Evaluation of the precision-fed rooster assay for detecting effects of supplemental enzymes on metabolizable energy
The precision-fed rooster assay has been used extensively to determine nitrogen-corrected true metabolizable energy (TMEn) of feed ingredients for poultry. However, this assay has not generally been used to evaluate effects of supplemental enzymes for this purpose. Therefore, 2 precision-fed rooster...
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Published in | Poultry science Vol. 101; no. 2; p. 101603 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
England
Elsevier Inc
01.02.2022
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | The precision-fed rooster assay has been used extensively to determine nitrogen-corrected true metabolizable energy (TMEn) of feed ingredients for poultry. However, this assay has not generally been used to evaluate effects of supplemental enzymes for this purpose. Therefore, 2 precision-fed rooster assays were conducted to evaluate several different carbohydrase enzymes on TMEn for a corn/soybean meal diet, a pearled barley diet, and diets containing different inclusion levels of rye/corn. In both rooster assays, Single Comb White Leghorn roosters were fasted for 26 h and then crop intubated with either 25 or 30 g of the test diets, depending on the assay. Excreta were then collected quantitatively for 48 h after feeding. In the first rooster assay with 56 birds, 6 carbohydrase combinations and/or levels (xylanase/alpha-galactosidase were evaluated using a corn/soybean meal control diet. All carbohydrase additions either numerically or significantly (P < 0.05) increased TMEn and the mean increase for the enzyme treatments was 66 kcal/kg DM compared with the corn/soybean meal control diet. The second assay consisted of twenty dietary treatments; 120 roosters were crop-intubated with 25 g of diets that were composed of 100% barley, 100% rye, 50% rye: 50% corn, or 25% rye: 75% corn. The diets were fed with and without inclusion of 2 different levels of either β-glucanase, xylanase, or a multi-carbohydrase combination. Both β-glucanase and the multi-carbohydrase significantly (P < 0.05) increased TMEn of the 100% barley diet, with the multi-carbohydrase increasing it from 3,722 to 4,086 kcal/kg DM at the highest inclusion rate. The xylanase and multi-carbohydrase either numerically or significantly (P < 0.05) increased TMEn of the 100% rye diet, with the multi-carbohydrase increasing it from 3,581 to 3,909 kcal/kg DM at the highest inclusion rate. The magnitude of enzyme response decreased as the level of rye in the diets decreased. Overall, results of this study indicated that the precision-fed rooster assay can detect effects of enzymes, primarily carbohydase, on TMEn of diets containing corn/soybean meal, pearled barley, and/or rye. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0032-5791 1525-3171 |
DOI: | 10.1016/j.psj.2021.101603 |