The isolation of non pregnant cows in a commercial dairy herd represents a substantial cost to the farmer. The majority of cattle pregnancy diagnoses (PD)'s in the U.K. are made from rectal palpation or by the use of (a) milk progesterone (b) milk oestrone sulphate or ( c) blood progesterone tests. A D.I.Y. pregnancy test has obvious advantages, namely:-

1. 1. Tests can be performed by farm stockmen at their own convenience.

2. 2. Diagnosis is made immediately.

3. 3. Tests can be made through complete pregnancy term.

4. 4. After initial capital outlay for equipment, the cost of tests is negligible.

Such an alternative is the doppler ultrasound (DOP) system (per rectum) which utilises audible changes in frequency of ultrasound between the transmitted signals and their echoes when moving surfaces are contacted.

Reduced performance may result from the failure to confirm pregnancy in dairy cows. The earlier after service that pregnancy can be reliably detected the more useful the method of detection is. Both milk progesterone and veterinary rectal palpation are useful for very early and mid pregnancy confirmation respectively but both have limitations. The BOVEQ (FarmKey Ltd.) detects pregnancy using ultrasonics. Ultrasound waves have the property of travelling through liquids and solids but not air (or any other gas). When they meet an interface between different materials (e.g. fat/muscle, muscle/bone or a pregnant uterus and its contents) thry produce an echo, the strength of which is dependant on how much difference there is at the interface. The uterus of a pregnant animal changes in “tone” and fluid content shortly after breeding and this change is characterised by a specific pattern of ultrasound echoes.

The efficiency of oestrus detection is probably the most important factor determining the profitability of the dairy farming enterprise. With current trends towards larqer herds and fewer stockmen, achieving a 365 day calving interval has become increasingly difficult, with each oestrus missed representing considerable economic loss (Esslemont and Bryant, 1976). This highlights the need for an accurate method of oestrus detection

An experiment was undertaken to evaluate the use of milk temperature as a method of oestrus detection.

The rate of milk secretion in dairy animals displays a trend throughout the lactation period. It increases to a maximum in a few weeks following parturition and decreases thereafter until the animal goes dry.This trend draws a certain curve, namely the lactation curve.The milk yield of a single lactation may be influenced by many factors but the general shape of the lactation curve defined by the locus of weekly yields remains substantially unchanged. It rises rapidly to the peak within a few weeks after calving followed by a more or less gradual decline until the end of lactation.

The analysis of the lactation curve, i.e. the week to week output of milk and trend of increase and decrease in yield with advancement of lactation is important for day to day management and forward planning of dairy herds by reliable forecasting of week by week milk production, seasonal variation and the total milk yield of individual cows or groups of cows.

A number of reports pertaining to dairy cattle have been published but very few studies have been concerned with buffaloes. In most of the countries, the buffaloes have been used for draught purpose but it is in the Indian subcontinent that this animal is seen at its greatest advantage as a source of animal protein, i.e. milk and meat for human consumption.

Although milk substitutes attract a large subsidy from the EEC provided they contain at least 600 g skim milk solids/kg, several cheaper whey-based products have been Introduced commercially in recent years. Nevertheless, information on the nutritive value of such products is lacking. Since the calf is vulnerable to digestive upsets especially during the first month of life, an experiment was made to assess the effect on health and performance of replacing some or all of the skim milk solids with a mixture of whey powder and whey protein concentrate.

Experimental Thirty-two Friesian bull calves in a randomised block experiment were given one of four milk substitute diets containing 200 g fat and 260 g crude protein/kg DM from 2 to 64 days of age. The reconstituted diets (1 powder:6 water, w/w) were offered to appetite twice daily by bucket at 38°C. The quantities of skim milk solids in each formulation were (g/kg DM): none (diet WP1), 200 (diet WP2). 400 (diet WP3) and 600 (diet WP4), as shown in Table 1. In vitro tests showed that coagulation with rennin did not occur with diets WP1 and WP2 and the clot formed with diet WP3 was much softer than that with diet WP4.

