Sweet Potato Meal versus Ground Corn in the Ration of Dairy Cows

Raw sweet potatoes have been used as a feed for domestic animals for some time.However, it has been only during the past decade that sweet potato meal has gained recognition as a possible substitute for corn in the ration of livestock.Several southern investigators (6, 7, 8, 9, 10, 11, 12, 13) have found dried sweet potatoes to be worth approximately 90 to 95 per cent as much as corn for fattening beef cattle.Hogs and mules preferred rations in which the sweet potato meal did not replace more than 50 per cent of the corn in the ration.Massey (14) at the Georgia Experiment Station conducted a series of experiments in which he studied the comparative value of sweet potato meal and ground corn as a feed for ewes.The 300 ewes that were fed these rations during a period of 3 years favored the sweet potato meal from a palatability standpoint and gained as much during the gestation period when fed the sweet potato meal ration as when fed the corn meal ration.The ewes that received the sweet potato meal ration proc~uced more milk after the lambs were born and thereby gave the lambs a faster growing start.Louisiana workers (15) report that dehydrated sweet potatoes have approximately 88 per cent of the value of yellow corn meal and are approximately 17 per cent more valuable than ground snapped corn, including cob and shuck, for milk production.Good quality dehydrated sweet potatoes contained from 76 to 81 per cent T.D.N. and a poor quality product contained 71 per cent T.D.N. on the dry basis.Vitamin A analyses of the butterfat from milk produced by cows fed sweet potatoes were 19 per ce~t higher than those of butterfat produced by cows fed ground corn.The basal feeds were common lespedeza hay, alyce clover hay, or kobe lespedeza hay and cottonseed meal.Briggs et al. (2) of the Oklahoma Station recently reported that on the dry matter basis the average T.D.N. value of dried sweet potatoes for steers was 86.05 as compared to 85.80 for the corn.The basal feeds were alfalfa hay or prairie hay and cottonseed meal.Copeland (5) of Texas reported that one could expect 3.08 per cent more milk as a result of feeding corn than when feeding sweet potato meal.It also was noted that butter produced from cows on the sweet potato meal contained 37.98 I.U. of vitamin A per g. as compared with 31.11I.U.from butter produced by cows fed yellow corn.