Lactation performance of ewes and the growth of lambs in awassi sheep under 2 different suckling regimes
Guirgis, R.A.; Kassem, M.M.; Kazzal, N.T.; Abdallah, R.K.
Journal of Agricultural Science 94(3): 607-616
ISSN/ISBN: 0021-8596 Accession: 005791088
The present study was carried out on 39 local Awassi ewes. After parturition, lambs were left to suckle their dams for the 1st mo. of age, after which they were separated into 2 suckling regimes, restricted and continuous. The average milk yield of ewes in the continuous system was 155.7 kg during the lactation period of 167 .+-. 6.1 days; that of the restricted system was 139.8 kg during a lactation period of 183 .+-. 5.7 days. Differences were not significant. Significant differences (P < 0.01), in favor of the continuous system, occurred in the amount of milk suckled by lambs in the different suckling systems from the 8th wk onwards till weaning. Measured hand milk showed no significant differences between the 2 regimes. Averages of butter fat percentages were 5.63 and 6.69 in the continuous and restricted systems, respectively. The total percentage suckled milk, regardless of suckling regime, was 36.7 .+-. 1.99; averages were 41.6 .+-. 0.89 and 31.7 .+-. 3.52 in the continuous and restricted systems, respectively. The averages of commercial milk production from the 9th wk after lambing until the end of lactation were 45.9 and 61.7 kg in the continuous and restricted systems, respectively (P < 0.01). Averages of butter fat quantities in the commercial milk yield were 3.25 and 5.03 kg in the continuous and restricted systems, respectively (P < 0.01). The weights of lambs in the 2 suckling regimes started to differ significantly from the 14th to the 46th wk of age; lambs reared under the continuous system were 4 kg heavier at the yearling age than those of the restricted system. It might be advisable to use the restricted system and wean the lambs at 12 wk of age; the excess milk obtained will outweigh the extra gain in body weight of 1.52 kg encountered in the continuous system.