Growth Response of Chicks and Rats Fed Alfalfa with Saponin Content Modified by Selection

Growth responses of chicks and rats which were fed diets containing alfalfa leaf meals made from populations selected for low and high saponin concentration from the varieties ‘Ladak,’ ‘Lahontan,’ and ‘DuPuits’ were determined. The original varieties were included in these tests. Growth responses of chicks were less for high-saponin selections than the original varieties and the low-saponin selections. Chicks gained more on low-saponin DuPuits than on unselected DuPuits, but differences between low-saponin Ladak and Lahontan and the unselected parent varieties were not significant. Correlations between weight gain and saponin concentration of the alfalfa, and weight gain per unit of feed and saponin concentration were —.892 (P < .01) and —.958 (P < .01), respectively. Rats on feed containing low-saponin alfalfa gained more than rats on feed containing high-saponin alfalfa the first 16 days. Subsequently, four rats on high-saponin treatments died. After 28 days, differences in gain of surviving rats were not significant. Correlations between weight gain and saponin concentration of the ration for low-saponin selections, original varieties, and high-saponin selections were —.754 (p < .05), —.828 (P < .01), and —.796 (P < .05), respectively. Corresponding correlations between feed efficiency and saponin concentration of the ration were —.757 (p < .05), —.836 (P < .01), and —.901 (P < .01), respectively.