A Doctoral Dissertation at the College of Agriculture Explores the Genetic Evaluation of Holstein and Jersey Cattle Based on Selected Productive Traits.

The College of Agriculture at the University of Diyala Discussed a Doctoral Dissertation Entitled:
“Genetic Evaluation of Holstein and Jersey Cattle Based on Selected Productive Traits.”

The study, submitted by Riyadh Taha Talak, aimed to assess field traits such as birth and weaning weights, colostrum and milk yield, as well as the influence of breed and season on the laboratory characteristics of milk components, both chemical and physical. The research also sought to estimate genetic parameters and provide scientifically grounded recommendations.

The study yielded several key conclusions, including:

• Holstein cattle significantly outperformed Jersey cattle in terms of colostrum and milk yield, as well as in calf birth weight, weaning weight, and average daily weight gain.

• Jersey cattle milk was superior to Holstein milk in terms of fat percentage and non-fat solids content.

• The highest heritability estimate in Holsteins was observed for colostrum yield, with the strongest genetic and phenotypic correlation found between birth weight and weaning weight.

• In Jersey cattle, the highest heritability estimate was also recorded for colostrum yield, while the strongest phenotypic and genetic correlation was observed between average daily weight gain and weaning weight.

The study recommends:

1. Determining the age of puberty and sexual maturity in females of both breeds to facilitate artificial insemination and standardize age and weight at breeding;

2. Crossbreeding Holstein and Jersey cattle to improve both milk yield and milk composition (fat and solids content);

3. Breeding purebred bulls, conducting fertility tests, and preserving semen locally to reduce the financial burden of importing semen from abroad.