Brown, Hayden (hbrown@uark.edu), University of Arkansas;
Brown, Mike (mike.brown@ars.usda.gov), ARS-GRL, El Reno, OK;
DeRouen, Sid (sderouen@agcenter.lsu.edu), LSU AgCenter;
Franke, Don (dfranke@agcenter.lsu.edu), LSU AgCenter;
Godfrey, Bob (rgodfre@uvl.edu), University of the Virgin Islands;
Hansen, Gary (gary_hansen@ncsu.edu), North Carolina State University;
Herring, Andy (andy.herring@tamu.edu), Texas A&M University;
Holloway, Bill (JW-Holloway@tamu.edu), Texas A&M University;
Johnson, Zelpha (Zelphaj@uark.edu), University of Arkansas;
Morrison, David (dmorrison@agcenter.lsu.edu), LSU AgCenter;
Sanders, Jim (jim-sanders@ansc.tamu.edu), Texas A&M University;
Smith, Trent (ts289@ads.msstate.edu), Mississippi State University;
Thrift, Fred (fthrift@uky.edu), University of Kentucky;
Vann, Rhonda (rcv2@ra.msstate.edu), Mississippi State University;
Wyatt, Wayne (wwyatt@agcenter.lsu.edu), LSU AgCenter;
The annual meeting of the S-1013 technical committee was called to order on June 2-4, 2008 at the Pauline Whitaker Arena of the University of Arkansas, Fayetteville, AR (see attached agenda). Dr. Sid DeRouen opened the meeting at 8:30 A.M. on June 2 with introductions of meeting participants. Dr. Sid DeRouen then announced members for this years resolutions committee, Drs. Bob Godfrey, Jim Sanders, and Trent Smith; and nominating committee, Drs. Mike Brown, Rhonda Vann, and Fred Thrift.
Individual station reports had been distributed electronically to all members of the committee prior to the meeting. Dr. Hayden Brown gave an overview of the structure of the data collected for Objective 3. Discussion followed regarding subjective chute scores in terms of what was actually being measured and whether or not the 5-point scale should be recoded into a 3-point scale. Also discussed were correlated responses among the different measures of temperament (disposition), i.e., subjective chute scores, subjective pen scores, chute exit velocity, etc. It was reiterated that, while we may be interested in breed differences, a rereading of Objective 3 clearly states that the intent is to estimate genetic variances and correlations for and among temperament and nematode burden measures and production measures in cattle. It was generally concluded that data from the different locations could be combined for analyses.
A discussion of Objective 2 focused on a replacement for Dr. Larry Cundiff (retired) as objective leader. Data structure was discussed and it was generally concluded that a combined data analyses per se may not be possible. However, a collaborative publication, wherein the participants addressed various portions of an overall theme, was certainly possible.
Dr. Sid DeRouen opened the second half of the morning session with submitted research ideas for a new regional project, as a replacement for the current project which will terminate in September 2009. The group entered into a discussion of possible objectives for the replacement project. Prior to dismissal of the morning session, Dr. David Morrison advised the group as to the options for future group interaction. A replacement regional research project (S-XXXX), associated with experiment stations, would entail common objectives with multistate linkages in terms of either a pooling of data for an overall analyses or a sharing of technology or equipment not present at each location but integral to meeting an objective. Another option would be a coordinating committee (SCC; formerly an information exchange group), again associated with experiment stations, which would entail a thematic orientation of shared objectives, but without the rigor of data pooling or sharing technology and/or equipment per se. Another option would be an extension and research activities group (SERA) which would entail a bringing together of researchers and extension specialists to address common objectives, with the intent of providing a functionally integrated forum for discussion and coordination of joint activities to address stakeholder needs.
Lunch was provided at the Pauline Whitaker Arena, after which the group traveled to the XXG Angus Ranch in Summers, AR. Mr. Murle Gilbreath, owner, provided a tour of the ranch and an evening meal for the group.
On June 3, 2008, the group met at the Pauline Whitaker Arena at 8:00 a.m. Dr. Sid DeRouen presented an overview of the previous days discussion of possible objectives for a new project. Several participants, in reflection of the options outlined by Dr. Morrison the previous day, urged the group to strive toward the development of a regional research project (S-XXXX), rather than an SCC or SERA project. Discussion of possible objectives for an S-XXXX project followed and four possible objectives were identified. Following a mid-morning breakout session for each objective, the group came back together and objective leaders presented the working objectives (see below) for the development of a replacement S-XXXX project. Dr. Andy Herring accepted the responsibility of overall author and editor for the new project. Dr. David Morrison outlined a working timetable (see below) for the development and submission of a replacement S-XXXX project.
