Evaluation of Covering, Dry Matter, and Preservative at Ensiling of Alfalfa in Bunker Silos

Abstract

In 1978, alfalfa at 30 or 40% dry matter was ensiled in four bunker silos. Propionic acid (.02% wet basis) was applied to one bunker of each dry matter. Bunkers were covered with black plastic. Dry matter recovery, temperatures during storage, and weight gain of heifers fed these silages were similar between treatments. In 1979, alfalfa (44% dry matter) was ensiled in four bunker silos of which two were not covered. Two silos, one covered and one not, were treated with propionic acid (.02% wet basis). Average temperatures during storage (7 wk) 34.1, 36.4, 42.6, and 50.3°C and dry matter recovery 84.1, 96.2, 86.3, and 68.0% were recorded for treated-covered, covered, treated-uncovered, and uncovered silos. Heifers gained more when fed untreated and covered silages. In 1980, alfalfa (32% dry matter) was ensiled in two bunkers. One silo was covered and untreated (covered), and the other was treated topically (treated) with a 100% propionic acid solution. Average temperatures during storage (7 wk) were 33.7 and 43.0° C, dry matter recovery 86.2 and 77.6%, average daily gain .58 and .44 kg/day, and dry matter consumption 7.3 and 5.8 kg/dry matter per day for silages or heifers fed covered and treated silages. In general, covering with black plastic was as effective as or more effective than treatment with propionic acid for preserving alfalfa stored in bunker silos. © 1983, American Dairy Science Association. All rights reserved.