An asymmetric distribution of the sexes within the left and right uterine horns has been described in multiple polytocous, laboratory species. A series of experiments were conducted to evaluate the sex ratio (% male) of calves gestated in the left and right uterine horns, as well as the sex ratio of embryos originating from the left and right ovaries of cattle. In Experiment 1, the sex ratio of calves and fetuses gestated in the left and right uterine horns was investigated. The sex ratio of calves and fetuses gestated in the right uterine horn was significantly higher compared with the sex ratio of calves and fetuses gestated in the left uterine horn. In addition, the sex ratio of the left and right uterine horns differed significantly from parity. In Experiment 2, embryo transfer data were analyzed in an effort to determine if sex-specific selection pressures were applied to embryos in the uterine horn of transfer. The sex ratio of ET calves born following transfer to the left and right uterine horns was not significantly different. Similarly, the overall sex ratio of calves born in this experiment did not differ significantly from parity. The sex ratio of embryos recovered from the left and right uterine horns of superovulated beef cows was evaluated in Experiment 3. The proportion of male embryos collected from the right uterine horns was significantly greater than from the left uterine horns. The sex ratio of embryos recovered from the uterine horns in this experiment was not different from parity. In an effort to determine the role of interovarian communications in the sex selection process, the sex ratio of embryos recovered from unilaterally ovariectomized superovulated beef heifers was investigated in Experiment 4. The sex ratios of embryos recovered from left- and right-ovary intact heifers were not significantly different. In Experiment 5, the sex ratio of IVP embryos was evaluated. The sex ratio of the IVP embryos was significantly lower than parity and was not different between ovary of origin. In addition, length of time in maturation was determined not to influence the sex ratio.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-01162007-180732 |
| Date | 22 January 2007 |
| Creators | Hylan, Darin Alan |
| Contributors | Earle Pope, Dale Paccamonti, Robert Godke, Claudia Husseneder, John Lynn |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-01162007-180732/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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