Toxicity of N-(phosphonomethyl)glycine to chick embryo

The LD₅₀ values, 12.88 $\text{mg}\text{100 g egg}$ and 13.22 $\text{mg}\text{100 g egg}$, obtained when the N-phosphonomethyl derivative of glycine was injected into the air sacs of White Rock and White Leghorn eggs respectively, were significantly lower (P < 0.01) than the values, (24.72 $\text{mg}\text{100 g egg}$ for White Rocks and 25.44 $\text{mg}\text{100 g egg}$ for White Leghorns) obtained by injection into the yolk sac. These findings suggest that the toxicity of N-(phosphonomethyl)glycine (PMG) to the chick embryo depends on the route of injection.