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. We also determined polymorphism of reflected in three loci: 2, 4, and 9. Significant differences among 9 genotypes (AA, AB, and BB) were displayed for all studied traits as well as among 2 genotypes, except for CE, while 4 genotypes significantly differed only in BW, WW, TMY, stillbirth, GL, and AFC. In practice, strong associations among genotypes of the gene and the traits of interest candidate this gene to be selective in Egyptian buffalo breeding for improving both productive and reproductive traits.