D J Patterson

University of Missouri, Columbia, Missouri, United States

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Publications (88)108.26 Total impact

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    ABSTRACT: Abstract Text: Putative loss of function (LOF) alleles that are never seen as homozygotes despite their allele frequency suggesting that they should be seen are strongly implicated as being lethal. For this approach to lead to effective strategies for the improvement of fertility, there must be a relatively large number of recessive embryonic lethal alleles which due to natural selection will be individually at low frequency within the target population. In order to identify putative LOF alleles we have re-sequenced >100 bovine genomes to an average of >20x depth of coverage and characterized the resulting variants. These variants will be used to design a genotyping assay that we will use to genotype ~10,000 Angus heifers to identify, validate and characterize the impact of recessive lethal alleles associated with reproductive failure in Angus cattle. Keywords: beef cattle, genome sequence, fertility
    10th World Congress on Genetics Applied to Livestock Production; 08/2014
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    ABSTRACT: Abstract Text: We determined the effect of administration of PGF at CIDR insertion during the 7-day CO-Synch+CIDR estrus synchronization protocol on subsequent pregnancy rates of suckled beef cows. At 13 locations, cows were ovulation synchronized with the 7-day CO-Synch+CIDR protocol (100 μg injection of GnRH at CIDR insertion [d -10] with 25 mg injection of PGF at CIDR removal [d -3], followed by an injection of GnRH and fixed-time AI (TAI) on d 0). Cows were stratified by days postpartum, BCS, and parity and assigned to 1 of 2 treatments: CO-Synch+CIDR (n = 819) and PG-CO-Synch+CIDR (a 25 mg injection of PGF was administered at CIDR insertion of the CO-Synch+CIDR protocol; n = 827). Follicle dynamics and corpus luteum development were assessed on d -10 and -3 and pregnancy status determined on d 30-35. Blood was collected on d -20, -10, -3, and 0 to determine progesterone (P4). Overall fixed-time artificial insemination (TAI) pregnancy rates (53.5 ± 1.9% and 50.4 ± 1.9%, for CO-Synch+CIDR and PG-CO-Synch+CIDR, respectively) did not differ (P = 0.802) between treatments. A location effect (P < 0.001) existed with pregnancy rates being the greatest at the KS2 location (67.2 ± 6.1%) and the poorest at the KS4 location (15.3 ± 5.3%). Of the 1,217 cows in which cyclic status was assessed, 55% were determined to be cyclic; however, incidence of pregnancy was not associated with cyclic status or the treatment x cyclic status interaction. Concentrations of P4 were greater (P < 0.001) for CO-Synch+CIDR (4.1 ± 0.3 ng/mL) than PG-CO-Synch+CIDR (3.4 ± 0.3 ng/mL) on d -3 whereas diameter of largest follicle on d -3 tended (P= 0.094) to be greater for PG-CO-Synch+CIDR (13.4 ± 0.3 mm) than CO-Synch+CIDR (12.6 ± 0.3 mm). We concluded that administration of PGF at CIDR insertion of the CO-Synch+CIDR protocol failed to increase TAI pregnancy rates in suckled beef cows, but at CIDR removal, decreased concentrations of P4 and tended to increase dominant follicle diameter. Keywords: Ovulation Synchronization, Artificial Insemination, Beef Cow
    2014 ADSA-ASAS-CSAS Joint Annual Meeting; 07/2014
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    ABSTRACT: Abstract Text: An experiment was designed to test the hypothesis that pregnancy rates in postpartum beef cows after fixed-time artificial insemination (FTAI) may be improved by delaying insemination of those cows that have not expressed estrus prior to the standard FTAI time. Estrus was synchronized for 951 mature, suckled cows across 9 locations using the 7-d CO-Synch + CIDR protocol (100 μg GnRH + CIDR [1.38 gm progesterone] on d 0; 25 mg PGF2α at CIDR removal on d 7; and 100 μg GnRH on d 10, 66 h after CIDR removal). Estrus detection aids (Estrotect) were applied at PGF2α and CIDR removal on d 7, and estrous expression was recorded at GnRH on d 10. Treatments were equally represented across locations, and cows within each location were assigned to one of two treatments based on age, days postpartum (DPP), and body condition score (BCS): (1) FTAI (concurrent with GnRH, 66 h after PGF2α) regardless of estrous expression prior to GnRH, or (2) FTAI for cows having expressed estrus, and delayed AI (20 h after GnRH) for cows failing to express estrus. In both treatments, cows that expressed estrus prior to FTAI achieved higher pregnancy rates than cows that did not (P < .0001). However, no significant effect of treatment was found on AI pregnancy rate (P = .757). In summary, mature suckled beef cows may be successfully artificially inseminated using a strategy of “split-time” AI: insemination at the standard time of 66 h after PGF2α for cows that have expressed estrus and delayed insemination at 20 h after GnRH for cows that have not expressed estrus prior to the standard AI time in the 7-d CO-Synch + CIDR protocol. However, such a strategy does not appear to offer a significant improvement in pregnancy rates compared to a standard FTAI approach. Keywords: artificial insemination estrus synchronization beef cow
