The relationship between leptin gene polymorphisms and reproductive traits in Jersey cows.

The aim of the study was to analyse the relationship between three leptin gene polymorphisms, and indices of reproductive performance--age at first calving, days open, calving interval, number of inseminations per conception, and gestation length in Jersey cattle. A total of 219 cows were tested for the R4C, A59V and C(-963)T mutations using the PCR-RFLP technique. The following allele frequencies were found: R4C--0.80 (C) and 0.20 (T), A59V--0.67 (C) and 0.33 (T), C(-963)T--0.83 (C) and 0.17 (T). The statistically significant correlation (P < or = 0.05) was found only for the A59V mutation. Cows with the TT genotype were characterized by shorter calving interval and time of days open than animals with CT and CC genotype. Also, the number of inseminations per conception was lower in A59V--TT homozygotes compared with two other genotypes. The association analysis did not reveal any significant correlations for both R4C and C(-963)T polymorphisms.