Brief Summary of Minutes of Annual Meeting

Bob Godfrey (Chair and host of the meeting) called the joint meeting of the W-1173 and S-1023 projects to order at 8:30 a.m. Attendance was taken and self introductions were made. Both groups met together to share information. Don Lay - Chair of the W-1173 group, made some general introductory comments about the format of the meeting. There were two presentations discussing an overview of each group followed by poster presentations. Bob Godfrey, in place of Scott Willard, presented a summary/overview of the S-1023 project describing what activities were taking place and which participants were working in each area. Don Lay gave an overview of Stress physiology past and present. After both presentations there was a general discussion that generated extensive discussion among the group regarding difference in terminology and general measurements of stress. What is/are the best measurements of stress? This was followed by general group discussion regarding-best/appropriate measurements of animal stress. The group discussed the possibility of conducting a review of all food animal stress (heat stress primarily) experiments and evaluate the data to see what is missing in the literature. Further discussion included developing a publication through the Journal of Animal Science regarding the minimum measurements that should be taken when trying to study and publish stress in animals based on the outcome of the above mentioned review paper. Several researchers were interested in potentially leading this effort. Further discussion followed indicating that this seems like a good idea but caution needs to be used when trying to dictate what measurements are best to measure stress because of the array of different types of stress and the difficulty in defining stress. Concern was also expressed regarding the potential impact on producers having to implement the recommendations from the standardized research guidelines and outputs to production operations. General comments that resulted: 1) Needs to be biologically significant, 2) Measure production output, 3) Genetic/environment interaction, 4) Types of stress, 5) Develop a stress index (overall change rather than absolute values), 6) Combination of physiology and behavior, 7) Standard methods. There were also suggested guidelines to standardize stress research in production animals: 1) Minimal measures/standards of stress in animals in order to publish data related to stress, 2) Combination between physiological and behavioral measurements, 3) Sample size. A discussion followed regarding the Journal of Animal Science and different types of communications that the Journal was considering. Two 1-hour poster sessions were held in the afternoon. The first hour session, ½ of the attendees stood by their poster and answered questions, and then the second group stood by their posters and answered questions during the second hour. The poster session was well received. Afterwards, collaborations among participants were discussed. Business Meeting: 1) The station reports were discussed and it was decided that they should be sent to Bob Godfrey by September 15 to be summarized for the annual report. 2) The issue of the joint meeting was discussed and it was decided that it was a good idea to meet together, but the entire S-1023 group would be polled to see if there is a consensus. 3) It was also discussed as to whether S-1023 should merge into W-1173 in the future instead of trying to stand alone with a specific dairy heat stress focus. The dwindling number of active participants in S-1023 is an indicator that this may be a worthwhile move. 4) The poster session met with good reviews. All members present liked the extra time for discussion and the ability to focus on specific studies of interest to them. 5) The topic of research protocols and their placement on the web page was brought up. Bob Godfrey has been keeping the web page and will make an effort to get it up to date (new project number, protocols, members list, etc.). 6) John Smith (KS) was nominated and accepted as secretary. 7) Because of the short time between meetings it was decided that we would not meet as we usually do in conjunction with the Southern Section Animal Science Meetings, but instead will meet jointly with W-1173 again, pending a poll of all S-1023 members. That meeting will be in Colorado in August 2008. 8) After the business meeting the group met jointly with the W-1173 group to have a final discussion followed by adjournment.

