Efecto de la raza de toro y factores ambientales sobre el porcentaje de gestación en la provincia de Cañar

Abstract

In the present work the objective was to evaluate the effect of the bull breed used and environmental factors on the percentage of gestation (PG) in dairy cows in the Cañar province. For that, 2316 records of artificial inseminations of the breeding project incorporated by the Ministry of Agriculture and Livestock of Cañar during the period between June 2013 and December 2015 were analyzed. The effects of the following variables on the percentage of gestation: race (R), parish (P), technical inseminator (TI), zone (Z), zeal (C), year (A), time (E) and interactions (Z * E; R * E; A * E and C * E). Statistical analysis was performed using the Chi-square method to determine the degree of independence between the levels of each variable. The overall PG was 60.7%. Significant effects were found on the percentage of gestation in the variables: zone (P = 0.0001), estrus (P = 0.01), time (P = 0.003) and in all interactions. On the contrary, year and race had no significant effects (p> 0.05). In the case of the parish, inseminator technician, no probabilities were made since there was not sufficient data available that allow to statistically differentiate these values. The results indicate that at least three of the factors that had an effect on gestation are under the control of the inseminator and suggest the need for a periodic review of the artificial insemination practices, when it is necessary to increase the gestation rate.