Detection of estrous behavior in buffalo heifers by radiotelemetry following PGF2α administration during the early or late luteal phase.
This study examined the usefulness of radiotelemetry for estrous detection in buffalo heifers and the impact of prostaglandin F2α (PGF2α) administration during the early or late luteal phase on estrous behavior and ovulatory follicle variables. Induction of estrus with PGF2α at a random stage of the estrous cycle was followed by the arbitrary division of heifers into groups receiving a second dose of PGF2α during either the early (n=33) or late (n=17) luteal phase (6-9 or 11-14 days after estrus, respectively) for the induction of synchronized estrus. The electronic detection of synchronized estrus by radiotelemetry was confirmed using ultrasonography every 6h until ovulation. Radiotelemetry was 90% efficient and 100% accurate for estrous detection. Intervals between the PGF2α dose and the beginning of synchronized estrus (40.7 ± 10.9 vs. 56.7 ± 12.8h) or ovulation (70.0 ± 11.3 vs. 85.6 ± 12.5h) were shorter (P<0.05) for heifers receiving PGF2α during the early luteal phase. PGF2α administration during the early or late luteal phase produced similar (P>0.05) results for the duration of estrus, the intervals from the beginning or end of estrus to ovulation, the number and duration of mounts per estrus, the duration of mounts, the diameter of the ovulatory follicle and the luteal profile on day 5 after estrus. In conclusion, radiotelemetry was a suitable tool for the efficient and accurate detection of estrus in buffalo heifers. Treatment with PGF2α during the early luteal phase had a shorter interval to synchronized estrus and ovulation; however, estrous behavior, ovulatory follicle dynamics and subsequent luteal activity were similar following PGF2α administration during the early or late luteal phase.
Departamento de Reprodução Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, São Paulo, Brazil.
R M
RM
Porto-Filho
Departamento de Medicina Veterinária Preventiva e Reprodução Animal, Faculdade de Ciências Agrárias e Veterinárias, Jaboticabal, São Paulo, Brazil.
L U
LU
Gimenes
Departamento de Reprodução Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, São Paulo, Brazil.
B M
BM
Monteiro
Unidade de Pesquisa e Desenvolvimento de Registro-Pólo Regional do D.S.A. do Vale do Ribeira/APTA, Registro, São Paulo, Brazil.
N A T
NA
Carvalho
Department of Veterinary Gynaecology and Obstetrics, College of Veterinary Science, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India.
S P S
SP
Ghuman
Departamento de Reprodução Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, São Paulo, Brazil.
E H
EH
Madureira
Departamento de Reprodução Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, São Paulo, Brazil. Electronic address: barusell@usp.br.
P S
PS
Baruselli
D000818:Animals; D001522:Behavior, Animal; D002020:Buffaloes / Q000502:physiology*; D015237:Dinoprost / Q000008:administration & dosage*; D004334:Drug Administration Schedule; D030762:Estrous Cycle / Q000097:blood / Q000187:drug effects; D004972:Estrus Detection / Q000379:methods*; D004973:Estrus Synchronization / Q000379:methods; D005260:Female; D008183:Luteal Phase / Q000187:drug effects*; D011374:Progesterone / Q000097:blood; D013686:Telemetry / Q000379:methods* / Q000662:veterinary
D011374:Progesterone; D015237:Dinoprost
Buffalo heifers; Estrus; Prostaglandin; Radiotelemetry; Synchronization