Lactation curves of different cattle breeds under cooperative dairying conditions in Bangladesh

Study the live weight and live weight gain of black bengal and jamunapari goat breeds by fitting the linear regression under semi-intensive conditions

The present study was conducted to know the live weight gain of goats under semi-intensive conditions of Chittagong district of Bangladesh during the period of July, 2012 to January, 2013. Data were collected from 72 black Bengal and 32 Jamunapari goats and the kids birth weight and their subsequent live weight at weekly intervals up to age and weight of weaning at sexual maturity was recorded. The weight gains from birth to sexual maturity of two different breeds under 2 different farms were studied. Average birth weight of male and female black Bengal goats kids were 1.22 +/- 0.15, 1.01 +/- 0.14, 1.42 +/- 0.10 and 1.12 +/- 0.27 kg, respectively for farm 1 and 2. For Jamunapari goat's kid birth weight were 1.51 +/- 0.07 and 1.42 +/- 0.09 kg, for male and females, respectively in the farm 2. The average weaning age was 4 months and the average weaning weight of male and female black Bengal goats were 5.19 +/- 0.358, 5.05 +/- 0.28, 5.63 +/- 0.61 and 5.54 +/- 0.41 kg, in the farm 1 and 2, respectively. However, the average weaning weight of male and female Jamunapari was 6.59 +/- 0.69 and 6.79 +/- 0.31 kg, respectively in farm 2 which was higher than black Bengal. The average age at sexual maturity of black Bengal goat was 8 months. The average weight at sexual maturity of male and female black Bengal goats were 9.82 +/- 0.75 and 9.52 +/- 0.62 kg, respectively in farm 1 and 9.65 +/- 0.75 and 9.138 +/- 0.70 kg, respectively in farm 2. The average age at sexual maturity was 9 months for Jamunapari goat. The average weight at sexual maturity of male and female Jamunapari goats was 13.2 +/- 0.75 and 14.1 +/- 0.82 kg, respectively. The average daily body weight gain from birth to weaning for male and female black Bengal goat was 33.70, 35.11 g day(-1) and was 35.67 and 45.94 g day(-1), respectively in farm 1 and 2 and for Jamunapari goat was 42.97 and 45.47 g day(-1), respectively. The males were grew faster than the females. The predicted live weight gains for both breeds were lowered after fitting the linear regression. The co-efficient of determination (R(2)) of male and female black Bengal and Jamunapari goats kids similar.