434 - Tamegrass Forage Options for Growing Heifers During the Summer

Developing methods to provide high quality forage through a majority of the year is important for cattle operations. The purpose of this study was to determine forage management options to off-set the summer “slump” with fescue. Four grass pasture treatments (10 pastures total; 1.67 ha each) were used in a completely randomized design and stocked with growing heifers (initial wt 190 ± 9.1 kg). Pasture treatments consisted of fescue (FES; n = 2 pastures with 4 head/pasture), crabgrass (CRAB; n = 3 pastures with 4 head/pasture), bermudagrass (BERM; n = 3 pastures with 5 head/pasture), and sorghum-sudan interseeded into fescue (SS-FES; n = 2 pastures with 6 head/pasture from April to July, then 4 head/pasture from July to November). Heifers were weighed in April, May, July, September, and November. Heifers assigned to FES/SS-FES pastures grazed from April to November (213 d) and for CRAB and BERM treatments, May through September (131 d). Heifers on FES grazed continuously, while other grass treatments were rotationally grazed. Heifers remained in treatment pasture through the entire grazing period. Data were analyzed using mixed procedures of SAS with pasture as experimental unit. Average daily gain for the entire grazing period was greater for heifers on SS-FES as compared to all other grass treatments (P = 0.001). Between April and May, FES heifers had greater ADG than SS-FES (P = 0.001); yet, heavier stocking rate in SS-FES resulted in similar BW gain/ha (P = 0.16). May to July ADG and BW gain/ha was greatest for BERM, then CRAB, with FES and SS-FES having the lowest gains (P < 0.001). From July through September, ADG was greater for SS-FES and CRAB as compared to FES, with BERM intermediate (P = 0.03); and BW gain/ha tended to be lower for FES compared to other treatments (P = 0.10). Average daily gain and BW gain/ha were greater for SS-FES than FES (P = 0.001) from late September to November. As a summer grazing option, warm season grass alternatives, either as the sole source of pasture or interseeded into fescue, are better options for gain as compared to fescue alone.