Factores subjacentes à eficiência da raça Mertolenga. Intervalo entre partos e idade ao desmame

Mestrado em Engenharia Agronómica - Instituto Superior de AgronomiaThe aim of this study was to identify the most effective way to produce cattle, considering season of birth, age of weaning, calving intervals and weaning weights and their market prices. Another objective was to try to discover if there was any relationship between the age of weaning and calving interval to ensure larger profitability. Fertility of the cows, in general, increases with their age and spring is the season when cows have higher fertility. The daily average gain since birth to weaning also increases with the age of the cows, and it occurs during the spring season, when the winnings are lower. Observing the weight at 90 and 205 days remains the case that there is a positive relationship with the age of the cow, and it’s at the autumn and winter that calves weight more at 205 days. The calving interval is influenced very significantly by year, for the farm, season of calving, age at calving but not for age at weaning. However for the ratio between weight weaned and calving interval the season of birth have no influence but the season of weaning and age of the calf influence a lot. Was concluded that isn’t the extension of the calving intervals or weaning period that the efficiency increases. It’s because the management feeding override the effects of variability of the system