The use of IL-10 to reduce early embryonic mortality and improve fertility in dairy cows

• Grant number: 15/21779-1
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: November 01, 2015
• End date: April 30, 2016
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Clinics and Surgery
• Principal Investigator: Lilian Gregory
• Grantee: Bruno Leonardo Mendonça Ribeiro
• Supervisor: Rodrigo Carvalho Bicalho
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Cornell University, United States
• Associated to the scholarship: 14/02676-4 - Evaluation of the bovine uterus with endometriosis by the technique of Doppler ultrasonography, BP.MS

Abstract

The reproductive efficiency plays a key role in the economic success of the dairy herds, because it determines the production of milk per day, calving interval and culling policy. With this requirement of the animal there are concomitantly associated with inflammatory processes. Reproductive efficiency is associated with inflammatory processes. The establishment of pregnancy by itself depends on modulation of uterine immune response to ensure the survival of the fetus. Disease events postpartum increases the proportion of embryonic degeneration, decreases the intrauterine concentrations of tau interferon (IFN-t) during the pre-deployment phase and increases the risk of embryo loss. Interleukin 10 (IL-10) is an anti-inflammatory cytokine associated with successful pregnancy in mammals. For example, the content of IL-10 is smaller placenta in a murine model (rodent) prone to fetal loss induced by pathogens. Compared with the control strains and intraperitoneal treatment with recombinant IL-10 (rIL-10) reversed this process. Whereas in ruminants IFN-T is important for the establishment of pregnancy, these results suggest the potential of rIL-10 on reducing the fetal and embryonic mortality in cattle. The objective is to evaluate the effects of rIL-10 supplementation on the expression of selected genes in interferon from peripheral blood leukocytes study, B protein, specific of pregnancy plasma concentrations, embryo size and embryonic loss in lactating cows. Will be evaluated in 1650 commercial herds of cows and selected according to nutritional and reproductive management. Cows diagnosed with abnormal reproductive intervals (ie, adhesions and abscesses in the uterus or ovaries) will not be used. Within each block, the cows will be randomly assigned to two treatments: Cows with high IL-10 (hIL-10; n = 550) and low IL-10 (LIL-10; n = 550), the groups will receive infusions Intravaginal weekly with 1.0 mg and 1.0 mg of rIL-10 diluted in 15 ml of sterile buffer solution, respectively, while those assigned to the control group (control, n = 550) will receive weekly infusions intravaginal 15 ml of sterile buffer solution. Body condition score (BCS) will be evaluated on day 0. The diagnosis of pregnant will be performed by transrectal ultrasonography on day 35 ± 3 after insemination. The presence of bladder and amniotic content containing an embryo with heartbeat will be used as key to confirm pregnant. 63 ± 3 after artificial insemination will be held rectal palpation confirming. The study will be conducted as a randomized and block. Binary responses will be analyzed using multivariate logistic regression using the SAS GLIMMIX Procedure. (AU)