Biotin plays a critical role in the differentiation of epidermal tissue, in the fatty acid and glucose metabolism. Qualitative and quantitative changes in the synthesis of keratin filaments, interruption of the co-ordination from keratinisation until cornification and intercellular cementing substance of poor quality occur in the hoof horn of biotin deficient calves (Mulling et al., 1999). The addition of supplementary biotin in diets has been found to significantly increase hoof hardness and reduce lameness of cows (Schmid, 1995; Fitzgerald et al., 2000). The aim of this experiment was to compare changes in locomotion score and lesion score with the results of mechanical testing of the sole and white line horn in cows supplemented and not supplemented with biotin.

Genetic potential for milk production has increased rapidly in the Holstein-Friesian breed and there is concern that this might be causing an increased incidence of health problems. We have recently (Ingvartsen et al., 2002) reviewed the inter-relationships between lactation performance and health, demonstrating the importance of considering effects on/of body reserves as well as effects on/of milk production. Whilst we identified mechanisms whereby body reserves can have a direct effect on susceptibility to disease, disease also affects body reserves making it difficult to study their inter-relationships. The dry period is a particularly interesting period in this regard, because additional nutrients are directed towards reserves, whilst it is followed by a period (early lactation) of high disease incidence. The objective of this study was to investigate the effects of body condition score (BCS) at calving, as well as the effects of dry period diets designed to alter BCS, on disease incidences in the first 100 days of lactation.

The cost of disease within the dairy industry is associated with loss of yield, discarded milk, cost of treatment and reduced fertility. Mastitis and lameness are two of the most financially important health problems associated with dairy production in the UK. Mastitis alone is estimated to account for approximately 10% of all cull cows and to have an associated cost of £218 per case (Kossaibati and Esslemont, 1995). Lameness accounts for approximately 6% of cull cows and has an associated cost of £273 per case (Kossaibati and Esslemont, 1995). In the present study somatic cell count (SCC) and locomotion score (LS) records were used as indicators to estimate the influence of genetic merit for milk production on mastitis and lameness.

Clinical copper (Cu) deficiency in ruminant animals is mainly attributed to antagonistic interactions with molybdenum (Mo), iron (Fe) and sulphur (S) and Williams et al. (2001) reported differential effects between Mo and S, compared with Fe and S on various copper parameters. Suttle and Jones (1986) reported an increased mortality of lambs and infection rate due to copper deficiency which suggests an effect of Cu deficiency on immune function. The aim of this study was to assess the effects of Mo or Fe and S on the cellular and humoral immune responses of growing lambs.

The treatment of sugarcane pith with various methods in order to upgrade its nutritive value and to increase the utilisation of its energy by ruminants has been widely employed in many parts of the world (Sansoucy et al. 1988). The aim of the experiment was to improve the nutritive value of sugarcane pith by a biological treatment and to assess the possibility of its maximum inclusion as a replacement with Lucerne hay in the diet of finishing Shal lambs.

Exogenous xylanases reduce anti-nutritional factors in feedstuffs and help optimise digestion in the small intestine through their positive effects on water holding capacity, nutrient packaging, digesta viscosity and flow. The net effect is reduced likelihood of both undesirable bacterial proliferation in the small intestine and migration of bacteria from the large to the small intestine leading to a disease challenge and hence reduced performance. Osmotic upsets have also been observed with pigs fed cereal-based diets, and the osmoregulatory role of betaine may strengthen the pig’s defence of this condition. As the mode of action of betaine is different from enzymes, it has been postulated that piglets may be responsive to combinations of these additives. The object of the experiment reported was to study the performance of weaner pigs fed diets containing differing rates of inclusion of exogenous xylanase and betaine.

Compared to meat from other animals lamb contains high levels of saturated fat, particularly stearic acid which comprises 18% of the total fatty acids (Enser et al, 1996). This stearic acid can be desaturated in the tissue by stearoyl coenzyme A desaturase (SCD) to produce oleic acid. In sheep SCD is produced from a single gene and the levels of SCD mRNA in the tissue correlate well with oleic acid (Ward et al, 1998, Barber et al, 2000) suggesting that an upregulation of SCD activity may increase the relative proportions of unsaturated and saturated fatty acids and so significantly improve the nutritional quality of sheep meat. Our recent studies have shown that insulin increases SCD mRNA levels and monounsaturated fatty acid synthesis in cultured ovine adipose tissue explants (Daniel et al, 2001). The present study was designed to investigate whether feeding a diet believed to manipulate SCD mRNA concentrations would significantly alter the fatty acid composition of lamb.