Lunch was provided at the Pauline Whitaker Arena, after which the group traveled to Cobb Genetics in Siloam Springs, AR. Dr. Mark Cooper welcomed the group and presented an excellent overview of product development and the selection procedures employed by Cobb Genetics in poultry breeding.
On June 4, 2008, the group met at the Pauline Whitaker Arena at 8:00 a.m. A copy of the working objectives and timetable (see below) was provided, by Dr. Wayne Wyatt, to each individual within the group.
The business meeting was called to order by Dr. Sid DeRouen at 9:00 a.m. Dr. David Morrison provided an administrative overview for the group. He thanked Dr. Sid DeRouen for diligently working to secure a project extension through September 2009 for the group. He reminded the group that an annual report will be due 60 days following termination of the annual meeting and that meeting minutes will be posted on the NIMSS website under the S-1013 project. He informed the group that a 1-2 page impact statement on the S-1013 project would be required 60 days prior to submission of a new project proposal. He also stated that the new project would require an impact statement in the third year of the new project.
Dr. David Morrison then gave an update on the new farm bill. He read through a set of ordered priorities (seven) derived by the Southern directors as a science roadmap for agriculture research in the southern region. It was with some dismay that the group noted that animal research per se, wasnt ranked until the third priority and then wasnt mentioned again until the last priority. There was some discussion regarding elevation of animal agriculture research within the scientific community.
Dr. David Morrison reported that Dr. Sid DeRouen had submitted the S-1013 project for consideration as the Southern Regions nominee for a new National Excellence in Multistate Award. He noted that the project was deemed worthy of nomination by the southern animal science department heads group (SAC-2), but was not selected as the Southern Regions nominee. Selection criteria included i.) objectives that are national in scope, and ii.) the ability to garner extramural funding, among others. The group expressed thanks to Dr. Sid DeRouen for his efforts in submitting the project for consideration.
The nominating committee (Drs. Mike Brown, Rhonda Vann, and Fred Thrift) made the following nominations: Dr. Wayne Wyatt (chair), Dr. Andy Herring (chair elect), and Dr. Bob Godfrey (secretary). The nominated individuals were elected by unanimous vote.
The resolution committee (Drs. Bob Godfrey, Trent Smith, and Jim Sanders) submitted their report (see below).
Dr. Sid DeRouen initiated discussion of the location for next years meeting. Dr. Wyatt invited the group to meet in south Louisiana the first week of June 2009, to which the group accepted the offer. Dr. Jim Sanders proffered a Texas location for the 2010 meeting and Dr. Bob Godfrey invited the group to St. Croix, V.I. for the 2011 meeting. The group readily accepted both offers.
A consensus was reached by the group that it would be desirable to include scientists from other states in the new project. Members were encouraged to individually contact scientists they thought might be interested in participation in the new project.
The meeting was ended with recognition of and appreciation expressed to those individuals who will be retiring before the next meeting. Dr. Jim Sanders made a motion that a standing invitation be extended to all retirees for future annual meetings. The motion was seconded by Dr. Rhonda Vann and was subsequently passed by acclamation.
The meeting was adjourned by Dr. Sid DeRouen at 10:30 a.m., June 4, 2008.
Meeting minutes are respectfully submitted by Dr. Wayne Wyatt, secretary.
WORKING OBJECTIVES FOR S-1013 REPLACEMENT PROJECT (S-XXXX)
Objective 1: To estimate genetic variation associated with susceptibility/resistance to specific measures of disease stress in cattle managed on forage. (Objective leaders: Drs. Fred Thrift and Bill Holloway.)
Objective 2: Characterize diverse, tropically adapted beef breeds in subtropical and temperate areas of the United States in comparison to Bos indicus influenced breeds and types. (Objective leader: Drs. Jim Sanders.)
Objective 3: Establish a DNA bank for discovery and characterization of molecular markers in traits of economic importance in pedigreed beef cattle populations. (Objective leaders: Drs. Trent Smith and Gary Hansen.)
