Effects of Separation of Cows and Calves on Reproductive Performance and Animal Welfare in Tropical Beef Cattle

SIMPLE SUMMARY: This review summarizes knowledge on the separation of cows and calves and its effect on the onset of ovarian activity and animal welfare, principally in tropical beef cattle. After a brief introduction establishing the importance of calf separation to induce ovarian activity in their mothers and the welfare aspects that are jeopardized during this process, subsequent sections describe different strategies used for the separation of cows and calves, highlighting the effect of each method on beef cattle reproductive performance and welfare considerations of both cow and calf; conclusions and practical implications. ABSTRACT: Nursing a calf suppresses postpartum ovarian activity prolonging the period of anestrus. Diverse methods are used to reduce the effect of suckling; the most popular, restricted suckling, reduces the number of encounters mother-calf. Temporal weaning of the calf for periods of 24 h, 48 h, or even 72 h also suppress the effect of suckling and is commonly applied to cow-calf operations in the tropics. Early weaning of the calf, usually three to five months after birth, is a practice gaining popularity over the traditional system of weaning at seven months. Furthermore, the use of nose-flaps in the calf to avoid suckling is a common procedure in South America. Finally, weaning during the first week after calving is an established method to reduce postpartum anestrus. The objective of the present review is to discuss the effects of these methods on the reproductive performance of beef cattle and their animal welfare implications.