Short communication: Heat stress does not affect induced luteolysis in Holstein cows

Author(s):Show less -

Mogollon, H. D. G. ^[1] ; Ferrazza, R. A. ^[1] ; Vallejo, V. H. ^[1] ; Destro, F. C. ^[1] ; Ochoa, J. C. ^[1] ; Nogueira, C. ^[1] ; Carvalho, R. F. ^[2] ; Moraes, L. N. ^[3] ; Rizzoto, G. ^[4] ; Sartori, R. ^[5] ; Wiltbank, M. C. ^[6] ; Ferreira, J. C. P. ^[1]

Affiliation

^[1] Sao Paulo State Univ UNESP, Sch Vet Med & Anim Sci, Dept Anim Reprod & Vet Radiol, Rua Prof Dr Walter Mauricio Correa S-N, BR-86868 Botucatu, SP - Brazil

^[2] Univ Sao Paulo State UNESP, Inst Biosci, Dept Morphol, R Prof Dr Antonio Celso Wagner Zanin 250, BR-18618681 Botucatu, SP - Brazil

^[3] Sao Paulo State Univ UNESP, Sch Agr, BR-1861004 Botucatu, SP - Brazil

^[4] Univ Calgary, Fac Vet Med, Dept Prod Anim Hlth, Calgary, AB T3R 1J3 - Canada

^[5] Univ Sao Paulo, Luiz de Queiroz Coll Agr ESALQ, Dept Anim Sci, Av Padua Dias 11, BR-13418900 Piracicaba, SP - Brazil

^[6] Univ Wisconsin, Dept Anim & Dairy Sci, Madison, WI 53706 - USA

• Document type: Journal article
• Source: JOURNAL OF DAIRY SCIENCE; v. 103, n. 6, p. 5629-5633, JUN 2020.
• Web of Science Citations: 0

Abstract

Heat stress (HS) has deleterious effects on bovine reproduction, including prolongation of the luteal phase in Holstein cows, perhaps due to compromised luteolysis. The objective was to characterize effects of HS on luteolytic responses of nonlactating Holstein cows given 25 or 12.5 mg of PGF(2 alpha) on d 7 of the estrous cycle. Cows were randomly distributed into 2 environments: thermoneutral (n = 12; 25 degrees C) or HS (n = 12; 36 degrees C). In each environment, cows were treated with 2 mL of saline, 25 or 12.5 mg of PGF(2 alpha) (n = 4 cows per group). The HS environment induced a significant increase in rectal temperature and respiratory rate compared with the thermoneutral environment. Heat stress did not have significant effects on luteolytic responses or circulating progesterone concentrations. Rapid and complete luteolysis occurred in all cows given 25 mg of PGF(2 alpha) and in 4 of 8 cows given 12.5 mg; the other 4 cows given 12.5 mg had partial luteolysis, with circulating progesterone concentrations initially suppressed, but subsequently rebounding. Therefore, we conclude that HS does not change corpus luteum sensitivity to PGF(2 alpha). (AU)

• FAPESP's process: 12/18297-7 - Effect of heat stress on follicular development and luteolysis in Honstein cows, role of LH during induced luteolysis and characterization of luteal sensitivity to PGF2± during the estrous cycle
• Grantee: João Carlos Pinheiro Ferreira
• Support Opportunities: Regular Research Grants
• FAPESP's process: 11/20449-7 - Role of LH during induced luteolysis and characterization of luteal sensitivity to PGF2alpha during estrus cycle and treatment with IFNt
• Grantee: Eduardo Trevisol
• Support Opportunities: Scholarships in Brazil - Doctorate