Objective 4: Evaluate the relationship between hair coat and production traits in beef cattle breed types. (Objective leaders: Drs. Bob Godfrey and Rhonda Vann.)
DEADLINES
" August 15, 2008 objective drafts due to Dr. Andy Herring
" February 1, 2009 first draft completed for review by internal S-1013 sub-committee
" March 1, 2009 second draft ready for review by external peers (e.g., Drs. Mike Tess, Dave Buchanan, Dave Notter, John Pollack, etc.)
" May 15, 2009 third draft to full S-1013 committee for review
" June 15, 2009 third draft ready for review by southern multi-state research committee
" August 1, 2009 final draft submitted to southern executive directors office
RESOLUTIONS COMMITTEE REPORT
Whereas the S-1013 Technical Committee is committed to improving beef cattle production systems in the southern region of the United States as well as other regions of the U.S.
And whereas the S-1013 Technical Committee is improved by exchange of research findings and approaches at different institutions and locations as well as observing different ranch production systems.
Therefore, be it resolved that the S-1013 Technical Committee expresses its gratitude to Dr. Hayden Brown, Ms. Dianna Watson and Dr. Sid DeRouen for planning and coordinating its 2008 annual meeting in Fayetteville, AR and for coordinating tours to XX-G Ranch and Cobb Genetics. The S-1013 technical Committee wishes to thank Dr. Fred Pohlman and Tyson Foods, Inc. for providing the lunches during the meeting.
Be it also resolved that the S-1013 Technical Committee extends its thanks to Mr. Murle Gilbreath and family of XX-G Ranch in Summers, AR for their hospitality and enjoyable tour of the ranch, and to Dr. Mark Cooper of Cobb Genetics in Siloam Springs, AR, for his hospitality and informative presentation on poultry breeding.
Be it also resolved that the S-1013 Technical Committee extends its thanks to Dr. David Morrison for his oversight, leadership and friendship as administrative advisor of this project.
Respectfully submitted 6/4/08
Bob Godfrey
Jim Sanders
Trent Smith
Objective 1: Determine heterosis effects in crosses representing two or more diverse, tropically adapted beef breeds.
Florida USDA/ARS, STARS - Use of the Criollo breed Romosinuano may permit cow-calf producers to take advantage of tropical adaptation and heterosis for a variety of production traits while possibly avoiding less desirable performance of some traits of tropically adapted cattle, such as poor animal temperament, poor marbling score, and late sexual maturity in females.
Objective 2: Characterize diverse, tropically adapted beef breeds in subtropical and temperate areas of the United States.
Florida USDA/ARS, STARS - Use of the Criollo breed Romosinuano may permit cow-calf producers to take advantage of tropical adaptation and heterosis for a variety of production traits while possibly avoiding less desirable performance of some traits of tropically adapted cattle, such as poor animal temperament, poor marbling score, and late sexual maturity in females.
Central Station, LSU Agricultural Center, Baton Rouge, Louisiana and U.S. Meat Animal Research Center, Clay Center, Nebraska - Results of this study clearly demonstrate the superior environment in NE for cow-calf production compared to that in LA. Cow breed types ranked the same in both environments. Romosinuano-sired cows appear slightly superior to other sire breed types for reproductive traits.
ARS-Oklahoma - In calves put directly on mixed grain rations after weaning, cow milk yield was unfavorably related to calf postweaning performance in calves sired by Gelbvieh and Bonsmara, whereas cow milk yield was favorably related to postweaning performance of calves sired by Brangus and possibly Charolais. In Romosinuano- and Hereford-sired calves on mixed rations, there was little evidence of a relationship of cow milk yield to postweaning performance. In calves grazed on wheat pasture after weaning, there was a trend for a favorable relationship of cow milk yield to postweaning performance in Gelbvieh-sired calves and a weaker trend for an unfavorable relationship in Romosinuano-sired calves. There was little evidence of a relationship of cow milk yield to postweaning performance in Bonsmara-, Brangus-, Charolais-, or Hereford-sired calves grazed on wheat pasture.
Texas A&M University / Texas Agricultural Experiment Station - Cows sired by Boran bulls and out of cows of the British beef breeds have been found to be extremely productive under central Texas conditions.
Objective 3: Determine genetic variation in disposition and parasite resistance in beef cattle and their association with economically important traits.
