Productivity and ovarian activity of Peul sheep under indigenous management in Niger

Parameters of reproduction and various ovarian activities were studied in Peul ewes bred in traditional management. The litter size was 1,1 ± 0,05 (X-bar ± s.e.m.); it was not affected by season and rank of birth. The intervals between successive parturitions lasted for 325 ± 12 days. This interval was affected by the wet season, but it was not affected by the rank of parturition. There were births all through the year. The maximum frequency of birth was found during the second part of wet season and during post rain period. The minimum frequency of birth was found during the dry season and during the first part of the wet season. The rate of reproduction was 1,25 lambs per ewe per year. The normal ovarian activity was characterized by the luteal phase, which lasted for 13 ± 0,2 days with a highest level of progesterone of 2,5 ± 0,2 ng/ml. The normal follicular phase lasted for 4 ± 0,2 days with progesterone levels varying between 0 and 0,2 ng/ml. During the year, normal ovarian activity was interrupted by short luteal phases (duration = 9 ± 0 days; frequency 10%) during the dry/cold season, and by prolonged follicular phases (duration = 20 ± 4,1 days; frequency = 39%) all through the year. The incidence of these anomalies after kidding was estimated at 25%. The resumption of the ovarian activity occurred between 32 and 191 days after parturition. This parameter was not affected by the season; but it was correlated negatively with the weight of animals during the first month after parturition (r = -0,77; P < 0,05). These results suggest that the Peul sheep kept on a poor diet preserve good reproductive potentials. The results also suggest that the improvement of diet during post-partum would allow the Peul sheep to increased their reproductive capacities. (author). 16 refs, 3 figs, 2 tabs