Inaugural ASAS–CAAV Asia Pacif ic Rim Conference Abstracts

T233 The effects of sire and breed on cleavage ratesof oocytes fertilized in vitro with sex-sorted semen. B. R. Sessions* 1 , J.Collier 1 , K. Perry 1 , B. A. Hicks 2 , and K. L. White 1 , 1 Department of Animal,Dairy, and Veterinary Sciences and Center for Integrated Biosystems, UtahState University, Logan, UT, USA, 2 J.R. Simplot Company Cattle ReproductionFacility, Boise, ID, USA.Sperm sorting is an efficient method to isolate sperm carrying only the Xchromosome and allows the dairy industry to determine the sex of the offspringin order to improve breeding programs and herd management. However, manylimiting factors prevent the widespread use of sex-sorted semen in traditionalartificial insemination programs. Optimizing sex-sorted semen for in vitrofertilization (IVF) would provide an avenue to improve the poor fertilizationrates associated with the typical method of artificial insemination. Matureoocytes were fertilized in vitro with sexed semen from different sires fromdifferent breeds with differing heparin concentrations in order to determinewhich variable had the greatest effect on IVF success rates: SAS was used tofit 2 logistic regression models to the data. The first model fit illustrates that thechoice of sire has a greater effect on cleavage rates than does optimization ofheparin concentration. The second model fit demonstrates that a significantlylower cleavage rate is associated with using a Jersey sire instead of a Holsteinsire at 3 of the 4 levels of heparin concentration. The data demonstrate thatthe choice of sire, in particular, the breed of sire utilized for IVF, is critical formaximizing cleavage rates.Key Words: bovine, in vitro fertilization, sexed semenT234 Season of feed intake testing affects genetic parameterestimation in residual feed intake evaluations. F. D. N. Mujibi and S. S.Moore*, Department of Agricultural, Food and Nutritional Science, Universityof Alberta, Edmonton, AB, Canada.In order to assess whether testing for feed intake in the fall and winter resultedin differences in the expected feed intake and subsequently if this affectedanimal residual feed intake (RFI) ranking and EBV accuracy, a group of 378young beef steers were tested for feed intake over a period of 3 yr. Two cohortswere evaluated in each year, one in the fall and one in the winter, with testsspanning approximately 90 d. All animals tested for feed intake in the fall wereallocated to group 1, whereas those tested in the winter were allocated to group2. A typical high-energy feedlot diet was fed ad libitum. Individual animal RFIwas obtained as the difference between standardized DMI and expected feedintake (EFI), which was obtained by regressing DMI on average daily gainand metabolic weight. When EFI was calculated within each season group, theRFI was designated as RFIS, whereas when calculated conventionally acrossall cohorts irrespective of season, it was designated as RFIC. Following REMLestimation of genetic parameters, heritability estimates for RFIS were highercompared to RFIC. Rank correlations (genetic and phenotypic) between RFISand RFIC were high (r ≥ 0.94), implying minimal re-ranking of animals withinthe RFI hierarchy. Accuracy of EBV was higher for RFIS compared with RFIC.These results suggest that effect of season should be considered for adjustmentwhen predicting EFI, especially when feed intake data are collected in fall andwinter seasons.Key Words: beef cattle, feed efficiency, residual feed intakeT235 Identification of candidate markers on BTA14 undermilk production trait quantitative trait loci in Holstein. E. Marques, J.Grant, Z. Wang, P. Stothard, G. Plastow, and S. S. Moore*, Department ofAgricultural, Food and Nutritional Science, University of Alberta, Edmonton,AB, Canada.The objective of this study was to identify single locus polymorphisms underQTL affecting milk production traits after accounting for the effect of DGAT1.Linkage disequilibrium information from 502 SNP was used to select markersfor a QTL scan on bovine chromosome 14 for milk production traits in 321Holstein animals. DGAT1 genotype information was used as a covariate in theanalysis in order to account for the major effect this gene has on productiontraits in dairy cattle. Results show a putative milk peak at 42 cM and 61 cM,both at P < 0.10; a fat yield peak at 42 cM and 63 cM, both at P < 0.05; aprotein yield peak at 42 cM (P < 0.01) and 84 cM (P < 0.05); fat percent peaksat 3 cM (P < 0.01) and 29 cM (P < 0.05); and a protein percent peak at 4 cM(P < 0.05). Once QTL positions were established, allele substitution effectsfor all markers were evaluated using the same statistical