| Effect of shade area on performance and welfare of short fed feedlot cattle. | |
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MedLine Citation:
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PMID: 21478450 Owner: NLM Status: Publisher |
Abstract/OtherAbstract:
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One hundred twenty-six Black Angus yearling heifers were used in a 119-d study to assess the effect of shade allocation (0 m(2)/animal, 2.0 m(2)/animal, 3.3 m(2)/animal, 4.7 m(2)/animal) on performance and welfare of feedlot cattle. Shade treatments were replicated 4 times and no-shade was replicated twice. Shade was provided by 70% solar block shade cloth, attached to a 4-m high frame with north-south orientation. Cattle were randomly allocated to a pen (9/pen; 19.2 m(2)/animal) within treatment. Performance was assessed using DMI, G:F, ADG, HCW, dressing percentage and rump fat depth (P8). Climatic data (ambient and black globe temperature, solar radiation, wind speed, relative humidity and rainfall) were recorded. From these data the heat load index (HLI) was calculated. When the daily maximum heat load index (HLI(Max)) < 86, individual panting score (0 = no panting, and 4 = open mouth, tongue extended), animal location (eating, drinking, under shade), animal posture (standing or lying) were collected at 0600, 1200 and 1800 h. When HLI(Max) was( )≥ 86 these data were collected every 2 h between 0600 and 1800 h. Feed intake was recorded weekly and water intake recorded daily on a pen basis. When HLI(Max )was( )≥ 86 mean panting score (MPS: mean of animals within treatment) was greatest (1.02; P < 0.001) for unshaded cattle compared with shade treatments, which were similar (0.82; P = 0.81). During heat waves the MPS of unshaded cattle was greater (2.66; P < 0.001) than for shaded cattle. The MPS of 2.0-m(2 )cattle (2.43 ± 0.13) was greater (P < 0.001) than the 3.3- (2.11 ± 0.13) and 4.7-m(2) cattle (2.03 ± 0.13). The MPS of the 3.3- and 4.7-m(2) cattle were similar (P = 0.09). Number standing were similar (P = 0.98) between unshaded and the 2.0-m(2) treatment at 4.75 and 4.76 animals/pen respectively. Fewer (P < 0.0001) were standing in the 3.3-m(2) (4.19 animals/pen) and 4.7-m(2) (4.06 animals/pen) treatments. Fewer (P = 0.004) cattle were under the 2.0-m(2) shade (47.1%) compared with the 3.3- (53.7%) and 4.7-m(2) (53.6%) shade. Unshaded cattle had the lowest (0.085 ± 0.006) G:F ratio (P = 0.01) followed by the 4.7-m(2) cattle (0.104 ± 0.006; P ≤ 0.001). There was no difference (P = 0.12) between the 2.0- and 3.3-m(2) treatments. There were no differences (P > 0.10) for final BW, HCW, dressing percentage and P8. Cattle with access to shade had lower panting scores, which suggests improved welfare, and had better feed efficiency. Shade reduced the intensity of heat load, but did not fully remove the impact. |
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Authors:
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M L Sullivan; A J Cawdell-Smith; T L Mader; J B Gaughan |
Publication Detail:
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Type: JOURNAL ARTICLE Date: 2011-4-8 |
Journal Detail:
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Title: Journal of animal science Volume: - ISSN: 1525-3163 ISO Abbreviation: - Publication Date: 2011 Apr |
Date Detail:
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Created Date: 2011-4-11 Completed Date: - Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 8003002 Medline TA: J Anim Sci Country: - |
Other Details:
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Languages: ENG Pagination: - Citation Subset: - |
Affiliation:
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School of Agriculture and Food Sciences, The University of Queensland, Gatton, Qld. Australia 4343. |
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From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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