A Comparison of Techniques Used in Digestibility Studies with Dairy Cattle

Abstract

A statistical analysis showed no significant difference between digestibility coefficients obtained by the use of lignin and chromium oxide ratios and those calculated by the standard total collection procedure. This held true for all nutrients in the ration. The use of indigestible materials such as lignin and chromium oxide shows promise of saving much of the time, labor, and expense involved in the present cumbersome method of conducting digestion trials. Although errors due to method have been proved to be not significant, the problem of avoiding significant errors due to sampling methods still remains to be solved. The data indicate complete recovery of lignin and chromium oxide. Therefore, these indigestible materials are suitable for digestive studies. The barn-cured alfalfa ration was significantly higher than the other two alfalfa rations in digestibility of dry matter, protein, crude fiber, and nitrogen-free extract. In etherextract digestibility, the barn-cured alfalfa ration was inferior to the other two. The alfalfa silage ration was significantly higher than the field-cured alfalfa ration (rain damaged) in digestibility of dry matter, protein, nitrogen-free extract, and ether extract.