Ruminant production systems can have a negative effect on the environment within three main areas 1) loss of nutrients to aquatic environment, 2) loss of nutrient to the aerial environment and 3) contribution to the global increase in temperature (green house effect).

In Denmark area 1) is considered as a very serious problem in particular NO3-leaching from the agricultural land. Within area 2) the loss of NH3 from ruminant production is considered as a major problem. Concerning the green house effect (area 3)) the loss of N20, C02 and CH4 are considered as a problem in connection to ruminant production.

The British government is encouraging livestock diversification and the production of those animal products which are still being imported. Currently most farm animal fibres such as mohair, cashmere and alpaca are imported with the result that there is a potential for developing production in the U.K. South American camelids can all be farmed for their fibre and present few nutritional or managemental problems. The llama is the largest of the four species with the male weighing about 116 kg. It produces coarse fibre of various colours. The alpaca is smaller than the llama, has short ears, a woolly face and a rounded rump. It averages 1 m in height and the male weighs 64 kg. There are two types of alpaca with different characteristics, the Huacaya and the Suri. Yields of 2.00 kg of good quality 18-30 micron fibre are normal. In South America the vicuna and the guanaco exist only in the wild state. Guanacos have shaggy coats of fine texture, usually chestnut borwn.

Observations of the effect of the immunogen ovandrotone-albumin (Fecundin ® Coopers Animal Health) when used in ewes mated in their breeding season have shown that with a boost-tupping interval (BT) of 21 days for natural oestrus and 28 days for synchronised oestrus there was an increased fecundity but that treated ewes lambed a little later than controls.

While this latter effect was not dramatic it was felt advisable to investigate the use of Fecundin as a means of boosting lamb production in an early lambing flock in conjunction with progestagen and PMSG treatments.

In previous experiments (Barbi, Owen & Theodorou, 1993; Barbi, Owen & Theodorou, 1994), to minimize the reliance on fistulated animals in feed evaluation, effluent fluid from the in vitro rumen simulation technique (RUSITEC - Czerkawski & Breckenridge, 1977) was used to replace strained rumen liquor as the inoculum for the Pressure Transducer Technique (PTT - Theodorou, Brooks, Dhanoa, McAllan & Gill, 1993). In Barbi et al (1993), two different dilution rates in RUSITEC were compared, whereas in Barbi et al (1994), the effect of increasing the solid food input to RUSITEC was assessed. In both experiments low microbial activity in the RUSITEC effluent fluid affected the PTT results, reducing rates and extent of fermentation profiles to below those in the rumen-liquor inoculated control cultures.

In the present study, mixtures of glucose and xylose, as sources of liquid-phase nutrients, were infused, in differing quantities, into RUSITEC vessels. Also, the effect of adding or not adding a source of solid nutrient (hay) to the effluent collection vessels, was investigated. The objective, in both treatments, was to increase the cellulolytic microbial activity of RUSITEC effluent fluid.

Several expert committees have recommended reductions in intake of saturated fat for health reasons and in Britain this advice has been accepted by Government. There will be increasingly more fat-conscious consumers demanding leaner meat and in order to supply this demand retailers will select leaner carcasses and adopt new cutting methods. The trend within the beef industry is towards leaner cattle, coupled with increased production rates in abattoirs. This has led to concern about possible damage to eating quality.

A trial was carried out to investigate the eating quality of lean beef cuts produced from leaner animals or by more severe trimming and to investigate the possible compensatory effects of electrical stimulation on quick chilling.

At each of 20 abattoirs, 12 steers were selected and slaughtered together. Four were Hereford x Friesian, four were Continental x Suckler and four were Friesian/Holstein.

Precise, unbiased estimates of genetic parameters, such as heritability and genetic covariance, are necessary to optimise breeding programs and to predict rates of change for various selection schemes. A classical method of estimation is to use high and low selection experiments. We consider two generation selection experiments when observations in the parental generation are only taken on one sex, resulting in half-sib family information. We consider cases of two standardised traits, with zero mean and unit variance, and assume that the traits are normally distributed. The genetic and phenotypic variance-covariance matrices for the traits are denoted by G and P respectively. The genetic variances and covariances of the standardised traits are then heritabilities and co-heritabilities.

The construction of other designs is examined, assuming the phenotypic correlation of rp between traits is known. For simplicity, comparisons of designs are developed by considering the variance of the genetic variances when the traits are uncorrelated both phenotypically and genetically.

