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Effects of age at calving, parity, year and season on reproductive
performance of dairy cattle in Tehran and Qazvin Provinces,
Iran |
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M.
Khodaei Motlagh*1, Z. Roohani2, A. Zare Shahne2
and M. Moradi2
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1Department of Animal Science, Faculty of Agriculture, Arak University,
Arak
38156-8-8349. Iran; 2Department of Animal Science, Faculty of
Agronomy and Animal Science, College of Agriculture and Natural
Resource, Tehran University, Iran
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| Abstract |
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This study was carried out
to evaluate the reproductive performances of Iranian
dairy cattle at Tehran and
Ghazvin
Provinces. Reproductive
traits included: calving interval, days open, and service per
conception. A total of 2500 cows were used in this trial. Some effective
factors were collected by the Animal Breeding Center of Iran from 1993
to 1998. Cows were classified into seven groups according to the age at
calving (22 to 23, 24 to 25, 35 to 36, 47 to 48, 59 to 60, 71 to 72 and
93 to 104 months respectively). The effect of age at calving, season,
year and parity on reproductive performance was significant (P<0.05).
Reproductive performance decreased from parity ≥ 6. Reproductive
performance during summer season was significantly lower than other
seasons, specially compared to winter. The result of this study
demonstrated that the reproductive performance decreased by increase in
age at calving, parity and warm season.
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Keywords:
Holstein; reproductive
performance; Qazvin;
Tehran;
Iran |
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To cite this article:
Motlagh MK, Z Roohani, AZ
Shahne and M Moradi, 2013.
Effects of age at calving,
parity, year and season on reproductive performance of dairy cattle in
Tehran and
Qazvin Provinces, Iran.
Res.
Opin. Anim. Vet. Sci., 3(10), 335-340. |
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