milk yield chemical and mineral composition in milk of tsigay sheep and their crossbreedings

摘要

The study has been carried out on raw aggregate sheep milk obtained -from sheep from Tsigai breed and their crossbreeds with Chios breed at the age of 2 5 and 3.5 years, which are raised in RIMSA-Troyan in the region of Central Balkan Mountains.The milk chemical composition was recorded by Milko-skan 133B, and that of content of ash by weight at 550 C Micro and macro-elements were determined after dry ashing of sample, their mineralization was done in a muffle furnace at 550°C and preparationof salt acid solution from the ash. The content of K and Na - (of Flamom-B), of P -molybdate-vanadate method, and the rest of the elements by Perkin-Elmer 380.A tendency for higher млечност of F_2 млечни cross-breeds (Tsigai - x -Chios) in comparison with Tsigai sheep and comparatively better indexes of dry matter and fat milk in the latter. The content of total protein and casein in milk of l-stlactation is significantly higher in F2 dairy cross-breeds.No significant differences have been recorded in the milk between the two breeds in relation to amount of macroelements calcium, phosphorus, potassium as well as the micro-elements manganese and copper. The milk from Tsigai sheep breed was superior during both years in the content of magnesium by approximately 47.9% for 2.5-year and 23% for the second in comparison to that of F_2 cross-breeds of Chios. A tendency for higher levels of zinc and iron in milk of F_2-breeds of Chios has been observed. High values of ration K/Na in both sheep breeds have been registered.