Milk yield in Nellore cows and suckling behavior of their calves of different production systems: NR- Extensive Nellore, NI- Intensive Nellore; and three crossbreeding systems (CN- Canchim-Nellore, AN-Angus-Nellore and SN-Simmental-Nellore in intensive management), were studied. Milk production of cows and number and length of suckles, and daily gain (kg/day) of calves were obtained in three moments of lactation (60, 120 and 180 days after calving). Moment of lactation and production system by lactation moment interaction had a significant effect in milk yield. Milk yield did not show any relationship with suckling behavior or daily gain in calves. Extensive grazing condition did not reduce milk yield of Nellore cows although it determined significant cow weight losses (80 kg) during the breeding season in the NR system. Daily length of suckling decreased in the NR system as lactation progressed, and was sustained or increased in the intensive systems. Crossbred calves showed higher daily gain and weaning weight than purebred.
beef cattle; milk yield; suckling behavior
