Nutritive value of Albizia lebbek supplements for growing sheep

Abstract

This study was undertaken to evaluate the effect of supplements of siris (Albizia lebbeck) flowers and leaves on Merino wethers fed Mitchell grass hay (Astrebla spp.). Three groups, each of 6 sheep, were fed the following diets: hammermilled Mitchell grass hay ad libitum (M); M + 181 g DM/day of siris flowers (MF), and M + 216 g DM/day of siris leaves (ML). The experiment, conducted over 17 days, measured feed intake and digestibility, nitrogen (N) retention, and plasma glucose and urea concentrations. The total DM intakes by MF and ML sheep were significantly (P<0.01) higher than those in M sheep. As a result of the supplement of siris flowers, the digestibility of the MF diet was highest (P<0.01). Sheep fed the M diet showed negative N retention, while MF and ML sheep showed positive N retention. The increased (P<0.01) N retention in the MF and ML sheep was associated with increased (P<0.01) urinary N excretion. The improved nutritional state of MF and ML sheep was associated with increases in plasma glucose and urea concentrations. Environmental temperature, which reached a mean daily maximum of 31.3¦C, did not interact with the dietary treatments.