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Journal of Cell and Animal Biology Vol. 1(4), 066-070, November, 2007
ISSN 1996-0867
© 2007 Academic Journals
Full Length Research Paper
Within-herd phenotypic
and genetic trend lines for milk yield in Holstein-Friesian dairy cows
Khalid Javed*, Masroor Ellahi Babar and Muhammad Abdullah
Department Livestock Production, University of Veterinary and Animal
Sciences, Lahore, Pakistan.
*Corresponding author. E-mail:
drjavedkhalid@yahoo.com.
Accepted 29 October, 2007
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A total of 937 pedigree,
breeding and performance records of 567 Friesian cows at the Livestock
Experiment Station Bhunikey Dist. Kasur (Pakistan) spanning the years
1982-2001 were analyzed using Best Linear Unbiased Predictions
procedure. Individual animal models were fitted to total milk yield from
all lactations to estimate breeding values by Restricted Maximum
Likelihood methodology. Milk yield and lactation length averaged 3391.66
± 137.97 kg and 278.40 ± 90.17 days, respectively. The estimated
breeding values for milk yield ranged from –354 to 503 kg. The
corresponding values for the standing herd ranged from –209 to 294 kg.
The genetic trend for milk yield was slightly positive indicating that
the sires used during the last 20 years were of better breeding values.
Phenotypic reduction in milk yield over time was observed, a probable
reflection of the inability of the cows to adapt to the local
environment and other environmental inadequacies.
Key words: Friesian,
pedigree, genetic, phenotypic, trend lines, Estimated Breeding Value (EBV),
animal model |
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