    2014 ADSA-ASAS-CSAS Joint Annual Meeting; 07/2014
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    ABSTRACT: Abstract Text: An experiment was designed to test the hypothesis that pregnancy rates in beef heifers after fixed-time artificial insemination (FTAI) may be improved by delaying insemination of those heifers that have not expressed estrus prior to the standard FTAI time. Estrus was synchronized for 931 heifers across three locations using the 14-d CIDR-PG protocol (CIDR insert [1.38 gm progesterone] on d 0 with removal of CIDR on d 14; 25 mg PGF2α 16 d after CIDR removal on d 30; and 100 μg GnRH on d 33, 66 h after PGF2α). Estrous detection aids (Estrotect) were applied at PGF2α on d 30, and expression of estrus was recorded at GnRH on d 33. Treatments were balanced across locations, and heifers within each location were randomly assigned to one of two treatments based on reproductive tract score (RTS) and weight: (1) FTAI (concurrent with GnRH, 66 h after PGF2α) regardless of estrous expression prior or (2) FTAI for heifers having expressed estrus, and delayed AI (20 h after GnRH) for heifers failing to express estrus. A significant effect of treatment was found on AI pregnancy rate, with heifers assigned to treatment 2 achieving a higher AI pregnancy rate than heifers assigned to treatment 1 (54% versus 46%, P = .012). The observed increase in AI pregnancy rate is attributed to the delayed AI of non-estrous heifers in treatment 2, as AI pregnancy rates for non-estrous heifers were significantly greater for treatment 2 (49% versus 34%, P = .024), while AI pregnancy rates of estrous heifers did not differ by treatment (P = .244). In summary, FTAI pregnancy rates in heifers can be improved through a strategy of “split-time” AI: insemination at the standard time of 66 h after PGF2α for heifers that have expressed estrus and delayed insemination at 20 h after GnRH for heifers that have not expressed estrus prior to the standard AI time in the 14-d CIDR-PG protocol. Keywords: artificial insemination estrus synchronization beef heifer
    2014 ADSA-ASAS-CSAS Joint Annual Meeting; 07/2014
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    ABSTRACT: Abstract Text: Utilization of existing and emerging management technologies enable beef producers to improve breeding performance of heifers during the first breeding season and during subsequent calving and rebreeding periods as 2-year-olds. These practices ensure that heifers that enter herds as raised or purchased replacements contribute to the general performance and productivity of an entire cowherd immediately, and cumulatively long-term. In 1996 extension specialists, veterinarians, beef producers and allied industry in Missouri linked arms to develop and implement a plan that would impact long-term sustainability of beef herds across the state. This plan was focused on the cyclical reproductive process in beef cattle and involves five basic steps: 1) Create an understanding of the importance of heifer development based on reproductive outcomes; 2) Implement changes in heifer development that eventually spill over into the cow herd; 3) Emphasize the importance of reproductive management which becomes apparent as changes are implemented; 4) Expand producer focus to genetic improvement; and 5) Emphasize to participating herds that creation of a value-added product requires a re-evaluation of marketing strategies. These five steps have built equity in herds that embraced the plan, and 17 years later the Missouri Show-Me-SelectTM Replacement Heifer Program has impacted the cattle industry state wide. The program objectives include: 1) A total quality management approach for health and management of heifers from weaning to late gestation; 2) Increased marketing opportunities for and added value from Missouri raised heifers; and 3) Creation of reliable sources of quality commercial and purebred replacement heifers. The program incorporates all available tools to support long-term health, reproduction, and genetic improvement of replacement beef heifers and includes provisions for ownership; health and vaccination schedules; parasite control; implant use; weight, pelvic measurement and reproductive tract score; estrous synchronization and artificial insemination; service-sire requirements for BW- or CE-EPD; early pregnancy diagnosis, fetal aging, fetal sexing, and body condition score. In a state that ranks second in total numbers of beef cows in production, the Missouri Show-Me-SelectTM Replacement Heifer Program is a working model that integrates improvements in selection, management, health, and genetics into a total development, management, and marketing program through emphasis on reproductive outcomes. Impact in Missouri stemming from the Show-Me-SelectTM program and the proof of concept it demonstrates, raises the question as to whether it is time to standardize requirements used in the program to broaden its scope to other major beef cattle producing states. Keywords: Missouri, Show-Me-SelectTM, Replacement beef heifer
    2014 ADSA-ASAS-CSAS Joint Annual Meeting; 07/2014
  • D. S. Brown, D. J. Patterson
