Influence of kidding season on the reproductive behaviour of undefined breed goats

Abstract

Twenty-seven does, pluripara, were distributed in two treatments (T_I and T_II) according to the kidding season. The T_I contained eleven does which kidded during the wet season, and T_II sixteen does which kidded during the dry season. The weaning was done on average at 112 days after birth. The first three estrus periods were recorded. The does were submitted to laparoscopy between 60 and 96 hours after the estrus have started. The interval between kidding and the first estrus was 52.3 and 112.3 days for T_I and T_II, respectively (P < , 0.1). The duration of estrous cycles was 22.5 and 27.1 days for T_I and T_II, respectively (P > . 0.5). However, under the T_II the first estrous cycle was longer (P < . 0.5) than in T_I (31.9 vs 19.2 days, respectively). The ovulation rate was 1.8 and 1.6 for T_I and T_II, respectively (P > . 0.5). However, the ovulation rate at first estrus under T_I was smaller (P < . 0.5) compared to the second one (1.5 vs 2.0, respectively). The season of kidding did not influence the estrus incidency neither the ovulation rate. However, the does kidded during the wet season re-started the ovary activity earlier than those kidded during the dry season.