"Effect of Protein Source on Nitrogen Metabolism in
Continuous Culture and Intestinal Digestion In Vitro"
[lysine, cannulae, amino acids]
Eight dual flow continuous culture fermenters were used in four replicated periods to study the effects of protein supplements on ruminal fermentation and protein digestion. Intake of essential amino acids was not significantly different between treatments but outflow was higher for SoyPass and corn gluten meal (P<.05).
 

Essential AA, mg/d

Lysine, mg/d

 

Intake

outflow

Intake

Outflow

Control
4900
4700
700
650

Soybean meal
5600
5200
760
540

SoyPass*
5400
6200
660
700

Corn Gluten meal
5400
6100
460
540

*Lignosulfonate-treated soybean meal
Lysine outflow was significantly higher with SoyPass than with other vegetable proteins (P<.05). The improvement in amino acid quantity and quality was made possible by the contribution of rumen undegraded intake protein added on top of the protein synthesized by rumen bacteria.
S. Calsimaglia, M. D. Stern, and J. L. Firkins (1995), J Anim Sci 73:1819-1827