COMPARISON OF HOLSTEIN’S GENETIC EVALUATION FOR MILK PRODUCTION USING 305-DAY AND TEST - DAY MODELS

Q: How can I download an article?

To download an article from SID, first log in to the site, search for the article title, and click on the 'Download Article' option.

Q: How can I download an ISI article?

To download an ISI article on SID, enter the keyword or article title in the search bar, view the relevant results, click on the desired article, and select the 'Download Article' option.

Q: How can I access the SID database?

To access the SID database, visit SID.ir, create an account, and log in to access scientific resources.

Q: Is downloading articles from SID free?

Some articles on SID are available for free, while others require payment. Details are specified on the article's page.

FARHANGFAR H.; REZAEI H.

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

Journal Paper

Paper Information

Journal: Journal of Water and Soil Science Year:2007 | Volume:11 | Issue:40 (B) Page(s): 375-383

Download Full-Text

Persian Verion

View:

15,177

Download:

Cites:

Information Journal Paper

Title

COMPARISON OF HOLSTEIN’S GENETIC EVALUATION FOR MILK PRODUCTION USING 305-DAY AND TEST - DAY MODELS

Author(s)

FARHANGFAR H. | REZAEI H. | Issue Writer Certificate

Keywords

GENETIC EVALUATIONQ3

COVARIANCE FUNCTIONQ3

IRANIAN HOLSTEINSQ3

Abstract

A total of 179,460 monthly test-day milk records (thrice a day milking) obtained from 17,946 Iranian Holstein heifers distributed in 287 herds and calved from 1986 to 2001 were used to predict breeding value of animals. Monthly test-day milk production was analysed by applying a COVARIANCE FUNCTION in which the effects of herd -year -season of production (HYSOP), age at test day (covariate), additive genetic and permanent environmental effects were included. Orthogonal legendre polynomials up to order 5 (quartic) were also implemented in the covariance model to take account of the genetic and environmental aspects of milk production variation over the course of the lactation. In the present research, breeding values of individual animals based upon 305-day and monthly test-day milk yields were compared. The results indicated that ranking of ten top sires, dams as well as progenies changed as the GENETIC EVALUATION of animals switched from the traditional (based on 305-day milk yield) to the new method that was based on the COVARIANCE FUNCTION. Regression analysis of average breeding value of progenies on the first year of their calving showed that the amount of genetic trend obtained from the COVARIANCE FUNCTION for 305-day milk yield was greater than that of the 305-day model (11.607 vs. 3.860 Kg/year) over the period of 16 years of calving. The phenotypic trend for lactation milk yield was 92.97 Kg per year which was statistically significant. This finding indicates that a large proportion of annual increase of milk production of Holstein heifers in Iran has been due to environmental rather than genetic improvement.

Cites

THE ESTIMATION OF GENETIC PARAMETERS FOR MILK PRODUCTION TRAIT IN HOLSTEIN COWS IN MAHDASHT OF SARI USING TEST DAY RECORDS

References

Cite

APA: Copy

FARHANGFAR, H., & REZAEI, H.. (2007). COMPARISON OF HOLSTEIN’S GENETIC EVALUATION FOR MILK PRODUCTION USING 305-DAY AND TEST - DAY MODELS. WATER AND SOIL SCIENCE (JOURNAL OF SCIENCE AND TECHNOLOGY OF AGRICULTURE AND NATURAL RESOURCES), 11(40 (B)), 375-383. SID. https://sid.ir/paper/15042/en

Vancouver: Copy

FARHANGFAR H., REZAEI H.. COMPARISON OF HOLSTEIN’S GENETIC EVALUATION FOR MILK PRODUCTION USING 305-DAY AND TEST - DAY MODELS. WATER AND SOIL SCIENCE (JOURNAL OF SCIENCE AND TECHNOLOGY OF AGRICULTURE AND NATURAL RESOURCES)[Internet]. 2007;11(40 (B)):375-383. Available from: https://sid.ir/paper/15042/en

IEEE: Copy

H. FARHANGFAR, and H. REZAEI, “COMPARISON OF HOLSTEIN’S GENETIC EVALUATION FOR MILK PRODUCTION USING 305-DAY AND TEST - DAY MODELS,” WATER AND SOIL SCIENCE (JOURNAL OF SCIENCE AND TECHNOLOGY OF AGRICULTURE AND NATURAL RESOURCES), vol. 11, no. 40 (B), pp. 375–383, 2007, [Online]. Available: https://sid.ir/paper/15042/en

Related Journal Papers