Malt distillers grains (MDG) and brewers grains (BG) are the fibrous residues remaining after the extraction of sugars from malted barley during the process of malt whisky and beer production, respectively. MDG and BG are popular supplements in beef finishing diets with up to 15kg/head/day being fed on Scottish farms (Lilwall, Smith and Wood, 1983). However, in some areas, close to distilleries and breweries, and particularly during the summer months, MDG and BG can be bought cheaply and ensiled, and could be fed to appetite as the sole or major part of the diet. This investigation explores this possibility.

Some unusual limitations of MDG and BG as a complete diet are that they are virtually devoid of soluble minerals such as Na and K and are low in some trace elements and vitamins. They also contain high levels of unsaturated fats which depress fibre digestion and voluntary dry matter intake (Miller et al., 1970). This effect can be partly overcome by supplementation with calcium carbonate (El Hag et al., 1972) probably by the formation of insoluble calcium soaps of fatty acids in the rumen. Based on these considerations a mineral/vitamin mix was designed specifically to supplement these materials.

The fibrous residue remaining after juice extraction from the sugar cane stalk is commonly referred to as bagasse. It consists mainly of the ligno-cellulosic polymer matrix and small amounts of ash and water soluble solids which are mostly sucrose. In sugar industry mills, most of the bagasse is used as fuel, and although figures vary within each factory, energy efficient units can have 2 tonnes of surplus bagasse (dry basis) per 100 tonnes of fresh cane processed (Rolz et al). The bagasse can be supplemented with urea and legume protein in cattle diets. Research in Mauritius (Wong et al. 1974) showed that high pressure steam treatment (200°C) for 2-5 minutes raised rumen “in situ” digestibility from 30 to 60%. Subsequent work (Naidoo et al.1977) emphasised the critical role of supplements providing bypass nutrients (protein and glucose precursors) , in addition to urea-N and minerals for rumen microbes. In Colombia this technology is now being applied commercially for cattle fattening, using the foliage from the legume tree, Gliricidia sepium as the main source of bypass protein.

The amount of connective tissue in meat is believed to be one of several factors which affect meat tenderness. Collagen, the major protein component of connective tissue in muscle, exists as an aggregate of three polypeptide chains, stabilized by intra- and inter-molecular cross-links. The degree of cross-linking determines its solubility to heat and affects the amount which is reduced to gelatine on cooking. This factor is now believed to be an equally important determinant of meat tenderness.

The aim of this work was to determine the effect of three different methods of carcass manipulation on muscle composition in young steers with particular reference to their effects on muscle collagen.

Twenty four Friesian steers (12 weeks age, 113± 6 kg) were offered silage ad libitum either alone (12 animals) or supplemented with 150g fishmeal/kg silage dry matter (DM). Half of the animals offered fishmeal-supplemented silage were also ear-implanted with oestradiol-17β. Six animals offered silage alone were also administered the β-agonist cimaterol via subcutaneously implanted osmotic mlnipumps (0.06 mg cimaterol/kg liveweight/d).

Meat production is a complex process in which the absorbed nutrients are directed under hormonal control towards muscle growth. According to consumer's standards a high quality carcass should contain a large proportion of lean meat and a small amount of fat. In Western Europe, cattle meat is produced both by beef and dairy breeds used as pure breeds or breed crosses. Holstein and Belgian Blue - double muscled type - are 2 extreme breeds in terms of meat production. The aim of the present experiment was to relate animal performances with plasma hormones and metabolites in these 2 breeds

Six Holstein bulls and 6 bulls from the Belgian Blue - double muscled type - were used. They were 4 and 6 months old respectively on the beginning of the experiment. They were kept in metabolism stalls. The fattening diet was based on dried sugar beet pulp supplemented with soja bean meal, rolled barley, hay, minerals and vitamins. The amounts of feed given were weighed daily. Live weight was recorded once weekly.

Successful and timely rebreeding is of major importance to the economics of suckler cow enterprises. Research into the causes of reprodutive failure and extended calving intervals can be difficult, not least because of the need for experiments involving large numbers of animals if statistically significant treatment effects are to be demonstrated. Useful information however, can be obtained from the analysis of data derived from a number of relatively small-scale experiments, not necessarily on reproduction per se, but in which records of reproductive performance are available.

This paper deals with the analysis of data on the reproductive performance of beef cows used in a number of experiments on the effects of nutrition during pregnancy and lactation on components of production such as milk yield and composition, calf birth weight and early calf growth rate. The objective of the analysis was to identify the major factors affecting calving interval and to quantify the magnitude of the effects of these factors.

