Edad al primer parto de la raza Holstein Friesian en el Ecuador

The objective of this work was to determine the age at first calving in Holstein Friesian cows based on information obtained from the S.I.G. version 1.2.6. of the properties registered in the Holstein Friesian Association of Ecuador. Distributed mostly in the mountain region at a height that goes up to 3,800 meters above sea level, with an annual rainfall of 800 to 1,500 millimeters. The database included: identification of the animal, date of birth, date of first birth, and geographic location of the property. In total, 94,163 first birth records were obtained between the period 1971-2019. As inclusion criteria, all cows with calvings between 22 and 34 months of first calving were considered. The measures of central tendency and dispersion of the variable age at first birth were considered, additionally the 95% confidence interval was determined for the independent variables on age at first birth. In Ecuador, the average age was 48 months in 1971 with a significant decrease from 35-41 months between 1972-1975 and 30-35 months between 1976-2018, consolidating between 23-29 months in 2019. At the same time, variability is demonstrated between the high categories in relation to the low one with a difference of 15.1 days in the coastal region, while in the eastern region it is 15.69 days and a difference of 13.82 days in the highland region. Likewise, it presents variation in the age of first calving in relation to the season-region and the height. This is the first work carried out in Ecuador, in which a sustained reduction in the age of first calving is established.

• Hlavní autor: Carrillo Alvarez, Israel Salomon (author)
• Médium: masterThesis
• Jazyk: spa
• Vydáno: 2023
• Témata: EDAD PRIMER PARTO; REGIÓN COSTA; SIERRA Y ORIENTE; NÚMERO PARTOS; VETERINARIA
• On-line přístup: http://repositorio.utc.edu.ec/handle/27000/10469