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    ABSTRACT: Abstract Text: The U.S. beef industry is confronted with a significant long-term decline in cattle numbers driven in part by record input costs and severe drought conditions in many major cattle producing states. These recent challenges only add to the long-term issues the industry has faced which include an aging producer population, increased global competition, increased competition from other meat proteins, weak domestic demand for beef and a perceived lack of economic incentives to expand the cattle herd. The weakness in beef demand provided the impetus for the industry to begin the Beef Quality Assurance program. Although the industry has experienced more consistency in beef products over the last three decades, there are major strides left when today less than 5 percent of cattle grade prime. In comparison to other domestic livestock sectors in the U.S., tradition and segmentation within the U.S. cattle industry has hindered the adoption of newer production and marketing strategies. Coordinating the various industry segments (cow-calf, stocker, feed yard, processor) with allied industry (AI companies, seed stock suppliers, feed and pharmaceutical industries) offers the potential to enhance technology adoption and contribute to increases in production efficiency. As the U.S. cattle industry moves to rebuild its declining numbers, the focus of much of the industry will turn to heifer retention and appropriate practices related to beef heifer development. The industry has provided better beef quality signal transmission through available marketing grids in the industry today. Yet, these grids generally require cow-calf producers to maintain some ownership stake in the cattle through the feed yard. Producers that have invested in developing higher quality cattle and beef in the past often found genetic improvement to be slow and inconsistent, which often times reduced economic incentives of the quality focus. The technologies that have come online over the past few years and new genomic advances on the horizon appear poised to rapidly increase genetic improvement and consistency. The combination of better market incentives for higher quality beef coupled with technologies that allow producers to more easily invest in genetics focused on quality provide the industry a unique opportunity to increase the cow herd with a more refined focus on the genetic potential of the herd as it relates to efficiency and higher quality. It would appear these technologies have the added value of reducing producer risk by providing more consistency in the beef produced. Keywords: Economic, Quality, Technologies
    2014 ADSA-ASAS-CSAS Joint Annual Meeting; 07/2014
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    ABSTRACT: Two experiments were designed to test the hypothesis that pregnancy rates after fixed-time artificial insemination (FTAI) in beef heifers and cows may be improved by delaying insemination of females that have not expressed estrus prior to FTAI. In Exp. 1, estrus was synchronized for 931 heifers across three locations using the 14-d CIDR-PG protocol (CIDR insert [1.38 gm progesterone] on d 0 with removal of CIDR on d 14; 25 mg PGF2α 16 d after CIDR removal on d 30; and 100 μg GnRH on d 33, 66 h after PGF2α). Estrous detection aids (Estrotect) were applied at PGF2α on d 30, and estrous expression was recorded at GnRH on d 33. Heifers within each location were randomly assigned to one of two treatments based on weight and reproductive tract score (RTS): (1) FTAI (concurrent with GnRH, 66 h after PGF2α) regardless of estrous expression or (2) FTAI for heifers expressing estrus, and delayed AI (20 h after GnRH) for heifers failing to express estrus. Heifers assigned to treatment 2 achieved a higher AI pregnancy rate than heifers assigned to treatment 1 (54% versus 46%, P = .01). The observed increase in AI pregnancy rate is attributed to the delayed AI of non-estrous heifers in treatment 2, as AI pregnancy rates for non-estrous heifers were significantly higher for treatment 2 (49% versus 34%, P = .02), while AI pregnancy rates of estrous heifers did not differ by treatment (P = .24). In Exp. 2, estrus was synchronized for 951 mature, suckled cows across 9 locations using the 7-d CO-Synch + CIDR protocol (100 μg GnRH + CIDR [1.38 gm progesterone] on d 0; 25 mg PGF2α at CIDR removal on d 7; and 100 μg GnRH on d 10, 66 h after CIDR removal). Estrus detection aids (Estrotect) were applied at PGF2α and CIDR removal on d 7, and estrous expression was recorded at GnRH on d 10. Cows within each location were assigned to one of two treatments based on age, days postpartum (DPP), and body condition score (BCS): (1) FTAI (concurrent with GnRH, 66 h after PGF2α) regardless of estrous expression or (2) FTAI for cows expressing estrus, and delayed AI (20 h after GnRH) for cows failing to express estrus. No significant effect of treatment was found on AI pregnancy rate (P = .76). In summary, FTAI pregnancy rates in heifers can be improved through a strategy of "split- time" AI. However, a statistically significant increase was not observed in the pregnancy rates of mature suckled cows when using a similar strategy.
