Influence of heifer development, calving and suckling manipulation on reproduction in primiparous Brahman percentage cows

Abstract

One hundred and six primiparous Brahman percentage cows were used to determine the effect of suckling manipulation on postpartum reproductive performance. Variables measured included weight, body condition scores, pelvic area, height, calving data, estrous dates and conception dates. Pre- and postpartum weight changes were determined. Classes of weights and body condition scores were developed from weights obtained within two days after calving. Calf parameters measured included birth weight, dystocia and weaning weight. Suckling manipulation treatments included once-daily suckling (ODS) and control (C). For ODS, 54 calves were removed from their dams at 30 days postpartum until two days following first estrus. Calves were permitted to nurse 30 min daily. In control cows, the 52 calves were permitted to remain with their dams continuously. The percentage of cows in estrus and conceiving by various intervals postpartum was evaluated using chi-square tests. By 60 days postpartum, 57% of the ODS group compared to 29% of the C group exhibited estrus (P < .005). By 90 days postpartum, 74 and 63 percent exhibited estrus in the ODS and C groups, respectively (P > .10). The conception rate by 60 and 90 days postpartum was 31 and 61 percent, respectively, in the ODS group, compared to 12 and 44 percent, respectively, in the C group (P < .005; P < .10).</p> ...