Nutritive value of a vegetable amaranth cultivar for growing lambs

Current interest in amaranth as a food resource for humans and animals has been stimulated by activities in germplasm collection and testing in the U.S. Fifteen growing, intact male lambs weighing 18.7 kg were assigned randomly to three diets (five lambs/diet) for a 14-d growth trial followed immediately by an 8-d (4-d adjustment, 4-d collection) digestion and N balance trial to determine the utilization of the forage component (leaves and stems) of an African cultivar (Zimbabwe cultivar PI 482049, Amaranthus cruentus L.) All diets contained 40.95% ground corn, 8.0% soybean meal and 1.05% mineral-vitamin supplement plus either 50% ground alfalfa hay, 25% ground alfalfa hay plus 25% ground amaranth forage or 50% ground amaranth forage. Lambs had ad libitum access to feed during the growth trial and at 4% of BW daily during the digestion and N balance period. Replacement of half or all the alfalfa in the diet with amaranth had no effect on weight gain or feed utilization. Apparent digestibility of cell contents, NDF, ADF, cellulose, ADL, N and GE and percentage of absorbed N retained did not differ among the three diets. The amaranth vegetable cultivar Zimbabwe PI 482049 promoted weight gain and feed utilization equal to that obtained with alfalfa as the sole forage for growing lambs. Additional research is needed to evaluate further the potential role of forage/vegetable amaranth as an animal feed resource.