COOL-SEASON ANNUALS FOR SUPPLEMENTING PERENNIAL PASTURE ON BEEF COW-CALF PRODUCTIVITY

The cow-calf operation is the primary beef cattle enterprise in the Southeastern USA. Cool-season annuals can be used to improve forage production and quality with the long growing season that the Gulf Coast offers. The objective of this study was to determine the effect of supplemental grazing of cool-season annuals, sodseeded on perennial Argentine bahiagrass (Paspalum notatum Flugge) pasture, had on cow-calf productivity. Five hundred forty-seven reproductive and calving records obtained over 8 yr from 150 purebred Angus cows (Bos taurus) were used to evaluate two pasture systems (PS). Stocking rates of 1 cow/2 acres were maintained for each PS. The two PS consisted of: (1) bahiagrass and (2) bahiagrass and bahiagrass sodseeded with cool-season annuals [rye (Secale cereale L.) or wheat (Triticum aestivum L.) with crimson clover (Trifolium incarnatum L.) and arrowleaf clover (Trifolium vesiculosum Savi)]. The amount of winter feeding of hay and supplemental protein were lower (P < 0.01) for cows in PS 2 than those in PS 1. Calving rate, weaning rate, survival rate, culling rate, calving date, and calving interval were not affected (P > 0.05) by PS. A greater (P < 0.08) percentage of cows in PS 2, however, calved in the first month of the calving season than cows in PS 1 (28 vs. 14%) Weaning and 205-d weights of calves from PS 2 were 6 to 7% heavier (P < 0.07) than those from calves in PS1. Cows in PS 2 were 48 lb heavier (P < 0.07) at the time of weaning and produced 13 lb more (P < 0.07) calf per 1000 lb of cow weight. The primary benefits realized from the grazing of the cool-season annual forages were reduced winter feeding of hay, protein supplement, and heavier calf and cow weights at weaning.