Association analysis of prolactin and prolactin receptor genes with selected productive and reproductive traits in Egyptian buffalo.

A total of 266 records of buffalo raised in two experimental herds in Egypt were assessed to detect prolactin () and prolactin receptor () genes' polymorphism using PCR-Single Strand Conformational Polymorphism (SSCP) and PCR-Restricted Fragment Length Polymorphism (RFLP) techniques as well as to investigate their association with calf birth weight (BW), weaning weight (WW), lactation period (LP), total milk yield (TMY), stillbirth, calving ease (CE), gestation length (GL), postpartum interval to pregnancy (PPIP), calving interval (CI), and age at first calving (AFC). Predicted breeding values were estimated and used in the association with detected genotypes. A monomorphic pattern of the studied 156 bp segment was recorded and absence of its polymorphism in buffalo was corroborated.

Genetic parameters and principal components analysis of breeding value for birth and weaning weight in Egyptian buffalo.

Objective: The objectives of the current study were to study the main environmental factors affecting birth weight (BW) and weaning weight (WW), estimate variance components, genetic parameters and genetic trend and to evaluate the variability and relationships among breeding value of BW and WW using principal components analysis (PCA).

Methods: A total of 16,370 records were collected from 8,271 buffalo calves. Genetic parameters and breeding values were estimated using a bivariate animal model which includes direct, maternal and permanent maternal effects.