Trends in the reproductive performance of Holstein dairy cows in Iran.

Tropical Animal Health and Production
Hadi AtashiAmir Akhlaghi

Abstract

The study was undertaken to determine the trends in the reproductive performance of Holstein dairy cows in Iran during 1994 to 2008. Reproductive performance data for 528,034 lactations of 246,132 cows in 1,822 Holstein dairy herds of Iran were used. The potential effect of calving season, herd, parity, calving year, as well as herd size and 305-day milk production on reproductive performance traits was investigated using multiple regression models. The least squares means of age at first calving decreased by 3.1 (± 0.06) days per year from 806.5 (± 96.3) days in 1994 to 788 (± 89.9) days in 2008. The least squares means of calving interval increased 1.02 (± 0.03) days per year from 394.1 (± 65) days in 1994 to 413.2 (± 81) days in 2008. Greater 305-day milk production was associated with an average increase of 6.55 (± 0.08) days in calving interval per 1,000-kg increase in milk yield. Larger herd size was associated with an average decrease of 0.22 (± 0.02) days in calving interval per 50 cows per herd. The mean number of days dry was 88.6 (± 51.3) days and increased by 0.82 (± 0.02) days per year. In conclusion, reproductive performance in Holstein dairy herds has generally decreased, whereas herd size and milk production hav...Continue Reading

References

Oct 1, 1990·Journal of Dairy Science·R O HarrisonA E Freeman
Oct 1, 1993·Journal of Dairy Science·R L Nebel, M L McGilliard
Jun 22, 2001·Journal of Dairy Science·M C Lucy
Feb 28, 2002·Journal of Dairy Science·S P WashburnA J McAllister
Feb 15, 2003·Animal Reproduction Science·P J Rajala-Schultz, G S Frazer
Sep 18, 2004·Journal of Dairy Science·O González-RecioR Alenda
Mar 2, 2005·Journal of Dairy Science·F MigliorB J Van Doormaal
Feb 14, 2007·Acta Veterinaria Scandinavica·Arne Ola Refsdal
Feb 6, 2009·Tropical Animal Health and Production·Maryam Ansari-LariMahdie Reiszadeh
Apr 8, 2010·Tropical Animal Health and Production·Maryam Ansari-LariHasan Nategh Ahmadi
Oct 5, 2010·Tropical Animal Health and Production·Berhanu YalewGebeyehu Goshu
Jul 21, 2011·Tropical Animal Health and Production·Sonia Maria Ataide MacielFrederick Wilhelm Cornelius Neser

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