Accurate prediction of daily food intake is a fundamental prerequisite of any nutritional model designed to provide feeding recommendations for lactating dairy cattle. Consequently, much research effort has been expended over the last twenty years in developing food intake prediction models. These range from relatively simple multiple regression models to much more complex theoretical models embracing animal and food characteristics and environmental influences. However, given the major changes in the types of diet now offered to dairy cows, coupled with changes in genetic merit/milk production potential, it is important to examine if the food intake prediction models currently used within the British Isles are appropriate for to-day’s dairy cow. This paper examines the accuracy of prediction of a range of intake models for diets based on grass silage, concentrates and brewers grains.

It is frequently assumed that energy intakes from mixed foods with a high proportion of silage (HS) are lower than those from mixed foods with a high proportion of concentrate (HC), because of short-term constraints, i.e. gut fill, that physically limit the amount of food a cow can consume. It was the aim of the present study to analyse how different proportions of concentrate in mixed foods affect short-term feeding behaviour. We hypothesised that cows offered HS are likely to have more meals that are more spread out during the day and vary less in size than cows offered HC. Alternatively, we expected higher correlations between meal size and the length of intervals before (pre-prandial) or after (post-prandial) meals for cows offered HS than for cows offered HC. We tested the hypotheses with a data set of 21195 meals.

One of the ways by which UK farmers can maintain profitability in the current low milk price climate is to increase home-grown forage utilization in livestock diets. Previous work has shown that pea/wheat bi-crops are energy and protein rich forages that give higher intakes and nitrogen (N) retention than grass silage but only marginal improvements in milk production (Adesogan et al., 2000). This study determined whether the milk response from such bi-crops could be improved by using a short-straw pea variety instead of the conventional tall straw variety.

The UK ruminant industry is currently reliant on soyabean meal and fishmeal as sources of high quality, digestible undegraded protein (DUP). However, there is increasing concern over the sustainability of fish stocks, and the world market price fluctuation and traceability of soya bean meal. There are a number of protein crops which will grow under UK conditions including sweet white lupins, peas, field beans and oilseeds (rapeseed meal and linseed meal). However, these proteins tend to be more rumen degradable than fish meal and soyabean meal (Moss and Givens, 1994). Heat moisture treatment has been shown to be particularly effective in reducing the rumen degradability of protein without reducing intestinal digestibility (Herland, 1996). This experiment was undertaken to determine the effect of feeding moist heat treated rapeseed meal, lupins and beans to dairy cows.

In a previous experiment with dairy cows at this Institute, in which fodder beet was included as a third component of the diet along with grass silage and concentrate, fodder beet considerably increased metabolisable energy intake (MEI), but there was little effect on milk yield (unpublished data). The main objectives of the present study were to examine the effects of including fodder beet versus concentrate in a grass silage diet, on milk production, digestibility of nutrients and the utilization of nitrogen (N) and energy at equal ME intake in lactating dairy cattle.

The efficiency of utilisation of grass nitrogen for milk protein production tends to be low, because rumen fermentable energy sources limit the amount of diet amino acids that are incorporated into microbial protein. As a consequence, absorption of ammonia from the rumen and excretion of high-N waste products is considerable. Previous studies (Miller et al., 1999) have shown that the efficiency of use of feed N can be increased in late-lactation dairy cows by feeding ryegrass bred to contain a high concentration of water soluble carbohydrates (WSC). The objective of this study was to investigate milk production and N partitioning in early lactation dairy cows using the same high WSC ryegrass variety, AberDove.

Betaine has three chemically reactive methyl groups attached to the nitrogen atom of the glycine molecule. Therefore, it can be used as a methyl group donor partially to replace methionine in poultry and pig diets. Recent work also suggests that betaine has an energy sparing role by reducing maintenance requirement of the pig (Schrama and Gerrits, 2000). Betaine has improved performance and carcass leanness in some studies but the results are variable and seem to depend on age and sex of the animal, feeding level and diet composition.