    Journal of Animal Science 07/2014; · 1.92 Impact Factor
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    ABSTRACT: This experiment compared two long-term CIDR-based protocols to synchronize estrus prior to fixed-time artificial insemination (FTAI) in postpartum beef cows. Cows were assigned to treatments by age, body condition score (BCS), and days postpartum (DPP). Cows assigned to the 14-19 d CIDR-PG protocol (n = 196) received CIDR inserts (1.38 g progesterone) from d 0 to 14 and prostaglandin F2α (PG; 25 mg, i.m.) 19 d after CIDR removal on d 33. Cows assigned to the 14-16 d CIDR-PG protocol (n = 195) received CIDR inserts from d 3 to 17, and PG 16 d after CIDR removal on d 33. Cows were artificially inseminated on d 36, 72 h after PG, with GnRH (100 μg, i.m.) at FTAI. Cows were exposed for natural service 14 d after FTAI for 75 d. Blood samples for progesterone (P4) were collected at d -10 and d 0 to determine pretreatment estrous cyclicity status, and again at PG. Blood samples for estradiol (E2) were collected at PG and FTAI. HeatWatch estrus detection transmitters were utilized from CIDR removal until FTAI to determine onset of estrus after CIDR removal and PG. Dominant follicle diameter was determined at PG and FTAI. Pregnancy diagnosis was performed 70 d after FTAI and confirmed at d 140 of gestation. Estrous response after CIDR removal was similar between treatments. Cows in both treatments had similar size dominant follicles on d 33 at PG, and d 36 at FTAI. Progesterone at PG was greater (P = 0.03) for 14-16 d compared to 14-19 d treated cows. Mean concentrations of E2 at PG were similar between treatments; but were greater (P = 0.01) at FTAI for 14-16 d compared to 14-19 d treated cows. Estrous response after PG was greater (P < 0.01) for 14-19 d compared to 14-16 d treated cows (47.4 vs. 29.7%, respectively). Pregnancy rate resulting from FTAI was affected by the treatment x age group interaction (P = 0.08). Pregnancy rate after FTAI among cows ≥ 4 yr tended to be greater (P = 0.06) for 14-19 d compared to the 14-16 d treated cows; suggesting that the 14-19 d schedule works better for older age cows compared with the 14-16 d schedule. Final pregnancy rates were similar between the two treatments. In summary, these data indicate that a range in intervals from CIDR removal to PG may be feasible when using long-term CIDR-based protocols in cows, and raise questions that warrant further study regarding the benefits of extending this interval based on cow age.
    Journal of Animal Science 02/2014; · 1.92 Impact Factor
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    ABSTRACT: This experiment was designed to test the hypothesis that delayed insemination of non-estrous cows would increase pregnancy rates when using sex-sorted semen in conjunction with fixed-time artificial insemination (FTAI). Estrus was synchronized for 656 suckled beef cows with the 7-day CO-Synch + CIDR protocol (100 μg GnRH + CIDR [1.38 gm progesterone] on d 0; 25 mg PGF2α at CIDR removal on d 7; and 100 μg GnRH on d 10, 66 h after CIDR removal). Estrus detection aids (Estrotect) were applied at PGF2α and CIDR removal on d 7, and estrous expression was recorded at GnRH on d 10. Cows were assigned to one of three treatments: (1) FTAI (concurrent with GnRH, 66 h after CIDR removal) with conventional semen regardless of estrous expression; (2) FTAI with sex-sorted semen regardless of estrous expression; or (3) FTAI with sex-sorted semen for cows having expressed estrus, and delayed AI 20 h after final GnRH for cows failing to express estrus. A treatment x estrous expression interaction was found (P < 0.0001). Higher pregnancy rates (P < 0.0001) were achieved with conventional semen (Treatment 1, 77%) than with sex-sorted semen (Treatments 2 and 3, 51% and 42%, respectively) among cows that expressed estrus. However, among cows that failed to express estrus, delayed insemination with sex-sorted semen yielded higher (P < 0.0001) pregnancy rates than with sex-sorted semen at the standard time (Treatments 2 and 3, 3% versus 36%, respectively). Furthermore, among cows that failed to express estrus, FTAI pregnancy rates when using sex-sorted semen at the delayed time (36%) were comparable (P = 0.9) to those achieved using conventional semen at the standard time (Treatment 1; 37%). These results indicate that delaying AI of non-estrous cows by 20 h from the standard FTAI improves pregnancy rates when sex-sorted semen is used with FTAI.
