Bayesian approach for assessment of co-variances and genetic parameters of economically important traits in Sahiwal cattle

Abstract

Precise as well as unbiased estimates of genetic parameters of economically important traits is important in lieu of framing breeding programmes for genetic progress of dairy animals. Present work was carried out to assess the co-variances along with genetic parameters of economically important traits in Sahiwal cattle with Bayesian approach. Records of Sahiwal cattle kept at ICAR-National Dairy Research Institute, Karnal, Haryana spanned over duration of 29 years i.e. 1988–2016 were used. Heritability estimates ± posterior standard deviation for 305 days’ milk yield (305DMY), lactation milk yield (LMY), lactation length (LL), peak yield (PY), days to attain peak yield (DPY), dry period (DP), gestation period (GP), calving to first insemination interval (CFI), days open (DO) and calving interval (CI) as obtained were 0.21 ± 0.04, 0.23 ± 0.04, 0.16 ± 0.03, 0.16 ± 0.03, 0.07 ± 0.02, 0.08 ± 0.02, 0.07 ± 0.02, 0.08 ± 0.02, 0.10 ± 0.02 and 0.11 ± 0.02, respectively and estimates of repeatability for the corresponding traits were 0.24 ± 0.04, 0.27 ± 0.04, 0.21 ± 0.04, 0.22 ± 0.03, 0.12 ± 0.03, 0.15 ± 0.03, 0.15 ± 0.03, 0.17 ± 0.03, 0.19 ± 0.03 and 0.19 ± 0.03. Moderate heritability values for 305DMY and LMY implies that sufficient additive genetic variability is available to obtain selection response. Repeatability estimates for 305DMY, LMY and PY were moderate, pointing towards the possibility of early appraisal of Sahiwal cattle for selection. Antagonistic genetic associations were observed between reproduction and production traits suggesting that reproduction traits need due attention while selecting high producing Sahiwal animals.

Computation of Heritability for Production and Reproduction Traits in Frieswal Cattle under Field Progeny Testing

“…Ratwan et al [47] also reported a similar estimate in Sahiwal cattle. Selvan et al [50], Lomole [36] and Ratwan et al [48] reported a lower estimate in Sahiwal cattle than the present study. Olson et al [42] and Easa et al [18] reported a higher estimate in Holstein Friesian cattle.…”

“…The dry period had an extremely low heritability (Table 1). Kannan [25] in Sahiwal cattle and Ratwan et al [48] in Sahiwal cattle reported similar estimates of heritability. Kaur et al [26] reported higher estimates in crossbred and Raja [46] reported high estimates in Sahiwal cattle.…”

“…Girimal et al [21] in Sahiwal cattle and Deshpande and Bonde [15] in Frieswal cattle reported higher heritability estimates than found in the present study. Radwan et al [45] and Ratwan et al [48] reported lower estimates in Holstein Friesian and Sahiwal cattle, respectively. Lakshmiet al [34] and Kumar et al [32] reported a lower estimate in Frieswal.…”

“…[53] reported a similar estimate in Karan Fries cattle. Divya et al [16], Parveen et al [44], Ratwan et al [48] and Dash et al [14] reported lower estimates in Karan Fries and Sahiwal cattle, respectively. Easa et al [18] reported a similar estimate in Holstein Friesian cattle.…”

“…The service period is a reproductive trait that is lowly heritable, however, the high estimate in the present study indicated a greater influence of genetic factors on this trait in Frieswal cattle. Mukharjee [40] in Frieswal cattle Kaur [26] in crossbred cattle, Easa [18] in Holstein Friesian and Ratwan et al [48] and Dash et al [14] in Sahiwal cattle reported low estimates.…”