Avaliação das características reprodutivas e produtivas de ovinos da raça Santa Inês, criados na mesorregião do nordeste paraense.

Abstract

Santa Ines sheep may suffer physiological changes due to climate change, influencing directly in its production capacity. In order to evaluate the reproductive performance and productivity of sheep and their relation to variations in the tropical Amazon, 148 matrices were used Santa Inês crossbred pluriparous, aged 24 to 36 months with an average weight of 40,0 ± 4,93 kg and body condition score 2,5 to 3,0, which were randomly divided into four distinct groups G - 1 G - 2 G - 3 and G - 4 and mated by natural service sires with four Santa Ines in the respective periods, January / February (G - 1), April / May (G-2), July / August (G - 3) and October / November (G - 4). Weights before and after the breeding season there was no difference p> 0.05, differing p <0.05 only in weight before and after birth to 40,75 ± 2,5 to 44,58 ± 6,2 kg, respectively . Coverage rates and cyclicity at 15 days remained constant over the four periods with an average of 100%, difference p <0.05 at 30 and 45 days only Cyclicality of G - 4 and G - 5. The fertility rate of 86,6% to 91,4% in G - 1 G - 4 showed only a linear growth. Similar behavior was also observed for calving rate of 70% and 87,2% respectively. The mean litter size was lower to 1,0 G - 3 and at most 1,4 G - 1. For the lowest multiple gestation was 0,0% in G - 3 and 4,6% higher in G - 2. Reproductive failure showed the lowest percentage of 2,1% in Group G - 4 and the highest value of 13,3% for G - 1, while mortality was 0,0% of matrices in G - and G 2 - and 3 6,7% in G - 1. In lambs there was a higher proportion of females and 60% growth from first to fourth season on weaning rate, without significant difference (p> 0.05). As for weights of lambs by sex, we observed higher weight of males over females p <0.05 at birth (3,2 ± 0,49 kg and 3,0 ± 0,33 kg) at 15 days (5,1 and 4,8 ± 1,01 kg ± 0,97 kg) and 30 days (8,1 ± 2,32 kg and 7,3 ± 1,94 kg), respectively. However, when analyzed between seasons, adding the weight of male and female means were different between seasons (p <0.05) with the exception of birth weight. The productivity indicators show growth in reproductive efficiency from 0,66 to 0,74, between breeding seasons with an average cycle of 0,73. In respect kg lambs / sheep parity kg from 0,24 to 0,33 kg and the ratio of lambs weaned/ewes mated kg from 0,18 to 0,29