Effects of different supplements on the nutritive value of maize and jowar to albino rats

Three trials were made with groups of 8 weanling albino rats. In the first trial 8 diets based on maize contained no supplement of niacin, lysine, isoleucine, lysine and methionine, lysine and methionine and isoleucine or fenugreek seeds [Trigonella foenum-graecum]. The basal diet was also given cooked. In the second trial 5 diets based on jowar (Sorghum vulgare) had no supplement or niacin, lysine, isoleucine or fenugreek. In the third trial 8 diets contained maize or sorghum, with no supplements or lysine, tryptophan or isoleucine. In trials 1 and 2 rats were pair-fed with the group eating the basal diets for 4 weeks; in trial 3 food was given freely. Daily food intakes and weekly bodyweights were recorded. Late in each trial 24-h urine collections were made for 3 days. Estimations were made in liver of protein spectrophotometrically and niacin chemically, and N1-methylnicotinamide in urine was estimated fluorometrically. In trials 1 and 2 growth was improved most by addition of lysine or fenugreek, further additions of niacin or amino acids being without effect. Isoleucine or niacin alone improved growth slightly. N1-Methylnicotinamide excretion was increased by the addition of niacin, lysine, isoleucine or fenugreek, or by cooking the basal diet. The results of the third trial suggest that sorghum and maize are of similar nutritive value, with lysine, tryptophan and isoleucine as limiting amino acids. It is suggested that protein and niacin status are related