Compared with other species of farm livestock the reproductive performance of beef cows is poor. Mating and calving periods are frequently extended to avoid having a large proportion of barren Cows. vs. For example the ‘average’ MLC recorded herd has a calving period of over 4months. This makes management of beef cow herds difficult and has a deleterious effect on biological efficiency and profitability.One of the major limitations to improvement of reproductive efficiency in beef cattle is the extended post-partum anoestrus. Beef cows have longer post-partum anoestrous periods than dairy cows. In one study of three different herds (Peters and Riley, 1982) the mean length of the anovulatory period ranged from 24 to 88 days.
Lameness in dairy cows has both important animal welfare and economic implications. High concentrate to silage ratios may be an important predisposing factor, whilst trimming has been advocated as an effective preventative measure. This trial examined the effects of these two factors on locomotion, incidence of lameness and hoof measurements.
There is increasing interest in the use of white clover rich swards in dairy cattle systems in response to evironmental pressures and the introduction of milk quotas. White clover (Trifolium repens) in association with Rhizobium bacteria in a mixed sward receiving no fertilizer nitrogen can produce yields equivalent to a grass sward receiving approximately 200 kg N/ha/annum. Field scale cutting experiments (Roberts et al, 1989) have deomstrated that under an intensive 3-cut silage regime a grass/white clover sward receiving no nitrogenous fertilizer can yield 0.71 of the DM herbage output of a grass sward receiving between 320 and 340 kg N/ha/annum. Feeding experiments have demonstrated the ability of white clover to improve milk yield and composition (Castle et al, 1983, Thomson, 1984). To further investigate the potential of white clover for dairy cattle a systems study is being conducted. This paper summarises the performance of the two herds in the first year.
The herbage intake of June/July calving cows in early lactation is limited by a number of factors including the quality of the sward. A typical management strategy is to graze dry cows at a high stocking rate at turnout to maximise the silage area and graze the freshly calved cows on silage aftermaths. A further refinement could be the use of clover rich swards. Winter feeding experiments have demonstrated that animals can eat more and perform better when offered a clover rich silage rather than a conventional silage. The following experiment was carried out to establish whether similar benefits would result from the grazing or clover rich swards.In a continuous design experiment lasting 12 weeks, sixteen summer calving British Friesian cows (mean calving date 7 June) were allocated to either a perennial ryegrass dominant sward (PRG) or a white clover rich sward (WC) silage aftermath. The target sward height was 7-10 cm measured by swardstick. Additional cows were available on a put and take basis to maintain parity between the sward heights in the two treatments.
The development of an efficient laboratory procedure which would enable cattle ovarian oocytes to be matured in vitro, fertilized and cultured in vitro to the blastocyst stage of development could have important practical and scientific implications. The commercial exploitation of certain embryo transfer techniques applicable in cattle (eg., twinning by embryo transfer) might be facilitated by the development of such a procedure and there would be many advantages to having a cheap source of embryos available for research purposes. The present report deals with some of the studies recently carried out in this laboratory aimed at utilising follicular oocytes recovered from the ovaries of cattle slaughtered for beef at the abattoir. Such studies have been undertaken over a period of almost twenty years, starting with the work of Sreenan (1968)* but it now realised that the oocytes of farm mammals are incapable of normal development until after the completion of complex changes during maturation.
Previous work reported at last years' conference (Hyslop, Offer and Barber, 1989) has demonstrated that the inclusion of molassed sugar beet shreds (MSBS) with malt distillers grains (draff) at ensiling; greatly reduces dry matter loss and enhances animal performance compared with ensiling draff alone. It has also been observed that draff may comprise up to 30% of dietary DM in silage based complete diets for dairy cows; without loss of performance (Hyslop and Roberts, 1989). This experiment examines the long term technical and economic consequences of replacing barley and soya with draff plus additional minerals in dairy cow diets. In addition; a comparison is made between draff ensiled alone, or in conjunction with MSBS.
Commercially produced grower diets for the period 10 to 30 kg liveweight normally contain 13.7 to 14.0 MJ digestible energy per kg. To achieve this level of energy, high energy ingredients such as fats or the higher energy cereals are necessary. These sources of energy normally cost more per unit of energy supplied than lower energy ingredients such as barley or wheat offal. Two experiments were conducted to examine the response of growing pigs to lower energy diets over the liveweight range 10 to 30 kg liveweight. In both studies the diets were given ad libitum as wet meal.
