In order that genetic progress in British beef breeds could be improved, performance traits have been recorded by the Meat and Livestock Commission for many years. A large number of pedigree beef herds have recorded with the Meat and Livestock Commission during this period. Until recently, these records were only made use of via within herd contemporary comparisons such that the results for animals could not be compared across herds or time.

Through the use of Individual Animal Model Best Linear Unbiased Prediction (BLUP), differences between herds and contemporary groups within herds can be accounted for provided there are genetic links between herds and contemporary groups. As a result of the small pedigree herd size in Great Britain, typically less than 20, sires are often chosen from outside the herd in order to reduce inbreeding. This practise has resulted in there being a relatively high level of connectedness between contemporary groups and this enables the BLUP procedure to disentangle management and genetic effects.

Near infrared spectroscopy offers an alternative to wet chemical methods for determining the composition of a diverse range of materials. This physical method requires only a single instrument and although this can be expensive initially, the cost per sample analysed is relatively low when compared with many chemical methods. If it is to be applied in a quantitative way near infrared spectroscopy requires calibration against chemical methods, but once calibrated the instrument is simple to use and there are few operator-induced sources of error. The objective of this work was to evaluate near infrared reflectance spectroscopy (NIRS) as a technique for assessing the composition of carcass samples from young steers.

Seventy-one, approximately 9-month-old, British Friesian steers with live weights ranging from 106 to 265kg were slaughtered. The left half carcass (including the left kidney and kidney knob and channel fat) was retained, blast frozen and subsequently minced in the frozen state through a 10mm plate of a KS Mincemaster.

Lamb producers in the Less Favoured Areas (LFAs) of the European Community appear, for different reasons, to be constrained by the economic value of the indigenous small-sized sheep breeds. The trial reported here forms part of a collaborative project whose overall aim is to improve the quality and marketability of sheep meat produced in the LFAs. The objective of this trial was to assess the growth potential of nine small sized sheep breeds, across three centres, providing a basis for subsequent production work. The three collaborating centres in Greece (paper no. 112), Spain (paper no. 26) and Scotland used indigenous breeds appropriate to their LFAs. The three British breeds studied were Scottish Blackface (SB), Welsh Mountain (WM), and Shetland (SH).

In the productive cycle of Latxa sheep we can distinguish two different periods. In winter and spring months the flocks are grazing the valley meadows and receiving indoors supplementation in relation to the productive situation of ewes, late pregnancy, suckling or milking. In the rest of the year, 120-180 days, which correspond to the main part of summer and autumn, the ewes are grazing mountain communal pastures (700-1.400 m. altitude) without any supplementation and little surveillance. Since in this period the ewes theoretically recover their body reserves, and the mating takes place, we have studied the evolution of Body Condition score (BCS) of ewes and the effect of BCS on the reproductive performance of the ewes.

During two years we have determinated monthly the BCS of 20% of the ewes older than 1 year in 14 commercial flocks of Latxa breed. During the visits we made also a visual evaluation of the grazed areas, and the height of the grass in the pastured areas was determinated by means of the H.F.R.O. Sward Stick, if possible.

The voluntary intake of roughage diets by ruminants is related to their degradation characteristics (Hovell et al., 1986). Furthermore, as forage quality is improved the outflow of undegraded particles is increased. Previous studies have shown that differences between forages in outflow from the rumen were mainly associated with the outflow of liquid from the rumen. In this context there could be chemical factors arising from the rapid fermentation of the more degradable forages that could stimulate salivary flow or movement of water across the rumen wall, increasing liquid outflow from the rumen, and thus washing undegraded residues from the rumen and enabling the animal to eat more. One possible signal is rumen volatile fatty acids (VFA) levels since YFA production and concentration are significantly greater with roughages that support greater intakes and rumen outflows. Intraruminal infusions of VFA have been shown to depress feed intake in ruminants (Baile & Forbes, 1974). However, most of the infusion studies have been conducted with animals fed diets containing concentrates or high-quality forages, and most of them examined short-term intake responses to intraruminal infusions of, probably, supraphysiological levels of VFA (Dejong, 1986). The aim of this experiment was to examine whether the voluntary intake of a low quality roughage by sheep could be affected by the infusion of VFA at different doses into the rumen.

The recently introduced metabolisable protein system for ruminants (Webster 1992) relates microbial nitrogen production to daily supply of fermentable metabolisable energy and effective rumen degradable protein but does not consider the effect of the pattern of supply of nutrients to rumen microbes on their efficiency and growth. However, synchronising the hourly supply of nitrogen and energy yielding substrates to rumen micro-organisms has been shown to increase the efficiency of microbial protein synthesis (Sinclair et al. 1993). The objective of the current experiment was to examine the effects of synchronising the hourly supply of energy and nitrogen in diets with a similar carbohydrate composition but differing in the rate of protein degradation, on rumen fermentation and microbial protein synthesis in sheep.

