The effect of age at first mating on lifetime reproductive performance of sows has been examined by Brooks and Smith (1980). They concluded that early mating had no adverse effects on later fertility and resulted in greater overall efficiency of feed utilisation. This may not be true in modern intensive production systems where early weaning results in depressed litter size (Clark and Leman, 1986).

Gilts were reared in groups of eight under an ad libitum feeding system and isolated from male pigs from 30 kg live weight until boar exposure at 200, 220 or 240 days of age (= B200, B220 and B240). Groups were transferred intact to the breeding area at the appropriate age. A mature boar was penned in the house, allowed in the pen with the gilts for 1-2 hours daily for the first 3 days and later only under supervision to allow heat detection. Animals were mated at the first observed oestrus after boar exposure. Those not mated by 35 days after boar exposure were culled.

Some reports have suggested differential tissue deposition of dietary trace minerals such as Zinc (Zn) when supplied to farm animals either chelated to amino acids or as inorganic salts. To test this hypothesis, an experiment was conducted to determine the ultimate tissue distribution of Zinc in rats fed either a radioactively-labeled 65Zn-chelate or 65ZnSO4. The 65Zn-chelate was prepared by heating a solution of 65ZnSO4 and an equimolar mixture of glycine and methionine for 5 minutes at 90°C. The resulting chelate was then separated from unincorporated 65ZnSO4 by gel filtration chromatography. Ten 25-d old male wistar rats (mean weight 34.5 g) were randomized by weight into two groups (n = 5/group), fasted for 18 hours and given 0.4 ml (8 μg Zn, 1 μCi65Zn) of one or other labelled solution by gavage. Four hours later, animals were returned to their normal diet for the duration of the experiment. The 65Zn activity of the animals was determined two hours after administration and daily thereafter for 7 days.

The perchery (barn) design for laying hens utilises the vertical space within a building which is occupied by the perches, slatted sections with feeders and drinkers all at several levels. There are also dust bathing areas and roll-away nest boxes. This arrangement allows the stocking density to be increased to 17 birds/m2. Consequently, capital costs are reduced and optimum environmental temperatures can be achieved. These two considerations give this system a marked advantage when compared with a deep litter system. The perchery system also gives the hens freedom of movement and allows them to exhibit their natural behaviours, such as wing stretching, dust bathing and nesting. Thereby, overcoming the objections made to housing hens in battery cages. This study was done to determine the use of resources within the perchery by laying hens and to compare their body condition at the end of the laying period.

In recent years there has been a concerted effort to reduce the cholesterol content of the human diet. The hens egg is a major source of cholesterol in the diet, and many attempts have been made to reduce its cholesterol content. Genetic selection [1,2], changes to the diet [1] and the use of hypocholesterolaemic drugs [1,3,4,5,6] have all been investigated. While some relatively modest changes have been reported, the majority of these studies suggest that egg yolk cholesterol is relatively resistant to change. However, little explanation has been given to account for these findings.

Egg cholesterol is derived from the liver and transported to the developing oocyte within very low density lipoproteins (VLDL). These particles are also responsible for the transport of triacylglycerol to me egg. If egg cholesterol is to be reduced, men VLDL must be specifically depleted of cholesterol. In me present study we investigated the effects of a cholesterol synthesis inhibitor on plasma VLDL concentrations and egg cholesterol. The compound used was simvastatin, known to be a potent inhibitor of mammalian hepatic hydroxymethylglutaryl CoA (HMG CoA) reductase, an important enzyme in regulating cholesterol synthesis.

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.

It is now accepted that variations in the concentration of skatole in fat tissue are important for the odour and flavour characteristics of pigmeat. Higher values lead to more complaints of ‘off odours’ and taints. Certain husbandry systems and diets have been implicated as producing high skatole concentrations whereas a previous study showed that increasing the concentration of a highly fermentable fibre source such as sugar beet feed reduced skatole levels (Wood, Longland, Enser and Nute, 1993). This was a surprising finding based on the literature (Lundstrom, Malmfors, Malmfors, Stern, Petersson, Mortensen and Sorensen, 1988) and this study was done to provide confirmatory information.

Forty-eight pigs, equal numbers of males and females, were fed a concentrate diet (15.3 MJDE, 215g crude protein per kg) containing different proportions of molassed sugar beet feed (MSBF) between 25 and 85 kg live weight. The proportions were 0, 150, 200 and 250 g/kg MSDF and 12 pigs in each treatment were fed ad libitum.

Weight loss on cooking contributes to the perceived value for money of lamb sold as chops or joints. Information on this attribute was monitored in the course of eating quality assessments made on cooked meat. Several factors are known to affect the weight loss of meat during cooking, greater loss occurring with increased time spent cooking and with increase in surface fat (Burfoot, 1987). Studies have shown differences between cuts in weight loss on cooking but effects due to dietary treatments are not known.