Non-starch polysaccharide (NSP) content of barley is predominately in the form of β-glucan, whereas in wheat it is predominately pentosans (containing the sugars arabinose and xylose). It has generally been accepted therefore that a high level of β-glucanase is needed in broiler diets containing barley, whereas wheat based diets require a high level of endoxylanase. Trials have however previously suggested that including an endoxylanase based enzyme in broiler diets will perform at least as well as enzyme containing highlevels of β-glucanase in diets containing up to 30% barley. To confirm this finding, a trial was initiated at Roslin Institute, Edinburgh to compare the effectiveness of Natugrain Blend 66% (an endoxylanase based product) against Natugrain 33% (endoxylanase/β-glucanase product) in diets containing up to 30% barley.

Modern feeding practices often lead to ruminal conditions being sub-optimal for fibre digestion. It has been speculated that fibrolytic enzymes, which usually show optimum activity at pH values below 6.0, may be of benefit when applied to diets of high producing animals. This study used a commercial enzyme mixture (EM), already identified as effective; to investigate its optimum pH range with respect to activity and its impact on the fermentation profiles of pure substrates, under differing pH conditions.

A number of fibrolytic enzyme preparations have been shown to increase the rate and extent of fermentation of alfalfa fractions (Colombatto et al., 2000a). However, responses to enzyme addition have been mixed and several factors are believed to be involved. Among these, specific enzyme activities and application rates are very important. The present study examined a commercial enzyme preparation already established as effective, for its ability to increase the rate and extent of in vitro fermentation of alfalfa stems, when applied at different levels.

Results in the literature concerning the efficacy of feed enzymes for ruminant diets have been mixed. Commercial preparations currently used are fermentation extracts containing several enzymic activities. It has been suggested that ruminal fermentation of grass and maize silages is enzyme-limited (Wallace et al., 2001). In order to design better enzyme additives, the enzyme activities likely to affect the animal responses should be identified. This study examined 23 commercial enzyme preparations for their biochemical properties and their ability to influence the in vitro degradation of alfalfa and maize silage.

Although wheat is an important ingredient in poultry diets, a large variability of the nutritive quality of wheat especially in its AME value is reported. A negative correlation between the lower AME in wheat or other cereal grains like barley, rye and triticle and their amount of soluble non-starch polysacharides (NSP) has been found in birds (Annison, 1990). A positive correlation between the amount of NSP in grains and the viscosity of the gut is also reported (Van der klis et al., 1995). High viscosity of the gut reduces the performance of the birds. Detrimental effect of NSP can be decreased by adding NSP degrading enzymes in the diet (Annison, 1992). Therefore the objective of this experiment was to study the viscosity of different wheat cultivars and triticle and the effect of NSP degrading enzyme supplements in young broiler chickens.

Yeasts have been studied and used as source of proteins for animal feeding over many years. Recently, new ideas on their use has lead to studies to enrich yeasts with micronutrients and use them as vehicles in feed production. Yeast cellular components are also used to improve the animal health and performance. The use of living yeasts are also thought to improve animal food consumption and reduce cell damage caused by substances such as aflatoxins found in animal foods. Aflatoxins, secondary metabolites produced by some fungi in foods and feeds can, on ingestion, result in the illness or death of animals. The aim of this study was to investigate the effects of Saccharomyces cerevisiae living cells and its derived products on animals when they are supplied with diets contaminate by aflatoxins.

Selected fibrolytic enzyme preparations applied at ensiling have been shown to reduce the fibre contents and to increase the initial rate of in vitro organic matter degradation (OMD) of maize silage (Colombatto et al., 2001). However, there is little information on changes in the fibre content of maize forage during the ensiling process, as affected by enzyme addition. The present study examined the effects of characterised enzyme preparations (Colombatto et al., 2000), derived from mesophilic and thermophilic fungal sources applied at ensiling, on the quality and in vitro rumen degradation characteristics of maize silage, as assessed using the Reading Pressure Technique (RPT, Mauricio et al., 1999).

