Brief Summary of Minutes of Annual Meeting

Additional information regarding Station activities and goals are included in the compilation of Abstracts submitted prior to the meeting (attached with Meeting Minutes) 

Stations included:  Colorado State, Cornell, Puerto Rico, Oregon State, Ohio State, Arizona, Maryland, Minnesota, Virgin Islands, Nebraska

Accomplishments (from Station Reports submitted to the Chair)

• Terry Engle, Lily Edwards-Callaway, John Wagner, Mark Enns; Colorado State University; Objective 1; Species-Beef Cattle

1) Published scientific, peer reviewed manuscripts, 2) initiated and completed experiments investigating appropriate methods of euthanasia, and 3) initiated and completed live animal and cell culture experiments to help understand mineral homeostasis and interactions with immunity in beef cattle.

• Juliana Ranches, David Bohnert; Oregon State University; Objectives 1,3; Species – Cattle

1) Conducted research trial looking at the effects of trace mineral supplementation prior to weaning and the effects of supplementation on calf health and wellbeing, 2) Conducted research trial looking at the effects the use of GPS-shock collars on behavior of beef cattle, and 3) Conducted research trial looking at the effects of bovine appeasing substance on calf behavior and wellbeing at weaning (Brazil).

• Cassandra Tucker, University of California-Davis; Karin Schutz, AgResearch New Zealand; Grazyne Tresoldi, California State University Chico; Objective 3; Species-Cattle

1) We completed analysis for a year-long project examining the effect of weather and cattle characteristics (age, posture, breed) on respiration rate. We found that respiration rates are higher than values reported in common veterinary textbooks and that calves respiration rates change more quickly than any other age class on the dairy in response to rising ambient temperatures. 2) We compared different types of loggers used to measure cattle body temperature. We found that device type and accuracy affect the measurements taken, as does how often measurements are taken. 3) We have been evaluating different technology to save water and energy when cooling dairy cattle and the results from some of this work have been published this year.

• Dustin Yates, Ty Schmidt and Jessica Petersen, University of Nebraska-Lincoln; Objectives 1,2,3; Species-Cattle, Sheep

1) Data analysis from our July – Sept 2019 beef cattle study conducted in collaboration with Dr. Diaz (Univ of Arizona) continued. The trial was a 24 steer (Red Angus), 2x2 study (heat stress and supplementation with a β2AA). An interaction between supplement and heat stress (P=0.02) was observed in rectal temperature as animals in heat stress had increased respiration rate; the increase in heat stressed animals compared to the thermal neutral controls, however, was not as great in those also fed the β2AA. Respiration rate was significantly increased due to the environment (P=0.01) and tended to be reduced in animals supplemented with the β2AA (P=0.06). 2) Studies of mitochondrial function were based upon data from years 1-3 of the project that revealed βAA supplementation likely alters oxidative phosphorylation. To pursue how the βAA may alter this characteristic of the cell, we used cell culture of skeletal muscle satellite cells. Analyses in cattle revealed that both β1AA and β2AA increased maximal respiration (P=0.004) and spare respiratory capacity (P=0.013) of the cells, demonstrating a mechanism by which these supplements may impact production efficiency. 3) Analysis of the subcutaneous adipose transcriptome from cattle in the heat stress and β2AA study revealed an interaction (P<0.05) of environment and supplement on the expression of some loci; the additional variable of time (-3, 3, 10, or 21 days of treatment) also altered expression. For example, acute phase signaling, a key inflammatory/immune pathway, was upregulated at day 3 compared to pre-trial levels but was inhibited at days 10 and 21. Various other components of inflammatory pathways were observed to be upregulated primarily due to heat stress although investigation of the role of the β2AA remains under investigation.  Pathways related to mitochondrial function (e.g., oxidative phosphorylation, TCA cycle) were also altered due to heat stress contributing to interest in studies outlined above. 4) Our team has been using camera systems developed (NUTrack System) to find a means to identify immune or stress-compromised animals prior to clinical symptoms. The tracking system was utilized in our previous live animal trials and will continue to be refined and tested in upcoming experiments.  Results thus far have shown that the method can accurately measure animal respiration rate and track movement through the duration of a 21 day trial.

