Association of artificial light and intravaginal progesterone device in anticipation of cyclicity in anestrous mares

• Grant number: 11/09890-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2011
• End date: July 31, 2012
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Cezinande de Meira
• Grantee: Adriana Etelvina Melotto
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

This study aims to evaluate the effect of using intravaginal progesterone implants associated with the program of artificial light in anticipation of the start of the breeding season in mares. This study will use 30 mares were divided randomly into three groups (n = 10 mares / group), as described below: Group Light Program (Artificial Lighting), P4 + Group Light Program (Artificial lighting associated with the implantation of intravaginal progesterone, CIDR-BTM) and Control (untreated). Animals in the Light Group will be treated daily with five hours of artificial light (beginning at 17 hours and end at 22 hours) as of June 15, staying for a period of sixty days. Mares will be 400m2 in a covered, which will be used incandescent lamps, metal vapor, providing not less than 100 lux / lamp. In group P4 + Light, a P4 intravaginal device (Primer ®, 1 g of progesterone without estradiol capsule) will be introduced in mares with characteristics of the spring transition, with follicles between 20 and 25 mm in diameter with absence of corpus luteum being kept for 12 days and these animals remain in the program for sixty days of artificial lighting. The mares in the control group will be maintained under natural conditions of light and will not receive any type of exogenous hormone treatment.