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1989). Effects of sh-meal supplementation on performance of overfat lambs fed on barley straw to reduce carcass fatness. Animal Production, 48, pp 131-138 ABSTRACT The effect of undegradable protein supply was studied in overfat lambs given low-energy diets to reduce carcass fatness. Two trials involving sequential batches of 48 overfat Suffolk x lambs investigated the effects of supplementing an ad libitum straw diet with either 0 or 100 g fish-meal pellets daily for 14-, 28-and 42-day periods. Lambs supplemented with fish meal in trials 1 and 2 lost significantly less weight. Weight losses (g/day) were -2 v. -129 (s.e.d. 26) and -58 v. -188 (s.e.d. 29) respectively. There were highly significant and favourable effects of fish-meal supplementation on carcass weight and composition (recorded in the second trial only). Carcass weight (kg) after 14, 28 and 42 days was 21-8, 20-4 and 18-3 for unsupplemented lambs and 22-4, 21-9 and 21-6 for supplemented lambs; saleable lean (kg) as determined by a commercial boning-out process was 12-1, 11-3 and 10-0 v. 12-7, 12-6 and 12-3 respectively. There were corresponding changes in conformation but fat trimmed off the carcass was not significantly reduced by the dietary treatments. There was, however, a reduction by one-fifth in excess carcass fat (about 0-5 kg) over the period 14 to 42 days on trial, and over the trial as a whole, fat trim fell from an estimated proportion of carcass weight of 0-17 to 012, equivalent to a fall in Meat and Livestock Commission fatness score from 4H to 3L. Results indicated very favourable financial rewards for supplementing diets of overfat lambs with fish meal.

1987). The effect of winter shearing of housed pregnant ewes on food intake and animal performance. ABSTRACTThe effects of winter shearing on the food intake and performance of housed ewes was studied in a series of three experiments. Winter shearing resulted in a proportional increase of dry-matter intake in ewes of 0-16 and 0-43 on two silage-based diets, of 0-09 on swede-based diets, but of only 0-02 on a hay-based diet. Shearing increased intake by a greater amount in smaller ewes and a similar trend occurred on diets containing a greater proportion of barley. Shearing increased average lamb birth weight by about 600 g (4-65 kg v. 4-06 kg), apparently as an effect of shearing per se rather than as a result of the increased energy intake. An increase in gestation length of around 1-8 days accounted for one-fifth of this increased birth weight. The effect on gestation length of shearing was to increase the unnaturally short gestation of housed unshorn ewes, this short gestation being attributed to problems of heat stress in late pregnancy. Results indicated management advantages of winter shearing in favourable climatic environments. * * 3-Z m /* X m > JO z o o •n X o c m D to tn C/5t Adjusted by covariate within breed for litter size.

This review brings together research findings on cervical relaxation in the ewe and its pharmacological stimulation for enhancement of the penetration needed for transcervical insemination and embryo transfer. On the basis that the success of artificial insemination is the percentage of ewes lambing, a review is made of recent research aimed at understanding and minimising the sub-lethal effects of freezing and thawing on the viability of spermatozoa, their membrane integrity and their ability to migrate through cervical mucus, as these characteristics have a major influence on fertility, particularly when semen is deposited, artificially, in the os cervix. Milestones of achievement are given for transcervical intrauterine insemination, embryo recovery and transfer and the birth of lambs of pre-determined sex, firstly following intracytoplasmic sperm injection, then laparoscopic intrauterine insemination using highly diluted flow-cytometrically sorted fresh semen and subsequently by os cervix insemination using sexed semen that had been frozen and thawed. Diversity of research endeavour (applied, cellular, molecular), research discipline (anatomy, histology, immunology, endocrinology) and research focus (cell, tissue, organ, whole animal) is embraced within the review as each has significant contributions to make in advancing recent scientific findings from the laboratory into robust on-farm transcervical insemination and embryo transfer techniques.Keywords: ovine cervix, semen cryopreservation, artificial insemination, embryo recovery and transfer ImplicationsIn bringing together the results of recent research on the cryopreservation of ram semen and the relaxation of the ewe cervix, this review provides a basis for identifying opportunities for improving the efficiency of cervical insemination and transcervical embryo recovery and transfer in sheep genetic improvement programmes.

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