Department of Animal Science, Arkansas Agricultural Experiment Station - Considerable economic loss occurs in cattle production in the U.S. due to internal parasite and excitable temperament. The loss generally does not result from mortality but results due to reduced animal performance. A recent survey revealed that bruising of cattle due to poor temperament cost the U.S. cattle industry 22 million per year. If these results are consistent across years and locations, this study would provide the basis for selection of animals resistant to some internal parasites reducing the use of anthelmintic treatment. Selection for docility may become a key factor in maximizing production efficiency and production quality. However, proper technology in the application of these results must be developed.
Florida USDA/ARS, STARS - Use of the Criollo breed Romosinuano may permit cow-calf producers to take advantage of tropical adaptation and heterosis for a variety of production traits while possibly avoiding less desirable performance of some traits of tropically adapted cattle, such as poor animal temperament, poor marbling score, and late sexual maturity in females.
Kentucky Experiment Station - A preliminary summary of the results to date indicate that weaning weights have been similar for calves classified according to the five temperament scores. Once data collection is completed, it is anticipated that results from this project will help determine if temperament evaluated at weaning is associated with preweaning production in Angus cattle.
LSU AgCenter, Baton Rouge, Homer, and Jeanerette - Correlations among CS and EV with postweaning gain were, in general, negative and significant. Correlations among weaning EV and summer EV with pregnancy rate were negative and important (P < 0.05). Sire (breed type* location) was highly significant for all temperament measurements. Heifers classified as slow, medium, and fast based on EV did not differ (P > 0.14) for postweaning gain or pregnancy rate.
LSU AgCenter, Baton Rouge and Jeanerette - Despite presumed inaccurate heritability estimates derived from the sire-model analyses, sire effects suggest that there are sires within both Angus and Brahman-influenced (i.e., Brangus and Braford) breeds that do differ in EPG, postweaning ADG, and pregnancy rates of their heifer offspring. It should be noted that improvements in both accuracy and precision of variance component estimates are anticipated with additional data (an additional year of data and combining of data across multiple locations) and the incorporation of pedigree information in the analyses. Results based upon preliminary data and simple analyses preclude conclusive statements regarding the data.
MAFES, Brown Loam Experiment Station, Raymond, MS - These results suggest that in Angus crossbred and Brahman steers hauling stress has negative effects on body composition traits specifically percent intramuscular fat and rib fat. Thus, fat cattle that are ready to be harvested and have to travel long distances to a harvest facility may have reduced percent intramuscular fat or marbling scores at time of harvest. Calf temperament scores from pre-weaning through 56 days post weaning are very repeatable measurements. Thus these measurements can be done at weaning and provide an accurate indication of the lifetime temperament of that animal. In addition, animals that are routinely worked through a cattle facility will become accustomed to human interaction and their overall temperament scores will continue to decline from weaning through yearling.
Texas A&M University / Texas Agricultural Experiment Station - Calves from all nine calf crops of the Genomics Project have been scored for disposition; variation for disposition has been found both between and within families. Data are being used in genome scans with the objective of identifying genes with major effects on disposition.
University of the Virgin Islands, Agricultural Experiment Station - These results show that the temperament of Senepol calves does not change over time after weaning and heifers are more temperamental than bulls.
Objective 4: Establish a DNA bank to utilize molecular markers to validate traits of economic importance.
All participating locations (Florida USDA/ARS, STARS and Texas A&M University College Station/McGregor) have stored DNA, tissue, or white blood cells on calves born in the previous year.
Texas A&M University College Station/McGregor - All cattle at the McGregor Station were bled for DNA extraction in the fall 2001; calves born in 2002, 2003, 2004, 2005, 2006, and 2007 were bled prior to weaning. Cattle in the McGregor Genomics Project were bled at birth and shortly before weaning; base of scrotum and testicles were also saved from males. The DNA will be available to utilize molecular markers to validate traits of economic importance.
- Three-years of data suggest individual animal variation for temperament score and fecal egg count.
- Breed of sire x location interactions may not be as important to commercial cow-calf operations as once thought; however, small differences tend to be important among the breed types evaluated.
- Correlations among chute score and exit velocity with postweaning gain indicate increased gains were associated with lower (more desirable) temperament measurements.
