Abstract
Peanut protein supported rapid growth in weanling rats when present in the diet in sufficient quantity. Defatted meal was prepared by cold pressing and hexane extraction of oil from seeds of Florunner, Tifrun, UF 70115, Tennessee Red, Tamnut and Comet cultivars of peanuts. A concentration of 16% peanut protein resulted in better growth than 12% protein from all cultivars tested. Increasing protein to 20% of the diet further improved growth of rats fed meal from some, but not all, cultivars of peanuts. Apparent digestibility of nitrogen in the meals was about 92%. Peanut meal is potentially a good source of protein for animal production if the peanuts and meal are properly handled after harvest to maintain the nutritional quality of the product. Some statistically significant differences occurred in growth performance of rats fed meals from the several cultivars of peanuts but these are not likely to be of practical importance. However, they suggest that protein quality of the peanut might be improved by breeding.
The nutritional quality of peanut protein is considered to be low because the concentration of several of the essential amino acids is below optimal levels for promoting growth of young animals. When compared with casein in the accepted bioassay for protein efficiency ratio (PER, Neucere et al., 1972) or by the slope-ratio technique (Hegsted et al., 19680), the biological value is commonly found to be 50 to 75% of that of the standard protein. Such tests are conducted with growth-limiting levels of dietary protein and provide little information on the potential capacity of a protein to support an acceptable rate of growth. Carpenter and de Muelenaere (1965) concluded that, under certain conditions, higher levels of poor-quality proteins would result in nearly as good growth of chicks, pigs, and rats as could be obtained with practical diets containing good-quality proteins. Defatted meal from Florunner peanuts, when incorporated into diets to provide 16.7% protein, supported growth of weanling rats at a rate comparable to that obtained with diets containing 12% to 24% of casein (Miller and Young, 1977).
This paper describes results of a study similar to that mentioned above using meal from several cultivars of peanuts that are of current commercial or genetic interest.
Author notes
1This work was supported in part by the Georgia Agricultural Commodity Commission for Peanuts.