Hay composition, and intake and digestibility in sheep of newly introduced cultivars of timothy, tall fescue, and reed canarygrass

Abstract

A 3-year experiment was conducted to compare the nutritive values of early maturing (Climax) and late maturing (Farol) cultivars of timothy ( Phleum pratense L.), low endophyte cultivars of tall fescue ( Festuca arundinacea Schreb.) (Kenhy and Johnstone), and low alkaloid cultivars of reed canarygrass ( Phalaris arundinacae L.) (Palaton and Vantage), on the basis of hay composition, and intake and digestibility in sheep. In each year, primary growth and regrowth of a cultivar were harvested as hays, and each was fed to four Dorset wethers for determining voluntary intake of dry matter (DM) over 10 days and apparent digestibility of DM over 5 days. Averaged across all cultivars, first-cut hay contained less total N and more acid detergent fiber (ADF), intake was lower but was digested better than second cut hay. Cutting cycle did not affect neutral detergent fiber (NDF) content in hay. Among first-cuts, total N content was least in Farol timothy and highest in Vantage reed canarygrass, NDF content was least in Kenhy tall fescue and highest in Farol timothy, and ADF content was low in Farol timothy and Palaton reed canarygrass versus high in Climax timothy and Kenhy tall fescue. Among second cuts, total N content was least in Kenhy tall fescue and highest in Climax timothy and Vantage reed canarygrass, and NDF content was least in timothy cultivars and highest in Johnstone tall fescue and Vantage reed canarygrass. Voluntary intake of DM in sheep was highest for tall fescue (954 g day −1), least for reed canarygrass (798 g day −1), and timothy intake was intermediate (856 g day −1) ( P < 0.05). Apparent digestibility of DM was not different between tall fescue cultivars at first (925 g kg −1) or second cutting (983 g kg −1). First-cut Climax was better digested than first-cut Farol (661 vs. 599; SE 4.0 g kg −1 DM) but digestibility ranked in reverse order for second-cut cultivars (630 vs. 650; SE 4.0 g kg −1 DM). First-cut cultivars of reed canarygrass were equal in apparent digestibility (638 g kg −1 DM) but second-cut Palaton was better digested than second-cut Vantage (605 vs. 580; SE 4.0 g kg −1 DM). Johnstone tall fescue was nearly as high yielding as timothy (7 vs. 7.7 t DM ha −1) and was better utilized than the other grasses.