Journal of Animal Science, Vol 68, Issue 2 515-531, Copyright © 1990 by American Society of Animal Science

JOURNAL ARTICLE

Supplementation of dormant tallgrass-prairie forage: I. Influence of varying supplemental protein and(or) energy levels on forage utilization characteristics of beef steers in confinement

T. DelCurto, R. C. Cochran, D. L. Harmon, A. A. Beharka, K. A. Jacques, G. Towne and E. S. Vanzant
Kansas State University, Manhattan 66506.

Three experiments were conducted to evaluate effects of supplemental protein vs energy level on dormant forage intake and utilization. In Exp. 1, 16 ruminally cannulated steers were blocked by weight (avg wt = 242 kg) and assigned randomly to a negative control or to one of three isocaloric supplement treatments fed at .4% BW: 1) control, no supplement (NS); 2) 12% CP, low protein (LP); 3) 28% CP, moderate protein (MP); 4) 41% CP, high protein (HP). In Exp. 2 and 3, 16 ruminally cannulated steers were blocked by weight (avg wt = 332 kg, Exp. 2; 401 kg, Exp. 3) and assigned randomly to a 2 x 2 factorial arrangement of treatments. The treatments contrasted low (LP) and high (HP) levels of supplemental protein (.66 g CP/kg BW vs 1.32 g CP/kg BW) with low (LE) and high (HE) levels of supplemental ME (9.2 kcal/kg BW vs 18.4 kcal/kg BW). In Exp. 1, forage DMI as well as ruminal DM and indigestible ADF fill at 4 h postfeeding were greater (P less than .10) with the MP and HP steers than with control and LP steers. Total DM digestibility increased (P less than .10) for supplemented steers (35.5% for control vs 47.3 for supplemented steers); however, LP depressed (P less than .10) NDF digestibility. In Exp. 2, forage DMI, indigestible ADF flow and liquid flow were depressed (P less than .10) in LP-HE supplemented steers. In Exp. 3, HP steers had greater (P less than .10) forage DMI, indigestible ADF fill values (4 h postfeeding), liquid volume and tended (P = .11) to have greater ruminal DM fill (4 h postfeeding). In summary, increased levels of supplemental protein increased intake and utilization of dormant tallgrass-prairie forage (less than 3% CP). Increasing supplemental energy without adequate protein availability was associated with depressed intake and digestibility.

This article has been cited by other articles:

				M. J. Hersom Opportunities to enhance performance and efficiency through nutrient synchrony in forage-fed ruminants J Anim Sci, April 1, 2008; 86(14_suppl): E306 - E317. [Abstract] [Full Text] [PDF]

				T. C. Gilbery, G. P. Lardy, S. A. Soto-Navarro, M. L. Bauer, and J. S. Caton Effects of corn condensed distillers solubles supplementation on ruminal fermentation, digestion, and in situ disappearance in steers consuming low-quality hay J Anim Sci, June 1, 2006; 84(6): 1468 - 1480. [Abstract] [Full Text] [PDF]

				J. L. Leupp, J. S. Caton, S. A. Soto-Navarro, and G. P. Lardy Effects of cooked molasses blocks and fermentation extract or brown seaweed meal inclusion on intake, digestion, and microbial efficiency in steers fed low-quality hay J Anim Sci, December 1, 2005; 83(12): 2938 - 2945. [Abstract] [Full Text] [PDF]

				M. W. Salisbury, C. R. Krehbiel, T. T. Ross, C. L. Schultz, and L. L. Melton Effects of supplemental protein type on intake, nitrogen balance, and site, and extent of digestion in whiteface wethers consuming low-quality grass hay J Anim Sci, December 1, 2004; 82(12): 3567 - 3576. [Abstract] [Full Text] [PDF]

				T. A. Currier, D. W. Bohnert, S. J. Falck, and S. J. Bartle Daily and alternate day supplementation of urea or biuret to ruminants consuming low-quality forage: I. Effects on cow performance and the efficiency of nitrogen use in wethers J Anim Sci, May 1, 2004; 82(5): 1508 - 1517. [Abstract] [Full Text] [PDF]

				T. A. Currier, D. W. Bohnert, S. J. Falck, C. S. Schauer, and S. J. Bartle Daily and alternate-day supplementation of urea or biuret to ruminants consuming low-quality forage: II. Effects on site of digestion and microbial efficiency in steers J Anim Sci, May 1, 2004; 82(5): 1518 - 1527. [Abstract] [Full Text] [PDF]

				T. A. Currier, D. W. Bohnert, S. J. Falck, C. S. Schauer, and S. J. Bartle Daily and alternate-day supplementation of urea or biuret to ruminants consuming low-quality forage: III. Effects on ruminal fermentation characteristics in steers J Anim Sci, May 1, 2004; 82(5): 1528 - 1535. [Abstract] [Full Text] [PDF]

				D. W. Bohnert, C. S. Schauer, M. L. Bauer, and T. DelCurto Influence of rumen protein degradability and supplementation frequency on steers consuming low-quality forage: I. Site of digestion and microbial efficiency J Anim Sci, November 1, 2002; 80(11): 2967 - 2977. [Abstract] [Full Text] [PDF]

				D. W. Bohnert, C. S. Schauer, S. J. Falck, and T. DelCurto Influence of rumen protein degradability and supplementation frequency on steers consuming low-quality forage: II. Ruminal fermentation characteristics J Anim Sci, November 1, 2002; 80(11): 2978 - 2988. [Abstract] [Full Text] [PDF]