Alternatives in Cattle Feedlot
Waste Management
RICHARD R. DAGUE, Assistant Professor
Department of Civil Engineering
University of Iowa
Iowa City, Iowa
INTRODUCTION
There are about 200,000 cattle feedlots in the 32 leading cattle feeding states
of the United States. Nearly 22 million cattle were marketed from these lots in 1967.
While on feed these 22 million animals defecated about 200 million lb/day (dry
weight) of manure. In comparison, the human population of the U. S. produced
about 100 million lb/day of garbage (wastes from food processing and preparation).
The above numbers may place the garbage disposal problem in perspective but
they are misleading as an indication of the relative importance of the two sources of
environmental pollutants. The numbers might indicate why compost produced from
garbage has little or no value as a soil conditioner — but they do not mean that the
manure disposal problem is twice as severe as the garbage disposal problem.
The management of wastes from cattle feedlots is a unique problem in
environmental quality control. It cannot be compared to the control of wastes from
domestic and industrial sources on any realistic or meaningful basis. The quantities
and characteristics of wastes from cattle feedlots are affected by many variables. In
turn, the effect that the feedlot wastes have on the environment is related to
numeroud other factors. The control practices employed in a given region or state or
at a given feedlot must consider these matters. A necessary and effective control
practice in the High Plains of Texas may not apply to Kansas or Iowa. An effective
procedure at one feedlot may prove ineffective at another.
Perhaps no other source of wastes, domestic or industrial, requires a larger "bag
of tricks" for satisfactory solutions than agricultural sources. In recent years workers
from many disciplines have contributed to the accumulation of the fundamental
knowledge needed to solve feedlot waste problems. These fundamentals provide a
reasonably solid basis for evaluating the alternatives in cattle feedlot waste
management.
FEEDLOT WASTE CHARACTERISTICS
The task of determining the physical, chemical and biological characteristics of
cattle feedlot wastes is difficult. As noted by Taiganides and Hazen, the
characteristics of animal wastes are affected by the physiology of the animal, the
feed ration and the environmental conditions to which the animal is subjected (1). In
addition, variations in the analytical procedures used to characterize the waste leads
to still further differences in reported results.
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