Document Type

Thesis - University Access Only

Award Date

2001

Degree Name

Master of Science (MS)

Department / School

Animal Science

Abstract

Experiments were conducted to determine the effectiveness of soybean hulls as an energy source (Exp. 1) and the effects of trace mineral inclusion management (Exp. 2) on ADG, DMI, gain/feed (G/F), morbidity rate (MR) and mineral status of newly received feeder calves. Experiment 1 consisted of previously weaned (PW) and non-weaned (NW) steers fed diets based on oat silage, supplement and either: (CRN) 45% rolled com or (SBH) 45% soybean hulls. Only the CRN diet required supplemental Cu and Zn to meet NRC requirements for these nutrients. Experiment 2 treatments were: 1) inclusion of a Cu and Zn supplement as percent of the diet or 2) inclusion at a fixed amount to meet the gram daily requirement of growing calves. Liver biopsy and blood samples were collected at initiation of the trials and -after 28 d (Exp. I) and 27 d (Exp. 2). In Exp. 1, steers fed CRN had lower ADG (P < 0.10) and DMI (P < 0.01) through d 28, lower DMI (P < 0.01) overall and lower G/F (P < 0.05). The PW steers had a higher ADG and DMI through d 28 (P < 0.10). The DMI through d 28 was affected by a diet x weaning group interaction (P < 0.10). Liver Cu concentrations decreased (P < 0.01) by 22% in steers fed SBH and were unchanged in steers fed CRN. The PW steers had a greater loss of liver Cu compared to NW (P < 0.01 ). Liver Zn concentration was affected by a diet x weaning group interaction (P < 0.05). Morbidity rate (6.5%) was not affected by any treatments. Exp. 2, ADG, G/F and MR were not affected by diet. Cumulative DMI tended to be greater (P < 0.10) in TDR diets. Steers receiving PER treatments tended (P < 0.11) to have less decrease in hepatic Zn. These results suggest SBH have the potential to stimulate DMI, and that Cu and Zn availability from SBH is limited. Increasing diet density of Cu and Zn to levels in this study did not improve performance or MR.

Library of Congress Subject Headings

Calves -- Feeding and feeds Soybean as feed Minerals in animal nutrition Feed additives

Format

application/pdf

Number of Pages

71

Publisher

South Dakota State University

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