model. Overlayinginformation between QTL and allele effect analysis enabled the identification(P < 0.01) of 20 SNP under the milk yield QTL, 2 under both of the fat yieldpeaks, 8 and 9 under the protein yield peaks, 2 and 6 for the fat percent peaks,and 5 for the protein percent peak. One SNP in particular showed associationwith 3 of the 5 traits: milk (P = 1.59E-04), fat (P = 6.88E-05), and proteinyields (P = 5.76E-05). The validation step for 12 SNP included genotyping anadditional 726 Holstein animals not available at the start of the experiment.Results showed that 11 of those markers increased their association with themilk production traits. Overall, combining information from marker-markerrelationships, familial informativeness, marker quality and genetic knowledgeof traits enabled the characterization of additional markers with significantassociations with milk production traits.Key Words: DNA markers, quantitative trait loci, milkT236 Insulin-like growth factor-I receptor genepolymorphism of Iranian Holstein cows in Isfahan Province. A. Bakhtari* 1 ,H. R. Rahmani 1 , M. A. Edriss 1 , and B. E. Sayed Tabatabaei 2 , 1 Department ofAnimal Science, College of Agriculture, Isfahan University of Technology,Isfahan, Iran, 2 Department of Biotechnology, College of Agriculture, IsfahanUniversity of Technology, Isfahan, Iran.The IGF axis, which consists of insulin-like growth factors I and II (IGF-Iand IGF-II) and their associated binding proteins and receptors, plays a keyrole in the metabolism and physiology of mammals. The insulin-like growthfactor-I receptor (IGF-IR) mediates the biological actions of IGF-I and IGF-II. This receptor has 2 alpha and 2 beta subunits, which combine to form aheterotetramer. IGF-IR plays an important regulatory function in mammarygland development and milk secretion. IGF-IR gene in cattle was mapped onchromosome 21. The IGF-IR polymorphism is located in a noncoding region(intron) of the IGF-IR. The objectives of the present study were to estimate theallele and genotype frequencies of the IGF-IR gene polymorphism in Holsteincows. In this study 266 Holstein cows from 4 distance industrial dairy farms inIsfahan province were selected randomly. Genomic DNA was extracted fromwhole blood. Concentrations of DNA, reconstituted in water, were quantifiedusing 0.7% Tris-acetate-ethylenediamine tetraacetic acid agarose gel. DNAwas amplified in a total volume of 20 μL containing 50 ng genomic DNA, 10pmol of each primer (sense primer: 5′-CCCAATGGATTGATCCTCATGT-3′and antisense primer: 5′-GCTGTGTAGTTCCCTGGGTT-3′), 0.25 mMdNTP, 2 mM MgCl 2, 1 × PCR buffer and 1.5 unit Taq DNA polymerase. A625-bp IGF-1R gene was amplified by PCR using bovine specific primers.Restriction fragment length polymorphisms in this segment was digested byTaq I restriction enzyme. The digested PCR products were electrophoresed,and the restricted fragments were determined under UV light. Genotype AAwas characterized by the presence of 2 restriction fragments of 580 and 45 bp.Genotype BB was determined by the presence of 3 fragments of 410, 170, and45 bp. Heterozygous individuals presented 4 fragments of 580, 410, 170, and45 bp. Genotypes BB and AA were not detected in any of 4 distance industrialdairy farms. The frequency of genotypes AA was 1.0 and frequencies of alleleA and B were 1.0 and 0.0 in Holstein cows, respectively. The A allele of IGF-1R appears to be fixed in Holstein cattle. Therefore, this polymorphism is notuseful in studies on the identification of QTL in Holstein.Key Words: insulin-like growth factor-I receptor, Holstein, polymorphismT237 Prediction of genomic relationship matrices using singlenucleotide polymorphism markers in Korean cattle. D. H. Lee* 1 , D. Vasco 2 ,J. H. Lee 1 , C. I. Cho 1 , N. S. Kim 3 , Y. S. Won 4 , and J. J. Kim 5 , 1 Hankyong NationalUniversity, Ansung, Kyonggi, Korea, 2 University of Missouri, Columbia, MO,USA, 3 Chungbuk National University, Cheongju, Chungbuk, Korea, 4 NationalAgriculture Cooperative Federation, Seosan, Chungnam, Korea, 5 YoungnamNational University, Gyeongsan, Gyeongsangbuk, Korea.Currently, as the analytic techniques of SNP have been developing, muchresearch on genetic evaluation in livestock using genetic relationship estimatedby polymorphisms among individual SNP data are accomplished actively. Inthis study, estimation of relationship matrix using genomic information (GRM)was compared with additive relationship matrix using pedigree information(PRM) in Korean cattle for preliminary study of the usefulness of genomicselection. Data used in this study were from 187 blood samples from progenyof 20 young bull collected after parentage test from Korean cattle improvement67