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VARIANCE COMPONENT ESTIMATION FOR REPRODUCTIVE TRAITS AND ANALYSES OF MYOFIBRILLAR PROTEINS AND AGE AT PUBERTY IN ANGUS BEEF CATTLE DIVERGENTLY SELECTED FOR BLOOD SERUM INSULIN-LIKE GROWTH FACTOR I CONCENTRATION

Yilmaz, Ahmet
http://rave.ohiolink.edu/etdc/view?acc_num=osu1041608790

Abstract Details

2003, Doctor of Philosophy, Ohio State University, Animal Science.
The first objective of this study was to obtain (co)variance component estimates for reproductive traits of beef cattle. Heritabilities for insulin-like growth factor I (IGF-I) concentration of three blood samples collected at d 28, 42, and 56 of the 140-d postweaning test, which are abbreviated as IGF28, IGF42, and IGF56, espectively, and mean IGF-I were 0.32, 0.34, 0.30, and 0.32, respectively. Heritabilities for scrotal circumference, percent sperm motility, percent normal sperm cells, age of heifers at first calving, and calving rate were 0.51, 0.09, 0.43, 0.26, and 0.13, respectively. The calving rate data were entered as either 1 (if conceived) or 100 (if not conceived). Additive genetic correlations of scrotal circumference, percent motile sperm cells, and calving rate with mean IGF-I concentration were 0.35, 0.43, and –0.41, respectively. These results suggest that selection for increased serum IGF-I concentration should increase scrotal circumference, percent motile sperm cells, and calving rate. The second objective in this study was to examine effects of high or low blood serum IGF-I concentration on age of heifers at puberty. Results of a progesterone assay showed that age at puberty did not differ between heifers in the high and low IGF-I selection lines. A cubic relationship existed between age at puberty and mean IGF-I concentration. Residual correlations of age at puberty with IGF-I measurements tended to be negative and nonsignificant. The third objective of this study was to examine effects of high or low blood serum IGF-I concentration on expression of myofibrillar proteins. Troponin C levels were higher in the high IGF-I line bulls and myosin light chain 2 levels were higher in the low IGF-I line bulls. Although their levels did not differ between the high and low IGF-I lines, desmin and the 32 kDa protein had significant correlations with IGF-I concentration. Coefficients for the quadratic regression of density of desmin on IGF28, IGF42, and mean IGF-I were significant. Cubic relationships existed between density of 32 kDa protein and IGF56 and mean IGF-I. Results from this study indicate that serum IGF-I concentrations are genetically correlated with reproductive traits, there are some IGF-I selection line effects on expression of myofibrillar proteins, and selection for blood serum IGF-I does not change age of heifers at puberty.
Michael Davis (Advisor)
177 p.
Biology, Genetics
cattle; genetics; igf; reproduction; breeding

Recommended Citations

Citations

  • Yilmaz, A. (2003). VARIANCE COMPONENT ESTIMATION FOR REPRODUCTIVE TRAITS AND ANALYSES OF MYOFIBRILLAR PROTEINS AND AGE AT PUBERTY IN ANGUS BEEF CATTLE DIVERGENTLY SELECTED FOR BLOOD SERUM INSULIN-LIKE GROWTH FACTOR I CONCENTRATION [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1041608790

    APA Style (7th edition)

  • Yilmaz, Ahmet. VARIANCE COMPONENT ESTIMATION FOR REPRODUCTIVE TRAITS AND ANALYSES OF MYOFIBRILLAR PROTEINS AND AGE AT PUBERTY IN ANGUS BEEF CATTLE DIVERGENTLY SELECTED FOR BLOOD SERUM INSULIN-LIKE GROWTH FACTOR I CONCENTRATION. 2003. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1041608790.

    MLA Style (8th edition)

  • Yilmaz, Ahmet. "VARIANCE COMPONENT ESTIMATION FOR REPRODUCTIVE TRAITS AND ANALYSES OF MYOFIBRILLAR PROTEINS AND AGE AT PUBERTY IN ANGUS BEEF CATTLE DIVERGENTLY SELECTED FOR BLOOD SERUM INSULIN-LIKE GROWTH FACTOR I CONCENTRATION." Doctoral dissertation, Ohio State University, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=osu1041608790

    Chicago Manual of Style (17th edition)

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