Beef Cow Reproductive Performance Evaluation with a Fertility Functional SNP Array in Northern México and the Southwestern United States

Beef cow reproductive traits are critical for system profitability and difficult to improve using selection. A custom array with 131 SNPs identified within genes related to cow puberty and fertility was evaluated in privately owned Angus (A), Charolais, Brangus, and Red Brangus cows in México (n = 828) and in A, Brahman (B), Hereford (H), Nellore (N), and crossbred (F1 and F2 B-H, F2 B-A, first- and second-generation 3/8 B 5/8 A, and 3/8 N 5/8 A) cows in a Texas research herd (n = 449). Cow traits included age at first and second calving, calving interval, and reproductive success. Calf traits were birth weight and occurrences of calving difficulty, calves with inadequate vigor at birth, and mortality. Residuals from fixed effect models were used in association analyses. The detection of associated loci was mostly within combined groups. A marker in RHEBL1 was associated (p < 0.05) with age at calving in Angus. A locus in FAM19A4 was associated (p < 0.05) with reproductive success in Brangus and inadequate calf vigor in all data combined. Markers in SYCE1 and CPNE5 were associated (p < 0.05) with reproductive success and calf mortality in Bos indicus. Functional panels may be more effective when designed for individual breeds or sub-species.