| dc.description.abstract | Studies were conducted to evaluate the use of pongamia seedcake (PSC) as a protein supplement and the interaction between mineral source and protein supplementation in cattle consuming low-quality forage. Five ruminally cannulated steers were used to determine the effects of PSC detoxification. Treatments consisted of a negative control (no supplemental protein, CON) and four supplemented treatments, each providing 100 mg of N/kg BW three of which contained PSC subjected to increasing levels of detoxification and a positive control supplement (0PSC). Two PSC supplements were mixed to contain 400 g/kg PSC with the PSC containing either 2 ppm karanjin (2PSC) or 49 ppm karanjin (49 PSC). The other PSC supplement (638PSC) contained 200 g/kg PSC with 638 ppm karanjin. Forage OMI and TDOMI was not greater for 0PSC than CON (P > 0.11). Supplementation with 2PSC and 49PSC tended to result in less FOMI (63.5 and 62.7 g/kg MBW, respectively; P = 0.08) than 0PSC (76.6 g/kg MBW). In experiment 2, thirteen ruminally cannulated steers were used to determine the effects of highly detoxified PSC (2 ppm karanjin) on forage utilization. Forage OMI, TOMI, and TDOMI were greater with supplementation of either 2PSC or 0PSC than CON (P < 0.01). Protein supplementation improved forage utilization by correcting the microbial N deficiency caused by forage low in ruminally degradable protein. Detoxification of PSC can result in a product comparable to conventional supplements for its ability to stimulate utilization of low-quality forage. Trial three used eight steers 0 (CON) or 175 mg of N/kg BW as cottonseed meal (CSM) consuming a basal diet of low-quality hay (38g/kg CP). No mineral source × protein supplement interactions (P ≥ 0.64) or significant effects of mineral source (P ≥ 0.06) were observed for all measures of intake and digestibility. Protein supplementation increased all intake measurements (P ≤ 0.01). There was a tendency (P = 0.06) for OMD to be greater (28 g/kg) for STM than HTM in both CSM and CON steers. Forage utilization increased in response to protein supplementation and there were minimal effects of trace mineral source on low-quality forage utilization by beef steers. | en |
