Producción de Leche de Suiz-Bú, una Raza de Doble Propósito en el Trópico Mexicano

The aim of this study was to determine the effect of environmental factors on milk production of Suiz-Bu cows reared under the Mexican tropical conditions. Milk yield records of 728 cows that were available from 2012 to 2014 were analyzed. Cows were milked twice a day as of the fifth day of calving, fed under grazing conditions and supplemented with commercial concentrates. Variables of milk production at 305 days (PL305) and average milk yield per day (MPD) were analyzed using a mixed model that included effects of lactation (NL), year of calving (AP), season of calving (EP), and simple interactions. The year of calving was statistically significant for PL305 and PMD (p<0.05), cows that calved during the rainy season had greater milk production (PL305 and PMD) than those calving during the dry season (p<0.05), and first calvers had lower PL305 than cows with two or three lactations (p<0.05). Moreover, the effects of interactions were significant (p<0.05).