Yields of milk and milk constituents In the National Milk Records (NMR) database are used not only to estimate total lactation yields at the end of a lactation, but also to predict future yields while the lactation is in progress. These predictions are based on the observed yields to date and on the anticipated pattern of future yields, i.e. on a.set of ‘standard’ lactation curves. New curves providing a better fit to the pattern of production of milk, fat, protein and lactose by cattle on a flat rate ration have recently been developed: In ( y ) =a + b ( 1 +t’ /2 ) t’ +ct ’ 2+d/t, where t is the days of lactation, t’ = (t-150 ) / 100 (Morant and Gnanasakthy, 1989). The next objective was to extend the model to take account of the increase In yields frequently observed following the change from winter feeding to grazing.

Records oolleoted from National Milk Reoords (NMR) are used by the Milk Marketing Board (MMB) to produoe genetio evaluations for bulls (Improved Contemporary Comparisons), cows (Cow Genetic Indices) and a management index for cows (Cow Production Index). It is Important to eliminate systematic environmental effects such as age at calving, month of calving and parity. The need for such adjustments and the factors involved have been documented by Schmidt and Van Vleck (1974). The purpose of this study was to calculate new adjustment factors for each dairy breed for inclusion In bull and cow evaluations.

Sire identified milk reoords of at least 200 days from cows completing laotations in 1885/8S were seleoted from the NMR data base for Ayrshires (A), Jerseys U) and Guernseys (G). Shorthorn (S) records from 1984 were also selected in order to provide sufficient data for analysis. A 10% sample of records were selected for Friesian/Holsteins (F/H) from 1987. The first five lactations were Included. The analyses were performed upon 16,878 S, 37,668 A, 38,925 J, 26,008 G and 80,445 F/H reoords respectively The data were analysed using a least square analysis of varianoe (Harvey 1977).

The ruminant is generally considered independent of an exogenous supply of folates; its synthesis by rumen microorganisms makes their inclusion in the diet unnecessary. According to Kon and Porter (1954), folates content of rumen is not affected by the quantity of folates in the diet. However, Dong and Oace (1975) reported that differences in feeding practices seem to be responsible for the variation of concentrations of folates in milk.

In previous studies, we observed that concentration of serum folates of calves aged 2 weeks was half the concentration in 4-month old heifers (Girard et al., 1989). Moreover, a supplement of folic acid administered by intramuscular injections from the age of 2 weeks to 18 weeks improved growth performances (Dumoulin et al., 1988). An increase of placental transfer of folates and/or of concentration of milk folates could have a beneficial effect on calf performances.

When autumn-calving dairy cows are turred out to grass, the sudden change in diet composition, particularly the drop in fibre content, can frequently result in a depression in the fat content of milk. This depression can be minimised by feeding forages such as hay or silage to cows at grass but this will usually result in a decrease in the overall energy concentration of the ration, thus decreasing potential performance. In rations fed to dairy cows during the winter, milk fat content can be increased by the use of supplements containing fibrous sources of carbohydrate or fat. Feeding high levels of fat can be counter productive, due to its effect on fibre digestion, but calcium soaps have been found to have less effect on runen fermentation than free fatty acids.

When concentrates are rapidly digested in the rumen of the dairy cows, turnover rate will increase and protein degradability consequently decrease. This may reduce the need for low degradability protein supplements but the rapid post-prandial release of energy for microbial digestion could cause a deficit of rumen - degradable nitrogen and low rumen pH. In two experiments two rapidly-digested energy sources were examined, molasses and extruded barley, and three nitrogen supplements, urea, soyabean and fishmeal, as well as the use of sodium bicarbonate to stabilize rumen pH.

A compound feed that is designed to be given in equal amounts with cereals for milk production would contain about 30% crude protein, and if rapeseed meal were the major high protein supplement to be used along with cereal, about 60% would need to be included. No observations have been reported in which this high proportion of rapeseed meal has been used and the experiment described was planned to provide this information, using low glucosinolate rapeseed meal. The control diet contained soyabean meal in place of rapeseed meal, and a third compound was used containing sunflower meal seed as the major protein supplement.

Thirty-nine Friesian cattle were used in a randomised block design: the three treatments, compounds containing low glucosinolate rapeseed meal, sunflower seed meal and soyabean meal, were applied for 16 weeks. There were 21 cows and 18 heifers, the mean days in milk at the start of the experiment was 62 days and the mean yield over the previous two weeks was 26.9 kg.

