Supplementary feeding value of urea-treated olive cake when fed to growing Awassi lambs

Thirty six Awassi weaned male lambs (mean body weight, BW 22.7 ± 0.52 kg and 3–4 months of age) were used in a growth experiment and 16 others (mean BW 41.6 ± 0.42 kg and 6 months of age) were used in a digestibility experiment. The objective was to evaluate urea-treated olive cake (UTOC) as an alternative energy source in diets of fattening lambs. as substituted for barley in four diets containing 0, 10, 20, and 30% UTOC on dry weight basis. Feed intake in both experiments was restricted to 1050 g DM day−1 for all diets. Urea treatment of olive cake (50 g urea per kg olive cake DM) doubled its crude protein content. Inclusion rate had no significant effect on daily live weight gain (176, 169, 171 and 157 g day−1) and final weight (36.0, 35.3, 35.4 and 34.5 kg) for the four levels respectively. Feed conversion ratio (kg DM kg−1 gain) ranged between 6.8 and 7.0. ificant reduction (P < 0.01 or P < 0.05) in digestibility of DM, OM, NDF, and energy occurred especially at the 20 and 30% UTOC levels. CP digestibility was similar across UTOC levels. The similar response obtained with lambs fed the different UTOC diets and the low price of UTOC emphasise the economical advantage of its use.