    Journal of Animal Science 02/2014; · 1.92 Impact Factor
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    ABSTRACT: This article provides an overview of the Missouri Show-Me-Select Replacement Heifer Program, and is included to provide an example of a working model for the collective considerations that relate to beef heifer development presented in this issue. This program expanded services provided by veterinarians to cow-calf producers, making veterinary practitioners a more integral part of the overall reproductive management of beef herds in their practice areas.
    Veterinary Clinics of North America Food Animal Practice 11/2013; 29(3):653-66. · 1.75 Impact Factor
  • David J Patterson, D Scott Brown
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    ABSTRACT: Use of existing and emerging management technologies enable beef producers to improve breeding performance of heifers during the first breeding season and during subsequent calving and rebreeding periods as 2 year olds. These practices ensure that heifers that enter the herd as raised or purchased replacements contribute to the general performance and productivity of an entire cowherd immediately, and cumulatively long-term. Rebuilding the US cowherd requires careful consideration and use of these newer management technologies. Veterinarians will play a crucial role in influencing the technologies used during the rebuilding process.
    Veterinary Clinics of North America Food Animal Practice 11/2013; 29(3):469-77. · 1.75 Impact Factor
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    ABSTRACT: Expanded use of artificial insemination (AI) and/or adoption of emerging reproductive technologies for beef heifers and cows require precise methods of estrous-cycle control. New protocols for inducing and synchronizing a fertile estrus in replacement beef heifers and postpartum beef cows in which progestins are used provide new opportunities for beef producers to synchronize estrus and ovulation and to facilitate fixed-time AI. This article reviews the various estrous synchronization protocols currently available for use in replacement beef heifers. New methods of inducing and synchronizing estrus now create the opportunity to significantly expand the use of AI in the United States cowherd.
    Veterinary Clinics of North America Food Animal Practice 11/2013; 29(3):591-617. · 1.75 Impact Factor
  • David J Patterson, Michael F Smith
    Veterinary Clinics of North America Food Animal Practice 11/2013; 29(3):xiii-xiv. · 1.75 Impact Factor
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    ABSTRACT: Two experiments were conducted to examine the necessity of adding a GnRH injection to a 14-d controlled internal drug release (CIDR)-based protocol for synchronization of estrus and ovulation in postpartum beef cows. The experiments were designed to characterize long-term CIDR-based protocols in cyclic and noncyclic postpartum beef cows on the basis of estrous response, follicular dynamics and serum steroid hormone concentrations. In Exp. 1 and 2, cross-bred lactating beef cows (n = 40 and 38, respectively) were randomly assigned to 1 of 2 treatments by age, days postpartum (DPP), BCS, and estrous cyclicity status: 1) cows received a CIDR from d 0 to 14, followed by GnRH 9 d after CIDR removal (d 23), and PGF2α on d 30 (CIDR Select) or 2) CIDR administration from d 0 to 14, followed by PGF2α 16 d later (d 30; Show-Me-Synch). Estrus detection was performed using HeatWatch transmitters applied from CIDR removal to AI. Cows in Exp. 1 were artificially inseminated based on detected estrus, while cows in Exp. 2 were inseminated at a fixed-time. In both experiments, follicle turnover on d 25 of treatment was greater among CIDR Select-treated cows (P < 0.001) compared to Show-Me-Synch-treated cows. In Exp. 1, CIDR Select-treated cows tended to have a reduced (P = 0.06) variance for the interval to estrus after PGF2α than Show-Me-Synch-treated cows. Also, cows assigned to the CIDR Select protocol had higher concentrations of progesterone (P < 0.05) on the day prior to PGF2α administration, as well as higher concentrations of estradiol-17β (P < 0.01) 48 h after PGF2α administration. In Exp. 2, mean dominant follicle diameter on d 23 and at FTAI did not differ between treatments (P > 0.10), but Show-Me-Synch-treated cows had larger follicles at d 28 (P < 0.001) and tended to have larger follicles at PGF2α (d 30; P = 0.06) compared to cows assigned to CIDR Select. In summary, the administration of GnRH on d 23 of a long-term CIDR-based estrus synchronization protocol increased follicle turnover; however, both long-term CIDR-based protocols yielded similar physiological outcomes among estrous-cycling and anestrous postpartum beef cows.
