title: Exploratory analysis of differences in sperm morphology in Nelore and Gir (Bos indicus) bulls.
abstract: The aim of this study was to evaluate the effects of breed and season on semen quality parameters of zebu bulls. Data (1,632 registers) of semen production from Gir (n = 4) and Nelore (n = 15) bulls were collected between October 2005 and November 2009. The ejaculates were collected twice a week during various seasons (summer, fall, winter, and spring) and evaluated for the following semen parameters: ejaculate volume, sperm concentration, sperm motility, forward progressive motility (FPM), and sperm morphology. Factor analysis was used to determine the relationship among variables. The effect of breed (Gir and Nelore) and season and their cross effect on each parameter and extracted factor were tested using ANOVA. A negative correlation (P < 0.05) was observed between FPM and proximal droplet, as well as with abnormal loose head, abnormal small head, pouch formation, abnormal mid-piece, and strongly folded tail. Gir bull sperm showed more major defects, detached acrosome, and minor FPM (P < 0.01), whereas Nelore bulls showed a higher number of sperm with normally loose head.
authors.affiliation: Departamento de Reprodução Animal, Faculdade de Ciências Agrárias e Veterinárias, UNESP, Via de Acesso Prof. Paulo Donato Castellane, s/n, Jaboticabal, São Paulo, 14884-900, Brazil, alinelucio@hotmail.com.
authors.forename: Aline Costa de
authors.initials: AC
authors.lastname: Lucio
authors.forename: Antonio Sérgio
authors.initials: AS
authors.lastname: Ferraudo
authors.forename: Leticia Zoccolaro de
authors.initials: LZ
authors.lastname: Oliveira
authors.forename: Adriana Santana do
authors.initials: AS
authors.lastname: Carmo
authors.forename: Benner Geraldo
authors.initials: BG
authors.lastname: Alves
authors.forename: Kele Amaral
authors.initials: KA
authors.lastname: Alves
authors.forename: Solange
authors.initials: S
authors.lastname: Almeida
authors.forename: Luis Alfredo
authors.initials: LA
authors.lastname: Deragon
authors.forename: William
authors.initials: W
authors.lastname: Pereira
authors.forename: Luisa Cunha
authors.initials: LC
authors.lastname: Carneiro
authors.forename: Vera Fernanda Martins Hossepian de
authors.initials: VF
authors.lastname: Lima
mesh_terms: D000818:Animals; D002417:Cattle / Q000145:classification / Q000502:physiology*; D008297:Male; D012621:Seasons; D012661:Semen / Q000502:physiology*; D055101:Semen Analysis / Q000662:veterinary; D013076:Sperm Count; D013081:Sperm Motility; D013094:Spermatozoa / Q000502:physiology*