Energy deficiency in kikuyu grass containing high levels of nitrogen

Abstract

Elevated rumen ammonia levels in sheep on high nitrogen kikuyu (Pennisetum clandestinum Hochst) grass were indicative of a protein/energy imbalance in the grass. To correct the imbalance, grass containing 22% crude protein required maize meal supplementation of at least 20% on a dry basis. Unsupplemented high nitrogen kikuyu grass had a low dry-matter intake and digestibility. The efficiency of conversion of plant nitrogen into microbial protein in the rumen was probably poor and resulted in a large proportion of the ingested nitrogen being excreted in the urine. Maize meal supplementation improved the dry-matter intake and significantly increased the apparent retention of nitrogen and gross energy of the kikuyu grass.

Hoë peile rumenammoniak in skape op hoëstikstof-kikoejoegras (Pennisetum clandestinum Hochst) het op 'n proteïen/energie-wanbalans in die gras gedui. Om die balans te herstel, moes gras wat 22% ruproteïne bevat met ten minste 20% mieliemeel op 'n droë basis gesupplementeer word. Ongesupplementeerde hoëstikstof-kikoejoegras het 'n lae droëmateriaalinname en verteerbaarheid gehad. Die doeltreffendheid van die omskakeling van plantstikstof na mikrobeproteïen in die rumen was waarskynlik swak en het veroorsaak dat 'n groot hoeveelheid van die opgeneemde stikstof in die urine uitgeskei is. Mieliemeelsupplementering het die droëmateriaalinname verbeter en die skynbare retensie van stikstof en bruto-energie van die kikoejoegras betekenisvol verhoog.

Keywords: Digestibility, intake, maize meal supplementation.