Milk production in the villages of Mauritius can be characterised as follows: about 90% of the ‘dairy’ cows on the island are owned by villagers. Cattle-rearing is a side-line activity of the family. Most villagers own one cow With a calf. No forage is cultivated. Forage sources for the cattle include sugar cane tops from June to December (harvest season) and shrubs and mixed grasses from road sides and common lands all the year round. All forages are available free and are collected by hand. There is very little or no use of concentrate supplements.

The cattle are a mixture of the local Creole breed, Friesians and their crosses. Artificial insemination is widely used. Milk production is generally low (1200-1500 litres per lactation) when compared with European dairy cows. Lactations are normally relatively short (225-250 days) and calving intervals long (15-18 months).

Since these cattle contribute more than 90% of the national production of fresh milk it Was decided, within the context of a project financed by the United Nations Development Programme, to investigate the extent to Which their productivity could be improved.

Almost all attempts to improve animal production systems in developing countries have failed because they relied on the transfer of technologies from developed countries. Livestock production systems in industrialized conuntries have high rates of animal productivity, which at the same time require high quality feeds, rich in energy and protein. Most developed countries are located in temperate climates in which cereals and high quality feeds and grains can be readily grown and have the currency to provide all the fossil fuel inputs required.

In order for Third World countries, located mostly in tropical regions, to adapt these systems, they must import exotic livestock and provide the high level of feeding at high cost. The transferred system has led to a loss of interest in indigenous breeds and local resources.

It is clear that there is a great need for new rural development strategies that should take into account not only food production but also renewable energy resources, employment generation, self reliance and protection of the enviroment. This strategy includes selection of crops and cropping systems which maximize biomass production, nitrogen fixation and minimize the use of imported or expensive inputs.

A simple and reliable aid to detection of oestrus in cattle would help to improve reproductive efficiency particularly where AI or embryo transfer is being used. A marking web, devised by Mr P M P Lumbar, was reported (Farmers Weekly, p40, 10 June 1988) to perform this function satisfactorily.

The marking web device is constructed simply from a piece of calico (8.5 cm x 8.0 cm) and a 8.5 cm x 2.5 cm strip of red household tape covered by a layer of black mastic stuck across the calico (Figure 1). The device is fixed to the sacral region of the heifer or cow using a suitable adhesive. Some of the devices were supplied by Mr Lumbar and the remainder were made by us. Pressure from the chest of the animal mounting peels the adhesive mastic from the underlying tape.

The marking web devices (MWD) were evaluated using two groups of maiden Hereford x British Friesian heifers. These heifers were 15 to 18 mo. old, they had a live weight of 421 kg and were in body condition score 2.4 units on average. Group I heifers (n=134) were housed in straw-bedded pens at a stocking rate of 4-5 m2 per head and fed on cut grass ad libitum supplemented with minerals and vitamins. Group II heifers (n=22) were set stocked on pasture at 6 heifers per ha.

Poor reproductive performance of dairy herds is seldom attributable to a high incidence of embryonic loss or to long periods of anoestrus, but is generally due to the failure to inseminate cows that are cycling normally.

Even in the best managed herds, oestrus detection rates rarely exceed 70-80%, and often 10-20% of non-oestrous animals may be recorded as being on heat. These shortcomings in oestrus detection can be overcome by monitoring oestrous cycles in Individual animals, thus enabling the time of ovulation to be predicted. For example, when cows that failed to show oestrus, were inseminated on the basis of milk progesterone profiles, the conception rates achieved were similar to those in cows inseminated at observed oestrus (Ball and Jackson, 1979). In addition, in groups of animals inseminated at progesterone-timed rather than at observed oestrus, the number of cows served over a one-cycle period increased dramatically (98 v 71%), and days from calving to first service decreased (78 v 92 days), (Foulkes, Cookson and Sauer, 1982). In this study, the feasibility of using on-farm milk progesterone kits as a practical method of predicting ovulation, and its effects on herd reproductive performance were assessed.

Genetic and technological studies have revealed correlations between different individual, or combinations of, alleles of milk proteins and parameters such as cheese yield, the compositional characteristics of milk and total lactation yield. The kappa casein B allele is better for cheese-making, for example (Table 1): the mutation may alter the mechanism by which this protein stabilises the micelles of the caldum-sensitive caseins against precipitation. When rennin cleaves kappa casein between amino acids 105 and 106 the micelle is destabilised and clotting of milk into curds ensues. Therefore, selection for defined alleles or haplotypes could be desirable.

Until now selection for milk protein alleles was only possible by the analysis of the proteins in milk. For sire selection this required analysis of milk from daughters which is time consuming and expensive. However, phenotypic variation in the proteins arises from base substitutions in the DNA, as is illustrated in Figure 1 for the kappa casein gene.

