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چکیده
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The present study aimed to evaluate the effects of crossbreeding on milk yield, physical and chemical composition and fatty acid profiles of milk fat in Qazvini goats and its crosses with Saanen goats. Records of 316 lactations and 1745 test-day milk were available for Qazvini (Q), Qazvini×Saanen (QS), and QS×Saanen (QSS) goats. The least squares means and standard errors of daily milk yield in Q, QS, and QSS goats were 716±75, 1188±61, and 1373±107 g/day, during the lactation length of 163, 160 and 166 days, respectively. In Q milk, the percentages of total solids, fat, protein, lactose and ash, and the density (- 1000, g L-1) and freezing point (-°C) were 15.12, 6.01, 3.39, 4.91, 0.80, 29.91 and -0.601 being higher (P<0.01) than those of crossbred goats (except for milk density). Concentration of milk saturated fatty acids (SFA) and polyunsaturated fatty acids (PUFA) for Q, QS, and QSS were 68.31, 67.42, 75.34, and 2.74, 4.10 and 3.25 g/100g total fatty acids, respectively (P<0.05). Concentration of monounsaturated fatty acids (MUFA) for those groups were 20.16, 19.18 and 18.43 g/100g total fatty acids, respectively (P>0.05). Despite decreased concentration of milk components, crossbreeding might be recommended in increasing the milk production and the amount of PUFA fatty acids in Qazvini goats.
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