Registro completo |
Provedor de dados: |
OAK
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País: |
Japan
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Título: |
Effects of heat stress on production, somatic cell score and conception rate in Holsteins
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Autores: |
Hagiya, Koichi
Hayasaka, Kiyoshi
Yamazaki, Takeshi
Shirai, Tatsuo
Osawa, Takefumi
Terawaki, Yoshinori
Nagamine, Yoshitaka
Masuda, Yutaka
Suzuki, Mitsuyoshi
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Data: |
2017
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Ano: |
2017
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Palavras-chave: |
Genetic correlation
Heat-stress
Holsteins
Temperature-humidity index (THI)
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Resumo: |
We examined the effects of heat stress (HS) on production traits, somatic cell score (SCS) and conception rate at first insemination (CR) in Holsteins in Japan. We used a total of 228242 records of milk, fat and protein yields, and SCS for the first three lactations, as well as of CR in heifers and in first- and second-lactation cows that had calved for the first time between 2000 and 2012. Records from 47 prefectural weather stations throughout Japan were used to calculate the temperature-humidity index (THI); areas were categorized into three regional groups: no HS (THI<72), mild HS (72THI<79), and moderate HS (THI79). Trait records from the three HS-region groups were treated as three different traits and trivariate animal models were used. The genetic correlations between milk yields from different HS groups were very high (0.91 to 0.99). Summer calving caused the greatest increase in SCS, and in the first and second lactations this increase became greater as THI increased. In cows, CR was affected by the interaction between HS group and insemination month: with summer and early autumn insemination, there was a reduction in CR, and it was much larger in the mild- and moderate-HS groups than in the no-HS group.
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Idioma: |
Inglês
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Identificador: |
http://ir.obihiro.ac.jp/dspace/handle/10322/4575
info:doi/10.1111/asj.12617
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Editor: |
Wiley-Blackwell
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Direitos: |
This is the peer reviewed version of the following article: Animal Science Journal: 88(1); JAN 2017; 3-10, which has been published in final form at http://doi.org/10.1111/asj.12617. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.
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