P. Lebzien et J. Voigt, Calculation of utilizable crude protein at the duodenum of cattle by two different approaches, ARCH ANIM N, 52(4), 1999, pp. 363-369
Citations number
26
Categorie Soggetti
Animal Sciences
Journal title
ARCHIVES OF ANIMAL NUTRITION-ARCHIV FUR TIERERNAHRUNG
The duodenal how of utilizable crude protein (crude protein minus endogenou
s protein) in cows was estimated using dietary parameters, first by multipl
e regression and secondly by the addition of microbial protein and undegrad
ed feed protein. These estimates were compared with 327 results from experi
ments conducted with fistulated cows in Braunschweig-Volkenrode and Rostock
-Dummerstorf. The regressions and the measurements for microbial protein sy
nthesis as well as feed protein degradation and organic matter fermentation
in the rumen were based on the same experimental data set. The prediction
of utilizable crude protein (uCP) at the duodenum by regression with digest
ed organic matter (kg DOM) and undegraded feed protein (g UDP) as predictin
g variables, was more accurate than the value given by microbial protein sy
nthesis and rumen protein degradability. The regression model [g uCP = [188
.5 similar to (116.5 (UDP/CP))] DOM + 1.03 UDP] had the highest coefficient
of determination (r(2) = 0.91) and the lowest coefficient of variation (cv
= 8.6); indicating the model's superiority over the other method of estima
tion.