Factors affecting actual weaning weight, preweaning average daily gain and relative growth rate in Asturiana de los Valles beef cattle breed

F Goyache,I Fernández,L J Royo,I Álvarez,J P Gutiérrez

doi:10.5194/aab-46-235-2003

Abstract

Abstract. In this paper we analyse the major environmental and genetic factors affecting actual weaning weight (WW), preweaning average daily gain (ADG) and relative growth rate (RGR) in a representative sample of field data of Asturiana de los Valles beef cattle breed. Major environmental factors affect preweaning growth performance of Asturiana de los Valles calves in the direction usually found in the literature. However RGR seems to be self-corrected for sex of calf and calving number. Heritabilities for the direct and maternal genetic effects were 0.67 and 0.29, 0.51 and 0.31 and 0.18 and 0.12 respectively for WW, ADG and RGR. The estimates of genetic parameters affecting RGR are more realistic than those estimated for the WW and ADG. Selection for RGR would lead to obtain higher growth rates and lower birth weights. RGR could be an interesting selection criterion in beef cattle improvement programs.

Highlights

Since knowledge of factors affecting preweaning growth in beef calves is helpful in formulating management and selection decisions, preweaning growth traits are usually evaluated in most of the current improvement programs in beef cattle (SHI et al, 1993; GUTIÉRREZ et al, 1997)
Three traits have been analysed in this paper: a) actual weaning weight (WW); b) preweaning average daily gain (ADG), computed as ADG = (WW-BW)/AGE, being BW the actual birth weight and AGE the age of the calf at weaning, and c) relative growth rate (RGR), defined as average daily gain relative to body weight, was computed as RGR = log (WW/BW)/AGE, being log the natural logarithm (FITZHUGH and TAYLOR, 1971; AHUNU and MAKARECHIAN, 1987) The statistical analysis was done with GLM Procedure of SAS (SAS, 1999)
Overall means and standard deviations of the preweaning growth traits were of 217.60 ± 35.22 Kg, 0.970 ± 0.199 Kg/day and 0.009241 ± 0.001226 points/day for WW, ADG and RGR, respectively

Summary

Introduction

Since knowledge of factors affecting preweaning growth in beef calves is helpful in formulating management and selection decisions, preweaning growth traits are usually evaluated in most of the current improvement programs in beef cattle (SHI et al, 1993; GUTIÉRREZ et al, 1997). Preweaning growth has usually been evaluated as average daily gain from. GOYACHE et al.: Preweaning growth traits in Asturiana de los Valles birth to weaning using records at these ages. Some authors have proposed to characterise the growth ability as a relative rate taking into account the average body mass (FITZHUGH and TAYLOR, 1971; AHUNU and MAKARECHIAN, 1987). The aim of this paper is to determine the importance of the main environmental and genetic factors influencing preweaning growth in the Asturiana de los Valles cattle, focusing on relative growth rates

Objectives

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Results

Conclusion