The importance of subclinical parasitic gastroenteritis (PCE) in terms of reduced productivity has recently been recognised, and this has caused attention to be focussed on prevention of infection as opposed to cure. The process of strategic treatment with anthelmintics and movement to fresh grazing proposed by Michel (1969), has been superseded by the need for preventative measures based solely upon anthelmintic control, rather than strict grazing rotation, and in response to this demand several systems have been developed.

In this trial the efficacy of a controlled release bolus containing albendazole, Captec, (Smith Kline Animal Health, Ltd., CSIRO) against gastro-intestinal nematode infections in first season calves was evaluated, the nematode challenge being monitored using untreated control calves.

2 groups of 20 heifer calves of approximately 9 months of age at turnout, were grazed from May to October on separate, adjacent paddocks obtained by splitting a single field which had been grazed by cattle the previous autumn. The allocation of calves to each group was such that the mean liveweight and range of liveweights within each group were similar. At turnout each calf in group A received a Captec bolus, group B being untreated controls. Total numbers and species of infective larvae present on the pasture were monitored throughout the grazing period. The calves were weighed and samples were regularly collected for the determination of faecal egg output, serum pepsinogen and plasma gastrin concentration. Post mortem worm burdens were assessed in 7 calves per group on day 100 after turnout, and again in 3 calves per group 1 week after housing.

Recent evidence indicates that body condition at calving has an important effect on the length of the post-partum anoestrous period in beef cows being longer in cows calving in low body condition (Richards et al, 1986, Wright et al, 1987). It is known that body condition affects baseline concentrations of LH (Rutter and Randel, 1984) and LH pulse frequency (Wright et al, 1987). However, the effect of body condition on ovarian follicles has not been studied.

An experiment was designed to examine the effect of body condition score (BCS) at calving on follicle populations, follicular steroidogenic capacity, follicular histology and patterns of gonadotropin release at two different stages of the post-partum period (5 and 9 weeks after calving) in suckling beef cows.

Thirty-eight suckling Blue-Grey cows with a mean live-weight of 567 ± 9.4 kg and mean BCS of 3.0 ± 0.05 at 110 days before calving to a synchronized insemination were differentially fed so that they achieved BCS of 2.83 ± 0.05 and 2.30 ± 0.05 for cows on a high (H) and low (L) plane of nutrition, respectively. After calving cows were fed a live-weight maintenance ration according to individual requirements. Cows of each BCS were ovariectomized at either 5 (w5) or 9 (w9) weeks after calving and follicles > 3mm in diameter were dissected from the ovaries and incubated for 2 h in culture medium (Medium 199) at 37°C. Follicles were then kept in Bouin's solution until histological examination. Follicle incubates were assayed for progesterone, testosterone and oestradiol. Blood samples were taken 2 days before ovariectomy for 10 h every 15 minutes and were later assayed for LH (all the samples) and FSH (every third sample).

In the United Kingdom, the use of rapeseed products in pig diets is limited, primarily because of the adverse effects of glucosinolates, a group of sulphur containing compounds which yield goitrogenic and toxic compounds on hydrolysis. Varieties of winter oilseed rape (B.napus) are now grown in the EC which have a much reduced level of glucosinolate in the meal. Rapeseed meal (RSM) contains other compounds principally sinapine,tannins and phytate which may reduce the nutritive value of diets into which it is incorporated.

The pig trial reported here was designed to determine the effect on growing pig performance of diets containing a range of glucosinolate contents but with a fixed amount of rapemeal. A rat metabolism study was also conducted which was designed to assess the biological value (BV) of the protein in the two rapeseed meals used.

Several experiments have shown (see Armstrong and Ross, 1968) that the addition of fats to ruminant diets can lead to a reduction in the digestibilities of forage cell walls due to adverse effects on the rumen microflora. Jenkins and Palmquist (1982) showed in vitro that the in situ formation of calcium soaps in the rumen could prevent this problem. Subsequently Jenkins and Palmquist (1984) have provided evidence that the feeding of preformed calcium soaps of tallow and soya oil fatty acids to dairy cows allowed normal rumen digestion of cell walls whereas non-saponified tallow fatty acids caused cell wall digestibility to be reduced.

Givens et al (1988) reported that a calcium soap of palm fatty acids (Protector, UFAC-UK Ltd) did not cause any reduction in the digestibility of neutral detergent fibre (NDF) when fed to sheep at up to 152.4 gkg-1 of total diet dry matter (DM). Since it is believed that these beneficial effects of calcium soaps are due to their reduced rumen solubility, the present experiment has examined this aspect in further detail.