Synthetic Amino Acid Formula and Nitrogen Use

To the Editor: The bottom line in the study by Smith et al. (April 29 issue)* is the nitrogen retention of the four subjects. Despite the seemingly large differences among treatments shown in Figure 2 of Smith et al., the fact is that there were no statistically significant differences in nitrogen retention among the subjects receiving the three dietary treatments as shown in Table 3 of the article. The variation among subjects is very large, so that the standard deviations exceed the means for two out of three treatments. Although the observation may suggest a trend for a very.