Effect of heat stress in late gestation on subsequent lactation performance and mammary cell gene expression of Saanen goats

Autor(es)

Hooper, H. B. ^[1] ; Silva, P. dos S. ^[1] ; de Oliveira, S. A. ^[1] ; Meringhe, G. K. F. ^[1] ; Lacasse, P. ^[2] ; Negrao, J. A. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Fac Anim Sci & Food Engn, Dept Basic Sci, BR-13635900 Pirassununga, SP - Brazil

^[2] Agr & Agri Food Canada, Sherbrooke Res & Dev Ctr, Sherbrooke, PQ J1M 0C8 - Canada

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF DAIRY SCIENCE; v. 103, n. 2, p. 1982-1992, FEB 2020.
• Citações Web of Science: 0

Resumo

Little is known about the effects of heat stress during the late gestation period on lactation in dairy goats. For this reason, 32 Saanen goats were randomly assigned to 1 of 2 groups, control (CT; n = 16) or heat stress (HS; n = 16), during late gestation. The HS goats were housed in a climatic chamber before parturition and subjected to heat stress for the last 45 d. After parturition, the HS goats were housed in the same conditions as the CT group. Mammary gland biopsies were performed on 7 goats per treatment at -30, -15, 15, and 30 d relative to parturition, so that the expression levels of several genes could be determined. The HS goats produced less milk than the CT goats did during the first half of lactation, but not during the rest of lactation. Before parturition, apoptosis-related transcripts (TP53 and BAX) were higher in the mammary glands of the HS goats than in those of the CT goats. The HS goats also had higher levels of HSPB1 gene expression during gestation and lactation. however, expression of the prolactin receptor gene was lower after parturition in the mammary glands of HS, suggesting downregulation of prolactin signaling. In summary, heat stress during final gestation reduces milk yield in the subsequent lactation. Although the upregulation of apoptosis signaling in the HS goats suggests that heat stress affects mammary cell number, the loss of the effect on milk production is more compatible with an effect on cell activity, which could be due to a downregulation of prolactin signaling. (AU)

• Processo FAPESP: 16/00123-3 - Produção leiteira em cabras Saanen: relações entre estresse, apoptose, cortisol e IGF-I.
• Beneficiário: João Alberto Negrão
• Modalidade de apoio: Auxílio à Pesquisa - Regular