title: Influence of biostimulation and temporary weaning on follicular dynamics and pregnancy rates in Nelore cows (Bos taurus indicus).
abstract: The objective of this study was to evaluate the effect of biostimulation and temporary weaning on the follicular dynamics and pregnancy rates in Nelore cows. We used three groups of 75 cows: a control group without biostimulation and suckling calves (WB), a group that was biostimulated and had suckling calves (BE) and a group that was biostimulated and subjected to temporary weaning for 56 h (BETW). Ovarian dynamics were examined using ultrasonography. All groups showed follicular atresia. The interval between beginning of the treatment and wave emergence was 3.25 ± 0.30 days for BE, 3.40 ± 0.27 days for BETW and 3.37 ± 0.50 days for WB. The time between implant removal and ovulation was 64.50 ± 1.88 h for BE, 66.75 ± 1.35 h for BETW and 60.85 ± 3.10 h for WB. Eight cows were submitted to ultrasound analysis, and the percentages of cows that had ovulatory follicles of the new follicular wave with maximum diameters greater than 0.80 cm were 100 % (8/8) in BE (1.28 ± 0.12 cm), 100 % (8/8) in BETW (1.52 ± 0.07 cm) and 87.5 % (7/8) in WB (1.21 ± 0.10 cm). The pregnancy rate was 52 % (39/75) in BE, 69.3 % (52/75) in BETW and 37.3 % (28/75) in WB. The association of biostimulation and temporary weaning increased follicular development, ovulation synchronisation and, consequently, the pregnancy rate in beef cows.
authors.affiliation: Department of Zootecnia, Federal University of Piauí, Bom Jesus, Piauí, 6490000, Brazil. manoellopes@ufpi.edu.br.
authors.forename: Manoel Lopes
authors.initials: ML
authors.lastname: Silva Filho
authors.affiliation: Department of Zootecnia, Federal University of Piauí, Bom Jesus, Piauí, 6490000, Brazil. leilson@ufpi.edu.br.
authors.forename: Leilson Rocha
authors.initials: LR
authors.lastname: Bezerra
authors.affiliation: Department of Animal Reproduction, Federal University of Pernambuco, Recife, Permanbuco, Brazil.
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Ferreira-Silva
authors.affiliation: Department of Animal Reproduction, Federal University of Pernambuco, Recife, Permanbuco, Brazil. pfmps@hotmail.com.
authors.forename: Francisco Maciel Póvoas Paulo
authors.initials: FM
authors.lastname: Souto
authors.affiliation: Department of Animal Reproduction, Federal University of Piauí, Teresina, Piauí, Brazil. neyromulo@ufpi.edu.br.
authors.forename: Ney Romulus Paula
authors.initials: NR
authors.lastname: Oliveira
authors.affiliation: Department of Animal Reproduction, Federal University of Pernambuco, Recife, Permanbuco, Brazil. paulolima4045@hotmail.com.
authors.forename: Paulo Fernandes
authors.initials: PF
authors.lastname: de Lima
authors.affiliation: Department of Animal Reproduction, Federal University of Pernambuco, Recife, Permanbuco, Brazil. ccbartol@gmail.com.
authors.forename: Claudio Coutinho
authors.initials: CC
authors.lastname: Bartholomew
authors.affiliation: Department of Animal Reproduction, Federal University of Pernambuco, Recife, Permanbuco, Brazil. maloufrpe@uol.com.br.
authors.forename: Marcos Antonio Lemos
authors.initials: MA
authors.lastname: de Oliveira
mesh_terms: D000818:Animals; D000833:Animals, Suckling; D002417:Cattle; D003008:Cloprostenol / Q000008:administration & dosage / Q000494:pharmacology; D004958:Estradiol / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D006062:Gonadotropins / Q000008:administration & dosage / Q000494:pharmacology; D008460:Meat; D006080:Ovarian Follicle / Q000502:physiology*; D010060:Ovulation / Q000187:drug effects / Q000502:physiology*; D011247:Pregnancy; D018873:Pregnancy Rate; D011270:Pregnancy, Animal / Q000502:physiology*; D012098:Reproduction; D014886:Weaning
chemical_list: D006062:Gonadotropins; C074283:estradiol 3-benzoate; D003008:Cloprostenol; D004958:Estradiol
keywords: Anoestrus; Calf; Cattle; Ovarian dynamics; Reproduction