Abstract #T198

# T198
Effect of feeding increasing amounts of beet pulp on weaned calf performance and digestion.
T. S. Dennis*1, F. X. Suarez-Mena1, G. J. Lascano2, T. M. Hill1, J. D. Quigley1, W. Hu1, R. L. Schlotterbeck1, 1Nurture Research Center, Provimi North America, Brookville, OH, 2Department of Animal and Veterinary Sciences, Clemson University, Clemson, SC.

Soluble fiber sources in calf feeds are commonly included to reduce costs compared with using traditional cereal grains as energy sources. Beet pulp (BP) contains relatively high concentrations of soluble fiber and pectin compared with other fibrous feed ingredients and has been shown as an acceptable replacement for corn in adult cow diets. However, limited information is available on BP digestibility and growth performance in young weaned calves. In this study, 48 male Holstein calves (60 d of age, 77 ± 2.2 kg initial BW) were group-fed (4 calves/pen) 95% concentrate, 5% chopped grass hay diets for 56 d. Pens were randomly assigned to 1 of 3 dietary treatments using textured grower mixes containing 0, 17, or 34% BP with 18% CP (DM basis). Body weights (BW), hip widths (HW), and body condition scores (BCS) were assessed at the beginning of the study and at 84 and 112 d of age. Dry matter intakes and refusals were recorded daily by pen. Digestion coefficients (dC) of the diets and microbial protein flows were estimated when calves were approximately 84 d of age. Fecal samples were collected daily from pen floors over a 7 d period to estimate apparent dC using acid-insoluble ash as a marker. Urine samples were collected from 2 calves/pen over 2 d and analyzed for purine derivatives to estimate microbial protein flow. Data were analyzed as a completely randomized design using the MIXED procedure of SAS with linear and quadratic polynomial contrasts and pen as the experimental unit. Average daily BW gain and HW change decreased linearly (P ≤ 0.01) and final HW decreased quadratically (P = 0.03) with increasing BP. Dry matter intake, feed efficiency (BW gain/DM intake), and BCS were similar among treatments. Dry matter, OM, CP, and starch dC decreased linearly (P ≤ 0.02) with increasing BP. Conversely, NDF and ADF dC increased linearly (P ≤ 0.04) with increasing BP. Estimates of urine output and microbial protein flow using purine derivatives did not differ among treatments but were highly variable. Under the conditions of this study, BP reduced growth by reducing diet DM, OM, CP, and starch digestibility in dairy calves from 2 to 4 mo of age.

Key Words: calf, soluble fiber, digestibility