Pre-weaning growth of lambs and productivity in Sudano-Sahelian traditional area in Mali

Abstract

Average lambs growth performance rates in this Sndano-Sahelian region (2.71 ± 0.12, 6.32 ± 0.27, 9.52 ± 0.41, 12.23 ± 0.54, 14.74 ± 0.68 and 17.18 ± 0.98 kg respectively at birth, 30, 60, 90, 120 and 150 days) are compared to those observed in other African sheep flocks. The mean daily weight gains (“GMQ”) fluctuate between 120.20 ± 7.80 g/d. and 62.04 ± 8.60 g/d. from birth to weaning. As an expression of their genetic potential, these performances were also dependant on non-genetic factors, of which the flock is the most important because it determines about 50 % of the total variability of growth performances. Finally, as well as the great phenotypic variability between individuals, the low correlation between GMQ 0-30 and GMQ 30-60 may indicate a probable changeover of diet for lambs of 30 to 60 days old. Overall flock productivity was estimated at two crucial breeding stages: birth and weaning. At birth, it was 4.56 and 4.67 kg respectively for flocks I and II. At weaning, these values were increased respectively by coefficients of 4.32 and 6. Estimated mean individual productivity values were respectively 30.72, 0.98 and 2.31 kg for indices 1, 2 and 3. They were affected by sex, litter number and year of birth. To increase individual animal productivity and consequently that of the flocks, all these elements must be considered.