- Correlations among weaning chute score and exit velocity with pregnancy rate indicate improved pregnancy rates were associated with slower (more docile) heifers.
- Significant variations among sires were found for all the temperament measurements.
- Sires within breed appear to significantly differ for fecal egg count.
- The extent to which nematode parasitism in beef cattle is affected by host genetics should be of great importance to beef producers.
- The relationship between maternal performance in the cow-calf phase of beef production and the subsequent postweaning gain in the stocker/backgrounding phase is important in the design of efficient beef production systems because of a potential negative relationship between milk production of the cow and postweaning gain of her calf.
- The impact of maternal performance of the dam on calf postweaning ADG depended on both the sire breed of the calf and the postweaning management.
Brown, M. A. and D. L. Lalman. 2008. Preweaning performance of calves from Bonsmara, Brangus, Charolais, Gelbvieh, Hereford, and Romosinuano sires bred to Brangus cows managed on native rangeland or improved forages. Prof. Anim. Sci. 24: 67-75.
Brown, M. A., X. Z. Wang, F. Q. Gao, J. P. Wu and D. L. Lalman. 2008. Postweaning gains in calves sired by six sire breeds evaluated on two preweaning forages and two postweaning management systems. Prof. Anim. Sci. (Accepted 3/5/2008).
Brown, M. A., X. Z. Wang, F. Q. Gao, J. P. Wu, and D. L. Lalman, 2008. Postweaning gains in calves sired by six sire breeds evaluated on two postweaning management systems. J. Anim. Sci. 86 (Suppl. 1):1.
Carroll, J. A., Arthington, J. D., Chase, C. C., Jr., Coleman, S. W., Riley, D. G., Spiers, D. E., and Reuter, R. R. Genetic influences on the bovine acute phase protein response following an endotoxin challenge. J. Anim. Sci. 86(Suppl. 2):21(Abstr.). 2008.
Chase, C. C., Jr., Randel, R. D., Riley, D. G., Coleman, S. W., and Olson, T. A. Genetic effects on circulating concentrations of cortisol at and after weaning in breed-types adapted to the subtropics. J. Anim. Sci. 86(Suppl. 2):2(Abstr.). 2008.
Coleman, S. W., Phillips, W. A., Chase, C. C., Jr., and Riley, D. G. Feed efficiency of tropically adapted breed and breed cross steers when fed in the southern plains. J. Anim. Sci. 85(Suppl. 1):189(Abstr.). 2007.
Cunningham, S.F., A.H. Maiga, K.L. Key, A.E. Ducoing, J.O. Sanders, A.D. Herring, and D. K. Lunt. 2008. Evaluation of F1 cows sired by Brahman, Boran, and Tuli for reproductive and maternal performance and cow longevity. 2008 Beef Cattle Research in Texas. (in press).
DeRouen, S.M. 2008. Temperament effects on development of replacement heifers. Hill Farm Research Station Field Day Summaries. Louisiana Agriculture Experiment Station.
Franke, D. E., D. H. Fischer, Jr., M. G. Thomas, and T. D. Bidner. 2007. Calpastatin and calpain genetic marker influences on shear force in Brahman steers. J. Anim. Sci. 85 (Suppl. 2): 3 (Abstr.).
Franke, D. E., and L. V. Cundiff. 2007. Tropically adapted F1 beef female and location influences on early performance. J. Anim. Sci. 85 (Suppl. 2): 6 (Abstr.).
Franke, D. E., M. G. Thomas, A. J. Garrett, and T. D. Bidner. 2007. An evaluation of SNP associations with calpastatin enzyme activity and shear force measurements in Brahman steers. J. Anim. Sci. 85 (Suppl. 1): 259 (Abstr.).
Franke, D. E., D. H. Fischer, Jr., M. G. Thomas, and T. D. Bidner. 2007. Calpastatin and calpain genetic marker influences on shear force in Brahman steers. J. Anim. Sci. 85 (Suppl. 2): 3 (Abstr.).
Franke, D. E., and L. V. Cundiff. 2007. Tropically adapted F1 beef female and location influences on early performance. J. Anim. Sci. 85 (Suppl. 2): 6 (Abstr.).
Franke, D. E., M. G. Thomas, A. J. Garrett, and T. D. Bidner. 2007. An evaluation of SNP associations with calpastatin enzyme activity and shear force measurements in Brahman steers. J. Anim. Sci. 85 (Suppl. 1): 259 (Abstr.).
