Botanical Examination of Forage from Esophageal Fistulas in Cattle

Abstract

The microscopic point method of botanical analysis gave a satisfactory estimate of species composition on a percent dry-weight basis in this two component mixed forage sample collected by the esophageal-fistula technique. The Y=X relationship was nearly as accurate as a linear, quadratic, or cubic regression equation through the origin for this particular two-component mixture where Y= percent weight and X=percent points. Even though there were no significant differences among observers, there was a significant weight × man interaction. Two of the observers were more consistent and required one-half as many points as the other two for the same degree of accuracy. Multiple comparison test shows that estimates in one and possibly two weight groups were significantly different from the other groups. Four hundred points estimated percent dry matter at 90% confidence limit to within 20% of the mean if the weight is 16 to 30%, to within 10% of the mean between 30 and 50% weight, and to within 5% of the mean from 50 to 95% weight.