The objectives of the experiment were:

1. 1. To assess the suitability of antigen-free soya protein concentrate (SPC) and whey products as major ingredients and the sole protein source in milk substitute diets for calves.

2. 2. To compare the effects of inclusion rates of 0, 350 and 700 g protein from SPC/kg dietary protein.

3. 3. To investigate the suitability of introducing these diets to calves at 2 or at 16 days of age.

A fat-filled whey based milk substitute (diet WP1) was compared with similar diets in which SPC provided 350 g/kg protein (diet SK1J or 700 g/kg protein (diet SK2). Thirty-six Friesian bull calves were given one of these three diets reconstituted in water (1 powder:6 water w/w), offered at 38°C by bucket to appetite in two feeds daily, either at 2 days of age or after a 14-day period in which they were given a skim-based milk substitute (diet WP4).

When straw was included in a ration and given to calves from 14 up to 84 days of age, dry matter intake was increased by up to 30 per cent from 1.36 to 1.77 kg per day compared with calves given the diet without straw (Williams, unpublished data). The calves given straw apparently gained an extra 8 kg in weight by 84 days of age compared with calves given the diet without straw. In order to assess the effect of roughage inclusion on the live-weight gains of calves an estimate of the rumen volume of the calves was required. Further since the majority of measurements of the volume of the digestive tract of calves were made after slaughter no studies have described the relationship between diet and the development of rumen volume in individual calves. Differences in rumen volume may be responsible for the large coefficients of variation in intake reported in groups of calves.

In the first 3 weeks of age the calf is most susceptible to diarrhoea. In a review of the literature, Williams (1977) concluded that the lower critical temperature of 3-day-old calves on restricted levels of feeding was between 9°and 13°C and by approximately one month of age was between 0° and 5°C. these temperatures can be increased by air movement (Blaxter and Wainmann, 1964). Grimble (1982) suggested that calves should not be exposed to air speeds greater than 0.25 m/s. Studies in older cattle and sheep, with a functional rumen, have shown that exposure to cold was associated with a lower apparent digestibility of feed, irrespective of changes in feed intake (Christopherson, 1976). Williams and Innes (1982) fed a milk substitute diet to calves from 24 to 38 days of age and compared housing the calves in air temperatures of 3° and 18°C. There were no significant differences between air temperatures in the apparent digestibilities of dry matter (DM), fat and nitrogen (N) (p>0.05) but there were significant increases in faecal water excretion and significant decreases in water intakes and urine volumes at 3° compared to 18°C (p<0.05). The present experiment was designed to determine the effects, at different feeding levels, of continuous exposure to cold (10°C) compared with warm (25°C) air and to low (<0.2 m/s) compared with high (>3.0 m/s) air speeds on (a) the apparent digestibility of a high fat milk substitute diet, (b) water intakes and faecal water excretions and (c) growth rates, in calves from 2 to 24 days of age.

A survey was conducted on 3200 purchased Friesian male calves to see if any easily measured parameters could provide an indication of possible problems in the subsequent rearing of the animals

The survey was conducted at the Agricultural Institute farm at Grange in the period January 1976 to June 1982. The effects of serum immunoglobulin status, purchase weight, calf source and feeding system on calf mortality and incidence of disease were assessed. The following catagories were used in the analysis.

1. 1. Immunoglobulin status as indicated by the Zinc Sulphate Turbidity Test (ZST). Calves were categorised as “low” (less than 15 ZST units) or “high” (greater than 15 ZST units).

2. 2. Purchase weight: Calves were categorised as “light”(less than 40kg) or “heavy”(more than 40kg).

3. 3. Calf source: Calves were categorised as “farm” (purchased direct from farms) or “market“ (purchased in auction markets).

4. 4. Feeding systems: Calves were categorised as “bucket” (individually penned on straw and fed various quantities of milk replacer by bucket) or “ad libitum” (group penned on straw and fed their milk replacer allowance ad libitum by teat).

Additional daily artificial illumination during winter has been reported to increase growth rates in both cattle and sheep.

