Authors : A. Cordova-Izquierdo , V.M. Xolalpa Campos , C. Gustavo Ruiz Lang , J.A. Saltijeral Oaxaca , S. Cortes Suarez , C.A. Cordova-Jimenez , M.S. Cordova-Jimenez , S.D. Pena Betancurt and J.E. Guerra Liera
Abstract: With the purpose of determining the reproductive efficiency in a dairy farm, 412 registers of production were revised. The objective of this study was to value the effect of the sex of the calf on the open days up in a dairy farm. The study was carried out in a farm located in the municipality of Tizayuca, Hidalgo State, Mexico. The variables involved in this investigation are: number of childbirths, dates of childbirth, sex of the offspring and date of the service-conception. Of these the open days were obtained, with the objective to determine if the sex of the offspring influences in the open days. The registrations were divided in 2 groups (males and females), same that were subdivided in 6 groups by childbirth number. The analysis was carried out in Excel. The obtained results are the following ones: in general, the cows that birth males presented a smaller period of open days (132.56 days) that those that birth females (143.69 days) with a difference of 11.13 days.
A. Cordova-Izquierdo , V.M. Xolalpa Campos , C. Gustavo Ruiz Lang , J.A. Saltijeral Oaxaca , S. Cortes Suarez , C.A. Cordova-Jimenez , M.S. Cordova-Jimenez , S.D. Pena Betancurt and J.E. Guerra Liera , 2008. Effects of the Offspring�s Sex on Open Days in Dairy Cattle. Journal of Animal and Veterinary Advances, 7: 1329-1331.