Document Type

Thesis - University Access Only

Award Date

2006

Degree Name

Master of Science (MS)

Department / School

Animal Science

Abstract

Three experiments were conducted to determine the effects of limit-feeding rolled barley based diets as an alternative to hay for beef cattle. Treatments were: 1) hay (Hay); 2) barley replacing hay at approximately 30% of the diet (LB); 3) barley replacing hay at approximately 70% of the diet (HB). In Exp. 1, ninety-six gestating cows (average BW = 642 ± 17 kg) were stratified by BW, age, and BCS and randomly allotted to one of twelve pens ( 4 pens/treatment). In Exp. 2, 106 gestating cows and heifers (heifer and cow BW = 505 ± 34 kg and 674 ± 64 kg, respectively) were blocked by age and randomly allotted to one of twelve pens (4 pens/treatment). Alfalfa hay was used for the Hay treatment in Exp. 1 and grass hay was used in Exp. 2. Diets were fed for approximately the last 90 d of gestation. All diets were formulated to meet nutritional requirements and were changed monthly to account for changing cow requirements during late gestation. In both Exp. 1 and 2, the cows on the Barley diets (LB and HB) gained more weight (P < 0.01) than the cows on the Hay diet. Similarly, cows consuming the Barley diets had greater BCS change (P < 0.01) than cows consuming the Hay diet. Pregnancy rates were not affected (P > 0.10) by treatment in either experiment. Calf birth weights, measured only in Exp. 2, were not different (P > 0.10) between treatments. Feed costs were lowered in Exp. 1 by limit-feeding barley compared to feeding alfalfa hay, but in Exp. 2 it was cheaper to feed the grass hay as opposed to limit-feeding barley. In Exp. 3, six cross-bred steers (average BW = 464 ± 18 kg) were used in a replicated 3x3 Latin Square design to determine the effects of limit-feeding barley on total tract digestibility of DM, OM, CP, ADF, NDF, and GE. The feeds in Exp. 3 were the same as Exp. 2. Digestibility ofDM, OM, and GE was increased (P < 0.01) for the Barley diets compared to the Hay diet, and the HB had a higher digestibility (P < 0.01) ofDM, OM, and GE than the LB treatment. Barley diets had higher (P < 0.01) CP digestibility than the Hay diets. The digestibility of NDF and ADF were not affected (P > 0.10) by treatment. In conclusion, limit-feeding barley can maintain cow BW and BCS through late gestation without having any detrimental effects on pregnancy rates, calf birth weights, or fiber digestion. Barley may be used to replace hay in diets for gestating cows when economically warranted.

Library of Congress Subject Headings

Beef cattle -- Feeding and feeds

Barley as feed

Format

application/pdf

Number of Pages

62

Publisher

South Dakota State University

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