Wk. Coblentz et al., PERFORMANCE COMPARISONS OF CONVENTIONAL AND LABORATORY-SCALE ALFALFA HAY BALES IN ISOLATED ENVIRONMENTS, Agronomy journal, 86(5), 1994, pp. 811-819
Negative quality changes, including Maillard reaction damage, in alfal
fa (Medicago sativa L.) hay frequently are associated with spontaneous
heating resulting from packaging and storing forage at moisture level
s in excess of 200 g kg-1. Forage at three moisture levels (268, 229,
and 185 g kg-1) was packaged in laboratory-scale bales at 1.0, 1.3, 1.
7, and 2.0 times the density of parent, conventional bales and subsequ
ently incubated in two different isolated environments such that all m
easured heat accumulation was the result of self-generated heat. Labor
atory-scale hay packages generated measurable heat and exhibited quali
ty changes when incubated (i) between straw bales stacked in an open-a
ir pole shed and (ii) in insulated incubator boxes in a storeroom the
minimum ambient storage temperature was set at 25-degrees-C. Heat deve
lopment and negative quality changes were greater in the box-incubatio
n system, indicating a need to control ambient storage temperature. At
the high and medium moisture levels, acid-detergent insoluble N (ADIN
) fractions for high-density, box-incubated laboratory bales were at l
east similar (P > 0.05) to those of parent, conventional bales, despit
e large disadvantages in measures of accumulated heat. These responses
in laboratory bales were consistent with those reported in previous h
aystack-incubated studies and suggest that the environmental heat comp
onent created by adjacent conventional bales in those studies may have
had a limited direct effect on ADIN content. Increasing density of la
boratory bales probably rendered alfalfa proteins more susceptible to
Maillard reaction damage and/or allowed the reaction to proceed more e
fficiently with respect to self-generated heat than it did in conventi
onal bales.