Potential of Croton megalocarpus Nut as an Alternative Protein Supplement for Feeding of Ruminants in the Tropics

Abstract

Croton megalocarous is a tree native to the arid and semi-arid rangelands of East Africa that produces nuts reported to contain high crude protein (CP). However, they are often neglected as a potential feed due to lack of information on how best to utilize them. This study was conducted to evaluate the chemical composition and in sacco dry matter (DM) degradability of four forms of croton namely whole nut (WN), peeled nut (PN), De-husked nut (DhN) and Defatted seed (DfS). DM of all forms was above 89%, ash content was highest in WN (5.9%) and least in PN (2.2%). Crude fibre content was high in WN (52.2%) and PN (57.8%) while the DhN and DfS had the highest CP (15.7%) and (19.8%) respectively. Ether extract content was highest in DhN (36.2%) and least in DfS (11.2%). In sacco DM degradability was highest after 48 hours of incubation in all forms with highest degradability recorded for DhN (60.5%) and the least for PN (34.5%). The rapidly soluble fraction (a), potentially degradable fraction (a+b), index value (IV) and effective degradability (ED) were significantly high in DhN compared to the other forms. High DM was an indication of good keeping quality implying that nuts could be harvested and stored for future feeding while ash content reflected on potential as a source of minerals for livestock. The CP and IV of all the croton forms was above the 7% and 33% minimum required for optimum rumen function and to support sufficient feed intake, respectively. Processing of croton nut by de-husking and oil extraction enhanced the CP, soluble and potentially degradable fractions of croton nut. Subsequently, the two forms could satisfy the minimum of 15% CP required for lactation and growth in addition to provision of readily fermentable nutrients to boost intake of low-quality forages.