Supplemental Degradable Intake Protein Research Articles

Effect of urea level in protein supplements on performance by beef cows consuming low-quality, tallgrass-prairie forage (1997)

One hundred thirty two Hereford x Angus cows grazing tallgrass-prairie range during winter were used to evaluate the effects of varying the amount of supplemental degradable intake protein (DIP) derived from urea on cow and calf performance. Treatment groups were: 0, 15, 30, and 45% of the supplemental DIP from urea. Supplements were formulated to contain 30% crude protein (CP), with approximately 70% of the CP being DIP. Palatability was not a significant problem within the range of urea inclusion tested. In general, prepartum weight and condition losses were greater with increasing levels of urea, although the magnitude of condition loss was greater when urea comprised more than 30% of the DIP. Calf performance was not affected by treatment.

Effect of increasing degradable intake protein on intake and digestion of low-quality, tallgrass-prairie forage by beef cows.

Five ruminally and duodenally fistulated Angus x Hereford cows were used in a 5 x 5 Latin square to monitor intake, ruminal fermentation responses, and site and extent of digestion associated with providing increasing amounts of supplemental degradable intake protein (DIP). Cows had ad libitum access to low-quality, tallgrass-prairie forage (1.9% CP, 77% NDF) that was fed twice daily. The supplemental DIP (sodium caseinate; 90% CP) was infused intraruminally at 0630 and 1830 immediately before feeding forage. Levels of DIP were 0, 180, 360, 540, and 720 g/d. Each period consisted of 14 d of adaptation and 6 d of sampling. Forage OM intake increased quadratically (P < .01) with increasing supplemental DIP reaching a peak at the 540 g/d level. True ruminal OM and NDF digestion increased with the addition of 180 g/d supplemental DIP, but exhibited only moderate and somewhat variable responses when greater amounts of supplemental DIP were infused (cubic, P < or = .03). Microbial N flow and efficiency increased linearly (P < .01) with increasing supplemental DIP. However, a quadratic effect (P < .01) was observed for total duodenal N flow, which was maximized at 540 g/d supplemental DIP. A linear (P = .02) treatment effect was observed for ruminal fluid dilution rate. Total ruminal VFA and ammonia concentrations increased (P < .01) in response to DIP supplementation. In conclusion, increasing supplemental DIP generally improved forage utilization; intake of digestible OM was maximized when it contained approximately 11% DIP.

The influence of various levels of supplemental starch and degradable intake protein on prairie hay intake and digestion by beef steers (1996)

A study was conducted to determine the effect of varying the amount of supplemental degradable intake protein (DIP) and starch on prairie hay intake and digestibility. In general, DIP increased forage intake, whereas starch decreased intake. Diet digestibility also improved with increasing DIP; however, the effect of starch on digestion depended on the level of feeding. Digestible dry matter intake (which estimates total energy input) r esponded dramatically to DIP but not to starch. These results illustrate the positive effect of DIP on forage intake and digestibility; however, supplying additional starch within a DIP level appeared to have minimal effect on altering total energy supply.

Influence of increasing proportion of supplemental nitrogen from urea on intake and fermentation characteristics in beef steers consuming low-quality, tallgrass-prairie forage (1995)

Five ruminally and duodenally fistulated Angus x Hereford steers were used to determine intake and fermentation responses associated with increasing the proportion of supplemental degradable intake protein (DIP) provided by urea. Steers had free access to a dormant, tallgrass-prairie forage. The supplemental DIP was provided by sodium caseinate and (or) urea , at a level that was determined previously to optimize use of a similar forage. Supplemental DIP was balanced with corn starch to provide a final supplement of 40% crude protein. Percentages of DIP from urea were: 0, 25, 50, 75, and 100%. Supplements were given intraruminally. Increasing the percentage of urea as supplemental DIP from urea did not significantly affect forage DM intake; however, fermentation characteristics changed.

Influence of degradable intake protein on site and extent of digestion in beef cows consuming low-quality, tallgrass-prairie forage (1995)

Five Angus x Hereford cow s with ruminal and duodenal fistulas were used to evaluate the effect of providing increasing degradable intake protein (DIP) o n the site and extent of digestion of dormant, tallgrass-prairie forage. The DIP was provided from sodium caseinate, divided in two equal portions and infused intraruminally twice daily. Levels of DIP were: 0, 180, 360, 540, and 720 g/day. Supplemental DIP generally improved utilization of low quality forage, with maximum effects on duodenal N flow and forage organic matter intake at 540 g DIP/day.