Veterinary Archives, Vol. 90 No. 3, 2020.
Original scientific paper
https://doi.org/10.24099/vet.arhiv.0567
Tropical climate induces seasonal changes in the reproductive parameters and hormonal profile of Saanen bucks
Maria G. F. Salles
; Institute of Rural Development, University for International Integration of the Afro-Brazilian Lusophony, Redenção, Brazil
Aderson M. Viana Neto
; eterinary College, Ceara State University, Fortaleza, Brazil
Maurício F. Vieira Neto
; Morphology Department, Medicine College, Federal University of Ceara, Fortaleza, Brazil
Inti C. S. Rodrigues
; Health Department, Ocara, Brazil
David R. da Rocha da Rocha
; Animal Science Department, Federal University of San Francisco Valley, Petrolina, Brazil
Priscila T. de Souza Carneiro
; Agricultural and Biodiversity Sciences Center, Federal University of Cariri, Crato, Brazil
Airton A. de Araújo
; Veterinary College, Ceara State University, Fortaleza, Brazil
Abstract
This study evaluated the effects different seasons (rainy, rainy-dry transition, dry, dry-rainy transition) throughout the year on the reproduction and endocrine profile of Saanen bucks reared in a tropical climate. During these seasons environmental data were recorded (ambient temperature and relative air humidity) to calculate the temperature and humidity index. Reproductive parameters were also evaluated in the same periods to check seasonal variations, wherey semen was collected twice a month from nine Saanen bucks using an artificial vagina. Furthermore, scrotal circumference, scrotal surface temperature and serum levels of testosterone, triiodothyronine (T3), thyroxine (T4) and cortisol were measured. The climate parameters influenced the reproductive parameters, mainly during the dry period, when higher values of ambient temperature reduced sperm quality, however, scrotal circumference and surface temperature, as well as serum levels of testosterone increased. In conclusion, Saanen bucks reared in a tropical climate are subject to heat stress, evinced by transient seasonal variations in reproductive parameters, where the first season is the most favorable to reproduction.
Keywords
bucks; reproductive parameters; heat stress; testosterone
Hrčak ID:
241819
URI
Publication date:
22.7.2020.
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