Evaluation of the plasmatic concentration of progesterone and efficiency of the intravaginal device with slow release of progesterone in the synchronization of the estrus in gilts

• Grant number: 17/22088-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2018
• End date: March 31, 2019
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: André Furugen Cesar de Andrade
• Grantee: Rafaella Fernandes Carnevale
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The present project intends to evaluate if the use of a new intravaginal device of slow release of progesterone, developed for the swine species, has the same results when compared with Altrenogest (Regumate®) over plasma progesterone concentration, estrus syncronization, pregnancy rate and fertility rates in gilts. Due to the importance of reducing costs with replacement gilts, and have a less expensive and laborious alternative to estrus syncronization than oral progesterone (Altrenogest - Regumate®), the project will consist of dividing 30 nulliparous females according to body condition, backfat thickness, body weight, in order to give origin to three groups: G1 (n=10) Control Group, G2 (n=10) Altrenogest (20 mg/day,per 18 days) and G3 (n=10) intravaginal progesterone device per 18 days, and the concentration of P4 is stealthy. Estrus identification will be performed by a sexually mature male, twice a day in the three groups, until the time of inseminations. All females will be inseminated at time 0, with repetition every 24 hours until the end of estrus. Blood collections will be realized in the following moments: D-1 (One day before the treatment begins), D0 (treatment begins), D2, D4, D6, D8, D12, D14, D16, D17, D18 (end of the treatment) and D19 (24 hours after treatment ends) to dose the plasmatic progesterone concentration. Trans-abdominal scanning will also be done, with an ultrasound device to do the mapping of the ovaries every 8 hours from the onset of estrus to the time of ovulation. About 21 days after the ovulation will be realized the pregnancy diagnosis through ultrasound evaluation. Females will be slaughtered on the 28th day of gestation in order to obtain the fertility rate, wich will be calculated between the proportion of retrieved fetuses and the number of luteal bodies of each female. (AU)