Estimation of Genetic and Phenotypic Parameters for Production Traits and Somatic Cell Count for Jersey Dairy Cattle in Zimbabwe

Edward Missanjo,Tinyiko Halimani,Venancio Imbayarwo-Chikosi

doi:10.1155/2013/470585

Edward Missanjo, Tinyiko Halimani + Show 1 more

Open Access

https://doi.org/10.1155/2013/470585

Copy DOI

Abstract

Genetic and phenotypic parameters for production traits and somatic cell count (SCC) for Jersey dairy cattle in Zimbabwe were estimated. A total of 10986 lactation records were obtained from Zimbabwe Livestock Identification Trust, with cows calving in the period from 1996 to 2008. An ASReml program fitting an animal model was used for the analyses. Heritability estimates for milk yield, fat yield, protein yield, fat percentage, protein percentage, and Log10SCC were 0.30, 0.32, 0.33, 0.42, 0.44, and 0.08, respectively. The corresponding repeatability estimates were 0.39, 0.38, 0.39, 0.49, 0.51, and 0.16, respectively. The genetic and phenotypic correlations between different production traits ranged from −0.86 to 0.95 and from −0.88 to 0.98, respectively. The genetic and phenotypic correlations between production traits and Log10SCC were weak almost nonsignificantly differentl from zero. The results imply that milk traits for Jersey dairy cattle in Zimbabwe are more heritable. Therefore, these traits may be preferred by breeders as selection criteria for development of effective genetic improvement programme.

Highlights

Knowledge of genetic parameters is the basis of sound livestock improvement programmes
Estimates of heritabilities and genetic correlations are essential population parameters required in animal breeding research and in design and application of practical animal breeding programmes
One of the assumptions behind the use of repeatability models in the present study is that all lactations are genetically the same trait

Summary

Introduction

Knowledge of genetic parameters is the basis of sound livestock improvement programmes. Estimates of heritabilities and genetic correlations are essential population parameters required in animal breeding research and in design and application of practical animal breeding programmes. The Jersey is one of the dairy breeds found in Zimbabwe It is the second most important breed of dairy after HolsteinFriesian. It is a small breed of dairy cattle, with mature live weight ranging from 360 to 540 kg. Jerseys can thrive on locally produced food. They can tolerate high temperatures; heifers mature more quickly than those of other breeds and can be mated at 13 to 15 months; they produce an average herd milk production of 3500 to 5000 kg [2]

Objectives

Methods

Results