Digestibility of Mechanical Mixtures of Early and Late Cut Tall Fescue

Abstract

AbstractIn vitro and in vivo dry matter digestibilities for four qualities of tall fescue (Festuca arundinacea) hay were determined. The variations in quality we obtained by harvesting low and high quality material from the same field and the intermediate qualities were obtained by making mechanical blends (33% high quality and 66% high quality) of the high and low quality materials. The in vitro procedure used was a modification of the Tilley and Terry procedure.Dry matter digestibility and ad libitum intake of the above feeds were determined with lambs using a 4 ✕ 4 Latin square. Increasing the proportion of high quality forage in the mixture gave a linear increase in in vivo digestibility, but there was no significant difference between the 66% high quality and 100% high quality samples. The pattern of increasing digestibility was similar in vitro and in vivo.The use of mechanical blends of extremely different qualities of samples of the same forage species appears to be a potentially valuable approach to elucidating factors influencing forage quality.