There is little published data on the detailed performance of continental genotypes as suckler cows in a hill environment. The work presented investigates further, aspects of reproductive performance and metabolic profiles published previously (Christensen et al 1994) and (Keatinge et al 1994), for an autumn calving herd, during the post-partum period.

The herd consisted of 41 Piemontese X Holstein/Friesian (PXH/F) and 43 Simmental X Holstein/Friesian (SXH/F) cows which were grazed on upland pasture from May-September, with calving (second, @ approx. 3.5 years) from late September through October. The herd was housed in early November in a cubicle shed with barrier access to clamped grass silage, the calves had access to adjoining creep areas.

The selection objective of the SAC Simmental MOET Project, is to improve the economic efficiency of lean, or saleable, meat production in crossbred beef production systems.

The factors which contribute to the selection objective are the yield of saleable meat, feed intake and calving difficulty. These goal characteristics are combined into an index by taking into account their respective financial values and costs. Calves generated by multiple ovulation and embryo transfer (MOET) are weaned from their recipient dams at 10 weeks old and placed in performance test from 5 to 11 months of age. At the end of the performance test, saleable meat yield is estimated from liveweight at end of test, ultrasonic fat depth measurements and muscling score. Calving difficulty is predicted from the birthweight and gestation length of the animal on test whilst feed intake is measured directly by recording individual food intakes during performance testing. The estimated breeding value for the selection index of an animal is expressed in £'s (pounds sterling) as deviations from a mean of zero for the SAC population of Simmentals. It is calculated using the information for each animal plus that of all its relatives in its own and other performance tests by means of BLUP procedures.

The objective of the work described here was to evaluate the effectiveness of the selection index in identifying sires of superior genetic merit for use in crossbred beef production systems.

Mastitis constitutes a major source of economic loss in the national dairy herd. Although good management practices can produce a major reduction in mastitis, there is considerable interest in the reduction of mastitis through breeding. Somatic cell counts (SCC) have been used as a way of indirectly measuring sub-clinical mastitis within a herd. Since 1991, average cell count is obtained for all herds and this is used to adjust milk payments.

Milk recording organisations introduced a cow cell count service in 1990. The data are now available for the preliminary analysis of the usefulness of somatic cell counts. The objective of this study was to estimate genetic parameters for SCC for three major breeds in the UK.

A multi-variate animal model Best Linear Unbiased Prediction (BLUP) on milk, fat and protein yields in different lactations, as different traits, is the optimum method for genetic evaluation in dairy cattle for production. However, this is computationally demanding and usually a repeatability model is performed separately for milk, fat and protein yields. A simulation study by Visscher (1991) showed that the repeatability model on canonical transformed yield rather than on observed yield was a better approximation to a multi-variate analysis using selection index. The aim of this study is to verify, using an animal model, the efficiency of the repeatability model relative to a multi-variate analysis on observed or transformed yields.

The International Dairy Cattle breeding industry characterises itself by ever increasing competition between countries. Frozen semen and embryos are easily transportable, providing breeders with access to bulls from almost anywhere in the world. Problems arise from the fact that each country produces genetic evaluations with different units, different expressions of genetic merit and different genetic bases. Without some means of standardisation it is very difficult to make the correct selection decisions.

Procedures have been recommended and described by the International Bull Evaluation Service (INTERBULL) to convert foreign genetic evaluations to the genetic equivalents in the importing country (Philipsson et al. 1986). Previous research carried out in the UK has shown that converting foreign proofs to Improved Contemporary Comparisons (ICCs) worked well for Canada and New Zealand (Swanson et al, 1989). The change in the evaluation systems in the UK and elsewhere, to an Individual Animal Model, plus the availability of more data from more countries, were reasons to re-look at the accuracy with which the current conversion method predicts the actual PTA for milk, fat and protein within the UK.

Group breeding schemes were introduced into Britain in the 1970s as a means of increasing the rate of genetic improvement in sheep and providing a vehicle for breeders to cooperate and pool resources. The Lleyn Group Breeding Scheme was set up in 1978 with the aim of improving several maternal traits in a breed known for its prolificacy. Although the breed originates from North Wales members of the group were drawn from different parts of Britain. Flocks in the scheme were all recorded by MLC and sheep had the possibility of being selected using MLC's selection index, appropriately weighted for the traits of interest to group members.

This analysis was designed to investigate the genetic progress made in the scheme between 1979 and 1993. Three traits were analysed; adjusted early lamb weight (LW) (at eight weeks of age), mature weight (MW) (at 18-months) and litter size (LS) in the form Number of lambs born per ewe lambing (NLBEL). These three traits were investigated in ten flocks which participated in the scheme, at varying levels, during the 14-year period 1979-1993. However, only genetic progress in the nucleus flock is reported in this paper.