    Journal of Animal Science 04/2013; · 1.92 Impact Factor
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    ABSTRACT: The objective was to compare pregnancy per AI (P/AI) with conventional (CON) or sex-sorted (SS) semen from a single sire within a fixed-time AI (FTAI) program designed for dairy heifers. Holstein heifers (n = 240) were assigned to treatment (CON or SS) according to body weight and reproductive tract score. All heifers underwent FTAI by using the "Show-Me-Synch" protocol [controlled internal drug release (CIDR) insert from d 0 to 14 followed by PGF(2α) (25 mg i.m.) 16 d after insert removal (d 30) with GnRH (100 µg i.m.) and FTAI at 66 h after PGF(2α)]. A single professional technician performed the FTAI. Heifers were fitted with heat detection patches at PGF(2α) to characterize estrous response. Estrous response did not differ between CON (63/120; 53%) and SS (70/120; 58%) treatments. The CON heifers, however, achieved greater FTAI P/AI (82/120; 68%) compared with SS (45/120; 38%) heifers. The P/AI did not differ for CON heifers that exhibited or failed to exhibit estrus before FTAI [44/63 (70%) vs. 38/57(67%), respectively]. For SS heifers, however, those that exhibited estrus had greater P/AI compared with those that failed to exhibit estrus [32/70 (46%) vs. 13/50 (26%)]. Pregnancy per AI resulting from FTAI was greater for heifers that were inseminated with CON semen compared with those that received SS semen. The expression of estrus before FTAI did not affect P/AI when CON semen was used, whereas the P/AI with SS semen was greater for heifers detected in estrus. Further studies are required to develop strategies for using sex-sorted semen when inseminating heifers at predetermined fixed times on the basis of expression of estrus before FTAI.
    Journal of Dairy Science 12/2012; · 2.55 Impact Factor
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    ABSTRACT: The mission of the Cooperative Extension Service, as a component of the land-grant university system, is to disseminate new knowledge and to foster its application and use. Opportunities and challenges facing animal agriculture in the United States have changed dramatically over the past few decades and require the use of new approaches and emerging technologies that are available to extension professionals. Increased federal competitive grant funding for extension, the creation of eXtension, the development of smartphone and related electronic technologies, and the rapidly increasing popularity of social media created new opportunities for extension educators to disseminate knowledge to a variety of audiences and engage these audiences in electronic discussions. Competitive grant funding opportunities for extension efforts to advance animal agriculture became available from the USDA National Institute of Food and Agriculture (NIFA) and have increased dramatically in recent years. The majority of NIFA funding opportunities require extension efforts to be integrated with research, and NIFA encourages the use of eXtension and other cutting-edge approaches to extend research to traditional clientele and nontraditional audiences. A case study is presented to illustrate how research and extension were integrated to improve the adoption of AI by beef producers. Those in agriculture are increasingly resorting to the use of social media venues such as Facebook, YouTube, LinkedIn, and Twitter to access information required to support their enterprises. Use of these various approaches by extension educators requires appreciation of the technology and an understanding of how the target audiences access information available on social media. Technology to deliver information is changing rapidly, and Cooperative Extension Service professionals will need to continuously evaluate digital technology and social media tools to appropriately integrate them into learning and educational opportunities.
    Journal of Animal Science 10/2012; 90(10):3677-92. · 1.92 Impact Factor
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    ABSTRACT: This experiment was conducted to compare pregnancy rates in postpartum beef cows resulting from fixed-time AI (FTAI) after treatment with controlled internal drug release (CIDR)-based protocols to synchronize estrus. Cows assigned to the Show-Me-Synch (n=167) protocol received a CIDR from d 0 to 14, and prostaglandin F(2α) (PGF(2α)) on d 30. Cows assigned to 7-d CO-Synch+CIDR (n=177) received a CIDR and gonadotropin releasing hormone (GnRH) on d 23. On d 30, CIDRs were removed and PGF(2α) was administered. Blood sampling occurred on d -10 and 0 of treatment to determine estrous cyclicity status (progesterone ≥0.5 ng/mL estrous cycling). Treatments were balanced on age, DPP and BCS. Estrous detection was performed using HeatWatch from PGF(2α) to FTAI. Artificial insemination was performed at predetermined fixed times (72 h, Show-Me-Synch; 66h, 7-d CO-Synch+CIDR) and all cows were administered GnRH at FTAI. This experiment was conducted over a two year period; no differences were found between years so the data were pooled for further analysis. Pregnancy rate resulting from FTAI did not differ (P>0.10) between technicians or AI sires. Pregnancy rate resulting from FTAI was similar between treatments (P=0.20); however, cows that exhibited estrus prior to FTAI had a higher pregnancy rate (P<0.01) than for those that did not. Pregnancy rate at the end of the breeding period was similar between treatments (P=0.28). In summary, FTAI pregnancy rates were similar among postpartum beef cows following treatment with either a short- or long-term CIDR-based estrous synchronization protocol.
