Performance of Italian ryegrass varieties: Effect of cutting stage on dry matter and total non-structural carbohydrates percentages
Patrick N Rakau1*, Khuliso E Ravhuhali2, Mpho Nzeru1
1Agricultural Research Council, Cedara, Animal Production Institute, Forage Breeding, P.O. Box 1055, Hilton 3245, Kwazulu Natal, South Africa
2School of Agriculture Sciences, Department of Animal Science, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046 Mmabatho, 2735, South Africa
Abstract
Plant dry matter (DM) is one of the most limiting factors on the rumen fill. Due to variation in seasons, forages are prone to different stresses ranging from abiotic and biotic factors. The study was done to assess the effect of cutting stage on dry matter yield r and total non-structural carbohydrates of Italian ryegrass varieties (14 varieties). Diploid varieties namely: Supercharge, Sukari, Kigezi, Bartrento, ARC-148 BQX, Maximus and 14 LMD 43 and Tetraploid varieties namely: Green-Spirit, Barmulta II, ARC-214 GQX, Supreme Q, Agriton, AgriBoost and Mona. The trial was run at the Cedara research station in KwaZulu-Natal province (KZN). All 14 varieties were planted in rows which were 150mm apart (at the population rate of 30 kg/ha for both diploid and tetraploid) replicated three times in a laid out and fitted into randomized complete block design (RCBD). Dry matter yield and non-structural carbohydrates were analysed. A consistent effect of cutting stage on DM yield and TNC was not observed on average mean values. The cutting interval did not influence the DM yield and TNC concentration of both on diploid and tetraploid Lolium multiflorum varieties. The cutting stages can be reduced to four or five to allow the plant to regain its vigour after cutting /defoliation in order to and enforce the source-sink relationships.
Keywords: Rumen fill, ruminant, dairy cattle, carbohydrates, linear regression.