The indigenous sheep breeds of Greece, which are used mainly for milk production, produce lambs which are killed at weaning to provide carcasses (including the head, pluck, liver, spleen and the omental and mesenteric fat) of 5 to 9 Kg. The production of heavier carcases could be of benefit if they are acceptable to consumers and if they could be economically produced. The purpose of this experiment was to characterise the growth and development of the entire males and females of three Greek breeds under conditions presumed to be non-limiting.

Animals. From each of three breeds, Boutsiko (B), Serres (S) and Karagouniko (K), 20 lambs of each sex were used in a serial slaughter experiment. Four animals of each breed/sex combination were killed at live weights which were 25, 35, 50, 70 and 100% of the estimated mature values. All sheep were weaned at 6 weeks of age and the males were entire.

Chaudhry and Miller (1993) have demonstrated the effectiveness of Alkaline hydrogen peroxide (AHP) in improving in vitro digestibility (IVD) of cereal straws. Further experiments were conducted to evaluate the use of AHP on a larger scale compared with varying amounts of sodium hydroxide (NaOH) in improving the nutritive value of wheat straw (WS) for sheep.

The weight of secondary fibre (including fibre ˂18µ diameter (cashmere)) produced by goats differs greatly between genotypes. The reasons for such differences are unknown but may include differences in rate of growth, duration of the period of growth, the number of secondary hair follicles and fibre diameter.

Studies of the effect of dietary protein level on secondary fibre production have so far indicated that there is little potential for nutritional manipulation of fibre yield. However, these studies have been confined to breeds which have relatively low yields of fibre.

There are conflicting data in the literature on the effects of litter size on colostrum production. Shubber et al.,(1979a) reported highest colostrum production in triplet bearing ewes compared with ewes carrying singles or twins. Other researchers (Hall et al.,1989; Shubber et al.,1979b) agree that ewes producing twins yield most colostrum. Hall et al., (1989) also reported that progesterone concentrations before and after parturition increased with litter size and Hartmann et al.,(1973) found that progesterone withdrawl is a prerequisite for lactogenesis and the onset of copious milk secretion. The objective of this experiment was to evaluate the performance of single, twin and triplet bearing ewes in relation to ewe performance, progesterone concentration, quantity and quality of colostrum.

Single (Tl, n=35), twin (T2, n=25) and triplet (T3, n=29) bearing oestrous synchronised ewes of mixed lowland breeds (mainly Suffolk cross, greyface and halfbred), were selected following winter shearing and pregnancy scanning in December.

Lamb carcass quality is becoming economically more important. Crossbred lamb production in the UK is based upon the use of terminal sire breeds, chosen for carcass characteristics, mated to crossbred ewes, chosen for maternal attributes. The choice of terminal sire breed represents the most immediate option available to the commercial producer to improve the carcass characteristics of finished lambs. Previous studies (Croston, Guy, Jones, and Kempster, 1983; Cameron and Drury, 1985; Merrell, Webster and Ellis, 1990) have compared several terminal sire breeds, but these have tended to concentrate on the British Down breeds, particularly the Suffolk, and tne numerically more important imported breeds, such as the Texel and Charollais. Vendeen sheep were imported from France in 1981 but little information was available on growth and carcass traits of Vendeen crossbred lambs. A three year experiment compared, within a flock, the performance of the crossbred progeny of Suffolk and Vendeen rams.

A number of recent reports relating to human health have suggested that pregnant women should limit their consumption of sheep's liver because of the possible dangers of hyper-vitaminosis from high vitamin A levels in this organ. Foetal defects, especially in early pregnancy, have been mentioned (Dept. of Health, 1990; Ilback, Busk, Halen & Slorach, 1991) as possible dangers resulting from high consumption of vitamin A.

Since the introduction of the sheep meat regime in 1980, under CAP, the output of early lamb production in Ireland has increased significantly. As early lamb has traditionally been a high priced product, geared towards the Easter market, high lamb performance is a high priority. This invariably necessitates high feed inputs in the form of concentrate feed. For various reasons, most commercial concentrates have added vitamina A levels higher than is necessary to meet animal requirements. It has been suggested that this source of vitamin A may be responsible for elevated vitamin A levels in the liver. Consequently, the aims of the present experiment were to quantify the vitamin A status in lambs liver selected from scientifically controlled production systems and to relate the values to lamb sex and age.

Protein-rich supplements often enhance production of ruminants grazing native pastures during the winter on the northern tablelands of New South Wales. However, graziers report that animals offered supplements often do not consume them; there is also experimental evidence, obtained using tritiated supplements, that intake of supplements by individuals within a flock may exhibit wide variation. The objectives of this study were first, to evaluate a commercial protein-rich supplement when given to winter-grazed weaners, by determining the effect of supplementation on liveweight gain, wool production and fibre diameter, and second, to estimate the changes in patterns of intake of supplement by individual animals over time during a 12 week supplementation period.

