Seminal plasma insulin‐like growth factor I and total protein concentration in peripubertal period of the Gyr bulls

Made available in DSpace on 2022-04-29T08:30:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 This study aimed to evaluate the correlation of seminal plasma IGF-I and total proteins from peripubertal bulls with semen characteristics and onset of puberty. Sixteen dairy Gyr bulls were separated into early (n = 8) and regular (n = 8) groups, according to the onset of puberty. Semen was monthly collected by electroejaculation from 14 to 26 months of age, and the onset of puberty was retrospectively determined (17.0 ± 1.6 and 19.2 ± 1.5 months, to early and regular group, respectively). Five time points were evaluated (day −60, day −30, day 0, day 30 and day 60 days of puberty), being day 0 considered as beginning of puberty. Scrotal circumference and body weight were also assessed. Semen characteristics were evaluated, the seminal plasma was separated by centrifugation and total protein and IGF-I concentrations were determined. There was no difference between groups to concentration of the seminal plasma total proteins, but we found an interaction between group and age. Seminal plasma IGF-I concentrations were not different between early and regular groups; thus, the data were combined for analysis. Combined IGF-I concentrations were positively correlated with sperm motility and concentration, age, body weight and scrotal circumference. Negative correlation was found between IGF-I concentration and total sperm defects. Increased IGF-I was observed in day −30 and day 0 of puberty in early and regular groups, respectively. Seminal plasma total proteins are involved in peripubertal modifications and IGF-I from Zebus dairy bulls can influence the seminal characteristics and the growth factor increase occurs concomitantly with body growth but cannot be used to define puberty bulls earlier. Departamento de Medicina Veterinária Universidade Federal do Paraná Centro de Ciências Agrárias e da Biodiversidade Universidade Federal do Cariri Universidade Federal Rural da Amazônia Facultad de Ciencias Agropecuarias Universidad de La Salle Departamento de Cirurgia Veterinária e Reprodução Animal FMVZ Universidade Estadual Paulista UNESP Departamento de Salud Animal y Producción de Hato Universidad Nacional de Colombia Universidade Federal de Minas Gerais Escola de Veterinária da UFMG Departamento de Cirurgia Veterinária e Reprodução Animal FMVZ Universidade Estadual Paulista UNESP