Reducing Protein in Swine Diets
Two other studies were conducted to evaluate the effects
of adding fiber sources to reduce crude –protein, amino acid-supplemented
diets on nitrogen excretion, growth performance and carcass traits of
growing-finishing pigs. The treatments consisted of: 1) a fortified
corn-soybean meal control diet; 2) a fortified corn-soybean meal diet
with 4% reduced crude protein and supplemented with lysine, threonine,
methionine, tryptophan, isoleucine and valine; 3) treatment 2 plus 10%
soybean hulls; and 4) treatment 2 plus 10% dried beet pulp. The results
indicated that nitrogen intake, absorption and retention were reduced
(P<0.04) in pigs fed the low crude protein diets. Fiber sources had
no affect (P<0.10) on these measurements. Urinary and total nitrogen
excretion was reduced (P<0.01) by 50 and 40%, respectively, for the
pigs fed the low crude protein diets, but these measurements were not
affected by fiber additions. In the second experiment, growth performance
and most carcass traits were not affected (P<0.10) by dietary treatments.
The effects of adding fiber to the low crude protein-amino acid supplemented
diets had little effect on overall nitrogen balance or growth performance.
The fiber sources tended to increase the ammonium nitrogen content of
the waste slurry and urinary urea nitrogen excretion.
Shriver, J.A. and co-workers. 2003. Effects of adding fiber sources
to reduced-crude protein, amino acid-supplemented diets on nitrogen
excretion, growth performance and carcass traits of finishing pigs.
J. Animal Sci. 81(2):492-502
