Milk Production in Dual-Purpose Cattle Systems under a Humid Sub-tropical Climate Af(c)

Resumen

and parity on milk production and lactation duration in Holstein × Zebu and Brown Swiss × Zebu cows in a humid subtropical region.

Design/methodology/approach: Data from 2010 to 2021 were analyzed from the dual-purpose production unit El Paraíso de Ayotoxco, located at 240 meters above sea level in the municipality of Ayotoxco de Guerrero, Puebla, under a humid subtropical climate Af(c). The studied traits included total milk yield (TMY), daily milk yield (DMY), milk yield per day of calving interval (MYDCI), and lactation duration (LD). Data were analyzed using the GLM procedure in SAS. The final model included year, season, and parity as fixed effects.

Results: A total of 934 lactations were evaluated, with an average LD of 339.65 ± 94.75 days and a TMY of 3,392.6 ± 1,185.9 kg. The average DMY and MYDCI were 9.94 ± 1.99 kg and 7.43 ± 2.36 kg, respectively. Year and parity significantly affected all traits (P < 0.05), whereas the calving season was significant only for MYDCI. The parity effect showed that first-lactation cows had lower TMY, DMY, and MYDCI, while cows with more than three calvings exhibited the highest performance in these traits. The average values for TMY, DMY, MYDCI, and LD in the validation module were 3,392.6 kg, 9.94 kg, 7.43 kg, and 339.65 days, respectively. A productive improvement was observed over the years, attributed to the adoption of new technologies.

Findings/conclusions: Year and parity significantly influenced all analyzed variables, while calving season affected only MYDCI.