Yearling Cattle Performance on Continuously Stocked ‘Tifton 85’ and ‘Florakirk’ Bermudagrass Pastures

Abstract

Cynodon grasses are a major feed source for livestock in the US Gulf Coast region. Although continuous stocking is widely used for regional perennial grass pastures, there has been limited evaluation of animal performance on continuously stocked bermudagrass [Cynodon dactylon (L.) Pers.]. This 3‐yr experiment compared forage and animal performance on continuously stocked ‘Tifton 85’ (Cynodon spp.) and ‘Florakirk’ bermudagrass pastures using a variable stocking rate during summer (average of 159 d yr−1). Tifton 85 had greater herbage accumulation than Florakirk (average of 13.6 vs. 7.5 Mg ha−1 yr−1, respectively), in part because Florakirk percentage cover declined from 89% at initiation of the experiment to 35% after 3 yr. Change in cover of Tifton 85 over the same period was 93 to 90%. The Tifton 85 forage concentrations of in vitro digestible organic matter was greater than for Florakirk (563 vs. 523 g kg−1, respectively), but yearling cattle average daily gain did not differ between grasses (0.61 kg d−1). Greater herbage accumulation for Tifton 85 resulted in a greater average stocking rate than for Florakirk (6.4 vs. 3.8 head ha−1, respectively) at a similar herbage allowance of approximately 1.0 kg forage dry matter kg−1 animal body weight. Gain ha−1 was greater for cattle grazing on Tifton 85 than on Florakirk (638 vs. 358 kg ha−1, respectively). Tifton 85 was superior to Florakirk bermudagrass under continuous stocking in northern Florida because of its greater herbage accumulation, herbage in vitro digestible organic matter, average stocking rate, animal gain ha−1, and persistence.