Loading...
Trends in milk production, calving rate and survival of cows in 14 Irish dairy herds as a result of the introgression of Holstein-Friesian genes
Evans, R. D. Dillon, Pat Buckley, Frank Berry, Donagh Wallace, Michael Ducrocq, V. Garrick, Dorian J.
Evans, R. D.
Dillon, Pat
Buckley, Frank
Berry, Donagh
Wallace, Michael
Ducrocq, V.
Garrick, Dorian J.
Citations
Altmetric:
Date
2006-08
Collections
Files
Research Projects
Organizational Units
Journal Issue
Citation
R. D. Evans, P. Dillon, F. Buckley, D. P. Berry, M. Wallace, V. Ducrocq and D. J. Garrick (2006). Trends in milk production, calving rate and survival of cows in 14 Irish dairy herds as a result of the introgression of Holstein-Friesian genes. Animal Science, 82, pp 423-433. doi:10.1079/ASC200660.
Abstract
Trends in milk production, calving rates, and survival were monitored on a potential 5580 primiparous and multiparous Holstein-Friesian dairy cows across 14 Irish seasonal spring-calving dairy farms between the years 1990 and 2001. Over this period calving rate to first service (CALV1) reduced by 0·96% per year (55 to 44%; P< 0·001), calving rate to first and second service (CALV12) reduced by 0·84% per year ( 77 to 70%; P< 0·001) and herd average parity number reduced by 0·10 lactation per year (4·3 to 3·5; P<0·001). The proportion of North American Holstein Friesian (NAHF) genes in the cows increased by 5·5% per year (8 to 63%; P<0·001), while pedigree index for milk yield (PIMILK) of the cows increased by 25 kg per year ( P<0·001). The predicted difference of the sires of the cows for calving interval and survival increased by 0·5 days (P<0·001) and reduced by 0·12% ( P<0·001) per year, respectively. A negative association was found between increased phenotypic milk yield, NAHF and PIMILK and reduced calving rates as assessed by CALV1 and CALV12. Increased proportion of NAHF genes exhibited a negative effect on survival ( P<0·001) whereas increased levels of heterosis had a positive impact on survival ( P<0·001). The results of the present study indicate that in seasonal calving herds in Ireland a need for direct selection on traits related to fertility and survival is required to arrest and reverse the declining trends in calving rates and survival.