Development of sustainable performance index based on production, reproduction, health and longevity for genetic improvement of Sahiwal cattle

Abstract

An attempt was made for the first time in India to develop the performance indices for quantifying the relative emphasis to be given to production, reproduction, health and longevity traits for selection and genetic improvement of Sahiwal cattle in a sustainable manner. The study was conducted using information related to various production, reproduction, health and longevity traits spread over a period of 29 years in Sahiwal cattle. Using income and expenditure method, the relative economic values for 305 days milk yield (305DMY), average daily milk yield (ADMY), calving to first insemination interval (CFI), days open (DO) and longevity (LNG) were estimated as 1, 1, −6.62, −6.62 and 5.96 in Sahiwal cattle. A total of three performance indices were constructed using three‐trait combination, that is production, reproduction and longevity before and after excluding the days suffered by the animals. Correlation between the aggregate genotype and index (RIH) was computed to determine the accuracy of each performance index, and based on highest RIH value, best performance index was identified for selection of Sahiwal cattle. Developed indices were further assessed for robustness by increasing the relative economic values of the traits by 25% and 50%. The performance index (305DMY, DO and LNG) was found to be the best index before as well as after excluding days suffered by the animals, but in later case emphasis to be given to different traits was found to be more balanced. The best index indicated that about 47, 42 and 11% relative emphasis to be assigned to 305 days milk yield, days open and longevity for selection of Sahiwal animals for sustainable genetic improvement.

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

“…Posterior mean of permanent environmental (above diagonal) and residual correlations (below diagonal) along with posterior standard deviation for different performance traits in Sahiwal cattle LMY, LL, PY, DPY, DP GP, CFI, DO and CI as 1935.13 kg, 2022.49 kg, 277.90 days, 12.62 kg, 43.90 days, 137.13 days, 286.82 days, 85.62 days, 134.22 days and 425.42 days, respectively in Sahiwal cattle.Means observed for different traits were in concordance with the results of earlier studies(Ratwan et al 2018a(Ratwan et al , 2019a(Ratwan et al , 2020b(Ratwan et al , 2021. Period of calving had signi cant (p < 0.01) in uence on all considered traits except DPY and GP.…”

Evaluation of relative economic value of performance traits in Sahiwal cattle

“…Wolf et al (2011) reported that formulation of profit function from which economic values are derived depends on the traits considered in breeding objective. Economic values are important for judging the economic significance of traits to be incorporated in a breeding objective and economic value refers to the probable increase in herd annual profit due to a unit increase in the trait as a result of selection (Jorge-Junior et al 2007, Ratwan et al 2021a. Selection index generally refers to a linear combination of various traits which are used to calculate total score for each individual and is used as a selection criterion in animal breeding.…”