R. Slavov1*, G. Mihaylova1, S. Ribarski2, P. Slavova3, D. Pamukova1

1Department of Animal Science – Ruminants and Dairy Farming, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria 2Department of Morphology, Physiology and Nutrition, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria 3Agricultural Institute, 6000 Stara Zagora, Bulgaria

Abstract. A comparative analysis of physicochemical parameters of meat from lambs of North East Bulgarian fine fleece breed and its 25% crossbreds from internal breeding with heredity from Australian merino breed and Ile de France breed. Upon starting the experiment lambs were equal and during the experiment they were placed under similar conditions of feeding and rearing. To establish the quantitative and qualitative parameters of heredity slaughter analysis were performed at 100 and 130 days of age. From the carcass of each slaughtered animal pooled samples and individual samples from m. Longissimus, m. Semitendinosus and m. Semimembranosus were taken. Studies were carried out in the Research Laboratory of the Faculty of Agriculture at Trakia University. As a result of the study the following conclusions were made: The use of the Ile de France breed in a sophisticated crossing scheme within the North East Bulgarian fine fleece breed and subsequent internal breeding relates primarily to the achievement of the highest content of protein and phospholipids in the meat of crossbred lambs from internal breeding with 25% heredity from Ile de France breed. The highest is the level of protein in all three tested muscles in the same type of crosses. Water retention and pH24 of meat from m. Longissimus, m. Semitendinosus and m. Semimembranosus of 100- and 130-day-old lambs in all three groups of lambs vary within narrow ranges and values give a reason for the meat to be described as having good quality. Internal breeding of crossbreds with 25% heredity from Australian merino breed does not affect adversely the physicochemical parameters of meat.