There has been much recent interest 1n the Duroc as a possible ‘third breed’ in the UK. In particular, claims have been made that meat obtained from Durocs has high eating quality because of raised levels of intramuscular (marbling) fat. In practice, the Duroc 1s likely to be used 1n crosses involving the ‘white’ breeds. Therefore, in this study, carcass and meat quality were examined 1n Duroc, Landrace and Duroc x Landrace pigs produced contemporaneously.Twenty-one entire males from each of the breed types were used. Landrace pigs were from a long-established Nucleus population of British Landrace. The Durocs were from a selected Nucleus line, originally established from an importation from Canada 1n 1968, expanded and improved by subsequent North American importations and then extensively upgraded by frozen semen from the USA over the period 1980-85 using a wide range of sires. The D x L progeny were produced alongside the purebreds in the Nucleus. All pigs were fed ad libitum on a ration containing 13.8 MJ DE, 200g crude protein and lOg lysine per kg and slaughtered at approximately 80 kg live weight at the IFR abattoir following a standard pre-slaughter procedure.
The Welsh Plant Breeding Station at Aberystwyth has bred varieties of oats which do not retain their husk (Lemma and Palea) when threshed. These “naked” oats (Avenu nuda) are of a relatively high nutritional value, and at Trawsgoed EHF a spring sown variety, Rhiannon, has been used to evaluate their suitability as an alternative to expensive cereal products, such as oat flakes, presently used in piglet rations. Chemical analyses showed Rhiannon to contain in each kg 15.5 MJ of digestibile energy, 132 g of crude protein, 5.5 g of lysine and 8.2 g of lipid. Crude fibre content was low as expected (21 g/kg).
The recent renewed interest in the feeding of fibrous feedstuffs to pigs has been precipitated by a number of economic and welfare issues. To reduce the costs of pig meat production, farmers have increased the use of cheaper ingredients which tend to contain a high proportion of fibre. The feeding of finely ground cereals in intensive systems has been linked with high rates of mortality resultant from gastric lesions. Adding materials rich in fibre can be beneficial in this respect through its effects on the gut environment.The addition of fibrous feeds to a diet will however have the effect of diluting the energy concentration of the diet and it is likely that counterbalancing levels of high energy materials will need to be added in order to maintain energy levels.Fibre digestion in the ruminant is known to be depressed by the addition of lipid to a diet and it may be that fermentation in the hind gut of the pig is similarly affected. Tallow, a saturated fat, and maize oil, an unsaturated oil, were used to investigate the effect of saturation of lipid on the digestibility of fibre from wheat bran. The effect of level of wheat bran on fibre digestibility was also examined.
A recent survey of the handling of commercial slaughter pigs suggested that many animals could experience long periods without food before they were killed. Because prolonged food deprivation is detrimental to carcass yield, meat quality and possibly the animals’ welfare, fasting times in pigs killed in four slaughter plants were assessed. Length of fast was estimated indirectly from the concentration of glycogen in the animals’ livers. The relationship between time of food withdrawal and liver glycogen was determined in laboratory experiments using 341 pigs killed after defined fasting periods ranging from 0 to 48h.
An animal's rate of protein accretion (or nitrogen retention) is determined by the most deficient (or first limiting) amino acid in the diet, in a perfectly balanced (or ideal) protein all essential amino acids and the sum of the non-essential amino acids are equally limiting. If a dietary protein had any amino acids in excess of the ideal pattern, then the removal of any of the excess should not affect nitrogen retention. This principle was used to determine the ideal dietary amino acid pattern for growing pigs.Three nitrogen balance trials were carried out with a total of 64 gilts of weight from 30 to 55 kg. Casein and a mixture of amino acids were used in the semi-purified diets. The animals were given the diets at the rate of 93 g/kg BW0.75/d in three equal meals mixed with 0.3 L water. The feeding times were 08.30, 12.30 and 17.30. All pigs received their experimental diets for 7 days, made up of 3 days preliminary and a 4-day collection, except that the preliminary period before the first collection in the first period was 7 days. Before the first collection bladder catheters were introduced.
Copra meal is a by-product of the coconut oil industry and is a potential source of protein and energy in the diets of pigs and poultry in the tropics. However, previous studies with pigs have suggested that its use may be limited because of poor growth performance associated with levels of inclusion above 300 g/kg (Creswell and Brooks, 1971). The experiment reported here and conducted under tropical conditions at the University of the Philippines at Los Banos was designed to study possible ways of feeding copra meal at levels of inclusion greater than 300 g/kg in the diets of pigs while maintaining acceptable animal performance.
