Effect of Processing Temperature and L-Lysine Supplementation on Utilization of Sunflower Meal by the Growing Rat

Abstract

Rate and efficiency of gain of rats fed semi-purified diets were used to evaluate the effects of heating sunflower seed at 0, 75, 100, 115 or 127 C for 1 hr before oil removal and to determine the quantity of L-lysine required to maximize utilization of heated and unheated sunflower meal (SFM). Rats fed SFM from seeds heated to 100 C gained faster than rats fed SFM from unheated seed. However, any benefit from heating the seed was lost at temperatures above 100 C. Meal from sunflower seed heated to 127 C produced less growth than the 100 C SFM and was about the same as that from SFM from unheated seed. Most of this decrease in gain was attributed to losses of the basic amino acids. Growth of rats receiving soybean meal (SBM) supplemented diets was superior to SFM-supplemented diets which contain adequate lysine. However, feed required per unit of gain was equal between those fed SBM or SFM plus lysine-supplemented diets. Maximum growth was obtained from 100 C SFM plus .51% L-lysine; whereas, only .34% L-lysine was needed in diets containing unheated SFM. The latter observation suggests changes in biological availability of L-lysine even though total lysine in the two meals was not affected by heating.