Dr.. A. M. Y. Khandoker
Professor
Department of Animal Breeding and Genetics, Bangladesh Agricultural University, Mymensingh-2202,
Black Bengal, Growth traits, Milk yield, Semen parameters, Traits
Variety and Species
The study was conducted in the nucleus breeding flock at the Artificial Insemination Center under the Department of Animal Breeding and Genetics, Bangladesh Agricultural University, Mymensingh with the financial support of the USDA project entitled “Conservation of Black Bengal Goat as the Potential Genetic Resource in Bangladesh” during the period from January, 2010 to June, 2012. Animals were managed and raised under confinement as an intensive system. They were housed in individual pens (4×2.5 sq.ft) in a galvanized iron sheet shed with a wooden slatted floor raised above the ground level. The house was provided with necessary arrangements for feeding and watering and for sufficient access to fresh air. Semen was collected by Artificial Vagina method and semen was frozen by reducing temperature gradually (Hussain, 2004). The bucks used in this experiment were kept under zero grazing management and stall fed twice daily on a diet consisting of Napier, German and/or Maize fodder ad labium. The feed was supplemented with commercial (Surma Feed, BRAC Feed Mill, Sreepur, Gazipur) pellet in two meals twice in a day @ 100gm/ buck. They were allowed for grazing and exercise for 1 to 2 hours daily. The breeding bucks were supplied germinated gram (20gm/buck/day). Clean and safe water was made available at all the time. Throughout this study, almost identical ration was provided for each of the bucks. All bucks were vaccinated against Peste des Petits Ruminants (PPR) and dewormed routinely. The animals were identified with neckband tags. The identities of newborns and their parents, date of birth, sex of kid, type of birth and parity of dam were recorded. For each individual a record sheet with full details of each parameter along with pedigree information were maintained. New-born kids were allowed to suckle their mothers and were left with them up to 3 months of age. Kids were weaned at three month of age. Following weaning, kids were offered 50-100 g/head/day of the same commercial concentrate. All the female kids were kept in shed with their dams, but males over 3 months of age were housed separately in individual pen (4×2.5 sq.ft) to avoid uncontrolled breeding. No castration was performed on the male kids. A total of 197 Black Bengal progeny of 15 Black Bengal Bucks of were 19 to 34 months in age. The body weight and scrotal circumference (SC) of bucks were 19.0 to 25.0 kg and 17.0 to 22.0 cm respectively. Data on body weights and semen characteristics of individual animals were recorded at a regular basis (Mia, 1997). The milk yield were recorded fortnightly. The traits analyzed were growth traits (birth, 3, 6, 9 and 12-month body weight), semen characteristics (semen volume, sperm concentration, mass motility, sperm livability and normal spermatozoa) and milk yield of progeny. The significance of fixed effects was tested conducting least-squares analyses of variance using the general linear model (GLM) procedure of the Statistical Analysis System (SAS, 1998) according to the following liner model: For growth performance: Yijklm = µ + Si +Mj + Rk + Tl + Eijklm , where Yijklm is the body weight at different ages (individual animal record for the trait), µ is the overall mean, Si is the fixed effect of ith sex of kid, Mj is the fixed effect of jth type of birth, Rk is the effect of kth parity of dam, Tl is the effect of lth season of birth and Eijklm is the residual error. Sex of kid was grouped into male and female. The year was divided into three seasons; winter (November to February), summer (March to June) and rainy (July to October). Number of kid born was grouped into single, twins and triplets. Parity of dam was grouped into first, second, third and fourth parities. For semen characteristics: Yijklm = µ + Si +Mj + Rk + Eijklm , Where Yijklm is the semen characteristics, µ is the overall mean, Si is the fixed effect of ith age, Mj is the fixed effect of the jth body weight, Rk is the effect of kth scrotal circumference and Eijklm is the residual error. Age of bucks was grouped into classes of 7-9 and >9-12 months. Body weight of bucks was grouped into classes of 10-15 and >15-20 and kg. Scrotal circumference of bucks ranges from 16-20 cm. For milk yield: Yijk = µ + Si +Mj + Eijk, Where Yijk is the dependent variable, µ is the overall mean, Si is the fixed effect of ith season of kidding, Mj is the fixed effect of the jth litter size and Eijk is the residual error. The year was divided into three seasons; winter (November to February), summer (March to June) and rainy (July to October). The significant means were separated using the Duncan’s multiple range test.
J. Bangladesh Agril. Univ. 11(1): 79–86, 2013, ISSN 1810-3030
Journal