Choline can also be used as methyl donor in animal feeds. In poultry, methyl groups are available after the conversion to betaine in the liver. However, dietary betaine is twice as efficient as the equi-molar dietary choline for increasing liver betaine levels in broiler chick (Saarinen et al., 2000). The aim of this study was to compare the response of pigs fed equi-molar betaine and choline in terms of pig performance and carcass characteristics.

There is a well-established relationship between particle size of processed grains in diets and pig performance. It has been reported that as the particle size of feed is reduced there is an increase in the performance of pigs (Wondra et al., 1995). Increasing the surface area of feed ingredients by reducing particle size facilitates greater enzyme activity. Liquid feed provides an excellent medium for endogenous enzyme activation and the opportunity to improve the availability of nutrients (Brooks et al., 1996). The current study investigated the effect of particle size, processing and feed form on pig performance.

In a previous study (Slade and Miller, unpublished), weaners fed a protein source high in porcine immunoglobulin (Ig) outperformed contemporaries fed an isonutritious and amino acid balanced diet containing an Ig rich bovine protein source (WGC). Diet analysis indicated differences between the protein source contributions to total dietary methionine (Met); 21.5% and 12.5% of 5.2 g/kg total Met respectively for bovine and porcine materials. Hydrolysis of bovine IgG in the proximal and medial thirds of the weaner small intestine is limited (Morel et al. 1995) and Met absorption from the piglet large intestine is insignificant (Darragh et al., 1991). Small intestine failure to degrade bovine Ig would therefore limit dietary Met availability. This limitation may be further confounded by retention of dietary Cys within the disulphide bridges of non-degraded Ig thereby increasing metabolic demand for Met. The objective of this study was therefore to determine the effect of Met supplementation on the performance of weaners fed an isonutritious diets containing the same level WGC.

The responses of pigs to diets supplemented with enzymes have been variable (review by Partridge, 2000). The situation has not been eased due to an uncertainty over the usefulness of laboratory analyses of enzyme activity as a measure of performance. One issue has been the temperature of feed pelleting in which laboratory assays for apparent enzyme activity have shown very low levels compared with the known level included in the feed, whereas experimental data have indicated typical poultry responses from the enzyme-supplemented feed (Bedford and Pack, 1998). The experiment reported here studied the performance of pigs fed diets to which enzymes were added either pre-or post- pelleting (which was conducted at 850 C).

Leg-weakness in female breeding pigs has serious implications both in terms of economics and welfare, accounting for up to 0.2 of first litter gilt cullings at an estimated cost to the UK pig industry of up to £3.0 million (Douglas, 1992), with the principal predisposing cause in the growing pig being osteochondrosis. It has been reported that selection for increased lean tissue growth rate and increased growth rate accompanied by ad libitum feeding of diets with high energy and nutrient concentration may increase the incidence of osteochondrosis and leg- weakness (Jorgensen and Sorensen, 1998), although evidence is largely equivocal. The effect of protein level in the diet is uncertain. Although both high and low levels of dietary protein lead to bone growth failure and fracture in human studies ( Reid and New, 1997), protein level has not been found to affect osteochondrosis in pigs (Jorgensen, 1995), thus the aim of the current study was to assess further the effect of protein nutrition on leg weakness in gilts.

Paratuberculosis (Johne’s disease) is a chronic invariably fatal enteritis of cattle caused by the bacterium Mycobacterium avium subspecies paratuberculosis and has recently been isolated from wild rabbits. One potential route of transmission of M.a.paratuberculosis from rabbits to cattle is the ingestion of rabbit excreta contaminating pasture. Here we (1) determine the prevalence and level of infection in rabbits and their excreta (2) quantify the level of rabbit faeces contaminating cattle pastures and (3) determine the impact of rabbit faeces on cattle grazing behaviour.

