Meat productivity of fine-wool sheep breeds being bred in the Republic of Kalmykia.

摘要

This study was conducted to investigate the effectiveness of crossing rams of the Australian Merino (AM) breed with ewes of finewool sheep breeds in the Republic of Kalmykia. The ewes used were from 4 sheep farms and 4 breeds (Grozny, Stavropol, Soviet Merino and Caucasus), whereas the rams were from farms in South Australia and one breed (Australian Merino). The experiments were based on a method which, not disturbing the universal wool and wool-meat type of sheep productivity that has developed historically, was directed at obtaining animals with a high wool clip, good meat productivity and adaptability to local conditions. At each farm, 7 groups of 30 animals each were selected. The maximum preslaughter liveweight was observed in wool-meat ram lambs of the Caucasus breed, which surpassed its wool-type contemporaries by 6.93%. Crosses with 1/4 and 1/2 AM differed little in preslaughter weight from their purebred contemporaries. An advantage in meat productivity of purebred ram lambs was observed compared with 5/8 and 3/4 blood crosses of all variants of crossing. However, the greatest difference was obtained on crossing AM with Caucasus sheep. The dressing percentage of purebred ram lambs was 3.5%, and the carcass weight was 2.2 kg higher. The carcasses of both purebred and hybrid lambs were characterized by a low meatiness. They had a comparatively low meat yield (72-74%), high bone yield (26-28%) and low meat to bone ratio (2.68-2.87%). Insignificant differences were observed between animals of different groups in the chemical composition of meat, with the exception of the meat of the Caucasus breed and its hybrids, which contained 1-2% less water and more protein and fat. Insignificant differences in the amount of dry matter per one kg flesh and carcass were established. Significant differences in caloric value of one kg of meat were not found between all genetic groups of purebred and hybrid animals. The cost effectiveness of using AM rams in different variants of crossing showed that under equal conditions of almost year round pasture and semi-stall feeding and housing, the best results were obtained from raising purebred animals. Their cost per head was 2.61-2.65% lower than crossbreds. The greatest amount of meat products among the compared groups of hybrids both in real and value terms was obtained in 1/2 blood crosses of the Caucasus breed with AM and in 5/8 and 3/4 blood crosses of other wool breeds with AM..