Improving Forage Quality in Bermudagrass by Breeding1

Abstract

Twenty‐three clones of bermudagrass, cut at 2‐, 3‐, 4‐, and 6‐week intervals, differed significantly in crude‐protein content and nylon bag dry‐matter digestibility. These quality measurements decreased as age of forage increased. Genotype ✕ age interactions were not significant. F₁ hybrid ‘Coastal’ ✕ ‘Kenya 56 #14’ (the best‐quality hybrid) averaged 12.3% more digestible dry matter than Coastal bermuda over a 4‐year period. With the same forage intake, 1,760‐kg (800‐lb) steers should gain 30% more per day with this hybrid than with Coastal bermudagrass. Fiftyseven F₁ ‘Midland’ ✕ ‘Kenya 61’ hybrids cut at 33 days of age ranged from 45.2 to 59.6% in dry‐matter digestibility with a 5% LSD of 2.8%. Midland and Kenya 61 parents included in this test gave dry‐matter digestibilities of 49.7 and 60.5%, respectively. Dry‐matter digestibility, determined by a special nylon‐bag technique (the most precise of eight methods used for estimating forage quality at Tifton, Ga.), appears to be well suited for screening many genotypes in a forage‐breeding program directed toward quality improvement.