Genetic parameters for various semen production and quality traits and indicators of male and female reproductive performance in Nellore cattle

Table 4 Statistical models fitted for the male and female fertility and reproduction traits in Nellore cattle

Model effects	Traits
Male traits
CG, IDAP, IDAP², a, and e	VOL; VIG; TURB; MOT; LTL; RTL; LTW; RTW; VESIC_L; VESIC_W; TV; FT; MID; MAD; TD; SMN_ASCP; and BULL_FIT
CG, IDAP, IDAP², GMAND, a, and e	SC
Female traits
CG, CIR, a, and e	REB; REBA; REBB
CG, DTJN, GMAND, a, and e	PP14
CG, a, and e	STAY

VOL Ejaculate volume, VIG Spermatic vigor, TURB Spermatic vortex, MOT Rectilinear progressive sperm motility, SC Scrotal circumference, LTL Left testicular length, RTL Right testicular length, LTW Left testicular width, RTW Right testicular width, VESIC_COMP, VESICL Seminal vesicle length, VESICW Seminal vesicle width, TV Testicular volume, TF Testicular format, MAD Percentage of sperm cells with major sperm defects, MID Percentage of sperm cells with minor sperm defects, TD Percentage of total sperm cells with sperm defects, BULL_FIT evaluation andrological bull's fitness, SMN_ASPC Evaluation of seminal aspect, REB All records of rebreeding of females, REBB Rebreeding of females that entered reproduction at two years old, REBA Rebreeding of precocity heifers, PP14 Pregnancy probability at 14 months, STAY Ability to remain productive in the herd, CG Contemporary group, IDAP Age measured around 15 months as a covariate, IDAP² quadratic effect of age, GMAND is the weaning management group as an uncorrelated random effect, CIR Calving rest intervals, DTJN Calf birth date, a Random animal additive genetic effect, e residual random effect

ISSN: 1471-2164