Performance study and estimating genetic parameters of production and reproduction traits of Khuzestani buffaloes

    In this research, production and reproduction performance data of 526 buffalo herds of Khuzestan, collected by the deputy of improving livestock production of Agriculture Organization of Khuzestan from 1992 to 2009, were studied. The GLM method of SAS software was used to study the effect of none genetic factors on considered traits. Variance components and hertabilities were also estimated by restricted maximum likelihood using DFREML software package. The average and standard error were estimated as 1939.76 ± 6.5 kg for milk yield, 120.27 ± 0.48 kg for fat yield, 6.1 ± 0.01 % for fat percentage, 83.94 ± 0.40 kg for protein yield, 3.9 ± 0.004 % for protein percentage, 200.34 ± 0.44 days for lactation length, 4.68 ± 0.02 kg for milk yield per day of calving interval and 9.58 ± 0.04 kg for milk yield per day of lactation length, respectively. The average and standard error of reproductive traits were estimated as 240.27 ± 1.89 days for dry period, 156 ± 2.05 days for the number of open days, 465.21 ± 2.05 days for calving interval and 3.68 ± 0.02 years for age at first calving, respectively. The effect of herd, calving year and parity were significant for all traits. However, calving season had not significant effect on protein percentage, calving interval and the number of open days. The estimated heritability coefficient was zero for all studied traits, except age at first calving with heritability of 0.21. Some factors such as inappropriate feeding and breeding management in these buffalo herds and particularly errors in milk recording, pedigree registering and relationships were some of main reasons for this estimating