Genetic parameter estimates for male and female fertility traits using genomic data to improve fertility in Australian beef cattle

Context Studies have shown that favourable genetic correlations exist between female and male fertility traits. However, investigations regarding these in Australian tropical beef cattle are limited to either pedigree or single-breed analysis. Aim The study aims use genomic information estimate parameters of six seven traits measured during the first 2 years life, two breeds. Methods Single-, bivariate multi-trait models were used analyse data from Brahman (BB; 996 cows 1022 bulls); Tropical Composite (TC; 1091 998 bulls) genotyped with high-density single-nucleotide polymorphism chip assay. Key results Heritability estimates BB ranged low (0.07 ± 0.04) for days calving at opportunity (DC1, days) high (0.57 0.08) age corpus luteum (AGECL, days). In bulls, varied (0.09 0.05) sperm motility (score 1–5) (0.64 0.06) scrotal circumference (SC) 24 months (SC24, cm). Similarly, heritability TC (0.04 0.03) DC1 (0.69 0.02) AGECL. was 0.07) SC24. Within-sex both breeds, blood concentrations insulin growth-factor 1 (IGF1) 18 (IGF1c) negatively correlated phenotypes. BB, across-sex, bulls’ concentration IGF1 6 (IGF1b) a good indicator trait following four traits: AGECL, postpartum anoestrus interval, DC1. TC, IGF1b percentage normal predictors Conclusions present generally support confirmed earlier analyses. findings suggest selection will benefit fertility, vice versa. Implications we can select early benefits within across sex. Using available through veterinary assessment bull as indicators enhance cow which lead better breeding rates herds.