Efecto del tratamiento con dosis reducida de progesterona después de la inseminación artificial sobre el funcionamiento del cuerpo lúteo y el porcentaje de concepción, en vaconas en el altiplano ecuatoriano 2500 msnm

Abstract

The objective of this research was to assess the effect of applying progesterone P4 of high duration in low doses, in the days immediately following the artificial insemination AI, on the function and morphology of the corpus luteum CL and the percentage of early conception. It was held at Irquis farm - University of Cuenca, on 28 cows, between the ages of 30 to 40 months, the body condition BC was 2.5 to 3, clinically healthy, fed with pasture, they were divided into three groups: G1 control n1 = 9, and two experimental groups: G2 n2 = 10 75mg of P4 and G3 n3 = 9 100mg of P4, respectively. PGF2α was applied in intervals of 14 days to synchronize rut, they were inseminated 12 hours post detection of the rut and 2 days post-IA. P4 was applied SC. Plasma P4 by sample was measured from day 0 to 16, the size of the CL by transrectal ultrasonography Usx and percentage of conception 28 days post IA. A design of blocks at random DBR was used, the data was analyzed using SPSS statistical software version 22.0. Statistical differences were obtained P< 0.05 in P4 plasma in 3, 4, and 5 days, attributing efficiency for G3. Only some differences were found in the morphology of the CL P<0.05 in day 2 home obtaining respectively, for G3= 15.6±0.33, G2= 14.4±0.82, G1= 12.5±0.18mm. In the percentage of early conception, although values were high, they did not show statistical differences P>0.05. In conclusion, the exogenous administration of low doses of P4 via SC in cows of the Ecuadorian highlands 2 days post IA does not affect the functionality and morphology of the CL, or the percentage of early conception.