Funkhouser, R.R. 2008. Evaluation of disposition scores in Bos indicus/Bos taurus cross calves at different stages of production. M.S. Thesis, Texas A&M Univ., College Station.
Funkhouser, R.R., J.O. Sanders, A.D. Herring, C.A. Gill, D.K. Lunt, and J.E. Sawyer. 2008. Evaluation of disposition scores in Bos indicus/Bos taurus cross calves at weaning. American Society of Ani. Sci., Southern Section Abstracts.
Godfrey, R. W. and R. C. Ketring. 2007. Temperament and chute exit velocity scores of Senepol calves after weaning. J. Animal Sci. 85(Suppl. 1):95.
Hansen, G. R., Carstens, G. E., and Riley, D. G. Relationship between residual feed intake, water intake and ultrasound body composition traits in Angus bulls. J. Anim. Sci. 85(Suppl. 1):551(Abstr.). 2007.
Murphy, K., S. Reiter, M. Brown, R. Okimoto, H. Brown, Jr., and C. Rosenkrans, Jr. 2008. Identification of genomic polymorphisms in upstream elements of the bovine CYP3A28 gene. . Anim. Sci. 86 (Suppl. 1):36.
Nabhan, I., M. Lamb, S. Reiter, R. Okimoto, M. Brown, H. Brown, Jr., and C. Rosenkrans, Jr. 2008. Relationships among bovine heat shock protein 70 genotype, forage type, and plasma concentrations of HSP-70. J. Anim. Sci. 86 (Suppl. 1):3.
Peng, Yun Shou, Jian Ping Wu, Li Xin Wei, M. A. Brown, Ji Ling Wu, and Duo Zeng Sanbei. 2008. Fatty acid profile in milk fat from Qinghai Plateau yak at different altitudes and parities. Prof. Anim. Sci. (Accepted 4/28/2008).
Phillips, W. A., Coleman, S. W., Chase, C. C., Jr., and Riley, D. G. Predicting back fat thickness in beef cattle using A-mode ultrasound technology. J. Anim. Sci. 86(Suppl. 2):25(Abstr.). 2008.
Qiu, X., Arthington, J. D., Riley, D. G., Chase, C. C., Jr., Phillips, W. A., Coleman, S. W. and Olson, T. A. Genetic effects on acute phase protein response to the stresses of weaning and transportation in beef calves. J. Anim. Sci. 85:23672374. 2007.
Riley, D. G., Loneragan, G. H., Phillips, W. A., Gray, J. T. and Fedorka-Cray, P. J. Fecal shedding of foodborne pathogens by Florida-born heifers and steers in U.S. beef production segments. J. Food Prot. 71:807810. 2008.
Riley, D. G., Hansen, G. R., Coleman, S. W., and Chase, C. C., Jr. Residual feed intake and temperament differences among Florida heifers. J. Anim. Sci. 85(Suppl. 1):263(Abstr.). 2007.
Riley, D. G., Chase, C. C., Miller, M. F., Brooks, J. C., Johnson, D. D., Phillips, S. W., and Olson, T. A. Genetic analyses of crossbred and purebred Romosinuano, Brahman, and Angus steers. J. Anim. Sci. 86(Suppl. 2):2(Abstr.). 2008.
Scharf, B., Wax, L. E., Carroll, J. A., Riley, D. G., Chase, C. C., Jr., Coleman, S. W., Keisler, D. H., and Spiers, D. E. Evaluation of physiological differences in heat tolerant (Romosinuano) and heat susceptible (Angus) Bos taurus cattle during controlled heat challenge. J. Anim. Sci. 85(Suppl. 1):466(Abstr.). 2007.
Van Eenennaam, A.L., J. Li, R. M. Thallman, R. L. Quass, M. E. Dikeman, C. A. Gill, D. E. Franke and M. G. Thomas. 2007. Validation of commercial DNA tests for quantitative beef quality traits. J. Anim. Sci. 85:891-900.
Zhao, D., Starks, P.J., Brown, M.A., Phillips, W.A., and Coleman, S.W. Assessment of forage biomass and quality parameters of bermudagrass using proximal sensing of pasture canopy reflectance. Grassl. Sci. 53:39-49. 2007.