EFFECT OF SEASON ON REPRODUCTIVE PERFORMANCE OF BLACK BENGAL GOAT IN DINAJPUR DISTRICT

Abstract

This study was conducted at different places of Dinajpur district namely Kornai, Noshipur, Bangibachar hat, Vagobanpur from July/2017 to June/2018. Birth weight of kids were 0.94±0.02, 1.05±0.02 and 0.90±0.02 kg respectively in summer, rainy and winter season of Black Bengal goat. The birth weight of Black Bengal kids at 1st, 2nd, 3rd and 4th parity were 0.95±0.02, 0.97±0.01, 0.98±0.02, 0.96±0.03 kg respectively. There is no significant effect of parity on birth weight of Black Bengal kids. Average gestation length of Black Bengal goat at summer, rainy and winter season were 142.9±0.52, 143.2±0.54 and 145.6±0.48 days respectively. The average litter size of Black Bengal goat at summer, rainy and winter season were 2.09±0.10, 2.01±0.10 and 2.07±0.09 respectively. The average litter size of Black Bengal goat at 1st, 2nd, 3rd and 4th parity was 1.53±0.09, 1.83±0.08, 1.97±0.09 and 2.17±0.15 respectively. There is no significant effect of season on litter size of Black Bengal goat. But there is highly significant (p<0.01) effect of parity on litter size of Black Bengal goat. Average age at puberty of Back Bengal goat at summer, rainy and winter season were 185.45±3.03, 182.72±3.10 and 183.95±2.76 days respectively. There is no significant effect of season on age at puberty of Black Bengal goat. The average age at first kidding of Black Bengal goat at summer, rainy and winter season were 369.82±1.76, 371.92±1.80 and 366.02±1.60 days respectively. There is no significant differences between season and parity on kid mortality rate but there is a significant (p<0.05) effect of season on birth weight of kid, gestation length, age at first kidding and weight at first kidding of Black Bengal goat. The average weight of first kidding of Black Bengal goat at summer, rainy and winter season were 9.34±0.16, 9.33±0.16 and 7.79±0.14 kg respectively. There is no significant effect of season on lactation length of Black Bengal goat. The average lactation length of Black Bengal goat at summer, rainy and winter season were 72.8±0.54, 73.2±0.55 and 73.07±0.49 days respectively. Average kidding interval of Black Bengal goat at summer, rainy and winter season were 186.97±0.82, 184.3±0.84 and 190.48±0.75 days respectively. There is a highly significant (p<0.01) effect of kidding interval on season but having a significant (p<0.05) effect of kidding interval on parity. There is no significant effect of season and parity on kid mortality rate of Black Bengal goat. The average kid mortality rate of Black Bengal goat at summer, rainy and winter season were 16.66±6.39, 18.75±6.54 and 24.79±5.82 % respectively. The average kid mortality rate at 1st, 2nd, 3rd and 4th parity was 17.36±5.75, 20.60±5.40, and 20.64±6.14 and 14.09±9.31 %. From this experiment it can be concluded that better reproductive performance found in rainy season because the birth weight of kid, age at puberty, lactation length, kidding interval was better than other season. The reproductive performance was excellent in fourth parity because litter size, kidding interval, kid mortality rate were better than other parity.