Evaluation of Cenchrus ciliaris: 1. Effects of nitrogen level and cutting frequency on digestibility and voluntary intake.

Abstract

Cenchrus ciliaris (cv. Molopo) was cut at 3, 5 and 7 week intervals and fertilized with 50, 160 and 270 kg N/ha respectively. The treatments provided hay of nine different qualities with a range of ash (8, 5 to 10, 6%), N (0, 9 to 2, 5%) crude fibre (38, 5 to 45, 4%), in vitro digestibility (53, 8 to 70, 5%) and voluntary intake (57, 1 to 70, 3 g/kg W 0, 75). Unfertilized C. ciliaris and C. ciliaris fertilized with 50 and 100 kg N/ha and cut at eight weeks provided three qualities of hay with a range of ash (8, 5 to 10, 1%), N (0, 6 to 0, 9%) and fibre (42, 9 to 44, 7%). The hay of the 0, 50 and 100 kg N/ha treatments varied in in vitro digestibility (61, 2, 63, 5 and 59, 0%) in vivo digestibility (49, 3, 57, 9 and 59, 3%), voluntary intake (50, 1, 67, 5 and 65, 1 g/kg W0, 75) and mean daily livemass gain/sheep (-4, 5, 57, 3 and 52, 8 g) respectively. It is concluded that voluntary intake provides one of the best measures for determining the nutritive value of C. ciliaris.

Keywords: cenchrus ciliaris; crude fibre; cutting frequency; digestibility; evaluation; hay; in vitro digestibility; intake; intervals; nitrogen; quality; south africa; treatment; treatments