Co-Authors:
Folman, Y., The Volcani Institute of Agricultural Research, Behovot, Israel
Volcani, R., The Volcani Institute of Agricultural Research, Behovot, Israel
Eyal, E., The Volcani Institute of Agricultural Research, Behovot, Israel
Abstract:
Ninety-seven Awassi ewes were included in three experiments. The ewes were milked twice daily, and also suckled lambs. Three different suckling regimes (12 hours per day, 4hr. and residual milk only) and three weaning times after lambing were compared. Milk yields. Mean milk yields of the various groups during the average 9 months lactation ranged between 315 and 380 kg. During the first 8 or 9 weeks of their lactation, the ewes produced 141-188 kg. milk. Suckled milk comprised 55-57 and 28-37% of total milk production in a 12 hr. suckling regime and under the more restricted regimes, respectively. Restriction of suckling, released about 50 kg. of extra milk for marketing. Effect of weaning. Weaning of lambs at 8 or 9 weeks was followed by an immediate drop in average daily milk production of 0-71-l-12kg. This drop was smaller when ewes were weaned at a later stage. Suckling of lambs to 12-16 weeks increased milk production in the various experimental groups by 13-36 kg. These extra amounts of milk wore consumed by the lambs. The extension of the suckling period did not have any effect on amounts of marketable milk. Persistency. During weeks 1-8, 9-16 and the last 5 months of lactation, the various groups produced an average of 42-46, 26-33 and 24-29 % of their total yearly yield, respectively. The coefficients of variation of the first 8-9 weeks' milk yield and that of the last 5 months of the lactation were 15-2 and 46-6, respectively. Persistent and non-persistent ewes produced an average 347-408 and 236-351 kg. of milk, respectively. Most of the difference was formed during the last 5 months of the lactation. Residual milk (amount of milk sucked by lambs immediately after stripping). Average amounts of residual milk during weeks 1-8, 9 and weeks 9-16 varied between 360-560 and 210-340 g., respectively (23-8-37-2 and 21-5-29-5 residual milk percentage). The difference in residual milk percentage between twice-daily and once-daily-residue suckling ewes was statistically significant (P < 0-05). Correlation coefficients in weeks 1-8, 9 between amounts of residual milk and total milk yield were significant at the 5 % level in one out of six cases. No significant correlation was found between residual milk percentage and milk yield. © 1966, Cambridge University Press. All rights reserved.