As it is essential for breeding societies to have their registered livestock classified objectively, linear trait assessment of Holstein Friesian cows was introduced in Great Britain in 1982. Currently, 15 traits describing the body, legs and feet, the udder, and teats are scored visually according to an underlying linear scale. For example the two legs and feet traits Rear Leg Side View (RLSV) and Foot Angle are scored from “straight” to “sickled” and from “low” to “steep”, respectively. In 1993, the Holstein Friesian Society of Great Britain and Ireland (HFS) decided to add a new trait “Locomotion” on an experimental basis to the list as an indicator of lameness, as it is felt that the existing data do not provide enough information for this specific area. Locomotion is scored according to Manson and Leaver's Locomotion Scoring System.

There are now a range of new reproductive technologies which are actually or potentially available for use in commercial dairy cows. To obtain an economic assessment of adopting the use of such new technologies, the effects of the technology adoption on milk production resulting from genetic lift, generic gain and the conception rate have to be estimated. This paper demonstrates a Markov chain model which allows die estimation of these effects by considering the change in physiological state of individual cows and the genetic improvement through me use of embryo transfer to produce replacement heifers.

The adoption of new reproductive technologies is likely to have far reaching consequences on commercial dairy and beef herds. Within a dairy herd, milk production is influenced by the animal's genotype and its environment and their interaction. Whilst environmental factors may be manipulated in many ways, the animal's genotype is determined solely by it's parents genetic make up; therefore, animal reproduction plays a vital role in determining the genetic progress that can be made within an enterprise. Reproduction is also important within a beef enterprise as the production of a large breed calf can increase the output and thus achieve a higher production efficiency. Any reproductive technology that offers a faster rate of genetic improvement and/or an increase in production would be considered desirable if any increased costs of using that technology are compensated by the economic benefits. In order to appraise such technologies it is necessary to estimate their implications at an enterprise level in terms of production levels, efficiency and economic benefits.

In Britain a range of new reproductive technologies for increasing annual milk yield through the genetic improvement of the herd or for improving the quality of beef calves produced are becoming available to the dairy industry or at a ‘near market’ state of development. Simulation models evaluating the potential physical and economic consequences of adopting a single technology into a dairy enterprise have been constructed (Yates, Rehman, and Chamberlain, 1995a and 1995b), however, these models rely upon predetermined strategies and do not take into account the potential of using several technologies simultaneously. This paper demonstrates a Markovian decision process which allows the choice of several technologies in determining optimal breeding strategy in economic terms by using a linear programme.

An ideal method of assessment of semen would be simple, rapid and objective with a high correlation with the ability of semen sample to cause conception in the ewes (Ahangari, 1992). Currently the proportion of motile spermatozoa is determined by visual microscopic appraisal. Although, this method of assessment is rapid and easy, it is subjective. Jasko et al (1989) described a spetrophotometric procedure for measuring equine spermatozoan motility objectively. In the present study a modification of the method of Jasko et al (1989) was tested and applied to ram semen.

The ovarian status of the donor animal before and at the time of gonadotrophin treatment appears to be a major determinant of superovulatory response in cattle. Transrectal ultrasonography is a non-invasive means of assessing the morphological status of the ovary which can be used on a repeated basis. Detailed evaluation of ovarian status by this means may enable superovulatory treatment protocols to be devised which are tailored to the individual donor animal. This possibility was evaluated in a preliminary study reported here.

Superovulatory stimulation of cattle with PMSG causes a second wave of ovarian follicular development (Saeed et al., 1989) accompanied by high concentration of oestradiol in peripheral blood (Alfuraiji et al., 1990) due to its long half life. This effect of PMSG is thought to create an unfavourable steroid environment for early embryonic development. Antibodies to PMSG (APMSG) can be used to remove PMSG from the peripheral blood of PMSG-stimulated cattle after the initial multiple follicular development and rise of oestradiol, and hence, to increases the number of transferable embryos. It has been shown that APMSG neutralises the effect of PMSG and increase the number of transferable embryos when administered relative to the preovulatory LH surge in PMSG-stimulated cattle (Alfuraiji et al., 1993). The beneficial effect of APMSG can not be realised in practice, however, because detection of the preovulatory LH surge is difficult. Therefore, using APMSG in a PMSG superovulation procedure requires further investigation to understand the mode of action of APMSG. The latter could be studied in vitro in a much more controllable way than in vivo. Furthermore, an in vitro method would allow us to test the neutralising capacity of different antibody preparations to PMSG.