Accomplishments and Impacts: Note that the principal reporting station is indicated in relation to the stated accomplishment and subsequent impact, but may involve more than one investigator from that station. Multi-state collaborative projects are indicated within the Accomplishments under each sub-objective and are further reflected in the List of Publications and Plans for the Coming Year follow the Accomplishments and Impacts. OBJECTIVE 1: DEFINING THE PHYSIOLOGICAL CHARACTERISTICS OF HEAT-STRESSED DAIRY CATTLE 1A: Quantifying heat stress in dairy cattle. " Accomplishments: Mississippi is coordinating an effort by S-1023 participants to develop a review paper or compendium on the effectiveness and comparative aspects of body temperature measures as applied to dairy cattle. It is hoped that this work will not only serve as a resource to investigators across the country, but also aid the group in standardizing body temperature measures across experiments to permit greater comparisons of body temperature measures and treatment effects across studies. Correlations of temperature readings among measurement methods (rectal thermometers, tympanic probes, rumen, implanted or intravaginal temperature recording devices and others) with ambient temperature and THI have been conducted among participating stations and are in the process of be consolidated into an outline for preparation of a body temperature measurement manuscript. In Mississippi a study was conducted to compare body temperature measures between Holstein and Gir x Holstein cows in relation to environment and stage of the estrous cycle. We have previously shown that Gir x Holstein (GxH) cows have higher body surface and lower rectal temperatures (RT) than Holstein (HOL) cows under heat-stressed conditions. However the influence of coat color and stage of the estrous cycle on body temperatures (BT) have not been evaluated, therefore our objective was to compare BT responses of HOL vs. GxH cows in relation to these parameters (coat color and estrous cycle) during summer heat stress. Cows were fitted with the HeatWatch estrus detection system, an intravaginal temperature probe inserted, and cows received two injections of PGF2-a 11 d apart to synchronize estrus (d -10 and 0). From d -10 to d 46 (56 d), measurement periods were conducted weekly (three times AM and five times PM weekly) and included: ambient temperature, temperature-humidity index, rectal temperature, respiration rate, digital infrared thermography of the eye (maximum eye temperature), and a blood sample (serum) for progesterone (P4) by RIA. Cow body temperature measures were analyzed in relation to environmental measures and stage of the estrous cycle [luteal (LUT) vs. follicular (FOL) phases]. To summarize our findings, HOL and GxH cows were similar in body temperature measures during the estrous cycle (LUT and FOL). For environmental measures, HOL cows exhibited higher body temperatures and respiration rates than GxH cows. These data demonstrate breed and time of day, but not stage of the estrous cycle differences, on body temperature measures that are important in assessing the relative impact of ambient environment and heat stress on cow responsiveness. 1B: The effect of various summer cooling strategies on symptoms of heat stress, endocrine status and lactation performance. " No accomplishments to report for this Objective within this reporting period. 1C: Characterize the impact of prepartum cooling and identifying prepartum metabolic and endocrine markers as indicators of postpartum performance. " Accomplishments: In Mississippi a preliminary study was conducted to determine the endocrine parameters related to the prepartum period in Holstein dairy cattle in relation to cooling strategy (Fans vs. Fans and Sprinklers). Samples were collected starting 21 days prior to anticipated calving date through day 60 postpartum. In addition to environmental measures (ambient temperature and relative humidity), body temperature measures (rectal temperatures and coat surface thermal measurements) and postpartum production data (milk production, calf weights, postpartum reproduction etc.) were acquired. Data is being analyzed currently, and will be used as preliminary data for a multi-state effort addressing prepartum cooling effectiveness on postpartum production performance and rebreeding. 1D: Characterize the effect of genetic selection in heat tolerance. " Accomplishment/Impact: Virginia is in the process of collecting data to examine potential benefits of crossbreeding to improve milk yield and reproductive performance of heat-stressed dairy cows. 1E: Determining the relationships between coat color and cow body size on production performance in heat-stressed dairy cattle " Accomplishments: In Mississippi a comparison of physiological responses between Holstein and Gir x Holstein cows of different coat color characteristics were assessed in relation to environmental parameters. Non-lactating Holstein [n=5 white (WH) and n=6 black (BH)] and GxH [n = 7 dark (DK) and n = 4 light (LT)] were fitted with intravaginal temperature probes to acquire vaginal temperatures at 5 min intervals from July to Sept 2006. During the 56 d measurement period, data was collected weekly (three times AM and five times PM weekly) and included: ambient temperature, temperature-humidity index, rectal temperature, respiration rate and digital infrared thermography of the eye. Cow