Effect of nitrogen fertilization application and maturity of wild sunflower on chemical composition and rumen degradation characteristics in sheep

Abstract

This study was conducted to investigate the influence of three levels of Nitrogen (N) fertilizer application (0, 125 and 250kg N/ha) and stage of maturity on chemical composition and degradation characteristics of wild sunflower forage meal in West African Dwarf sheep. Nitrogen (0,125 and 250 kg N/ha) as NPK was applied to field plots of established wild sunflower (Tithoninia diversifolia (Hemsl). A Grey). Sunflower fertilized with 250 kg N/ha had lower neutral detergent fiber (NDF) than those not fertilized (57vs 35). Leaf crude protein increased with increased N applied. Crude protein content of leaf decreased and NDF increased with maturity. NDF and crude protein degradation were improved with increased N application. This increase in CP increased N disappearance in the rumen as measured by in-sacco study. This might result in increased problem with utilization of wild sunflower N by the ruminants. Dry matter, nitrogen and neutral detergent fiber degradation declined with delayed harvest. Based on chemical composition and the effect of maturity on degradation characteristics of wild sunflower, 125kg N/ha was considered adequate and the forage could be harvested between the ages of 7-8weeks after the onset of flowering.