E. RAICHEVA, D. NEDELCHEV and N. PETROVA
Institute of Animal Science, Department of Sheep Breeding, BG-2232 Kostinbrod, Bulgaria
RAICHEVA, E., D. NEDELCHEV and N. PETROVA, 2004. Milk yield, composition and properties of milk from dairy sheep breeds. Bulg. J. Agric. Sci., 10: 269–274
The objective of the present study was to characterize and compare milk yield, composition and properties of milk from two Bulgarian dairy sheep breeds. The examination was carried out on 50 sheep on the second lactation from the two dairy breeds – Black head Pleven and newfound Bulgarian milk breed. In the days of milk control were taken individual milk samples of sheep and total milk samples for each breed according to requirements of Instruction (2003) for calculation of milk for control day and milk yield for milking period and for analysis. There were tendency for higher milk yield and average daily milk yield (93.14 and 0.776) for newfound Bulgarian milk breed in comparison to Black head Pleven (78.42 and 0.652). The values of total solids, % (19.56), solids non-fat, % (11.54), protein, % (6.30) and SCC (750 000/ml) of milk from Black head Pleven were significant higher (P < 0.05), (P < 0.01) with compare to same traits of milk from newfound Bulgarian milk breed (18.69, 11.19, 5.59 and 133 000/ml) respectively. The value of lactose, % (4.46) at Black head Pleven was significant (P < 0.01) lower from newfound Bulgarian milk breed (4.77). The obtained results for daily yield of fat, protein and lactose were 54g/d, 44g/d and 42g/d for newfound Bulgarian milk breed and 52 g/d, 40 g/d and 30 g/d for Black head Pleven breed but significant was only difference for daily yield of lactose (P < 0.05). The protein and lactose content were accounted for moderate rate (R2– 0.39 and 0.32) of the variation of the milk for control day for newfound Bulgarian milk breed.The daily yield of fat, protein and lactose were accounted for high (R2– 0.87, 0.93, 0.94), moderate (R2– 0.31) and high (R2– 0.81) rate of the variation of the milk for control day for Black head Pleven breed and newfound Bulgarian milk breed respectively. For the daily yield of protein were obtained high values of the coefficients of determination for the two studied breeds. The obtained average values were : of the titrable acidity (23.25°T and 21.5 °T), of the active acidity (6.69 and 6.94), of the density (1.036), of renneting time (133.5 s and 139.0 s), of curdling time (165 min and 167.5 min) for newfound Bulgarian milk breed and Black head Pleven breed respectively.