article explores a technique for measuring the energy (NEL) value of
feeds without respiration calorimetry or slaughter. The objectives were to
compare results obtained from goats with those from cows, and to describe
factors which limited the precision of these NEL estimates. One
lactating Alpine doe and one lactateing Holstein cow were assigned to each of
six different sequences of three 56-d feeding treatments consisting of low,
medium, and high doses of the basal diet, rice bran, or hominy feed. This
resulted in 30 observations of the basal diet and 12 of each byproduct feed for
each species and utilized a total of 18 cows and 18 does. The NEL values of the basal diet, rice bran, and hominy feed were calculated as the sum
of milk energy, change in body energy, and estimated fasting heat production
per kilogram of feed dry matter. Milk energy was determined by bomb calorimetry
and body energy from live body weight and deuterium oxide space. The NEL (MJ/kg) determined in this manner were basal diet, 5.73 and 5.98; rice bran,
7.11 and 7.07; and hominy feed, 6.99 and 8.20 for cows and goats, respectively.
Brown, D.L., De Peters, E.J., Taylor, S.J. and Baldwin, R.L. (1989) The influence of sometribove, USAN (recombinant methionyl bovine somatotropin) on the body composition of lactating cattle. Journal of Nutrition, 119, 633.
Thonney, M.L., Touchberry, R.W., Goodrich, R.D. and Meiske, J.C. (1976) Intraspecies relationship between fasting heat production and body weight: A reevaluation of W75. Journal of Animal Science, 43, 692-704.