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Author:
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García Ispierto, Irina; Bech Sàbat, Gregori; Serrano, Beatriz; Nogareda, Carmina; Almería, S.; Santolaria Blasco, Pilar; López Gatius, Fernando; Yániz, J. L.; Sanchez Nadal, J. A.
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Notes:
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The aim of this study was to determine if the factors affecting
the abortion rate in dairy herds with high incidence of
Neospora-associated abortions are different in pregnancies of
cows and heifers chronically infected with Neospora caninum.
In heifers (n = 229), an increase in the cumulative number of
days with a mean relative humidity (RH) lower than 60%
during the second trimester of gestation increases the risk of
abortion. Yet, the likelihood of abortion was 7.6 times lower
for pregnant heifers inseminated with Limousin bull semen,
compared with those inseminated with Holstein-Friesian bull
semen. In pregnancies of parous cows (n = 521), an increase
in rainfall and in the cumulative number of days with a mean
RH lower than 60% during the second trimester of gestation
increased the abortion rate. However, in contrast, an increase
in the lactation number produced a decrease in the abortion
rate, with a likelihood of abortion 4.8 times lower for pregnant
cows inseminated with Limousin bull semen, and three times
lower for those inseminated with Belgian Blue bull semen,
compared with dairy cows inseminated with Holstein-Friesian
bull semen. Finally, the likelihood of abortion was 3.2 times
lower for pregnancies of parous cows with low antibody titres
against N. caninum (6–30 units) as compared to those with
high antibody titres (‡30 units), whereas in heifers this variable
had no effect. The practical recommendations of the present
study include the control of the cow environment during the
second trimester of gestation, the priority of culling for parous
cows with higher antibody titres against N. caninum and the
insemination of Neospora-seropositive cows with semen from
the Limousin breed.
This work was supported by the Spanish CICYT, grants AGL2007-65521-C02-01 ⁄ GAN, AGL2007-65521-C02-02 ⁄ GAN. Serrano was supported by the Universidad de Zaragoza, grant OTRI 2007-182, and García-Ispierto and Bech-Sàbat were supported by FPU grants from the Ministerio de Educación y Ciencia, AP-2004-4279 and AP-2005-5378, respectively |
