Factors affecting the milk yield and composition of Rahmani and Chios sheep

Abstract

M. Abd Allah, S. F. Abass and F. M. Allam

Milk production and milk constituents were studied in 74 ewes of two purebred groups, Rahmani and Chios at the Experimental Animal Farm, Faculty of Agriculture, Al-Azhar University, Assiut, Egypt. Milk yield was recorded at weekly interval starting from the second week of lambing till the 15th week using lamb -suckling technique plus hand milking. Milk samples were collected for chemical analysis during early lactation (1st month), mid lactation (2th month), and late lactation (3nd month) and pooled into one sample per ewe. Breed of ewe had an effect (P<0.01) on total and average daily milk yield and length of lactation. Chios ewes had the highest lactation (87.99 kg in 101.3 day) than Rahmani ewes (53.15 kg in 92.62 day). Ewes rearing twins produced more milk than those suckling singles and the differences were significant (P<0.01). Lambing season had a significant (P<0.01) effect on average daily milk yield (P<0.05) on total milk yield and lactation length. The effect of age of ewe within breed was non-significant on average daily milk yield, total milk yield and lactation length, although ewes aged 4 to 5 years showed relatively higher milk yields than younger or older ewes. Rahmani and Chios ewes reached a maximum yield at the 5th week of lactation. Milk fat, solids not fat (SNF) and milk energy were significantly (P<0.01) influenced by breed of ewes, while total solids (TS), protein, ash and acidity not influenced by breed. Ewes lambed in February to March had significantly higher (P<0.01) TS, pH and (P<0.05) SNF and significantly lower protein than ewes lambed in October to November season. Age of ewe had a significant effect on fat percentage followed by milk energy, while no significant differences in percentages of TS, SNF, protein, acidity, pH and ash were observed. It is concluded that Chios ewes in Egypt have an important potential for milk production and possibility of improving milk production of the Rahmani ewes through selection program or crossing with Chios sheep.