    Animal reproduction science 04/2012; 132(1-2):11-6. · 1.56 Impact Factor
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    ABSTRACT: Since its formation, the Beef Reproduction Task Force (BRTF) has worked to enhance productivity and profitability of US beef herds by integrating research and extension efforts with the intent of more effectively transferring the use of reproductive technologies to the field. A key early step was to coordinate efforts in identifying effective breeding management protocols for beef cattle and to clarify their associated acronyms. A short list of recommended protocols and their acronyms for synchronization of estrus and ovulation in beef cattle was developed based on results from peer-reviewed, published research and a comprehensive review of data collected from the field. The list of recommended protocols was developed by the BRTF in cooperation with veterinarians and cattle AI industries. These protocols and their acronyms are presented uniformly in all of the major AI sire directories and are available online at http://www.beefrepro.info. Protocol updates are made annually to incorporate the most recent research findings related to estrous cycle control in beef cattle. The Estrus Synchronization Planner, a software program developed in cooperation with the Iowa Beef Center, now reflects these same recommendations. Beginning in 2002, the BRTF hosted and presented 11 educational workshops to more than 1,900 attendees in key cow-calf states. These Applied Reproductive Strategies in Beef Cattle workshops targeted beef producers, AI industry personnel, veterinarians, allied industry representatives, and academicians. A national media sponsor provided online coverage of the last 3 workshops at http://www.appliedreprostrategies.com. A postmeeting evaluation, developed to assess application of information from 2 recent workshops, was returned by 55% of those contacted (n = 150). Attendees averaged 16 (± 13.4 SD) yr of AI experience, and 80% of respondents represented more than 100 cows. Respondents were asked to estimate the value of AI-sired calves compared with natural-service-sired calves to their operation on a per-animal-marketed basis, and 17 and 31% responded $50 to $100 per animal and more than $100 per animal, respectively. As a result of what was learned at these conferences, 78% of respondents were better able to troubleshoot management-related issues, 60% made alterations to a protocol they had been using, and 35% of the respondents indicated they changed to a different estrus synchronization protocol.
    Journal of Animal Science 05/2011; 89(9):2950-4. · 1.92 Impact Factor
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    ABSTRACT: Two experiments were conducted to compare pregnancy rates resulting from fixed-time AI (FTAI) after administration of 1 of 2 long-term controlled internal drug release (CIDR)-based protocols. Heifers were assigned to treatment by age, BW, and pubertal status. The CIDR Select-treated heifers (Exp. 1, n = 37; Exp. 2, n = 192) received a CIDR (1.38 g of progesterone) from d 0 to 14, followed by 100 µg of GnRH, intramuscularly (i.m.) 9 d after CIDR removal (d 23) and PGF(2α) (25 mg, i.m.) 7 d after GnRH treatment (d 30). Heifers assigned to the Show-Me-Synch protocol (Exp. 1, n = 40; Exp. 2, n = 200) received a CIDR from d 0 to 14, followed by PGF(2α) 16 d later (d 30). Artificial insemination was performed at 72 or 66 h after PGF(2α) treatment for the CIDR Select- and Show-Me-Synch-treated heifers, respectively, and each heifer was given GnRH (100 µg, i.m.) at the time of AI. In Exp. 1, ovaries of each heifer were examined by transrectal ultrasonography on d 23 and 30 to characterize follicular dynamics. Follicles ≥5 mm and the presence of corpora lutea were recorded. On d 25, ovaries of each heifer were examined to characterize the status of dominant follicles recorded on d 23. Heifers were fitted with HeatWatch (DDx Inc., Denver, CO) estrus-detection transmitters at PGF(2α) to characterize estrus distribution up to FTAI. The diameter of dominant follicles on d 23 at PGF(2α) and on d 30, and the estrous response after PGF(2α) treatment up to the point of FTAI did not differ between CIDR Select- and Show-Me-Synch-treated heifers. Concentrations of progesterone in serum at PGF(2α) were greater (P = 0.07) in Show-Me-Synch- than CIDR Select-treated heifers (6.0 vs. 4.8 ng/mL, respectively). Pregnancy rates of heifers resulting from FTAI did not differ (P = 0.33) between CIDR Select- and Show-Me-Synch-treated heifers (CIDR Select, 59%; Show-Me-Synch, 70%). In Exp. 2, FTAI pregnancy rates tended (P = 0.07) to be greater in Show-Me-Synch-treated (62%) than in CIDR Select-treated (51%) heifers. Pregnancy rates at the end of the breeding season did not differ (P = 0.72; CIDR Select, 85%; Show-Me-Synch, 83%) between treatments. In summary, pregnancy rates resulting from FTAI were comparable for heifers assigned to each of the 2 long-term progestin-based protocols. The reduced treatment cost and animal handling associated with administration of the Show-Me-Synch protocol offer distinct advantages over the CIDR Select protocol despite similarities in pregnancy rates resulting from FTAI.
