Influencia de la distribución de parición anual y el aprovechamiento del pasto en los resultados alcanzados en vaquerías de la cuenca de Jimagüayú, Camagüey. I. Indicadores productivos y reproductivos

The impact of annual calving distribution upon productive and reproductive indicators on commercial dairy farms was determined in twenty-two dairy production centers during four years (April 2001-March 2005). Calving distribution into four groups was assessed every three-month intervals by calving percentages. Botanical composition and available pasture and forage utilization were estimated. Besides, seasonal annual forage balance and average forage availability per dairy cow and cattle unit were determined for each group. Performance of some indicators associated with herd composition, weaning, reproduction, and mortality, as well as milk production performance were analyzed. Although forage balance was negative as a whole, a better forage availability was detected from April to June with a forage production potentially suitable for consumption of 3,79 tons of dry matter. This three-month interval also showed a higher calving percent for Group 4, as well as an increase in birth rate up to 62,3 % and a decrease in intercalving period (586 days) and calf mortality rate (1,9%), which were significantly different from the other three groups (p<0,05). The best results registered for milk production corresponded to Group 4 either, showing differences of 25 399 kg, 18 613 kg, and 12 391 kg concerning groups 1, 2, and 3, respectively.