Interactions Among Forages and Nonforage Fiber Sources

¹ Department of Animal Science, University of Nebraska, Lincoln 68583-0908

Source, amount, and physical characteristics of dietary forage can interact with nonforage fiber sources and influence ruminal and total tract fiber digestion, passage, and performance of dairy cows fed diets containing substantial nonforage fiber in place of forage. Dietary NDF from forage can be reduced to 60% and still provide sufficient amounts of effective fiber for FCM production that is similar to or superior to that with high forage diets. Because of small particle size and high specific gravity, increased ruminal rate of passage may be responsible for lower ruminal NDF digestibility of nonforage fiber sources fed at high dietary amounts. As the amount of soybean hulls increased from 50 to 95% of a pelleted mix for dairy cows, passage rate increased by 8%. In five studies, the digestion of soybean hull diets was improved by the addition of coarse forage. Fiber digestibility might have improved because coarse hay increased ruminal retention time of nonforage fiber sources and allowed more complete digestion. Addition of coarsely chopped alfalfa hay to diets based on silage containing 25% soybean hulls increased ruminal mat consistency by 49% and tended to slow the ruminal escape rate of soybean hulls by 16%. When high percentages of nonforage fiber are fed, the amount of dietary forage is necessarily low, and forage particle size should be adequate to stimulate rumination and entrap small feed particles. The amount and particle size of forage in the diet interacts with the substituted nonforage fiber source to determine the net impact on the rate of ruminal digestion and passage of nonforage fiber.

Key Words: effective fiber • coproduct feeds • forage • performance

Submitted on June 26, 1995
Accepted on April 19, 1996

This article has been cited by other articles:

				Y.-H. Chung, M. M. Pickett, T. W. Cassidy, and G. A. Varga Effects of Prepartum Dietary Carbohydrate Source and Monensin on Periparturient Metabolism and Lactation in Multiparous Cows J Dairy Sci, July 1, 2008; 91(7): 2744 - 2758. [Abstract] [Full Text] [PDF]

				A. K. Sasikala-Appukuttan, D. J. Schingoethe, A. R. Hippen, K. F. Kalscheur, K. Karges, and M. L. Gibson The Feeding Value of Corn Distillers Solubles for Lactating Dairy Cows J Dairy Sci, January 1, 2008; 91(1): 279 - 287. [Abstract] [Full Text] [PDF]

				H. M. Dann, M. P. Carter, K. W. Cotanch, C. S. Ballard, T. Takano, and R. J. Grant Effect of Partial Replacement of Forage Neutral Detergent Fiber with By-Product Neutral Detergent Fiber in Close-Up Diets on Periparturient Performance of Dairy Cows J Dairy Sci, April 1, 2007; 90(4): 1789 - 1801. [Abstract] [Full Text] [PDF]

				A. Rotger, A. Ferret, X. Manteca, J. L. R. de la Torre, and S. Calsamiglia Effects of dietary nonstructural carbohydrates and protein sources on feeding behavior of tethered heifers fed high-concentrate diets J Anim Sci, May 1, 2006; 84(5): 1197 - 1204. [Abstract] [Full Text] [PDF]

				J. M. Calberry, J. C. Plaizier, M. S. Einarson, and B. W. McBride Effects of Replacing Chopped Alfalfa Hay with Alfalfa Silage in a Total Mixed Ration on Production and Rumen Conditions of Lactating Dairy Cows J Dairy Sci, November 1, 2003; 86(11): 3611 - 3619. [Abstract] [Full Text] [PDF]

				I. R. Ipharraguerre and J. H. Clark Soyhulls as an Alternative Feed for Lactating Dairy Cows: A Review J Dairy Sci, April 1, 2003; 86(4): 1052 - 1073. [Abstract] [Full Text] [PDF]

				J. M. DeFrain, J. E. Shirley, E. C. Titgemeyer, A. F. Park, and R. T. Ethington A Pelleted Combination of Raw Soyhulls and Condensed Corn Steep Liquor for Lactating Dairy Cows J Dairy Sci, December 1, 2002; 85(12): 3403 - 3410. [Abstract] [Full Text] [PDF]

				I. R. Ipharraguerre, R. R. Ipharraguerre, and J. H. Clark Performance of Lactating Dairy Cows Fed Varying Amounts of Soyhulls as a Replacement for Corn Grain J Dairy Sci, November 1, 2002; 85(11): 2905 - 2912. [Abstract] [Full Text] [PDF]

				D. R. Ouellet, M. Demers, G. Zuur, G. E. Lobley, J. R. Seoane, J. V. Nolan, and H. Lapierre Effect of Dietary Fiber on Endogenous Nitrogen Flows in Lactating Dairy Cows J Dairy Sci, November 1, 2002; 85(11): 3013 - 3025. [Abstract] [Full Text] [PDF]

				J. A. Voelker, G. M. Burato, and M. S. Allen Effects of Pretrial Milk Yield on Responses of Feed Intake, Digestion, and Production to Dietary Forage Concentration J Dairy Sci, October 1, 2002; 85(10): 2650 - 2661. [Abstract] [Full Text] [PDF]

				J. L. Firkins, D. I. Harvatine, J. T. Sylvester, and M. L. Eastridge Lactation Performance by Dairy Cows Fed Wet Brewers Grains or Whole Cottonseed to Replace Forage J Dairy Sci, October 1, 2002; 85(10): 2662 - 2668. [Abstract] [Full Text] [PDF]

				D. I. Harvatine, J. E. Winkler, M. Devant-Guille, J. L. Firkins, N. R. St-Pierre, B. S. Oldick, and M. L. Eastridge Whole Linted Cottonseed as a Forage Substitute: Fiber Effectiveness and Digestion Kinetics J Dairy Sci, August 1, 2002; 85(8): 1988 - 1999. [Abstract] [Full Text] [PDF]