Effect of pre- and postpartum supplementation on performance of red Maasai sheep and small East African goat
Two experiments were conducted at Kitenge!a Station, Machakos District, of Kenya to examine the effect of pre- and postpartum supplementation on performance of Red Masai sheep and Small East African goats under range conditions. Experimental animals grazed a predominantly Themeda trlandra pasture and browsed Acacia spp. shrubs during the day and were penned at night. A set-stocking grazing system was employed. In Experiment 1, three groups of pregnant ewes were steamed-up for 6, 4 and 2 weeks prepartum using 24.0, 20,0 and 16.0 kg of ewe-and-lamb nuts concentrate per ewe, respectively. A fourth group was not steamed-up. Four groups of pregnant does were nut or. similar treatments. After parturition, no supplement was fed, but performance of dams and their offsprings was monitered up to twelve weeks postpartum. In Experiment 2 ewes and does that were grazed on pasture alone throughout pregnancy were allocated to four postpartum concentrate supplementation levels of 0, 0.25, 0,50 and 0.75 kg per day. Supplementation started a day after parturition and lasted for twelve weeks weeks when lambs and kids were weaned, Lambs and kids were penned and given Themeda triandra hay ad libitum up to five weeks of age after which they were pastured. Routine management practices were observed for both dams and their offspring. Steaming-up had a significant (P< 0,05) effect on.weight gain of ewes prepartum. Ewes fed 24.0 kg concentrate gained weight faster (P< 0.05) than the control group. However, weight changes of dams during lactation were not significantly (xiv) (P> 0.05) affected by prepartum levels of supplementation. Birth weights, pre-weaning growth rates, weaning weights and body measurements of lambs and kids were not affected (P> 0,05) by level of supplementation of pregnant dams. Steaming-up did not affect (P> 0.05) weight changes of does pre- and postpartum. Postpartum supplementation had no effect (P> 0.05) on weight changes of ewes and does during lactation. However performance of lambs and kids in terms of growth rates, weaning weight and body development was significantly (P< 0.05) improved by postpartum supplementation of dams. The effect of postpartum supplementation levels of 0.50 and 0.75 kg per day on performance of lambs was not different (P> 0.05). Performance of kids from does supplemented postpartum with 0.75 kg concentrate was superior (P< 0,05) to that of kids from does supplemented with 0.50 kg concentrate per doe per day. Throughout the preweaning growing period, heartgirth was highly (P< 0.05) correlated to liveweight of lambs and kids. This study indicated that steaming-up of pregnant ewes and does was not necessary under Kenyan range conditions from the standpoint of lamb and kid performance and dam weight changes. However, it was deemed necessary to supplement ewes and does at a rate of 0.50 kg concentrate per day so as to improve lamb and kid performance through increased milk production. Although a higher supplemetnation level of 0,75 kg concentrate per dam per day promoted lamb and kid growth rate over and above the 0.50 kg per dam per day level, it was deemed uneconomical.