Chemical Additives and Hay Attributes

Abstract

ABSTRACT EXPERIMENTS were conducted at the Pennsylvania State University to evaluate the application of chemical preservatives to high-moisture hay crops. The chemicals used were: acetic acid, propionic acid, propionic-acetic acid mixtures, propionic-formic acid mixtures, isobutyric-propionic acid mixtures and ammonium isobutyrate (AIB). The levels of application ranged from 0.5 to 2.25 percent of the wet forage weight. Hay moistures at packaging time were in the 28 to 35 percent range. Application locations studied were: (a) at the mower conditioner, (b) at the rake, and (c) at the baler. Evaluations of hay quality included hay tem-peratures in storage, chemical and biological analyses, and animal acceptability and feeding trials using brood cows and mature ewes. Dry matter losses were measured for treated and untreated rectangular bales, large round bales and stacks from mowing through raking, har-vesting, storage and feeding. Results of chemical and biological quality estimates indicate that some acid-treated high moisture hays maintained quality and feed efficiency comparable to heat-dried hay. Acid-treated hay was better in many respects than field-cured hay. Dry matter losses were significantly less (P < 0.05) for chemically-treated hay than for untreated field-cured and high moisture control hays. An average yield increase of 650 kg DM/ha was obtained from treated hays over untreated hays harvested as rec-tangular bales, round bales and stacks. This is equiva-lent to an increase of more than 100 kg of protein/ha and is indicative of potential returns for treatment costs.