The consumption of condensed tannins has been associated with reduced faecal egg counts (FEC) and total worm burdens (TWB) in parasitised sheep. This can result from either a direct anthelmintic effect (Athanasiadou et al., 2000) and/or an indirect nutritional effect. Condensed tannins can protect dietary protein from rumen degradation and increase protein availability in the small intestine of the host; this could improve the expression of immunity towards parasites (Coop and Kyriazakis, 1999). The objective of the present study was to investigate the consequences of including a condensed tannin extract in foods of different protein content on the performance and development of immunity in parasitised sheep, during the phases of acquisition and expression of immunity.

Body reserves can be regarded as sources of nutrients at times of scarce nutrient intake. It has been suggested that the latter is responsible for the periparturient breakdown in immunity to parasites (BIP), since most scarce nutrients are expected to be allocated to the prioritised reproductive effort (Coop and Kyriazakis, 1999). Nutrient supply from body reserves may partly overcome scarce nutrient intake and, as a consequence, can be expected to affect BIP. It has been shown that an increased supply of dietary metabolizable protein (MP), but not of metabolizable energy (ME), reduces periparturient BIP (Donaldson et al., 1998). Therefore, we tested the hypotheses that body protein reserves, but not body fat reserves, affect BIP and its relationship with dietary MP supply in periparturient ewes.

Genetic evaluations in the United Kingdom (UK) for Somatic Cell Count (SCC) are currently based on a single trait repeatability model using the first five lactations. Only cows with completed lactations are included. However, to utilise information from cows with part lactation records and to achieve a better correction for environmental effects, a test day model (TDM) evaluation would be preferred. The objective of this study is to estimate genetic parameters needed for such a TDM evaluation by utilising a random regression (RR) approach.

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.

Anthrozoology (the study of human-animal interactions) is proving that human interactions with animals can have a severe impact on their welfare, production and ease of management; and can therefore have a substantial impact on productivity of a livestock unit. Recent research on dairy cattle shows how the quality of human-animal interactions has a potentially greater effect than with other intensively farmed species, due to the extended duration, intensity and frequency of contact. Early work by Bouissou and Boissy (1988) imposed various positive handling treatments on young heifers to determine the most sensitive time to socialise cattle to humans and investigate subsequent ease of handling; it revealed that the benefits of handling decreased with time, it was harder to establish a positive relationship with older animals but the work did monitor the heifers upon entry to the milking herd. Our research is designed to bring together techniques and hypotheses of previous pioneering work and carrying it to its commercially important conclusion when the dairy heifer calves, enters the herd and commences her productive milking life. The aim is to investigate whether the extent and nature of human contact during the rearing period has an effect on heifer welfare and subsequent production.

Extensive research into human-animal interactions, particularly in the pig industry, has led to the proposal that high fear of humans, through a stress response, can limit an animal’s growth, reproduction and welfare (Hemsworth et al., 1993). In a recent study in the Australian dairy industry, a significant negative between-farm correlation was found between the avoidance of an experimenter by cows in a standard test and milk yield of the farm, suggesting that fear of humans may also have implications for the productivity of dairy cows (Breuer et al., 2000). The behaviour of stockpeople is a likely factor affecting fear of humans in dairy cows (Breuer et al., 2000). It was the aim of this experiment to investigate the effects of handling on the stress physiology and behaviour of dairy heifers.

The open-field test can be used to measure temperament in dairy cows (Kilgour, 1975). Temperament or emotional reactivity reflects an animal’s ability to cope with an environmental change or challenge (Lawerence et al, 1991; Manteca & Deag, 1993), and consequently assessment of this can be effective in the development of novel production systems. The aim of this experiment was to identify temperament differences between two breeds of dairy cattle, Dutch Holsteins (DH) and Norwegian Dairy Cattle (NC), in two production systems.

The gastro-intestinal tract (GIT) microflora is thought to remain essentially stable in terms of the range of species present, but it is hypothesized that its activity can be influenced by the diet of the host. The addition of fermentable carbohydrates to an animal diet, may therefore affect the activity of the GIT microflora.