Breeding beef cattle for an extended productive life: Evaluation of selection criteria in the Retinta breed

R Morales,F Phocas,S Demyda-Peyrás,M Solé,A Menéndez-Buxadera,A Molina

doi:10.1016/j.livsci.2017.08.014

Abstract

We characterized genetically the longevity and the productive life of beef cows considering three different traits: length of true life (LTL), the length of productive life (LPL) and a number of calvings (NC), in the Retinta breed. Data considered in the analysis were collected in 30 Spanish herds and consisted of 3187 cows born between 1993 and 2013: 1802 cows had complete information while 1385 cows had censored information. Pedigree information accounted for 7359 individuals and the genetic evaluation was performed under an animal model using the Weibull proportional hazard model for survival analysis. Results indicated that cow effects (age at first calving, herd, season-year of cow birth), as well as some calf effects (breed group, season-year of birth), were significant (P < 0.05) for all traits; however, sex of calves did not affect the traits. The low heritabilities obtained for LTL and LPL (0.14 ± 0.01 and 0.14 ± 0.01 respectively) and modest heritability for NC (0.30 ± 0.01), suggest that a higher response to selection can be expected for NC than for LTL and LPL.

Highlights

Beef breeding programs are focused on increasing live weight or short-term weight gain in order to produce more kilograms of meat per individual
Pedigree information accounted for 7359 individuals and the genetic evaluation was performed under an animal model using the Weibull proportional hazard model for survival analysis
The low heritabilities obtained for length of true life (LTL) and length of productive life (LPL) (0.14 ± 0.01 and 0.14 ± 0.01 respectively) and modest heritability for number of calvings (NC) (0.30 ± 0.01), suggest that a higher response to selection can be expected for NC than for LTL and LPL

Summary

Introduction

Beef breeding programs are focused on increasing live weight or short-term weight gain in order to produce more kilograms of meat per individual It has hardly been studied how those criteria affect cow longevity. The costly period from birth to first parity will be best amortized in cows with an increased longevity because the cost per weaned calf will decrease proportionally (Dákay et al, 2006) The inclusion of this trait in beef cattle breeding programs would allow selecting heifers with an increased chance of remaining in the herd for a longer period of time and, at the same time, farmers would be able to determine the age of culling depending on their breeding objectives (Caetano et al, 2013)

Methods

Results

Discussion

Conclusion