Abstract:
Twenty-four intact male Bonga lambs were studied
in a 100-day experiment to evaluate the effect of feeding
tannin rich leaves of Albizia gummifera (AG) on nutrient
utilization, growth performance, and carcass composition.
The dietary treatments consisted of hay alone (T1, control),
AG at 30 % of control diet + T1 (T2), and T2 + polyethylene
glycol 6000 (PEG) (T3, 40 mg PEG, 1 kg AG/head on a dry
mass (DM) basis. The lambs were individually fed at
50 g DM/kg live weight. In the last 10 days of the experiment,
all animals from each treatment were harnessed with feces
collection bags. At the end of the experiment, lambs were
slaughtered after overnight fasting for measurements of carcass characteristics. Crude protein, neutral detergent fiber, and
condensed tannin contents of AG were 300, 586, and 108 g/kg
DM, respectively. Lambs fed AG with PEG had higher
(P<0.001) feed intake, digestibility, carcass weight, and
weight gain compared with other treatments. Although lambs
fed diet T2 were able to utilize AG, the efficiency of its
utilization was lower (P<0.001) than the PEG-treated groups.
The improvement in nutrient intake and digestibility, carcass
weight, and growth performance of lambs supplemented with
PEG emphasizes the negative effect of tannins on livestock
performance. Leaves of AG enhance digestibility and performance in tropical hay-fed sheep, and the addition of PEG
further improves this effect, likely due to the binding of
tannins