In an experiment conducted at Seale-Hayne College between September 22, 1982 and March 29, 1983, 20 Hereford x Friesian heifer calves (approximately 7 days of age at the start of the trial) were randomly allocated to either a natural daylength treatment or an artificially supplemented 16L:8D photoperiod. Animals were weaned at 5 weeks of age and then fed on a restricted concentrate ration (2.5 kg/head/day) with hay provided ad libitum. Body weight, girth and height at shoulder measurements were taken at 2-week intervals. Hair samples (4 cm2) were taken from the mid-flank on January 13.

New techniques developed for the detection and resuscitation of hypothermic lambs were evaluated in 1931 by farmers and shepherds on thirty farms varying widely in type and location in Scotland.

Flock size varied from 60 to 2000 ewes. All lambs showing dullness or lack of vigour were to be examined and treatment determined by rectal temperature and by age if severely hypothermic. A prototype electronic thermometer was used indicating by coloured lights whether the lamb was not hypothermic (>39°C) , mildly hypothermic (37-39°C), or severely hypothermic (<37°C).

The ewesplint method of treating broken mouth in sheep was evaluated on five farms in Caithness and Sutherland. The ewesplint is a commercially available technique for splinting together the eight incisor teeth of sheep using a stainless steel brace and acrylic resin. The technique of splinting proved to require considerable skill and practice and is likely to remain a contractor's operation rather than a farm skill. Three lowland Caithness farms which had park-type North Country Cheviot sheep co-operated in the trial. On these farms the sheeps’ teeth were short and broad (“good teeth“) and tooth loss was not a major problem. Two Sutherland farms, one of which was Achany, with hill Cheviots and Blackface X Cheviot sheep co-operated. On these farms incisors were long and rat-like (“bad teeth“) and tooth loss was a major problem. Results on the effectiveness of splinting are shown in Table 1. Most of the sheep on the Caithness farms were unsuitable for splinting because the teeth were too short to carry a splint. Of those that were splinted most lost their splints (62 %) after one year because of inadequate amounts of cement penetrating between the teeth. A more brittle dental cement was used in the Caithness farms which may also have contributed to the higher rate of splint loss.

The amount of grass 8 weeks prior to mating, the condition of the ewe at that time, the stocking rate and the rate of herbage growth in the late summer and autumn will determine the condition score and ewe liveweight achieved at mating and during the post-mating period. Evidence suggests that for Greyface ewes, lambing rate increases with an increase in condition score at mating up to 3 provided that the achieved condition score can be held for 4-6 weeks post-mating.

Ovulation rate and lambing rate of Cheviot ewes are improved by both increased body condition and premating food intake. The aim of this work was to investigate the endocrine mechanisms by which one of these factors, intake, could influence reproductive performance.

Two similar groups of 20 ewes were fed differentially to achieve condition scores of either 2.0 or 2.5 by 4 weeks before mating in November. Low condition animals were then fed ad libitum and achieved a mean condition score of 2.3 and mean liveweight of 58 kg at mating. The remainder were offered a maintenance ration and had a mean condition score of 2.5 and mean liveweight of 55 kg at mating. Blood samples were collected at 20 minute intervals for 10 h approximately 7 days before mating and for 5 h on each of the 3 days immediately prior to the anticipated day of oestrus.

On the basis of experimental results, Forbes, Rees and Boas (1967) recommended that silage for pregnant ewes should have a DM content of at least 200 g/kg. Higher silage intakes and improved animal performance may be achieved by feeding silage of DM content in excess of this level.

Increases in lamb birth weight have been achieved with additional protein supplementation to ewes on hay based rations in late pregnancy (Clark and Speedy, 1981). The response to protein supplementation on silage based diets is less well documented.

In a 3 x 2 factorial experiment, 23A Border Leicester x Welsh Mountain in-lamb ewes, penned in groups of 18 or 21,were offered either an unwilted silage 199 g DM/kg) made with a formalin/formic acid additive (UA); a wilted, silage (287 g DM/kg) made with additive (WA) or a wilted silage (272 g DM/kg) made without additive (WO). The silages were offered ad-libitum from housing in January until lambing in mid-March.

