Forage quality and grazing steer performance from Tifton 85 and Tifton 78 bermudagrass pastures.
A new high-yielding bermudagrass hybrid, Tifton 85, produced 26% higher DM yield (P = .05) with 11% higher IVDMD (P = .05) than Coastal in two 3-yr yield trials. Tifton 78 and Tifton 85 were established in duplicate .81-ha pastures in 1988 and were grazed during 1989, 1990, and 1991 using a variable stocking rate method. Four tester steers per pasture with 269 kg initial BW grazed continuously for 169 d/yr beginning in April. Forage mass, targeted at 2,800 kg of DM/ha, was maintained by adjusting stocking rates at 14-d intervals to correspond with ground-level forage samples taken at 14-d intervals. Pastures received 84 kg of N/ha in March, June, and August of each year. Nutritive value was assessed using whole masticate samples from two esophageal cannulated steers grazing each pasture in late May, mid-July, or early September. The 3-yr mean masticate analyses revealed similar CP for Tifton 78 and Tifton 85 in May and July, but higher (P < .05) CP for Tifton 85 than for Tifton 78 in September. The IVDMD was higher (P < .05) in May and September for Tifton 85 than for Tifton 78; and, mean and medium particle sizes were greater (P < .05) for Tifton 85 than for Tifton 78 in May, July, and September samples.(ABSTRACT TRUNCATED AT 250 WORDS)
Hill
G M
GM
Department of Animal and Dairy Science, University of Georgia, Coastal Plain Station, Tifton 31793-0748.
Gates
R N
RN
Burton
G W
GW
D000821:Animal Feed / Q000592:standards*; D000818:Animals; D002417:Cattle / Q000254:growth & development* / Q000502:physiology; D004043:Dietary Fiber; D004063:Digestion; D008297:Male; D009753:Nutritive Value; D010316:Particle Size; D006109:Poaceae; D011891:Rain; D012621:Seasons; D015430:Weight Gain