The isolation of bovine pregnancy-associated glycoprotein (bPAG) from foetal cotyledons (Zoli, Beckers, Closset, Wouters-Ballman, Falmagne and Ectors, 1991) and the subsequent development of a radioimmunoassay for the detection of bPAG in the peripheral circulation of cows (Zoli, Guilbault, Delahaut, Ortiz and Beckers, 1992) could provide a simple and rapid means of accurately diagnosing pregnancy early in gestation. This study reports on the efficacy of using plasma bPAG concentrations as a means of pregnancy diagnosis in purebred beef heifers mated at a first or second synchronised oestrus compared to failure to return to oestrus and transrectal ultrasonography.

Various methods of creating twin pregnancies in cattle have been investigated by other authors (see review by Sreenan and Diskin, 1987). However, virtually all of these methods have involved in vivoproduced embryos which, in separate studies, have employed either surgical or non-surgical transfer techniques, where embryos were transplanted either unilaterally or bilaterally in recipients which may or may not have been previously artificially inseminated. There have been no studies where all of these factors were examined collectively, and included with the transplantation of either frozen-thawed in vivoor in vitroproduced embryos. The objectives of the current study were, therefore, to compare pregnancy, twinning and embryo survival rates of recipients in which twin pregnancies were induced by various combinations of embryo source and transfer method to animals inseminated or not prior to embryo transfer, and the distribution of the embryos in the uterus.

Current variability in superovulatory response prevents the economical production of large numbers of high quality embryos and limits the use of embryo transfer. Pulsatile administration of GnRH (gonadotrophin releasing hormone) elicits pulsatile secretion of LH (luteinising hormone) while chronic treatment with a potent GnRH agonist reduces LH secretion. Using the latter, gonadotrophin-dependent preovulatory antral follicle development may be suppressed, resulting in a uniform cohort of small antral follicles in the absence of a dominant follicle which could then be superstimulated by exogenous gonadotrophin.

Spring calving suckler cows generally receive moderate energy intakes in winter resulting in a loss of body condition. When subsequently provided with adequate good quality pasture there is rapid recovery of liveweight and body condition and provided cows are in good body condition at housing in autumn there are no ill-effects of winter under nutrition on fertility or calf performance. Good pasture performance can be achieved at relatively high stocking rates with high inputs of nitrogen (N) fertiliser or, as is common practise with lower stocking rates and relatively low N inpyts. Lower stocking rates allows an opportunity to reduce costs by providing all (or most) of the winter feed requirements from 1 as opposed to 2 silage cuts. The objectives of the study, carried out over 2 years, were to determine the effects of 1) reducing N fertiliser on the grazing area, 2) allowing more land per animal, and 3) simplifying grass conservation (1 instead of 2 silage cuts) on cow and calf performance.

Winter feeding systems for autumn calving cows cannot manipulate body condition to the same extent in hill herds as in the lowlands. Maintaining the dry, pregnant hill cow economically in the grazing season means making use of rough grazings (SNRG) which will allow little body condition improvement. In effect, condition score needs to alter little throughout the year. Consequently, in the early part of the winter, at least, some concentrate supplementation is required for the moderate quality silage on offer from what are often limited supplies.

Cows are usually fed forage or a mixed complete diet with an automatic delivery feed wagon daily. The feeding is a laborious and time consuming task, however such a load can be reduced by alternate day feeding of cows (Wallace and Parker, 1966; Owen, 1987; Leaver, 1990). Refusals may be collected when more then ten percent of fresh supply. The objective of this study was to compare daily with alternate day feeding of complete diet to dairy cows.

To develop sustainable grazing systems based on mixtures of plant species and animal species, it is important to understand how much, and from which plant species animals eat. A prerequisite in the development of this understanding is a knowledge of dietary preference. Sheep have been shown to have a preference for about 70% clover in their diet (Parsons et al., 1994), but similar information is not available for cattle. It has been observed that grass/clover swards grazed by cattle often contain more clover than those grazed by sheep. This has been interpreted to imply that cattle have a lower preference for clover than do sheep. However, cattle are alleged to graze less selectively than sheep (Phillips, 1993) because of their mouth size and structure and so, the greater proportion of clover observed in swards grazed by cattle, may not reflect dietary preference but their relative inability to select. The preference for clover by cattle was tested by offering a choice of grazing from adjacent monocultures of grass and clover. It was anticipated that diets containing high proportions of clover might predispose cattle to bloat, and so half the animals received an anti-bloat prophylactic, to test whether this prevented bloat and modified preference.