Joints and chops from lambs reared on three pasture types and two weaning treatments were roasted or grilled and weight loss during cooking studied. Eight lambs were reared from birth to slaughter at 20 weeks (off mother) on either diploid perennial ryegrass (D), tetraploid perennial ryegrass (T) or tetraploid ryegrass/white clover (TC). Another group of 24 grazed for a further 8-9 weeks after weaning on the three pasture types and were then slaughtered (off pasture).

When fresh beef discolours, retailers either offer it at a discount to encourage sales or transform it into a processed product, in both cases incurring a loss in value. The bright red colour of meat is associated with the presence on the surface of oxygenated myoglobin (oxymyoglobin). The less desirable brown discoloration which develops in meat is due to oxidative changes transforming oxymyoglobin into metmyoglobin.

Various attempts have been made to reduce pigment oxidation in beef including supplementation of the diet with vitamin E. This is absorbed and incorporated into the cellular membranes where performs its antioxidant function, slowing pigment oxidation. The results of these experiments demonstrate how vitamin E supplementation improves colour stability and extends colour shelf life.

Packing meat in modified atmospheres, combining high concentrations of oxygen with carbon dioxide (i.e. 0.7 O2 + 0.3 CO2) has been shown to be very effective in extending colour life. Metmyoglobin formation is minimised by the high level of O2 and the high CO2 concentration inhibits bacterial growth.

Although the improvement in tenderness resulting from post mortem refrigerated storage of carcasses is of considerable commercial importance, the mechanism(s) by which this process occurs is unknown, although it has been suggested that intramuscular protein catabolizing proteolytic enzymes may play a key role (Etherington, 1984). In order to develop a clearer understanding of the biochemical mechanisms underlying meat tenderization, the objective of this work was therefore to compare the proteolytic capacity of muscle from species known to differ markedly in rate of meat tenderization (approximate time shown in parenthesis): chicken (2days), lamb (4 days), pig (5 days) and rabbit (8 days).

Two methods were used to quantify muscle proteolytic capacity: (i) at point of slaughter, a comprehensive range of cytoplasmic and lysosomal protease types were determined using specific fluorimetric procedures; (ii) in vitro, using tissue homogenate based time course assays to measure (via analytical electrophoresis) the rate of structural protein degradation by endogenous or lysosomal proteases.

1. 1. Major changes have taken place in the beef industry over recent years - in particular, the introduction of several continental breeds which have the potential for producing larger and leaner carcases. The Canadian Holstein has also been used extensively in the dairy industry, replacing British Friesians, with the result that beef cross carcasses from the dairy herd have tended to be larger and have poorer conformation.

2. 2. As a consequence of these changes there is concern in the industry that beef of poorer eating quality is now being produced. For this reason, and to aid in the development of MLC's Blueprint for beef eating quality, this trial was set up in collaboration with Genus to evaluate the eating quality of two traditional British beef breeds and four continental breeds slaughtered at different fatness levels.

3. 3. All progeny included in the trial were from Holstein Friesian type dams. They were sired by the following breeds:- Limousin (LM), Charolais (CH), Belgian Blue (BB), Piemontese (PM), Aberdeen Angus (AA) or Hereford (HF) and were finished on an 18 month beef production system.

Previous work has shown that grilling pork steaks to a high final internal temperature (80°C), which corresponds to “well done”, significantly reduces tenderness and juiciness but increases the intensity of pork flavour. This work was done to examine the effects of grilling on physical and chemical composition.

Two adjacent 25 mm-thick steaks with backfat and rind attached were cut from each of 62 deboned pork loins (taken from 90 kg live weight pigs, average 11mm P2 fat thickness). One steak was analysed fresh by dissection and standard analytical techniques and the other after grilling to 80°C final internal temperature.

Purchasing specifications for beef carcasses have been aimed at reducing carcass variability and elevating the visual and keeping qualities of retail cuts. But more recently, the Meat and Livestock Commission's blueprint for improved consistent quality beef has incorporated a number of post-mortem treatments aimed at improving tenderness. Do these treatments which include electrical stimulation, pelvic bone suspension, slow chilling and prolonged ageing, exert an influence on quality which masks the intrinsic variation due to the primary production factors of feed, age, sex and possibly breed, or are the production and post-mortem effects additive? To what extent are the post-mortem treatments themselves additive?

Abnormal behaviour can be caused by the animal's inability appropriately to express its “needs” (Hughes and Duncan, 1988) in modern husbandry circumstances. In pigs, close confinement and food restriction results in the development of abnormal stereotypies in some animals, but not in all. Individual temperament may influence the development of such behaviour and cause animals to cope differently with environmental stress (Terlouw et al., 1990). By determining an animal's temperament using individual behavioural characteristics, it may be possible to predict the response of a temperament “type” to certain conditions.

This study is part of a larger project concerned with the effects of housing and food level on the development of behaviours in group-housed sows. All the gilts entered a series of tests to measure individual characteristics prior to the main experiment. Two of the tests, one assessing an individual's response to a novel object and the other measuring social behaviour, are compared here.

