| Abstrakt: |
In situ rumen degradability of dry matter (DM) and crude protein (CP) in ruminant diets composed of graded inclusion levels of marula nut meal (MNM) as a protein source to replace soybean meal were evaluated. The five diets denoted as diet 1 (0.0 g kg−1 MNM: control), diet 2 (45.5 g kg−1 MNM), diet 3 (91.7 g kg−1 MNM), diet 4 (138.4 g kg−1 MNM), and diet 5 (185.9 g kg−1 MNM) were tested. Three cannulated mid-lactating Holstein cows were used to incubate triplicate subsamples of each diet for 2, 4, 8, 16, 24, and 48 h in polyester bags. The soluble fractions of DM and CP increased (P < 0.05) with increasing levels of MNM (138.4–185.9 g kg−1 MNM). However, the insoluble but degradable fractions of DM and CP increased (P < 0.05) with decreasing levels of MNM (45.5–0.0 g kg−1 and 91.7–0.0 g kg−1 MNM, respectively). While the degradation rate of fraction and the effective degradability of DM increased (P < 0.05) with decreasing levels of MNM (91.7–0.0 g kg−1), those of CP increased with increasing levels of MNM (138.4–185.9 g kg−1 MNM) in the diet. These results suggest that dietary inclusion of MNM up to 91.7 g kg−1 in ruminant diets can provide undegradable protein to be absorbed in the small intestines and used for metabolic function, while an inclusion of up to 185.9 g kg−1 can be degraded in the rumen for microbial protein synthesis. [ABSTRACT FROM AUTHOR] |
Full text from SpringerLink