Natural sucking performance and age of weaning in zebu cattle (Bos indicus)

Abstract
Sucking behaviour and age of weaning were investigated in a herd of East African zebu cattle in which all calves born had been retained for several years. Suckling rates were compared at different periods of the 24 h cycle and found to be less at night than during any day-time period. The highest rates of suckling took place in the early morning and in the late afternoon. The early morning suckling was triggered by the dawn. During both night and day, suckling was irregular and bouts were presumably due to sympathetic induction because a high proportion of the calves was suckled on each occasion. The total sucking time and the number of bouts varied significantly in inverse relation to age of the calf but the duration of a sucking bout was constant at 8 min and independent of age. There was an average of 4·8 sucking bouts within 24 h giving a total duration of 38 min. Sucking behaviour did not exhibit sex-specific differences. The average age of natural weaning was 10 months but there was a marked sex difference. Female calves were prevented by their mothers from sucking after an average age of 8·8 months but male calves continued to be suckled for a further 2·5 months and were weaned at an average age of 11·3 months.