be ruled out as a cause of the diarrhoea. However, seasonal, year-to-year and apparent breed differences in incidence led to the suggestion that outbreaks in autumn were caused by hypersensitive immune responses to the continuous ingestion of infective nematode larvae (Suttle, 1994). To maintain the nematode connection and distinguish the condition from those associated with anthelmintic resistance, it was described as an anthelmintic unresponsive diarrhoea (AUD). If the proposed aetiology is correct, one would expect hoggs to be affected in their second year of exposure to nematodes while lactating ewes with relaxed immunity might be less vulnerable. Furthermore, administration of anthelmintic in a slow release bolus might control AUD where monthly drenching failed.