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oai:www.ideals.illinois.edu:2142/83559 2023-07-11 col_2142_5131 col_2142_14771 com_2142_5130 com_2142_685 com_2142_397

Darrel J. Kesler Steckler, Teresa Lynn 2015-09-25T21:08:11Z 2015-09-25T21:08:11Z 10000-01-01 2003 2003 "Enhancing reproductive efficiency in beef and dairy herds can be accomplished through synchronization regimes. Synchronization of heifers and cows with 0, 1, 2 or 4 mg of estradiol benzoate (EB) at the onset of the CIDR/PGF 2alpha protocol resulted in a cubic effect on heifer conception rates (P < 0.02; 0 mg-60%; 1 mg-45%; 2 mg-63%; 4 mg-40%) vs a positive linear effect on cow pregnancy rates (PR) (P < 0.05; 0 mg-46%; 1 mg-53%; 2 mg-55%; and 4 mg-63%). Inclusion of a timed Al improved PR in cows not observed in estrus. There were no differences in days to emergence and ovulation of a new follicular wave, ovulation rate and ovulated follicle size when EB (0 vs 4 mg; P > 0.05) was administered. More follicles classified as ""maintained"" were observed in the 0 mg group (P = 0.01; 0 mg-53%; 4 mg-0%). The effect of an IPI during and after synchronization with COSynch was determined; PR were not affected by early weaning (EW) or the EWxIPI interaction (P > 0.05), but was affected by IPI administration (P = 0.04; COSynch-32.4% vs COSynch+IPI-44.5%). Supplemental P4 during early gestation (d 5 to 14) did not improve PR (P = 0.91). The effect of an IPI during synchronization or at ET was examined; the transfer rate was 92% and PR for anestrous cows differed (P 0.05; OvSynch-50% vs OvSynch+IPI-59%). Administration of an IPI at ET did not improve PR (P = 0.55). New functional CL induced by hCG in cows that had spontaneous CL regression subsequent to ET resulted in the rescue of 3/6 pregnancies. Inclusion of a CIDR during synchronization in dairy cows with or without ovarian cysts (COD) was examined. Day 35 and 84 PR were: OvSynch+P4-81% and 67%, OvSynch-61% and 56%; OvSynch+P4+COD-44% and 33%; and OvSynch+COD-40% and 22%, respectively. All OvSynch+P4+COD (100%) cows ovulated versus 82% of the OvSynch+COD. The presence of cystic structures on d 28 (P 0.3; OvSynch+P4-6% vs OvSynch+P4+COD-22%). The novel data reported herein demonstrates that reproductive efficiency can be enhanced in beef and dairy herds through novel synchronization regimes." Made available in DSpace on 2015-09-25T21:08:11Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 3086186.pdf: 7030886 bytes, checksum: 26c91885f99641d489d7e505ba68470f (MD5) Previous issue date: 2003 Embargo set by: Seth Robbins for item 84840 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 140 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2003. http://hdl.handle.net/2142/83559 (MiAaPQ)AAI3086186 eng Agriculture, Animal Culture and Nutrition Methods to Synchronize Estrus, Enhance Pregnancy, and Rescue Embryos in Cattle text Animal Sciences Animal Sciences University of Illinois at Urbana-Champaign Dissertation Ph.D.