Farmers in the Middle East have traditionally chopped cereal straw during threshing to produce tibn for feeding to sheep. They say this reduces feed selection and waste, and have recently developed hammer mills with large screens to make a similar product from combine-harvested straw. Some nutritional advisers have recommended urea or ammonia treatment of straw as an alternative to (or in addition to) this. These processes improve digestibility and nitrogen content. The nitrogen content of the ration may also be improved by supplementation using a smaller quantity of urea (Greenhalgh 1984).

Coarse milling is said to allow particles to flow rapidly from the rumen, to reduce rumen fermentation and to increase the quantity of nutrients digested in the small intestine. Part of the fibre that escapes the rumen is fermented in the large intestine. But because digestion of the microbial protein formed in the large intestine is less efficient than in the rumen, coarse milling is likely to increase animals’ protein requirements.

Sheep in West Java, Indonesia, are raised by smallholders using labour-intensive, cut-and-carry feeding of indigenous grasses. Flock sizes are small, ca. 5 sheep per household and animals are permanently housed in thatched sheds. The sheds are elevated on stilts and are fitted with slatted floors beneath which the excreta and feed refusals (ca. 400 g/kg offered) are composted. Compost is an important fertiliser for smallholders' crops.

Cutting and carrying grass is labour demanding (eg 2.1 h/sheep.day [Thahar & Petheram, 1983]; 1.4 h/sheep.day [Hill, 1973]); allowing sheep to refuse ca. 400 g/kg of grass offered would therefore appear wasteful. However research on feeding barley straw (Wahed, Owen, Naate & Hosking, 1990) has shown intake to increase when sheep and goats are allowed to refuse 500 g/kg offered instead of the more conventional 200 g/kg refusal-rate.

Malt distillers wet grains (MDG) are an important feed source of ruminants in Scotland with an annual production of 220,000 T. Ensiled MDG is commonly fed to ewes but little information is available on the optimal inclusion level in the diet for pregnant ewes. Of particular interest is the maximum inclusion rate as MDG is frequently the least cost dietary component. MDG are high in unsaturated oil, which, owing to its inhibitory effect on rumen bacteria, results in reduced intakes and digestibility of diets containing high levels of MDG. Furthermore MDG are devoid of soluble minerals such as potassium and sodium. Previous experiments with cattle (Lewis and Lowman, 1987) and lambs (Vipond et al, 1992) have shown that supplementation of MDG with a mineral mix (MDG mineral) containing high levels of potassium, calcium and magnesium can overcome these deficiencies and promote higher intakes and improve performance. Such a mineral was used in this trial.

Without chemical analysis, Blummel and Ørskov (1992) adapted the in vitro gas test (Menke and Steingass, 1988) and used the exponential equation p=a+b (l-e-ct) to describe the kinetics of fermentation of 10 straws. They reported high correlation with animal performance. The aim of the present study was to adopt a similar approach and assess the gas test in comparison with nylon bag for the prediction of intake or DM digestibility of 10 different quality hays.

Ten hays consisting of 3 harvesting stages of lucerne (Medicago sativa), sweet clover (Melilotus segetalis), persian clover (Trifolium resupinatum) and Italian rye-grass (Lolium multiflorum). Each hay was fed ad libitum to 4 Merino male sheep and their intake (g dry matter (DM)/day/KgW0.75) and in vivo DMD were recorded.

The effect of food restriction and subsequent realimentation depends on age of animals at restriction and energy/protein relationship during post-restriction period (Ryan, 1990). In Spanish Churra breed the internal fat depots are the most important energy reserves (Frutos et al., 1991) and the proportion of different depots after restriction could be affect to recovery during realimentation.

The aim of this paper is to study the effect of level of intake during milk-fed period and the protein content in the diet during the post-weaning period on the performance and different internal fat depots in the Churra lambs until they were 20 Kg of live weigth (LW).

Utilization of low quality roughage is fundamentally limited by its low energy content and low voluntary intake when fed to the ruminant animal; these being mainly determined by the simultaneous action of degradation in and outflow rates through the reticulum-rumen. While factors affecting rumen degradation rate are extensively described in bibliography, those related with rumen digesta outflow are not clear enough.

The objective of this study was to study the effect of the reproductive state and the level of concentrate supplementation upon ruminal outflow rates of digesta in ewes fed on straw based diets.

Different sources of dietary fibre (defined here as non-starch polysaccharides, NSP) are hydrolysed to varying degrees in the GI tract of pigs. Unlike starch, NSP cannot be digested to its monomeric constituents by mammalian enzymes, but instead must be fermented by the gut microflora, to yeild volatile fatty acids (VFA). These VFA, like the glucose derived from the digestion of starch, are subsequently absorbed and metabolised to yeild ATP, but with a lower efficiency than glucose. Clearly, therefore, knowledge of the relative amounts of products of fermentation and digestion which are absorbed, will enable the nutritive value of a feed to be described more accurately. We report the time course of absorption of glucose, VFA, lactate, and α-amino N from semi-purified diets containing two contrasting sources of NSP, wheatstraw (WS) and sugar beet pulp (SBP), by growing pigs.