| Seasonal pattern of mortality and relationships between mortality and temperature-humidity index in dairy cows. | |
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MedLine Citation:
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PMID: 19620660 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The 2 studies described investigated seasonal variations of mortality and temperature-humidity index (THI)-mortality relationships in dairy cows. Mortality data were extracted from the Italian Bovine Spongiform Encephalopathy databases, which contain records on cows older than 24 mo that died on a farm from all causes (98% of total records), were slaughtered in an emergency state, or were sent for normal slaughter but were sick in the preslaughter inspection (2% of total records). Both studies evaluated mortality data during a 6-yr period (2002 to 2007). The seasonal pattern study was conducted throughout Italy and was based on 320,120 deaths. An association between season and deaths was found for all 6 yr. Summer and spring were the seasons with the highest and lowest frequency of deaths (15,773.3 +/- 2,861 and 11,619.3 +/- 792.3), respectively, and within summer months, the number of deaths in July and August (5,435 +/- 284 and 5,756 +/- 676.2, respectively) was higher than in June (4,839 +/- 344.8). The THI-mortality relationships study was carried out only for deaths (51,240) reported for the Lombardia and Emilia Romagna regions. For this study, the mortality databases were integrated with THI data, which were calculated by using data from 73 weather stations. Each farm where deaths were recorded was assigned the THI values (maximum and minimum) calculated at the closest weather station for each day the events (deaths) were reported. Analysis of data indicated that approximate THI values of 80 and 70 were the maximum and minimum THI, respectively, above which the number of deaths in dairy farms starts to increase. Maximum and minimum THI values of 87 and 77 were the upper critical THI above which the risk of death for dairy cows becomes maximum. This study defined quantitative relationships between mortality risk and THI in dairy cows and may help to provide emergency interventions and mitigation measures, which may ensure survival of dairy cows and reduce replacement costs associated with heat stress-related mortality. |
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Authors:
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A Vitali; M Segnalini; L Bertocchi; U Bernabucci; A Nardone; N Lacetera |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Journal of dairy science Volume: 92 ISSN: 1525-3198 ISO Abbreviation: J. Dairy Sci. Publication Date: 2009 Aug |
Date Detail:
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Created Date: 2009-07-21 Completed Date: 2009-10-19 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 2985126R Medline TA: J Dairy Sci Country: United States |
Other Details:
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Languages: eng Pagination: 3781-90 Citation Subset: IM |
Affiliation:
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Dipartimento di Produzioni Animali, Università della Tuscia, Viterbo, Italy. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Analysis of Variance Animals Cattle / physiology* Female Hot Temperature* Humidity* Italy / epidemiology Least-Squares Analysis Mortality* Risk Factors Seasons* |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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