Effects of altrenogest on uterine environment and embryo development during early gestation of pigs

Author(s)

Bruno Bracco Donatelli Muro

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD)
• Defense date: 2018-12-21

Examining board members

André Furugen Cesar de Andrade; Fernanda Radicchi Campos Lobato de Almeida; Carolina Lima Alvares da Silva

• Advisor: André Furugen Cesar de Andrade

Abstract

Progesterone plays a role of extreme importance for early embryonic development by regulating the uterine environment in the period prior to the adhesion of the embryos to the endometrium. In this context, the objective of the present study was to evaluate the effects of progesterone or progestogen supplementation during early gestation on the uterine environment and embryo development of pigs, as well as their effects on litter performance. Two experiments were carried out. In the experiment 1, 40 sows and 28 gilts were used, which were distributed in one of the three experimental groups: females supplemented with 20 mg altrenogest (Regumate®) from the 6th to the 12thh day of gestation (RU; n = 23); females supplemented with 2.15 mg / kg long acting progesterone (Sincrogest®), single injection at 6th day of gestation (PG; n = 24); females not supplemented (CON; n = 21). This experiment was completely randomized in a factorial arrangement, with the category (gilt or sow) being considered as factor 1 and the groups (CON, RU and PG) factor 2. 18 females were euthanized on the 13th day of gestation, and 50 females on the 28th day of gestation. Pregnancy rate, ovulation rate, embryo survival, embryo and uterus size and weight, volume and weight of corpora lutea, volume of embryonic vesicles, serum progesterone and 17β-estradiol concentrations, morphometric of uterine glandular epithelium and uterine luminal epithelium. In the experiment 2, 75 sows were used, which at the 6th day of gestation were allocated in a randomized manner in one of two groups: females supplemented with 20 mg of altrenogest (Matrix®) from 6 to 12 days of gestation (ALT; = 36); females not supplemented (CTR; n = 36). The variables analyzed were: pregnancy rate, gestation length, average of litter weight, within-litter variation, number of mummified, stillborn and live born piglets, number of piglets born with less than 800 grams. There was no influence of treatments on the pregnancy rate and embryo survival was impaired only for gilts in the RU group. For embryonic development the results differed among the categories, the gilts of the CON group had larger and heavier embryos when compared to the supplemented groups, as well as larger embryonic vesicles. For the sows the RU group presented larger and heavier embryos. In general, progesterone or progestogen supplementation stimulated the growth of the glandular epithelium at 13 days of gestation, but had no effect on luminal epithelium. However, on day 28 of gestation the stimulatory effect was only observed for gilts of the PG group. Treatments also stimulated the growth of corpora lutea that were larger and heavier for the supplemented groups (RU and PG). Regarding the performance of the litter, analyzed in experiment 2, there was no treatment effect for any of the variables analyzed. In conclusion, Progesterone / progestogen supplementation from day 6 of gestation affected the uterine glandular epithelium area, and early embryonic development, but did not have a significant effect on the litter performance. (AU)

• FAPESP's process: 17/00290-0 - Effects of altrenogest on the uterine environment and embryonic development in early gestation of pigs
• Grantee: Bruno Bracco Donatelli Muro
• Support Opportunities: Scholarships in Brazil - Master