Diet crude protein reduction on follicular fluid and cumulus-oocyte complexes of mid-lactating Girolando cows.

• Autor(a) principal: CARVALHEIRA, L. de R.
• Data de Publicação: 2022
• Outros Autores: SANTOS, G. B. dos, JASMIM, GUIMARÃES, C. R., CAMPOS, M. M., MACHADO, F. S., PEDROSO, A. M., SILVA, T. E. da, NOGUEIRA, L. A. G., RODRIGUES, A. L. R., CARVALHO, B. C. de
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice)
• Texto Completo: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1146377; https://doi.org/10.1590/1984-3143-AR2021-0088
• topic: Apoptose; Bovino; Gado Leiteiro; Nutrição Animal; Reprodução Animal; Uréia; Apoptosis; Animal nutrition; Animal reproduction; Urea

This study evaluated the effect of crude protein (CP) reduction in four diets (156, 139, 132, and 127 g Kg-1 DM) maintaining constant metabolizable protein (188 g/day) on the follicular fluid and cumulus-oocyte complexes of mid-lactating Girolando cows. Twenty-two Girolando cows with average of 21.55 ±3.19 L daily milk yield, 105.30 ±22.62 days in lactation and 3.22 ±0.03 body condition score were selected. To reduce CP in diets and maintain constant metabolizable protein, urea and soybean meal were gradually replaced by lignosulfonate-treated soybean meal (SoyPass®, Cargill), resulting in an increase in rumenundegradable protein and a reduction in rumen degradable protein. A linear and quadratic reduction was observed in the plasma and follicular fluid urea nitrogen concentration following CP reduction, with the most intense reduction occurring in the 127 g Kg-1 DM group (p<0.001). As CP reduced, there was a tendency for a linear increase in the follicular growth rate (P=0.0696), on the number and proportion of viable oocytes (P<0.09), and also a linear increase for the number (P=0.0397) and proportion (P<0.09) of grade I viable oocytes. Plus, there was a linear effect for the number of cumulus oophorus cells. Cows fed with the lowest amount of CP had cumulus-oocyte complexes with higher numbers of cumulus oophorus cells (P=0.0238). Also, the reduction of diet crude protein was followed by a decrease in the probability of oocytes? DNA degradation. In conclusion, the reduction of CP in the diet of mid-lactating Girolando cows, reduces urea nitrogen concentration in both blood plasma and follicular fluid, and, as a consequence, increases the viability of oocytes and the number of cumulus oophorus cells while reducing oocytes? DNA degradation of follicular included cumulus-oocyte complex. The reduction on dietary CP may improve in vivo oocytes-embryo development impacting fertility of lactating dairy cows.