body temperature was analyzed in relation to environmental measures. Ambient temperature differed AM vs. PM, with THI ranging from 69.8 to 90.6. DK and LT GxH cows did not differ in BT AM or PM. While BH was similar to WH in the AM, they differed from one another in the PM. Body temperature of Holstein cows increased from AM to PM, while GxH cows decreased or increased only slightly depending on the body temperature measure. Holstein cows had a greater increase in respiration rate from AM to PM than GxH cows. In summary, non-lactating HOL and GxH cows were similar in body temperature measures in the AM environment. However for PM measures, Holstein cows exhibited higher body temperatures and respiration rates which were further influenced by coat color. OBJECTIVE 2: IMPROVING FERTILITY OF HEAT-STRESSED DAIRY COWS WITHOUT DECREASING MILK PRODUCTION 2A: Use of supplemental hormone administration pre- and post-breeding to improve fertility of heat-stressed dairy cattle " Accomplishments: Previous efforts have shown that the size of the ovulatory follicle may be reduced in heat-stressed cows and that the oocyte contained within that follicle may mature faster than in cows not experiencing heat-stressed. With this in mind, efficacy of various strategies to increase ovulatory follicle size and reduce time to ovulation has become a focus in our laboratory. In Tennessee lactating Holsteins (65-115 DIM) received an EAZI-BREED CIDR and administered 100 ¼g of GnRH. Seven days later, CIDRs were removed, 500 ¼g of cloprostenol was administered. Cows were then randomly allocated to receive either 80 mg FSH (Folltropin-V) or sterile saline (SAL). Forty-eight hours later, cows within the FSH and SAL groups were then subdivided to receive 100 ¼g Cysterolin or 3000 IU Chorulon. Growth of the ovulatory follicle and ovulation was assessed using ultrasound. Although data analysis is ongoing, initial assessments have shown that the size of the ovulatory follicle at GnRH or hCG administration did not differ for FSH or SAL cows (16.7 ± 0.7 v. 17.5 ± 0.6 mm); nor did the total growth of the ovulatory follicle from CIDR removal to ovulation differ. As calculated from time of CIDR removal, ovulation occurred earlier in FSH (63.6 ± 4.5 h) versus SAL-treated cows (77.2 ± 4.4 h; P < 0.05). Combination of FSH\GnRH produced the earliest ovulation. Regardless of FSH or SAL treatment, cows treated with GnRH ovulated earlier than hCG (75.5 ± 0.7 v. 78.3 ± 0.6 h; respectively, P < 0.05). " Accomplishments: In North Carolina low doses of follicle stimulating hormone (FSH) were used to try and improve follicle development and oocyte competence in heat stressed cows. Lactating dairy cows were synchronized using the Ovsynch protocol and then assigned to either FSH (N=40) or control (N=38) groups. The Ovsynch protocol consists of an injection of gonadotropin releasing hormone (GnRH) followed seven days later by an injection of prostaglandin F2 alpha (PGF) and then 48 hours after PGF another injection of GnRH. FSH-treated cows received injections of 30 mg FSH twice daily on days 3-6 after ovulation in response to the Ovsynch protocol and in the AM of day 7 after Ovsynch induced ovulation for a total of 210 mg FSH. Luteolysis was induced with 25 mg of PGF at 40 hours after the final FSH injection. Cows were inseminated 12 hours after estrus detection or if not detected in estrus at 72 hours after PGF and simultaneously treated with 100 ug GnRH. Ultrasonography was used at day eight after insemination to determine the number of corpora lutea (CL) and again 30 days after insemination to determine if cows were pregnant and if so the number of embryos in each. The average number of CL were greater in FSH treated cows (2.31 ± 0.3 FSH vs. 1.09 ± 0.1 controls). One FSH treated cow had five CL. No control cows had more than two CL. The number of embryos was not affected by FSH treatment. Average number of embryos per cow for those that became pregnant was 1.0 ± 0.1 for controls vs. 1.3 ± 0.2 for FSH treated. No cows had more than two embryos. Pregnancy rates were not different between groups (26.1% FSH vs. 18.2% controls) due to low numbers per treatment. It was encouraging that the FSH treatment did not induce more multiple births or any greater than twins. FSH treatment had no effect on milk production. Repetition of the experiment this year will enable us to determine if pregnancy rates will be different for the treatment groups. 2B: Establishing hormone markers pre-breeding as predictors of reproductive success in heat-stressed and non-heat-stressed dairy cows " No accomplishments to report for this Objective within this reporting period. 