Castration is a routine procedure for male farm animals. The ethics of castration are widely debated because the procedure may potentially result in pain and distress. The indications for early castration in farmed guanacos are: 1) prevention of aberrant behaviour in human-imprinted males, 2) elimination of inter-male aggression, so that males may be housed together or with females, 3) avoidance of accidental breeding (Fowler, 1998). In addition, it has been argued (Molony and Kent, 1997) that to study the pain response to castration is ethically acceptable as the overall welfare of the animal is improved by the procedure. Guanaco farming has been recently established in South America, and there is therefore little information available on how guanacos respond to castration. The purpose of this study was to assess pain in farmed guanacos. The hypothesis was that pain experienced by guanacos due to castration may be displayed in behavioural and physiological changes, as has been reported in lambs, calves and piglets. The study was carried out in 2001 on four-month-old farmed male guanaco. Changes in plasma cortisol concentration and the frequency of specific daytime behavioural postures and activities following castration are reported.

The PECKA-BLOCK (Breckland International Ltd.) is a commercially available, cereal and baked-sand-based device designed to enrich the environment and reduce the incidence of behavioural vices, such as feather pecking and cannibalism. Pecking at this novel stimulus loosens cereal grains that can then be eaten. This device reduced inter-bird pecking in broiler chicks (Guy, 2001) though it is not clear whether the authors measured gentle or severe feather pecking, allopreening, or aggression. White string (polypropylene twine) elicits sustained interest by chicks and hens of various laying and its provision reduced feather pecking and pecking-related feather damage (Jones, 2001). The present study compared the responses of layer chicks to simple string devices and to soft and hard PECKA-BLOCKS.

Chickens can differentiate between cagemates and strangers and they are often exposed to unfamiliar birds in novel environments under modern farming practice; this can lead to xenophobia, aggression and distress (Rajecki et al., 1976; Jones, 1996). Chickens form olfactory memories and regulate their behaviour in response to naturally occurring and artificial odours (Jones & Roper, 1997). The presence of a familiar odourant (vanillin) increased social dispersal and feeding when familiar pairs of chicks from the same cage were tested in a novel environment (Jones et al., 2001); suggesting that familiar odourants can be reassuring. Here, we asked if the presence of a familiar odour (vanillin) would increase social affiliation when two unfamiliar pairs of chicks were placed in a novel test arena.

The importance of the quality of the human-animal relationship on the productivity and welfare of commercial farm animals is now well established. Previous work in pigs has found negative correlations between productivity and avoidance behaviour of a human subject (Hemsworth et al., 1981). However, other reports have shown no relationship between avoidance behaviour and growth or physiological measures of chronic stress resulting from aversive handling suggesting that other factors may affect this behaviour (Pearce et al., 1989). The present study examined the influence of environmental and husbandry factors on the response to humans in commercially housed grower and finisher pigs.

Gastric ulceration in pigs is an important condition as it has been associated with a number of signs indicative of poor welfare and reduced growth rate and FCE (Dybkjaer et al., 1994). The effects of diet, particularly feed processing methods, on the occurrence of this condition are well documented (O’Brien, 1992). It has also been suggested that “psychosomatic and other stress factors” may be important in the aetiology of this condition (O’Brien, 1992), but there is currently little information available. The present study was designed to investigate factors within the rearing environment and management techniques that were associated with the presence of gastric ulcers at slaughter.

When piglets are weaned at around 3 to 4 weeks of age consumption of creep food can be very variable between pigs, some not consuming any (Pajor et al, 1991), there being little opportunity to learn about solid food from the sow. Thus weaning results in a temporary reduction in nutrient intake while the pig learns to accept solid food and this results in a depression in growth, the weaning check. In other species, such as the rat, animals can learn about novel foods from a knowledgeable conspecific (Galef, 1994) but it is not clear if this transfer of knowledge occurs in pigs. Morgan et al. (2001) observed an enhanced food intake of pairs of pigs containing an experienced and inexperienced pig of the same age housed together compared to a similar pair housed apart or a pair of inexperienced pigs. Therefore, in this experiment the influence on solid food intake and growth by inexperienced piglets when housed with an experienced older pig was examined under more practical group-housing conditions.