QUALITY OF EASTERN GAMAGRASS COMPARED WITH SWITCHGRASS AND FLACCIDGRASS WHEN PRESERVED AS HAY

Eastern gamagrass [Tripsacum dactyloides (L.) L.] (GG) hays were harve sted May 23 when vegetative (GG-V) and 28 days later (June) when repro ductive culms were developing (GG-R) and were compared. The GG-V hay w as further compared with a vegetative switchgrass (Panicum virgatum L. ) (SG) hay harvested May 29. The GG-R hay was also compared with a lat e-early-boot flaccidgrass (Pennisetum flaccidum Griseb.) (FG) hay harv ested on the same day. Forages were direct-cut with a flail chopper, a rtificially dried (24 h) in a forced-air bulk dryer (82 degrees C), ba led after drying, stored, and without further processing fed to Suffol k wethers (Ovis aries) in a 4 x 4 latin square design. The GG-V and GG -R hays had similar apparent dry matter digestion coefficients averagi ng 0.64 and were also similar to SG and FG averaging 0.64 and 0.61, re spectively. All hays had similar concentrations of crude protein (100 g kg(-1)), neutral detergent fiber (715 g kg(-1)), acid detergent fibe r (373 g kg(-1)), hemicellulose (342 g kg(-1)), cellulose (305 g kg(-1 )) and acid detergent lignin (58 g kg(-1)). Dry matter intake (kg/100 kg body weight) was similar for GG-V (2.42) and GG-R (2.19) and for GG -V and SG (2.27), but wethers fed GG-R had higher intake compared with FG (1.27). Nitrogen (N) retention, as a percent of total N intake, wa s higher for wethers fed GG (23% for GG-V and 33% for GG-R) than for;e ither SG (15%) or FG (14%). Differences in N retention were reflected in N excreted in the urine. Eastern GG shows potential as a useful per ennial C-4 grass for ruminant production systems.