Embryo quality and gene expression of liver enzymes cytochrome P450 and ALDOKETO reductase and circulating progesterone of Holstein cows in diet insulinogenic

• Grant number: 13/10784-9
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): August 01, 2013
• Effective date (End): October 15, 2014
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal researcher: Roberto Sartori Filho
• Grantee: Monique Mendes Guardieiro
• Home Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

The energy source can influence rumen fermentation, yielding different profile of volatile fatty acids, and consequently changes in the circulating concentrations of insulin, however, it is not yet known whether it impairs the production of embryos. The objective of this study is to evaluate the influence of insulinogenic diet on embryo quality and expression of liver enzymes (Cytochrome P450 2C, 3A, and aldo-keto reductase 1C and 1D) and on circulating progesterone concentrations in non-lactating Holstein cows. Two experiments will be performed using 24 cows each, selected based on body weight, body condition score, follicle population and cyclicity. After 15 days under an adaptation diet, cows will be assigned to two experimental groups: 1) high insulinogenic diet or 2) low insulinogenic diet. Each group will receive the experimental diets for 70 days in experiment 1 and 35 days in experiment 2, in a cross-over design. Cows will be submitted to a superovulation protocol and embryos will be recovered on the last day of supplementation. Embryos will be classified according to the degree of development and morphological quality. Furthermore, ovarian ultrasound examinations will be conducted to evaluate the superstimulatory and superovulatory responses. In experiment 1, liver biopsies will be performed, 2 days after embryo collection, approximately 4 hours after feeding. The liver fragment will be conditioned for subsequent quantification in real-time PCR. Blood samples for determination of progesterone and insulin will be taken at the beginning of the experimental period, at the beginning of the superovulation protocol, at the day of embryo recovery and at the day of liver biopsy. (AU)