Turmeric (Curcuma longa) Root Powder and Mannanoligosaccharides as Alternatives to Antibiotics in Broiler Chicken Diets

Two bio-assays were conducted to evaluate turmeric root powder and mannan-oligosaccharides (MOS) as alternatives to feed antibiotics for broilers. In one trial, one hundred and eighty 19-days old broilers assigned to 18 groups of 10 were fed on one of six experimental diets with three replicates during four weeks. The diets included a basal feed without additives and with either virginiamycin, MOS, or turmeric at 1, 2 and 3 g/kg, respectively. In the second trial, one hundred and forty four 21-days old broilers arranged in 16 groups of nine were fed on the first four diets with four replicates for a similar period. Virginiamycin, MOS and turmeric (1 g/kg) in the first trial generally improved the weight gain of broilers by 3.4, 6.2 and 5.3%, respectively. In the second trial they increased the weight gain significantly (p<0.05) by 8.8, 8.0 and 15.1%, respectively. Additives improved the feed efficiency up to 15.1% and carcass recovery up to 3.1% (p<0.05). Virginiamycin, MOS and turmeric (1 g/kg) markedly reduced the abdominal fat content from 1.91% BW in the control to 1.44, 0.97 and 1.2% BW, respectively, in the first trial. The corresponding values obtained in the second trial were 1.01, 0.55 and 0.6%, respectively as compared to 1.22% in the control group. All additives showed a remarkable inhibition of duodenal coliform bacteria, yeast and mould in the caecum, and all viable microbes in the ileum. A significant (p<0.05) improvement in energy and protein utilization could be recorded with supplemented diets except for high turmeric diets. Dietary 2 and 3 g/kg addition of turmeric reduced energy and protein utilization as well as fat deposition. Present results reveal that turmeric and MOS are satisfactory alternatives to antibiotics in broiler feeds. Both MOS and turmeric possess an antimicrobial effect in vivo. Turmeric may also depress fat deposition in broilers.