Source of data: Experimental data were collected from the record sheets maintained at the Central Cattle Breeding Station and Dairy Farm (CCBDF), Savar, Dhaka and the book maintained for recording of body weight on individual animal at the upazila livestock office of the respective selected areas.
TraitsEconomically important traits of Brahman graded calves relating to growth performances were taken into consideration to estimate mean, standard deviation (SD), heritability, genetic and phenotypic correlation. Traits includedfor this study were birth weight (BWT), average daily gain (ADG) and yearling weight (YWT). The data on BWT was recorded within 12 hours of birth in kilogram (kg) on 233 calves. Amount of weight gained per day per animal during 1 year of age was considered as ADG.The YWT was taken at 365 days of age on 210 calves in kilogram (kg) was considered as YWT. Population size and data structure. A total of 233 graded calves were obtained from the study area of which 127 calves were males and 106 were females. In the project areas, the highest number of the calves (63) is found from Central Cattle Breeding Station and Dairy Farm (CCBDF), Savar, Dhaka. The second highest number of the calves (44) found from Thakugaon. A number of the calves in Chiribandor, Pirganj, Shariakandi, Belkuchi, Chouhali, Tungipara, Kustia, Jessore, Moulovibazar and Charghat were 20, 29, 08, 09, 14, 08, 10, 08, 12 and 08, respectively. Appointed animal recorders were worked to keep information on calves born, e.g. birth weight, yearling weight and average daily gain.
Experimental animals: The imported bull through the project was used to inseminate indigenous cows to obtain graded progeny in different areas of Bangladesh. With the collaboration of DLS, the Department of Animal Breeding and Genetics of Bangladesh Agricultural University (BAU) has started a sub-project entitled “Innovative research on livestock and poultry to increase milk, meat and egg production in Bangladesh” funded by the Higher Education Quality Enhancement Programme (HEQEP) of University grants commission (UGC). In the present research under the above sub-project, 4 (four) Brahmancrossbred (graded) breeding bulls have been selected from those graded population with the help of DLS. Bulls have been selected on the basis of average daily gain, physical appearance and libido. Analysis of DataMean and standard deviation for the traits studied were estimated using SAS computer package program (Version 7, USA). Variance and covariance components of the growth traits were estimated using the Restricted Maximum Likelihood approach by VCE (Variance Component Estimation) software (Groneneveld, 1998). Genetic and phenotypic co-relationship between different traits is also tested in this programme. For REML analysis animal model was used keeping season of birth as fixed effect. However, data were analysed using two –trait animal model.
The used model was.-Y = Xb + Za + e Where, Y = Vector of observation X, Z, and W = Known incidence matrices that associate with levels of b, a, and c with Yb = Unknown vector of fixed effects (season of birth)a = Unknown vector of fixed effect (sex of calves)c = Unknown vector of permanent environmental effect e = Vector of residual effects.