Grazing Evaluation of Bigalta and Floralta Limpograss

Abstract

The use of limpograss [Hemarthria altissima (Poir) Stapf et C.E. Hubb.] as a pasture plant is a relatively recent development. Available cultivars possess distinctly different characteristics. ‘Bigalta’ limpograss has been widely planted on peninsular Florida Spodosols, but stand loss under grazing is common. A more persistent cultivar, ‘Floralta’, has recently become the most widely grown limpograss cultivar in Florida. When grown in the same pasture, Bigalta was heavily grazed by yearling steers (Bos indicus L. and Bos taurus L. spp.) before any noticeable grazing of Floralta occurred. A series of grazing trials was conducted to investigate relative forage quality and plant growth responses of the two cultivars under grazing. Eight 0.5‐ha pastures were established to provide duplicate treatments of two stocking rates on each cultivar. Three summer grazing trials and two autumn grazing trials were conducted. Patterns of grazing differed distinctly between the two cultivars with distinct patchy grazing on Bigalta and rather uniform grazing of the upper canopy of Floralta. Bigalta had higher in vitro organic matter digestibility (IVOMD) and crude protein (CP) than Floralta in most instances, with Bigalta at the light stocking rate averaging 520 g kg−1 IVOMD and 61 g kg−1 CP vs. 480 g kg−1 IVOMD and 51 g kg−1 CP for Floralta. Bigalta produced greater average daily gains (ADG) than did Floralta prior to deterioration of Bigalta stands with 0.5 kg ADG on Bigalta vs. 0.3 kg on Floralta in 1986 and 1987 trials. Bigalta stands deteriorated rapidly especially when subjected to the higher stocking rate, but extended deferment from grazing allowed some stand recovery.