In general apparent ileal digestibility values of amino acids are lower than apparent faecal digestibility values (Just, 1980) and since nitrogen entering the large intestine may not be utilised by the pig (Zebrowska, 1973) apparent ileal digestibility values should offer a better estimation of the nutritive value of dietary protein. However, for this to be confirmed it must be demonstrated that such values when used in diet formulation are more accurate predictors of pig performance. Therefore, a trial was conducted to examine whether the detrimental effect of heat treated fish meal on pig performance could be reduced by formulating diets based upon either apparent faecal or ileal amino acid digestibility values.
The efficiency of pig production can theoretically be increased by combining the two productive functions, growth and reproduction in the same animal. This is the underlying principle of the once-bred gilt. The production of once-bred gilts also serves to solve another problem, which is the difficulty of providing adequate welfare for the sow over several parities. These problems arise because the Increasingly diverse size of sows as they mature, results in fighting, particularly when sows are mixed after completing the lactation. Similar reasons also virtually necessitate individual feeding.throughout pregnancy To overcome these problems, it is widespread practice to confine sows very closely in individual stalls or farrowing pens for several years, a practice which has rightly attracted some criticism.
The widespread use of artificial insemination (AI) in the United Kingdom sheep industry has been limited by the poor conception rates obtained after cervical insemination of frozen-thawed semen. The major problem in this respect is the impairment of sperm transport through the cervix, particularly when AI is used in conjunction with oestrus synchronisation.Previous studies (Killeen and Caffery, 1982; Maxwell, 1984) have indicated that a laparo-scopic technique for intrauterine insemination in ewes may overcome such limitations. At the moment, however, sufficient data on the optimum time of insemination and sperm doses required to maximise fertility in British breeds are not available. The present study was conducted to establish the optimum time of intrauterine insemination using frozen-thawed semen.
The importance of a high lambing percentage in early lambing flocks is well recognised as is the variability of the dose response to PMSG of early lambing ewes. It was hoped that the integration of the immunogen ovandrotone-albumin (Fecundin ® Coopers Animal Health) into such a system would give a reliable increase in ovulation rate without the danger of superovulation caused by higher doses of PMSG. Unfortunately, last year Logue, Gill and McClelland (1986) and Keeling, King and Gunn (1986) independently reported that although Fecundin treatment in early lambing flocks (using progestagen sponges with and without PMSG)gave an increased litter size over controls there was a considerable reduction infertility which negated this advantage. These groups employed a regime of a sensitising injection, a boosting injection 28-30 days later, and ram introduction to an induced oestrus after a further 28 days(i.e. a Boost Tupping Interval (BTI) of 28 days) for the second group and 35 days for the first.
Buffer-feeding of grazing dairy cows, by allowing cows access to forage for a few hours each day, has been widely advocated as a means of maintaining high animal performance whilst enabling efficient sward utilization. However, in practice, responses to buffer-feeding with January/February calving cows have been extremely variable. The objective of this study was to examine if part of the variability in response could be explained by differences in the level of nutrition during the winter feed period.
Pig improvement schemes have generally concentrated on producing lean, efficient pigs with rapid growth rates, but there is growing concern that pork is being produced which is too lean and that meat quality is deteriorating. The American Duroc breed may have an advantage over the Large White and Landrace breeds in eating quality through a higher level of intra-musclar fat. This study compares production and carcass traits in a three breed cross with Duroc and Large White boars as terminal sires and Large White x Norwegian Landrace dams. Pairs of sibs were penned and tested together and fed ad libitum or on a time based scale, and carcass measurements were taken at the end of test.
New developments in immunological techniques and increasing expertise in genetic manipulation, especially by gene transfer, have opened up a wide variety of approaches to the manipulation of the growth and metabolism of farm livestock. However, the most effective use of these techniques and the design of new pharmacological agents for growth promotion and nutrient “repartitioning” might well rest on a greater understanding of the factors and cellular mechanisms that coordinate growth and protein anabolism. It is this coordidnation that must be disturbed if persistent gains are to bke made. This greater understanding may well result from an examination of the mechanisms whereby currently available anabolic agents and techniques exert their effects and this paper will draw on these experiences. Growth is clearly a closely coordinated process and this has hampered many attempts to maintain accelerated protein deposition for long periods. For example forced increases in hormonal concentrations often induce hormonal insensitivity. It is possible that understanding and reducing the constraints on growth for example by reducing the levels of suppressive factors rather than concentrating on the active stimulation of anabolic factors may be more effective.
