| dc.description.abstract | Effects of increasing levels of the anti-nutritional compounds karanjin and
pongamol on intake, nutrient utilization and ruminal fermentation were evaluated with a
growing diet (trial I) and a forage diet (trial II).
Steers had ad libitum access to growing diet and Bermuda grass hay during trial
1 and trial 2, respectively. At the same time diets were fed, steers received their allocated
doses of karanjin and pongamol via ruminal cannula to determine acceptable inclusion
level of pongamia seedcakes containing varying levels of karanjin and pongamol, which
are contained in the residual oil of commercially available pongamia seedcakes. Twelve
steers in both studies were assigned to completely randomized block design consisting of
a control (no karanjin and no pongamol) and one of 3 levels of karanjin and pongamol.
Dosing increasing levels karanjin and pongamol linearly (P < 0.01) decreased
intake in Trial 1. No significant effects (P ≥ 0.12) were observed for total DMD, OMD,
NDFD, ADFD and CPD. Ruminal total VFA concentration and pH were not affected by
inclusion levels (P = 0.19 and P = 0.51, respectfully). The lowest dose of karanjin and
pongamol resulted in a greater (P < 0.01) molar proportion of propionate than other
treatments, resulting in a reduction in acetate:propionate ratio (P = 0.02) for that
treatment. Among all VFA molar concentration measurements, only isobutyrate
exhibited a treatment × hour effect (P = 0.02).
When a forage diet was fed (Trial 2) increasing levels of karanjin and pongamol
dosing resulted in a quadratic decrease (P < 0.05) in intake of total DM, OM, NDF and
ADF with the. Crude protein intake did not differ (P = 0.14) among treatments. There
was no effect (P ≥ 0.22) among treatments on DMD, OMD, NDFD and ADFD. Total
VFA concentration and ruminal pH were not affected by inclusion level (P = 0.59 and
0.72, respectively. Therefore, acetate:propionate ratio also had no treatment effect (P =
0.84).
Increasing levels of karanjin and pongamol decrease intake, although
digestibility is not impacted. Ruminal fermentation of steers fed with complete ration is
slightly altered with karanjin and pongamol intake, however, none alteration was
observed when steers were fed only Bermuda grass hay. | en |
