The effect of paddy straw and concentrate containing green tea dust on performance and nutrient digestibility in feedlot lambs

Abstract

The utilization of low-input paddy straw hay PSH for fattening lambs should be incorporated with a high-quality concentrate HQC in which green tea dust GTD rich in tannins can be added as a natural feed additive. Completely randomized design was used to compare 5 doses of GTD inclusions dry matter, DM basis at 0% GTD-0 , 0.5% GTD-0.5 , 1% GTD-1 , 1.5% GTD-1.5 , and 2% GTD-2 in an HQC as the main diet of PSH-fed fattening lambs on average daily gain ADG, g/head/day , dry matter intake DMI, g/head/day , and nutrient digestibility % using 6 replicates. The results showed that GTD-1.5 resulted in higher P < 0.05 ADG for the lambs compared with GTD-0 as a control diet during 69 days of a feeding trial, while GTD-0.5, GTD-1, and GTD-2 provided a nonsignificant increase in ADG for the lambs in comparison with GTD-0. There was no difference P > 0.05 in nutrient digestibility of the lambs for all GTD treatments, but GTD-1.5 resulted in better nutrient digestibility. Proper GTD inclusion in an HQC and PSHbased diet can therefore increase the performance of fattening lambs without any harmful effects on feed consumption and nutrient digestibility. GTD inclusion in an HQC as the main diet of feedlot lambs is recommended at 1.5%.