title: Influence of pressed beet pulp and concentrated separator by-product on intake, gain, efficiency of gain, and carcass composition of growing and finishing beef steers.
abstract: The objectives of this experiment were to determine a NE value for pressed beet pulp and the value of concentrated separator by-product (de-sugared molasses) as a ruminal N source in growing and finishing diets for beef cattle. One hundred forty-four cross-bred beef steers (282 +/- 23 kg of initial BW) were used in 2 experiments (growing and finishing). A randomized complete block design was used, with a 3 x 2 factorial arrangement of treatments (level of pressed beet pulp and inclusion of concentrated separator by-product) for both studies. Steers were blocked by BW and allotted randomly to 1 of 6 treatments. In the growing study, the control diet contained 49.5% corn, 31.5% corn silage, 10.0% alfalfa hay, and 9.0% supplement (DM basis). Pressed beet pulp replaced corn at 0, 20, or 40% of dietary DM, and concentrated separator by-product replaced corn and urea at 10% of dietary DM. The growing study lasted for 84 d. Initial BW was an average of 2-d BW after a 3-d, restricted (1.75% of BW) feeding of 50% alfalfa hay and 50% corn silage (DM basis), and final BW was an average of 2-d BW after a 3-d, restricted (1.75% of BW) feeding of 31.5% corn silage, 10.0% alfalfa hay, 25.0% dry-rolled corn, 20.0% pressed beet pulp, 5.0% concentrated separator by-product, and 8.5% supplement (DM basis). After the growing study, the steers were weighed (415 +/- 32 kg), rerandomized, and allotted to 1 of 6 finishing diets. The control diet for the finishing study included 45% dry-rolled corn, 40% high-moisture corn, 5% brome hay, 5% pressed beet pulp, and 5% supplement. Pressed beet pulp replaced high-moisture corn at 5.0, 12.5, and 20.0% of the dietary DM, and concentrated separator by-product replaced high-moisture corn and supplement at 10.0% of diet DM. Steers were slaughtered on d 83 or 98 of the study. In the growing study, the addition of pressed beet pulp to growing diets linearly decreased (P = 0.001) DMI and ADG and inclusion of 10% concentrated separator by-product decreased (P = 0.001) G:F. Increased levels of pressed beet pulp in the finishing diets caused a linear decrease (P = 0.001) in ADG and tended (P = 0.06 and 0.07 for kg/d and % of BW, respectively) to quadratically decrease DMI, whereas addition of concentrated separator by-product increased (P = 0.02 and 0.001 for kg/d and % of BW, respectively) DMI. Apparent NEg of pressed beet pulp was 94.2% of that of corn in the growing study and 81.5% of that of corn in the finishing study.
authors.affiliation: Department of Animal and Range Sciences, North Dakota State University, Fargo 58105, USA. Marc.Bauer@ndsu.edu
authors.forename: M L
authors.initials: ML
authors.lastname: Bauer
authors.forename: D E
authors.initials: DE
authors.lastname: Schimek
authors.forename: J J
authors.initials: JJ
authors.lastname: Reed
authors.forename: J S
authors.initials: JS
authors.lastname: Caton
authors.forename: P T
authors.initials: PT
authors.lastname: Berg
authors.forename: G P
authors.initials: GP
authors.lastname: Lardy
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D027461:Beta vulgaris; D001823:Body Composition / Q000187:drug effects* / Q000502:physiology; D002417:Cattle / Q000254:growth & development* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D002149:Energy Intake / Q000187:drug effects* / Q000502:physiology; D008297:Male; D009584:Nitrogen / Q000378:metabolism; D011897:Random Allocation; D012417:Rumen / Q000378:metabolism; D015430:Weight Gain / Q000187:drug effects*
chemical_list: D009584:Nitrogen