2C: Use of interval cooling (i.e., immediately before and after breeding) to improve fertility of problem breeders and heat-stressed dairy cows " No accomplishment to report for this Objective within this reporting year. 2D. Use of targeted vitamin and mineral supplementation in conjunction with estrous synchronization and timed-AI to improve fertility in heat-stressed dairy cows " Accomplishment: A field trial was initiated at Rose Ark Dairy Farm [elevation 802 ft (244 m), location N 35o 21.6 and W 92o 07.7] near Rosebud, Arkansas on July 1, 2005 to evaluate the effects of feeding Tasco Ascophyllum nodosum to high producing dairy cows under heat stress. Cow fed Tasco had improved respirations per minute on August 3rd (77.3 compared to 88.5 for control cows; P < 0.05), on August 10th (80.0 compared to 91.4 for control cows; P < 0.01), on August 31st (66.6 compared to 71.5 for control cows; P < 0.05), and on September 7th (60.6 compared to 68.1 for control cows; P < 0.01). These cows were bred, but the number of pregnancies from the larger breeds was very low (3 of 50) for control cows. That is probably typical of Holstein cows in the region, and many herd managers in the region do not even try to breed cows during hot weather because of low breeding efficiency. With Tasco in the diet, the pregnancy rate was enhanced (P < 0.01) dramatically (20 of 55). While that is not an exceptionally high percentage, it is quite high for summer months in central Arkansas. The number of inseminations per conception and the days open before first service did not vary (P > 0.05) among treatment groups. OBJECTIVE 3. IMPROVING MILK PRODUCTION OF HEAT-STRESSED DAIRY COWS WITHOUT DECREASING FERTILITY 3A: The effect of heat stress on nutritional requirements of high-producing dairy cows " No accomplishments to report for this Objective within this reporting period. 3B: The effects of high protein diets on production performance and summer breeding in dairy cows. " This sub-objective is not being investigated currently, but may be addressed in future years of this project by collaborating stations or as coupled with other sub-objectives. 3C. The effect of dietary supplements (antioxidants, minerals and probiotics) to enhance nutrient intake and digestibility " Accomplishment: Cows fed Tasco produced more (P < 0.01) milk during July, August, and September (Table 2). However, there was a significant interaction with size of cows during August (P < 0.01) and September (P < 0.05) caused by approximately a 2.3 kg difference for the larger cow groups compared to similar yield for smaller cows, and that should be considered in making recommendations. In other words, Tasco prevented the steep decline in milk yield of the larger cows. The results in central Arkansas indicate that Tasco is beneficial to milking cows during heat stress. PLANS FOR THE COMING YEAR  ESTABLISHED COLLABORATIONS AND ON-GOING PROJECTS " Coat color studies and determination of percentages of black vs. white hair coat. (OBJ 1E; PR, MS, TN and others?; VI-STX Lead) " Enzyme enhancements in diets while grazing southern forages. (OBJ 3C; PR, GA, Others?, GA - Lead) " Body temperature and estrous cycle - data mining and/or implementation of a summer study (OBJ 1A - MS, TN; TN- Lead) " Body temperature correlates among different measurement techniques, and the proposed coordination of S-1023 to compose a review article (i.e., for Southern Cooperative Series Bulletin; OBJ 1A - All stations - MS  Lead) " Prepartum Cooling - metabolic/postpartum/cooling methods will be investigated along with nutrition x reproduction interactions related to prepartum cooling (OBJ 1C - GA, TN, NC, MS - Lead). " Mississippi agreed to take lead effort to organize/develop a research proposal to be submitted as an integrated research and extension project to NRI-CGP.

Refereed Journals and Peer-Reviewed Proceedings: 1) Schrock G.E., A.M. Saxton, F.N. Schrick, and J.L. Edwards. 2007. Early in vitro fertilization improves development of bovine ova heat stressed during in vitro maturation. Journal of Dairy Science 90:4297-4303. 2) Giordano J.O., J. L. Edwards, G. M. Schuenemann, N. Rohrbach, and F. N. Schrick. Strategies to increase ovulatory follicle size and reduce ovulation time in lactating dairy cows. (Abstract submitted for consideration by International Embryo Transfer Society Meetings). 3) Kellogg, D.W., Pennington, J.A., Johnson, Z.B., Anschutz, K.S., Colling, D.P., and Johnson, A.B. 2006. Effects of feeding Tasco Ascophyllum nodosum to large and small dairy cows during summer months in central Arkansas. J. Dairy Sci. 89:65 (Abstr.). 4) Harrington, T.W., Pennington, J.A., Johnson, Z.B., Brown, A.H., Jr., Kellogg, D.W., Rosenkrans, C.F., Andrews, M.C., and Hawkins, J.A. 2006. Factors affecting udder singeing in dairy cattle. J. Dairy Sci. 89:112 (Abstr.). 5) Eicher, S.D., M.M. Shutz, S.T. Willard, S. Bowers, S. Gandy and K. Graves. 2007. Pre-partum milking and parlor habituation in primiparous Holstein heifers. Journal of Dairy Research 74 (4): 413-417. 6) Tyra, J.D., M. McGee, S. Bowers, A. Harris, A. Musselwhite and S.T. Willard. 2007. Development of a model for temperament modification in cattle: Investigation of fluphenazines effect on animal activity and physiological response. CVM Summer Research Fellowship Program, Mississippi State University, July, 2007. 7) Dray, S., A. Harris, R. Farrar, G. Grissett, S. Laird and S. Willard. 2007. A comparison of body temperature measures between Holstein and Gir x Holstein cows in relation to environment and stage of the estrous cycle. ASAS National Meeting  San Antonio, TX. 8) Willard, S.T., S. Dray, R. Farrar, M. McGee, S. Bowers, A. Chromiak and M. Jones. 2007. Use of infrared thermal imaging to quantify dynamic changes in body temperature following LPS administration in dairy cattle. American Society of Animal Science - Southern Section; Mobile, AL; Feb. 2007. Popular Press Articles/Meeting Abstracts/Experiment Station Reports/Others: 1) Kellogg, D.W., Anschutz, K.S., and Pennington, J.A. 2006 Report of research trial with Tasco at Rose Ark Dairy in Arkansas during summer 2005. Z.B. Johnson and D.W. Kellogg (ed). Arkansas Agric. Exp. Stat. Res. Series. 2006 Arkansas Anim. Sci. Rep. 100-104.