This study is consisted of two experiments and aimed to determine the nutrient composition and feeding value of the hydroponic barley fodder (HBF) and that HBF irrigated with bakers' yeast (HBFY) for the growing Californean (CAL) and White New Zealandean (NZW) rabbits. The first experiment included 36-weaned rabbit males, 18 rabbit males from each of CAL and NZW breeds, which were housed in 18 paired cages. The nine replicates (2 rabbits in each replicate) of each breed were then allotted randomly to three feeding treatment groups: Control. Basal diet, T1. Basal diet + HBF, and T2. Basal diet + HBFY. The rabbits were adapted to the tested fodders for one week, and the data collection continued for six weeks. The second experiment followed the same design, but using female rabbits instead of males.
The fresh-8-day HBF and HBFY contained 17.30% and 16.84% dry matter, 17.75% and 16.68% crude protein, 15.90% and 15.67% crude fiber, respectively. The one kg of barley grains yielded 6.12 kg of fresh HBF, versus 6.02 kg of fresh HBFY/ kg grains. The results of Exp. 1 showed that the male rabbits provided with fresh HBF recorded the highest body weight, body weight gain and carcass weight, while the HBFY males had the worst (P<0.01) feed conversion ratio. In Exp. 2, the HBFY females had the lowest BW and BWG and the worst FCR value. In both trials, the male and female rabbits which were provided with fresh HBF had a cheaper feed cost per gain than those of the control group, while the HBFY rabbits had the most expensive value. Besides, the tested treatments showed inconsistent impacts on the feed and fodder intake values, while they did not show any significant effect on the dressing percentage, carcass cuts, body muscles, or internal organ weights.
Conculsively, the results therefore revealed that feeding the growing male or female rabbits with the HBF displayed considerable nutritional benefits, while the HBFY is not recommended