Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/26/2001
Publication Date: N/A
Interpretive Summary: A number of hybrid bermudagrasses, beginning with Coastal in 1943, have been released from and are identified with the research program at Tifton, Georgia. Bermudagrasses have been popular for hay and pasture because they are productive and persistent on sandy and acidic soils. These hybrids are established with vegetative planting material, either roots and/or stolons rhizomes, or mature cuttings of top growth. Tifton 85, the most recent release, is increasingly accepted in the U.S. and is popular in Brazil, where 2 million acres have been established. Yield and digestibility of Tifton 85 have been consistently superior to Coastal, supporting higher stocking rates and greater gain per acre. Lower concentration of ether- linked ferulic acid in cell walls of Tifton 85 than Coastal have recently been demonstrated, likely contributing to improved digestibility. During cool weather, milk yields were comparable when either Tifton 85 hay or alfalfa hay were fed in total mixed rations. Research continues to identify high yielding bermudagrass cultivars with highly digestible fiber, superior cold tolerance and wide adaptation.
Technical Abstract: Bermudagrass (Cynodon dactylon) has been popular for hay and pastures in southern U.S. for decades, persisting on sandy, acidic soils. New cultivars thrive in the U.S. and are being established in South America and other tropical environments. Hybrid bermudas including Coastal, released in 1943, are sterile and require establishment from roots and rhizomes which may increase costs. Vigorous hybrid cultivars may be established using top- growth cut at advanced maturity and planted in moist soils. Seeded bermudas have been developed but few compare with hybrid cultivars including Tifton 44, Tifton 78, Midland and Tifton 85 (T85), for yield, persistence or quality. T85 offers hay production potential in the establishment yr, while most cultivars do not produce enough forage for hay production or heavy grazing until the 2nd yr. After 8 yrs, T85 enjoys increased acceptance and popularity among U.S. producers and more than 1 mil ha have been planted in nBrazil. Dry matter yield and forage digestibility have been consistently higher for T85 than for Coastal, supporting increased stocking rates and greater gain/ha. T85 has consistently had higher in vitro and in vivo digestibility than Coastal, even when NDF of the T85 exceeded 70%. Recent experiments confirmed lower concentrations of ether linked ferulic acid in T85 than in Coastal, contributing to digestibility differences. During cool weather, comparable milk yields occurred when T85 hay was substituted for alfalfa hay in dairy rations. In tropical countries Coastcross 1 and T85 have been rotationally grazed by dairy cows. Bermudagrasses will continue to be primary perennial grasses for much of the southern U.S. and research efforts may provide cultivars with more digestible fiber, greater cold tolerance and wider adaptability as forages for beef and dairy cattle.