Feed efficiency differences and reranking in beef steers fed grower and finisher diets

Durunna, O. N., Mujibi, F. D. N., Goonewardene, L., Okine, E. K., Basarab, J. A., Wang, Z. and Moore, S. S. (2011) Feed efficiency differences and reranking in beef steers fed grower and finisher diets. Journal of Animal Science, 89 1: 158-167. doi:10.2527/jas.2009-2514


Author Durunna, O. N.
Mujibi, F. D. N.
Goonewardene, L.
Okine, E. K.
Basarab, J. A.
Wang, Z.
Moore, S. S.
Title Feed efficiency differences and reranking in beef steers fed grower and finisher diets
Journal name Journal of Animal Science   Check publisher's open access policy
ISSN 0021-8812
1525-3163
Publication date 2011-01
Year available 2010
Sub-type Article (original research)
DOI 10.2527/jas.2009-2514
Volume 89
Issue 1
Start page 158
End page 167
Total pages 10
Place of publication Savoy, IL, United States
Publisher American Society of Animal Science
Collection year 2012
Language eng
Formatted abstract This 3-yr study used 490 steers to determine whether feedlot steers changed their feed efficiency (FE) ranking when fed a grower diet, then a finisher diet. The steers were crossbreds and were between 5 to 7 mo of age. There were 2 feeding periods each year. Within each year, approximately 90 steers had their diet switched from a grower to a finisher diet (feed-swap group), whereas another 90 steers were fed either the grower (grower-fed group) or the finisher (finisher-fed group) diet throughout the feeding trial. Each feeding test lasted for a minimum of 10 wk, and all steers were fed ad libitum. Individual animal feed intakes were collected using the GrowSafe feeding system, and BW were measured every 2 wk. Residual feed intake (RFI), G:F, and Kleiber ratio (KR) were computed at the end of each feeding period. For each measure of efficiency, animals were classified as low, medium, or high based on 0.5 SD from the mean. The majority of steers did not maintain the previous efficiency class in the second period. Approximately 58, 51, and 51% of steers in the feed-swap group, finisher-fed group, and the grower-fed group, respectively, changed their RFI measure by 0.5 SD. A low rank correlation occurred in all test groups but was less in the feed-swap group. Spearman rank correlations between the 2 feeding periods in the feed-swap group were 0.33, 0.20, and 0.31 for RFI, G:F, and KR, respectively. Classifications based on G:F and KR showed that a greater number of steers (P < 0.05) in the feed-swap group did not maintain their FE class from 1 feeding regimen to the other, whereas classification based on RFI did not show any difference (P > 0.05) between the proportions of individuals that changed or maintained their FE class. In the groups without a feed-swap, there was no difference (P > 0.05) in the proportion of steers that changed or maintained the same FE class for all FE measures. Our results suggest that diet type and feeding period affect the FE ranking in beef steers. A feedlot diet is ideal for evaluating the FE potential of steers for feedlot profitability; however, we suggest that tests involving less dense diets should be examined in an effort to understand the relationships between FE and feeder profitability.
Keyword Beef cattle
Feed efficiency
Finisher diet
Grower diet
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status Non-UQ
Additional Notes Published online before print September 3, 2010

Document type: Journal Article
Sub-type: Article (original research)
Collections: Non HERDC
Queensland Alliance for Agriculture and Food Innovation
 
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Created: Fri, 03 Feb 2012, 15:52:27 EST by Stephen Moore on behalf of Qld Alliance for Agriculture and Food Innovation