Milk yield of Chios-Ossimi crossbred ewes in relation to the yield of the parental breeds.

A study was carried out at Mallawi Research Station, 300 km south of Cairo, in which 16 Chios (CC), 31 Ossimi (OO) and 21 of their F1 crossbred ewes (50% Chios- 50% Ossimi (CO)). The CO crossbred ewes were mated to CC rams, whereas OO and CC ewes were mated to rams of the same breeds. The study included only ewes having single lambs in 2 lambing seasons; summer and winter. In the summer, total 8-week milk yield (suckling period) averaged 128.9, 53.4 and 77.1 kg in CC, OO and the crossbred ewes, respectively (P < 0.01). Total milk yield averaged 201.6, 65.0 and 110.2 and days of lactation were 151.1, 79.6 and 106.7, respectively (P < 0.01). In the winter, total 8-week milk yield averaged 138.6 (P < 0.01), 55.0 and 59.5 kg for CC, OO and the crossbred ewes, respectively. Total yield averaged 209.1 (P < 0.01), 65.9 and 76.5 kg and days of lactation were 153.3, 79.8 and 93.4, respectively (P < 0.01).