Comparación de la eficacia de un dispositivo intravaginal vs progesterona inyectable en la recuperación de la actividad ovárica en vacas anéstricas

Abstract

This study compared the efficacy of an intravaginal progesterone-releasing device (G1) versus a long-acting injectable progesterone formulation (G2) for restoring ovarian activity in postpartum anestrous cows. Thirty anestrous cows were divided into two groups of 15 animals each. Plasma progesterone levels were measured by chemiluminescence on days 4, 7, and 14 post-treatment. Ovarian follicular dynamics were monitored by transrectal ultrasound, and the presence of a functional corpus luteum was assessed on day 14. The study was conducted at the “Santa Clara” and “San Martín” farms, located in the Huapante Grande sector of the San Andrés parish, Pillaro canton, Tungurahua province, at an altitude ranging from 2,800 to 3,000 meters above sea level. On day 4, no significant differences were observed between groups (G1: 4.13 ng/ml; G2: 5.11 ng/ml; p-value = 0.3228). On day 7, G2 showed significantly higher P4 levels (3.50 ng/ml) than G1 (1.77 ng/ml). On day 14, no statistically significant differences were observed (p-value = 0.0552), but G1 showed higher P4 levels (3.92 ng/ml) than G2 (2.63 ng/ml). G1 also had a greater number of cows with functional corpora lutea (12 vs. 11), although this difference was not statistically significant. Regarding follicular dynamics, cows in G1 developed significantly larger dominant follicles. Numerically higher rates of return to ovarian cyclicity and presence of functional corpora lutea were observed in G1, which was reflected in elevated levels of endogenous progesterone on day 14