INVESTIGATION INTO THE EFFECT OF INCONSISTENCY OF (CO) VARIANCE MATRICES ON SELECTION INDEX

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JOUZI SHEKALGOURABI S.; SHAD PARVAR ABD ALAHAD

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Journal: Journal of Water and Soil Science Year:2009 | Volume:13 | Issue:48 Page(s): 187-194

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Title

INVESTIGATION INTO THE EFFECT OF INCONSISTENCY OF (CO) VARIANCE MATRICES ON SELECTION INDEX

Author(s)

JOUZI SHEKALGOURABI S. | SHAD PARVAR ABD ALAHAD | Issue Writer Certificate

Keywords

SELECTION INDEXQ3

INCONSISTENCYQ3

BENDINGQ3

REPEATED RECORDQ3

Abstract

In SELECTION INDEX procedure, phenotype and genetic (co) variance matrices of traits are used for calculating different genetic parameters like index coefficients, index variance, genetic gain in selection goal and selection accuracy. Sometimes, it is possible that these matrices become inconsistent or they are not positive, nor definite. In the current study, for investigation of the effect of INCONSISTENCY of (co) variance matrices on the results of SELECTION INDEX procedure, 6 kinds of different selection indices: milk production (Milk) , fat percentage of milk (fat%) and herd life (HL) in selection goal were constructed The first to third indices included Milk, fat% and one of the type traits, i.e. rear udder height (Ruh), front teat placement (Ftp) or front udder attachment (Fua) respectively, as correlated traits with herd life. The fourth index included productive traits and the three mentioned type traits altogether, and the fifth and sixth indices as reduced indices, included milk production and fat percentage and just milk production, respectively. Also, the results of using mean of 3 individual records were taken into account. All of calculations were done for both consistent and inconsistent matrices. For making consistency in inconsistent matrices, “bending” method was used. Results showed that the use of inconsistent matrices in SELECTION INDEX calculations will lead to wrong selections and will decrease genetic gain. This conclusion was independent of different economic conditions of production system in different years. When using consistent matrices, index 4, that had the most information from selection goal, was the best index.

Cites

DESIGNING OF OPTIMUM SELECTION INDEX FOR AFSHARI SHEEP BREEDING UNDER RURAL PRODUCTION SYSTEM

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APA: Copy

JOUZI SHEKALGOURABI, S., & SHAD PARVAR, ABD ALAHAD. (2009). INVESTIGATION INTO THE EFFECT OF INCONSISTENCY OF (CO) VARIANCE MATRICES ON SELECTION INDEX. WATER AND SOIL SCIENCE (JOURNAL OF SCIENCE AND TECHNOLOGY OF AGRICULTURE AND NATURAL RESOURCES), 13(48), 187-194. SID. https://sid.ir/paper/14683/en

Vancouver: Copy

JOUZI SHEKALGOURABI S., SHAD PARVAR ABD ALAHAD. INVESTIGATION INTO THE EFFECT OF INCONSISTENCY OF (CO) VARIANCE MATRICES ON SELECTION INDEX. WATER AND SOIL SCIENCE (JOURNAL OF SCIENCE AND TECHNOLOGY OF AGRICULTURE AND NATURAL RESOURCES)[Internet]. 2009;13(48):187-194. Available from: https://sid.ir/paper/14683/en

IEEE: Copy

S. JOUZI SHEKALGOURABI, and ABD ALAHAD SHAD PARVAR, “INVESTIGATION INTO THE EFFECT OF INCONSISTENCY OF (CO) VARIANCE MATRICES ON SELECTION INDEX,” WATER AND SOIL SCIENCE (JOURNAL OF SCIENCE AND TECHNOLOGY OF AGRICULTURE AND NATURAL RESOURCES), vol. 13, no. 48, pp. 187–194, 2009, [Online]. Available: https://sid.ir/paper/14683/en

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