Effects of frequency of concentrate supplementation on performance of early-weaned beef calves consuming annual ryegrass

Abstract

The objectives of this study were to evaluate the growth performance during a grazing period (experi- ment 1) and forage intake and apparent in vivo digestibil- ity (experiment 2) of early-weaned beef calves consuming annual ryegrass (Lolium multiflorum) and supplemented with concentrate either daily or 3 times weekly. The experiment was con- ducted in Ona, Florida. Treatments consisted of similar weekly concentrate amounts (1% of BW × 7 d) divided into equal amounts and then offered daily (7×) or 3 times weekly (3×) to early-weaned beef calves consuming annual ryegrass pastures from d 0 to 84 (experiment 1) and annu- al ryegrass hay in drylot from d 84 to 105 (experiment 2). From d 0 to 84, reducing the frequency of concentrate supplementation did not influ- ence herbage mass, herbage allowance, or nutritive value of annual ryegrass pastures, or calf ADG, BW, or plasma concentrations of glucose and urea N. The overall forage DM intake was 15% less for 3× versus 7× calves (1.51 vs. 1.78% of BW, respectively). Total DM intake did not differ between 3× and 7× (2.63 vs. 2.73% of BW, respec- tively), whereas in vivo apparent digestibility decreased for 3× versus 7× (85.3 vs. 86.5%, respectively). Reducing frequen- cy of concentrate supplementation from daily to 3 times weekly did not affect overall growth performance of early- weaned beef calves consuming annual ryegrass and can successfully be implemented to reduce feeding costs.