The utilization of diets high in fibre (defined here as non-starch polysaccharide - NSP) is dependent on the extent to which the NSP is fermented by the gut microflora, and the subsequent utilization by the animal of the end-products of fermentation - the VFAs. It has frequently been assumed that fermentation of NSP in the pig occurs almost exclusively in the hind-gut. However, a number of studies using pigs fitted with ileal-cannulas have suggested that some fermentation of NSP may occur prior to the hind-gut (e.g. Graham et al., 1985). The aim of this study was to determine the relative roles of the small and large intestine in a) the digestion of feeds containing non-starch polysaccharides, and b) the subsequent utilization of energy by growing pigs. This was achieved by comparing the abilities of intact or ileo-rectomised pigs to digest and grow on cereal-based diets containing 0 or 300 g/kg sugar beet pulp.

The selection of lactic acid bacteria for use as silage additives is normally based upon their ability to dominate the silage fermentation and not upon benefits in animal performance. The object of this study was to investigate whether two lactic acid bacteria selected for fermentation characteristics would support the same animal performance as an established silage inoculant.

On 5 June 1989, first cut, predominantly perennial ryegrass (Lolium perenne) was ensiled direct with no wilting in plastolene silos of 2 tonne capacity. The herbage was harvested with a precision chop forage harvester and the following additive treatments were applied: None, control (C); Formic acid (Add-F, BP Nutrition, 850g/kg; 3 litres/tonne), (F); inoculant E. (Ecosyl, ICI Pic, 106Lactobacillus plantarum /g): inoculant A, (Pediococcus sp, 10 /g); inoculant B (L. plantarum 106 /g). The silages were fed to 6 wether sheep (Suffolk x Halfbred), initial live-weight, 40.1 kg (s.d. 2.22kg). Because the silages were unstable aerobically and restricted quantities of each silage were available, all sheep were fed the silages in the same (random) order.

Previous experiments have shown important differences in milk production when mixed starch sources were replaced by mixed high quality by-products in high concentrate diets with hay as the forage (Sutton et al. 1987). The purpose of the present experiment was to compare rolled barley with sugar beet feed (SBF) in both molassed and unmolassed forms when given alone with grass silage in a high-concentrate diet. Additionally the effect of altering protein concentration of the concentrates was examined.

The removal of ciliate protozoa, or defaunation, results in the establishment of a new ecosystem in the rumen, consisting only of bacteria and fungi. Although extensive research has been done on ciliate-free ruminants, the role of protozoa in the rumen still provokes considerable debate. The diversity of experimental design, such as animal species, defaunation method, and diet could account for many of the differences observed between defaunation studies. Also it is important to examine the stability of the ciliate-free ecosystem. The aim of this study was to investigate changes in rumen fermentation of ciliate-free sheep over a period of one year.

Eight male castrated sheep, weighing 60-70 kg, received twice daily 700 g of a diet of hay, barley, molasses, fish meal and vitamins/minerals (500, 299.5, 100, 91 and 9.5 g/kg DM respectively). Four sheep were defaunated by the rumen washing technique (Jouany and Senaud, 1979) and kept in isolated pens while the other four were left faunated with a mixed type A ciliate protozoa population. Rumen samples were withdrawn via the rumen cannula and blood samples were taken from the jugular vein -1, 0, 1, 2, 4 and 6 h after feeding. There were three sampling periods: one month, six months and one year after defaunation.

There have been many attempts to use the measurement of cell wall fractions to predict the digestibility in vivo of untreated and alkali treated straws (see far example Sundstøl et al, 1978; Reid and Ørskov, 1987). All these attempts have shown this approach to have very low predictive ability for straws. Accordingly extensive use has been made of digestibility measurements in vitro using either rumen fluid (eg Sundstøl et al, 1978) or cellulase type enzymes (eg Jewell et al, 1986).

Whilst in vitro methods appear to be useful predictors of digestibility in straws, they are slow and relatively expensive. The work reported here has compared their predictive power with that of near infra-red reflectance spectroscopy (NIR).

A total of 123 cereal straws were used. These included 54 wheat, 43 barley and 4 oat straws all untreated and the 9 wheat, 9 barley and 4 oat straws oven-treated with ammonia previously described by Mason et al (1988).

The primary aim of the calf rearer is to ensure a successful transition from non ruminant to ruminant status while achieving rapid growth and an early intake of solid food. Newbold, Blake and Hagges (1991), found that increasing the concentration of ME in either the starter or milk replacer will not promote more rapid growth, but will simply reduce the rate of starter consumption. This present study investigated the extent to which the energy density of a calf starter ration affected starter intake and liveweight gain in calves receiving a fixed allowance of a high energy milk replacer with ad libitum access to solid calf starter rations.

