The Study of the Calving Interval of Tropical Cows Based on the Age of Jabres Cattle in Tropical Country

Abstract

Jabres cattle (Java-Brebes) is a local breed of cattle of Bantungkawang District, Brebes City, Province of Center Java, that has been cultivated for generations. Jabres cattle have the advantage of a good reproductive system, but no comprehensive data can analyze the reproduction performance. The calving interval can be used as a measure of reproductive efficiency. This study aims to determine the effect of age on the calving interval. This study used 70 samples of Jabres cattle which were grouped into three groups based on age, namely, <5 years with a total of 25 cattle, 6-10 years with a total of 25 cattle, and ages 11 years and over with a total of 20 cattle. The research was conducted by interviewing farmers using questionnaires and direct observation in the field carried out with local inseminators, veterinarians and breeders. The data taken were age and distance to give birth. The data obtained was then analyzed using the one-way ANOVA method, which aims to determine the significance of differences between groups. The results showed that the average calving interval at <5 years, 6-10 years, and >11 years, respectively, was 13.36 ± 1.777; 13.76 ± 2.006, and 13.50 ± 1.792 months. The conclusion from the results of this study is that the age variations of Jabres cattle does not show a significant difference to the calving interval.