The repeatability and phenotypic correlation estimated in fresh semen qualities of Bali bulls (Bos Javanicus)

The reproductive traits of bulls are important to produce straw with good quality. This study was aimed to estimate the repeatability (r) and phenotypic correlation (rp) values of fresh semen qualities. Five certified breed Bali bulls kept at Artificial Insemination Center (AIC) of Lelede, Indonesia with total of 1,478 records data of semen production from 2018-2019 years were used in this study. The semen evaluation consisted of semen volume (SV), motility rate (MR) and sperm concentration (SC). The semen collection procedure was performed according to the standard operational procedure (SOP) in AIC and Indonesian national standard (INS). The environmental effect analyzed by general linear model (GLM), the repeatability by intraclass correlation model and for the phenotypic correlation value was calculated using mathematical model. Research showed that the average of semen volume (SV), motility rate (MR) and spermatozoa concentration (SC) of Bali bulls were 3.74±1.68 mL, 64.89±10.08 % and 1091.20±496.99 ×106/mL respectively. Thus, the r value was estimated with intraclass correlation and nested models. Overall, SV and MR traits had low of r value (0.10 < r < 0.30). The SC trait had moderate (0.31 < r < 0.50) to high (r > 0.51) of r value. Thus, the highest of rp value was showed between MR and SC in each ejaculation. The Bali bulls in this study had good of SC trait and can be developed as the selection criteria for reproductive trait in the future.