Study of mechanisms by which the supplementation with sunflower seed increase the conception rate in bovine females

• Grant number: 16/02805-4
• Support type: Regular Research Grants
• Duration: November 01, 2016 - October 31, 2018
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Claudia Maria Bertan Membrive
• Grantee: Claudia Maria Bertan Membrive
• Home Institution: Faculdade de Ciências Agrárias e Tecnológicas. Universidade Estadual Paulista (UNESP). Campus de Dracena. Dracena , SP, Brazil
• Assoc. researchers: Mario Binelli

Abstract

The supplementation with polyunsaturated fatty acids (PUFA), among these compounds rich in linoleic acid (LA), favors the reproductive performance in bovine females. However, the determining mechanisms of this effect are little known. Among the sources of LA include the sunflower seed (Helianthus annuus L.). In previous studies by this group, it was found that supplementation with sunflower seed for 22 days in Nelore cows submitted to TAI (Proc. FAPESP 2007/04539-0) and in zebu crossbred heifers submitted to TET of embryos produced in vitro (Proc. FAPESP no 2011/12595-3; Proc. FAPESP no 2011/1444-2) increase in conception rate in 18.91 % (66.67 % vs. 47.76 %; p < 0.05) and 18.72 % (55.66 % vs. 36.94 %; p < 0.01) respectively (CORDEIRO et al., Theriogenology, 2015, v. 83, p. 1461-68). Brazil's Midwest region has 32% of the national beef bovine females and the largest sunflower seed producer; making such economically promising results. Making a retrospective analysis of previous research with PUFA in reproductive performance of bovine females, the majority prioritizes the effects of protected fat and dairy herds. In such studies, the effect in conception rates has become contradictory and often differs when the same treatment was compared by different authors. Whereas, in both studies by this group there was an increase very similar the conception rate, it was concluded that the delivery of the sunflower seed is an excellent experimental model for study to evaluate the mechanism by which PUFA supplementation, specifically sunflower seed, promotes increased conception rate in beef bovine females. Whereas the increase in conception rate was similar when such supplementation was associated with TAI programs and TET, and that there wasn't an increase in plasma progesterone, the hypothesis is that such supplementation increases the rate of conception by promote effects on the embryo, fetus, uterine microenvironment, endometrial tissue and corpus luteum. The hypothesis is that such supplementation increases the conception rate for to promote effects in conceptus, uterine microenvironment and endometrial tissue though not promotes effects in the embryo until the 7th day of the corpus luteum. The understanding of these mechanisms may help to develop new strategies that may increase the conception rate at TAI and TET programs through the use of specific PUFA. (AU)