    Journal of Animal Science 04/2011; 89(5):1358-65. · 1.92 Impact Factor
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    ABSTRACT: Two experiments evaluated long-term progestin-based estrus-synchronization programs on the basis of potential for use in facilitating fixed-time AI in estrous cycling and prepubertal beef heifers. In Exp. 1, heifers were assigned to 1 of 2 treatments by age, BW, and estrous cyclicity status. Heifers assigned to the melengestrol acetate-PGF(2α) protocol (MGA-PG; n = 50) received MGA (0.5 mg·animal(-1)·d(-1)) in a 1.0-kg carrier from d 0 to 13 and were administered PGF(2α) (25 mg, intramuscularly) 19 d after MGA withdrawal (d 32). Heifers assigned to the Show-Me-Synch protocol (n = 49) received a controlled internal drug release (CIDR) insert (1.38 g of progesterone) from d 2 to 16 followed by PGF(2α) administration 16 d after CIDR removal (d 32). All heifers were fitted with HeatWatch estrus-detection transmitters at the time of progestin removal for continuous estrus detection through the synchronized period after PGF(2α). In Exp. 2, heifers (n = 396) were assigned to the same 2 treatments described in Exp. 1 by age, BW, and reproductive tract score. Heifers in Exp. 2, however, were fitted with HeatWatch estrus-detection transmitters at PGF(2α) to characterize estrus-distribution patterns during the synchronized period after PGF(2α). Heifers in both experiments were inseminated approximately 12 h after the onset of estrus. In Exp. 1, estrous response after PGF(2α) and mean interval to estrus after PGF(2α) did not differ between MGA-PG and Show-Me-Synch treatments (P = 0.97). The variance for interval to estrus after PGF(2α) tended (P = 0.06) to be reduced among MGA-PG-treated heifers compared with Show-Me-Synch-treated heifers. Conception to AI, AI pregnancy, and final pregnancy rates did not differ (P > 0.1) between treatments. In Exp. 2, estrous response after PGF(2α) was greater (P = 0.01) among Show-Me-Synch-treated heifers (92%) compared with MGA-PG-treated heifers (85%); however, mean interval to estrus after PGF(2α) did not differ (P = 0.74) between MGA-PG (57.4 ± 2.5 h) and Show-Me-Synch (56.2 ± 2.5 h) treatments. The variance for interval to estrus after PGF(2α) was reduced (P < 0.01) among Show-Me-Synch-treated vs. MGA-PG-treated heifers. Conception to AI, AI pregnancy, and final pregnancy rates did not differ (P > 0.1) between treatments. In summary, the Show-Me-Synch protocol compared favorably with the MGA-PG protocol on the basis of estrous response, synchrony of estrus, and resulting fertility after treatment administration.
    Journal of Animal Science 11/2010; 88(11):3568-78. · 1.92 Impact Factor

Publication Stats

549 Citations
108.26 Total Impact Points

Institutions

  • 1997–2013
    • University of Missouri
      • Division of Animal Sciences
      Columbia, Missouri, United States
  • 1990–1996
    • University of Kentucky
      • Department of Animal & Food Sciences
      Lexington, Kentucky, United States
  • 1989–1992
    • Kansas State University
      • Department of Animal Sciences and Industry
      Manhattan, KS, United States