The assessment of well-being is of prime importance in the development of new production systems. For meaningful conclusions to be drawn, every aspect under the broad headings of physical, physiological and behavioural well being should be studied. There are a number of instances where, in extreme circumstances, physiological parameters have been shown to affect health and production, and are considered by some to be useful in determining long term welfare status. There is, however, evidence to suggest that the interactions between physiological functions are too complex to allow simple conclusions. As part of a comprehensive study into welfare of group housed gilts (Stewart et al 1993) this paper describes the results of an immune challenge, an adrenal function test (ACTH challenge) and adrenal weight and how they are associated with other welfare parameters.

A survey of dry sow housing across England (Baynes and Hunter, 1993) was conducted to assess farmers' future plans and opinions regarding the onset of the 1999 ban relating to stall and tether housing systems. Results from this survey showed that approximately one third of English pig producers currently with these types of systems were undecided as to which system to choose. A number of case studies are currently being conducted on existing group-housed systems to contribute to a data base on group housing options.

Sows were housed in a general purpose barn which had been divided into 12 pens, each housing ten sows. Sows were liquid fed once a day in a common trough with partial barriers. Total space allowance was 2.96m2/sow, of which 1.23m2 was kennelled.

Over the last few decades, the modern domestic pig has been genetically selected to maximise weight and length of back for meat production. Consequently, its body shape has changed and the physical acts of standing up and lying down have become difficult and relatively uncontrolled, even without any modification that housing systems may impose. Confined housing systems restrict the amount of exercise that locomotory muscles perform, and may affect muscular conformation and strength. It is possible, therefore, that confinement will decrease any element of muscular control during standing and lying, even further. The objective of this study was to determine any relationship between muscular conformation and time taken to lie down in sows housed in different dry sow systems.

Most sows in the European pig industry are kept in confinement, and are restricted in the amount of locomotory exercise they can perform. Any difficulty in carrying out the movements necessary for standing up and lying down, due to a lack of muscular and cardiovascular fitness, can indicate poor welfare for the sow. Also, because a large proportion of piglet mortality is attributable to over-lying by the sow when she lies down or stands up clumsily, there are welfare implications for her litter. The objectives of these studies were to investigate the time taken for sows to lie down in different dry sow housing systems, and to determine any relationships between the time taken and body dimensions of the sow.

A semi-outdoor system may provide low cost housing for non lactating sows in high rainfall regions where full outdoor systems are impossible. Two other means of minimising capital costs are dynamic grouping and communal floor feeding. These elements were incorporated into a pilot study using a dynamic group of 24 sows with a replacement rate of 5 sows every 2 weeks. One group of new entrants received so much aggression in the enclosed feeding arena that they subsequently refused to enter voluntarily and failed to integrate with residents in the straw-bedded house, preferring to nest as a sub group at the furthest end of the outdoor paddock. This failure may have been due to the enclosed feeding arrangements and/or to the size and replacement rate of the dynamic group. Experience with the pilot study lead to the experiment reported here in which two feeding systems were compared.

A survey of dry sow housing across England (Baynes and Hunter, 1993) indicated that 30% of producers currently with confinement systems would like to convert their existing sow buildings to conform with the ban on stall and tether systems in 1999. This study assessed the feasibility of a minimal cost conversion of part of a tether house in which the sows were liquid fed.

Sows were housed in a 21 year old tether house capable of housing 152 sows in four rows. The middle section of the house consisted of two rows of tethers, back to back, and part of this was gated off to create two pens, each capable of holding 10 sows in two rows of five. Total space allowance was 14m2/sow. Sows were of mixed weights and parities and all had previous experience of the tether house. Both groups were observed for three hours immediately after mixing, for two hours feeding on the following day, and for two hours on nine subsequent days. Eight categories of agonistic interaction (head swing with mouth closed, head swing with mouth open, push, attempted bite/slash, bite/slash, mount, vulva bite and fight of more than ten seconds), space usage and skin lesions (scored from one to five on eight regions of the body - Stewart et al, 1993) were recorded during each observation period. Sow weight and condition (scored from one to five - Whittemore, 1980) were assessed on entry to the building at four weeks post-weaning and on exit, approximately five days pre-farrowing.

Confinement of sows in farrowing crates and early weaning of piglets are two major areas of concern in relation to animal welfare in intensive pig production systems. In this project, two alternative lactation systems in which these potential stressors are absent or reduced were evaluated.

36 sows and litters were used in an experiment to evaluate, from weekly performance records and observations of behaviour, two alternative strategies for housing and management during lactation in comparison with a conventional current system:

• (1) Family system (F): Sows were housed throughout in groups of four with voluntary access farrowing pens. Piglets remained with the sows for 12 weeks and a boar was introduced after 3 weeks to induce oestrus.

• (2) Multisuckling system (M): Sows farrowed in individual crates but were grouped in fours in straw pens after 2 weeks. Piglets remained with the sows for 12 weeks and a boar was introduced after 3 weeks.

• (3) Conventional commercial system (C). Sows remained in part-slatted, unbedded farrowing crates throughout a four week lactation. Piglets weaned into flat decks and transfered after four weeks into fully slatted grower pens.