Effect of substituting hydroponic barley for a commercial feed on performance and blood metabolites of growing Baladi rabbits

Abstract

The effect of replacing a commercial feed with hydroponic barley (HB) was studied on feeding trial to investigate its effects on performance, visceral organs and blood biochemistry of growing local Baladi rabbits. Four mixed diets based on a pelleted commercial rabbit feed (18% crude protein) were made by substituting HB (containing 18% dry matter, 2% crude protein and 15% crude fiber) for the commercial feed (0, 20, 40 and 60%). Sixty fourBaladi rabbits, 32 d of age and with an average body weight (±standard error) of 525 ± 10 g were assigned to the 4 treatments and caged in groups of 4 rabbits (2 females and 2 males/ cage). HB was grown for 8 d, and fed immediately after harvesting, including roots, seed and leaves. Feed intake and growth rate from 32 to 74 d of age were recorded. The rabbits were then slaughtered and the dressing proportions was calculated.Dry matter feed intake and growth rate decreased linearly by 1.16±0.080 g/d (P<0.001) and 0.998±0.062 g/d (P<0.001) per unit of HB increase. Rabbits consumed daily all the HB offered 0, 6.4, 12.8, and 19.1 g DM for 0, 20, 40 and 60% substitution levels, respectively. Both crude protein and digestible energy intake decreased linearly by 0.24±0.071 g/d (P<0.001) and 2.88±0.040 MJ/d (P<0.001). Feed conversion (average 3.45±0.20) and carcass yield percentage (average 56.25±0.42 %) were not affected by treatments. Blood metabolites were within the MEDIRABBITstandards; however, level of HB had variable effects on visceral organs. It was therefore concluded that replacing pelleted commercial feed by wet HB had negative effects on rabbits' performance