Comparación de la eficiencia reproductiva entre vacas Holstein puras y Holstein mestizas, mediante análisis retrospectivo de datos en una ganadería a 3200 metros sobre el nivel del mar.

Abstract

The objective of this research was to compare reproductive efficiency between pure Holstein (HP) and crossbred Holstein (HM) through retrospective data analyses by a herd at 3200 meters above sea level. Seven reproductive indices were calculated: age at first service, age at first calving, gestation duration, services per conception, calving and first service interval, days open and calving and calving interval. Data were analyzed with the statistical program IBM-SPSS 26 and results were expressed as mean and standard error of the media. The Bayes independent sample Bayes factor test (Rouder method, null hypothesis vs. alternative hypothesis), with an α= 0.05, was used to infer differences between groups for each reproductive index, total 7 gestations. Results indicate that HP cows were different from HM cows for age at first service and age at first calving. Gestation length was similar between groups. Services per conception showed differences between HP and HM for the second and seventh gestation. nevertheless, calving interval and first service was different between HP and HM groups after first and second calving. Additionally, the HP and HM group were different in days open in the period prior to second, third and the seventh gestation. Finally, for calving interval in second, third and seventh calving they were different. In conclusion, a better reproductive performance of the HM group over the HP group in high conditions of (3200 masl) and grazing management in the Ecuadorian highlands is evidenced.