Effect of interrupted weaning on fertility in a herd of Nelore cows

Abstract

This experiment was conducted at Pocone county in the Pantanal of Mato Grosso State, Brazil, including 75 Nelore cows under range conditions with their calves 3 to 4 months of age. Cows were separated into 3 groups of 25, each group with ear tags of different colours: blue, red and yellow. Calves of red and yellow groups were subjected to interrupted weaning for 10 and 15 days, respectively, through adevice in their noses. Blue group acted as control. Estrus was detected by twice a day observations during 45 days, from 7 to 8 a.m. and 5 to B p.m. Pregnancy diagnosis was mad e throuh rectal palpation BO days after the end of the experiment. Interrupted weaning, for 10 or 15 days, increased both number of cows in estrus (41%) and pregnancy rate (40%).