• Abner Rodriguez and John Fernandez; University of Puerto Rico-Mayaguez; Objectives No 3; Species Sheep

1) The performance, carcass traits and meat quality of native lambs fed total mixed rations and raised under heat stress conditions was determined. 2) Experiments to determine growth characteristics, puberty, and sexual maturity of male lambs progeny of male crosses Dorper and Katahdin with native ewes raised under heat stress conditions are under progress.

• Shawna Weimer; University of Maryland; Objective 1; Species – chicken

1) Successfully completed an animal experiment where half of the population of 2 breeds of broiler chickens (N=108 birds) were challenged with Salmonella Typhimurium. Lab work has been completed on intestinal histology and sickness behavior and data is being analyzed. 2) Successfully completed an animal experiment where broiler chickens were raised in pens (N=16 pens) with and without spotlights, structural enrichments, or both. SOPs are being developed to train undergraduate students to code for behavior from video recorded throughout the experiment and tibia bones will be measured for morphology and ashed. 3) Preparations for a field study on an organic commercial broiler farm are currently underway.

• Yuzhi Li; University of Minnesota; Objectives 1,3; Species- Swine

1) We evaluated behavioral indicators of pain in castrated pigs. Male piglets (n = 88) were either castrated or sham castrated within 24 hours after birth. Behavior and vocalizations were recorded via video recording. Compared to sham-castrated piglets, castrated piglets kicked more frequently (P < 0.05) during castration. Additionally, 52% of castrated piglets displayed body flailing, whereas only 4.4% of sham-castrated piglets displayed the same behavior (P < 0.01). Castrated piglets had more high frequency calls than sham-castrated piglets (P < 0.05) during castration. Results indicate that castration without the use of analgesia increased the frequency of leg kicks, body failing, and high frequency calls. This suggests that leg kicks, body failing, and high frequency calls are useful behavioral indicators of acute pain in piglets. 2) We evaluated heat stress of lactating sows through behavioral indicators, determining the effects of chilled drinking water and cooled floor pads on their behavior under heat stress. Behavior of sows was video-recorded during farrowing, and days 1, 3, 7, 14, and 21 after farrowing. Cooling treatment had no effect on farrowing, drinking, or postural behavior of the sow.  As lactation progressed, sows increased drinking frequency and time spent lying on chest/belly, standing, and sitting, while decreasing time spent lying on the shoulder in both control and treatment rooms. This study indicates that chilled drinking water and cooled floor pads did not affect behavior of sows during farrowing and lactation. Behavior may be not a good indicator for farrowing/lactating sows under heat stress due to the nursing instinct of the sow. 3) This study evaluated electric-heated mat (EM), water-heated mat (WM), and infrared heat lamp (HL) systems as supplemental heat for piglets from birth to weaning using 42 litters of piglets in three trials, with 14 litters in each treatment group. Postural behaviors were video-recorded and performance data were collected from birth to weaning. Results indicate that piglets spent a similar amount of time on EM as under HL. Growth performance of piglets was comparable among the three heat sources. Taking into consideration the cost and ease of installation, electricity use, and durability of the three supplemental heat sources, EM appear to be a better choice to provide supplemental heat to suckling piglets compared to HL and WM. 4) We developed and tested the novel methods and strategies that are readily applicable on pig farms. Our research indicated that behavior is a good indicator of acute pain caused by castration in piglets. Our research also demonstrated the capacity and limitation of behavior as an indicator of pig welfare. Results of the projects have been disseminated to stakeholders and scientists through publications in peer-reviewed journals and social media, along with presentations at conferences and extension events. Pork producers will use the outcome of the projects to assess pain in pigs, and select proper heating and cooling systems for maintaining thermal comfort of piglets and lactating sows.