Abstract
The aim of this study was to evaluate the demographic performance of Djelli cattle herds as a function of the level of bran concentrate supplementation in three localities in western Niger. The 12 MO method was used to record the demographic parameters of 68 herds (1114 head) divided into three supplementation categories: those supplemented with 2.5 kg of bran per day per head (Category 1), those supplemented with 3.75 kg of bran per day per head (Category 2) and those supplemented with 5 kg of bran per day per head (Category 3). The results showed that the proportions of males were significantly lower than those of females for all categories of supplementation in the herds. There were more juveniles in the more highly supplemented herds (15.6% in Category 3 versus 7.2% in Category 1 and 6.5% in Category 2 for females, and 3.9% in Category 3 versus 1.3% in Category 1 and 2 for males). The results showed a significant difference in parturition rates between the categories (P = 0.027); these were higher among most supplemented (56.7% in Category 3 versus 38.4% in Category 2 and 36.4% in Category 1). There was a significant difference in abortion rates (P = 0.020) (4.8% in Category 3 versus 12.2% in Category 2 and 9.6% in Category 1) and a very significant difference in stillbirth rates (P < 0.001) (13.5% in Category 3 versus 30.2% in Category 2 and 46.7% in Category 1). With regard to herd exploitation, no significant differences were detected in terms of imports (P = 0.947) or exploits (P = 0.781) for all three supplementation categories. In conclusion, the higher the level of concentrate supplementation, the better the zootechnical performance of the females, with better exploitation of the males.