Comportamiento estacional de las categorías reproductivas y los nacimientos durante dos períodos en empresas lecheras vacunas

The purpose of this paper was to compare seasonal performance patterns of breeding females, reproductive categories, and birth number during two periods (1982-1992 and 1995-2005) at six dairy livestock centers from Camaguey province, Cuba. To this end, data were collected from monthly registers comprising both periods. Data included the entire population of breeding females classified according to these reproductive categories: pregnant, puerperal, inseminated, non-pregnant, first breeding, and off-production females. Birth number was also included. A seasonal distinction through a time series analysis was performed to determine annual seasonality indexes during both periods. Results were plotted to compare time series. Both periods showed a similar behavior for the evaluated series, except for non-pregnant cows which increased in number in March with a peak from June to August. Birth number index also differed from the other indexes which showed a marked seasonal performance from 1995 to 2005.