The current technique for artificial insemination (AI) of ewes during the breeding season necessitates the synchronisation of oestrus with progestagen sponges and PMSG, and involves depositing semen into the posterior cervix at a fixed time after sponge removal. Extensive field trials over a number of years in the UK have indicated that a single insemination using fresh diluted semen 56 h after sponge removal generally results in a conception rate of 70%, while conception rates following a single insemination of frozen-thawed semen 57 h after sponge removal have ranged from 19% to 34% (mean 28%). Giving two inseminations of frozen-thawed semen at 50 h and 60 h after sponge removal increased the overall mean conception rate, but only up to 48%. This inability to achieve acceptable conception rates with frozen-thawed semen nullifies many of the potential benefits of AI in sheep flocks.

It is well established that the cervix presents a major barrier to sperm transport in the ewe, particularly when oestrus has been synchronised with progestagens and PMSG.

It has been suggested that female broiler chickens, having lower growth potential, are overprovided with dietary protein and that they will benefit more than males from a choice between a commercial standard food and whole wheat. The need for an initial learning period, before animals make ‘correct’ dietary choices has been emphasised (Mastika and Cumming, 1987; Rose and Kyriazakis, 1991; Shariatmadari and Forbes, 1991), but the problem of predicting the amount of necessary sampling, the method of learning and consequently the length of the experience period, or how often it has to be repeated, remained to be considered.

Therefore, the present experiment was designed to study whether birds need a learning period when presented with two foods, a commercial standard food (N) and whole wheat (W) in a choice feeding system.

A breed improvement programme has been initiated at both ADAS Redesdale (Scottish Blackface) and ADAS Pwllpeiran (Welsh Mountain) to improve carcass conformation of hill ewes. From a base population of 1100 Welsh Mountain and 1600 Scottish Blackface ewes, nucleus flocks of 60 ewes have been established. Selection of ewes into the nucleus flock at each site has been based on their ability to consistently produce wether lambs crops with good conformation and above average carcass weights when selected for slaughter at a fat class 2/3L. The next objective is to replicate these ewes through multiple ovulation and embryo transfer (MOET) since theoretical studies (Smith, 1986) indicate that this can substantially increase the rates of genetic improvement through the female line. However, to date little work has been conducted to determine whether this technology can be successfully applied to hill sheep maintained in harsh hill environments in the UK, and this formed the basis of the current study.

The use of drinking water as a vehicle for the medication of early weaned pigs offers an advantage over infeed medication in that water intake postweaning is substantially higher than feed intake. A precondition for effective water medication is the accurate assessment of water intake. At present there is little published information on the water demand of early weaned piglets reared under contemporary conditions of housing and nutrition. The objective of this study was to establish whether the water intake of early weaned piglets could be predicted from easily measured variables such as feed intake and liveweight.

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.

Artificial drying is undoubtedly the most efficient method of grass conservation. The nutrient losses incurred in the drying process are low and, in contrast to other conservation techniques, grass drying is consistently efficient throughout the season and between seasons. However, both capital and running costs of a drying plant are high and inevitably the cost of production of dried grass is also high. Where there is a large proportion of small farms, as is the case in Northern Ireland, it appears to be out of the question for a farm unit to have a grass dryer because of costs. It is more than likely that under these conditions grass drying will be either undertaken on a cooperative or commercial basis, in the latter case the grass so used being a cash crop.

A number of abnormal activities had been observed in a group of 30 lambs (R lambs; 10 Shetland (SH),10 Scottish Blackface (SB) and 10 Welsh Mountain (WM), half females and half entire males), on a restricted allowance (about mature maintenance intake and 0.5 of ad libitum intake), of a high quality pelleted diet (Diet A; 200g/kg crude protein, HMJ/kg ME). The lambs had been individually housed since 8 weeks of age, in pens (2m x lm), made up of metal barred gates with wooden slatted floors. Abnormal oral activities included some that caused obvious husbandry problems, such as wool-biting and slat chewing, and others which caused no overt damage, but may nevertheless be associated with impaired welfare (Cooper and Nicol 1993), such as bar-biting and repetitive licking. In a preliminary observation at 22 weeks of age, lambs only ate in the hour following food presentation (Fig 1), after which all of the allowance had been eaten, and abnormal oral activities were recorded in 30% of scans. Similar repetitive activities, described as “stereotypies” have been associated with food restriction in dry sows (Appleby and Lawrence 1987). In a series of observations, we investigated the effect of increasing weight and nutrient value of the lamb's diet on the incidence of oral stereotypies, whilst minimising any influence on the ongoing feed trial.

Hill farms vary greatly in size, soil and climate and each has its particular problems. The task of the scientist is to investigate each facet of production from the hill and to provide information which will improve the overall understanding of the potentials and limitations to output. From that understanding, the solutions to the problems of the individual farms may be derived.