The induction of early breeding in flocks of ewes under natural daylength conditions was made possible following the evolution of a modified progestagen - PMSG treatment (Gordon, 1971). However, lamb production from early bred ewes has invariably been lower than that achieved from ewes bred within the main breeding season. In attempting to elucidate the underlying determinants of the inferior fecundity of the early bred ewe, the present experiment was undertaken to compare the ovulatory and hormonal responses of ewes subjected to progestagen - PMSG treatment at different times of the breeding season.

We have previously demonstrated that trenbolone acetate (TBA) treatment of female lambs and rats reduces both plasma glucocorticoid concentrations and the adrenal response to ACTH. It has been suggested that this reduction in the catabolic glucocorticoids may aid the anabolic effects of this agent.

Four groups of 6 wether lambs were implanted with TBA (40 mg), TBA (35 mg) plus oestradiol (5 mg) or with a long-acting oestradiol implant (Compudose). Hourly blood samples were taken for 24 h periods just before and 10 days after treatment and Cortisol concentrations measured using a competitive protein binding assay.

If the classical analysis of variance procedure is followed ignoring the time correlation within individual animals then the residual sum of squares will be inflated and significant effects can be missed. The correlation can be modelled by extending the analysis of variance to include a Fourier Analysis. For each Fourier cycle considerd the variation can be explained in terms of an overall model, separate treatment models and separate individual models.

The finishing of store Blackface lambs off grass is often relatively unprofitable due to low growth rates and relies heavily upon changes in seasonal price. Anabolic growth promoters offer means of increasing growth rates and thereby make a relatively large impact on profitability.

Sixty Blackface wether lambs were grazed in each of two years on grass from September until slaughter before March. Whole barley supplementation was commenced in December. Lambs were sold deadweight arid MLC carcase classified. Lambs were sold when judged to be at a standard fat cover.

Lambs were left unimplanted (U), implanted with 12 mg of Zeranol (Z) or with 15 mg of Oestradiol - 17β (O) in September.

Tracerglass is a phosphate-based glass which dissolves in an aqueous environment at a slow and steady rate in proportion to the surface area of the glass (Telfer, Zervas & Knott, 1983). Tracerglass contains the trace elements copper, cobalt and selenium as part of the glass structure and therefore as the glass dissolves these trace elements are released into the aqueous environment. When placed in the reticulo-rumen of a ruminant by means of the normal balling gun method the Tracer-glass will dissolve, release the elements into the reticulo-rumen and thus make these elements available for utilisation by the rumen microbes and the animal itself. The Tracerglass-L form is a tapered bullet of average diameter 14 mm, length 40 mm and weight of 18 g which has been produced for use in lambs from 6 to 8 weeks pf. age. The Tracerglass-L dissolves at a rate that will maintain its effectiveness in lambs for up to 6 months while the adult sheep and cattle Tracerglasses will last for 12 months.

Because the majority of lamb in Britain 1s sold to the consumer ‘bone-In’ it 1s difficult to trim excessive fat. Nevertheless, consumer acceptability of specific retail cuts 1s markedly affected by the fat content of that joint at the point of sale. Therefore, any strategy which aims to define breed-specific carcass weights at slaughter needs to consider the effect this will have on retail joint weights, their composition and hence acceptability. This study examined the effect of breed, sex and carcass weight on the proportions of the four main lamb cuts, and their composition.

In this study a total of 317 castrated males and 238 females from six pure breeds (Clun Forest, Dorset Horn, Hampshire Down, Suffolk, Colbred and Welsh Mountain), were slaughtered in. the conventional manner. The range 1n cold carcass weight (CCW) was from 12 to 24 kg. Carcasses were jointed and each of the nine joints then dissected into lean, bone, subcutaneous fat (SCF) and intermuscular fat (IMF) (Brown and Williams, 1979)1 For ease of presentation the data for nine joints were reduced to four by combining some of them. The shoulder Included the neck, the breast Included the brisket and flank, the leg Included the upper and lower leg and the loin included the best end of neck.