Brief Summary of Minutes of Annual Meeting

George Smith gave an update on the overall project, upcoming grant opportunities, and a budgetary update. He highlighted the importance of collaborations resulting from NC-2040. Participants discuss their work during the annual meeting, and these discussions should facilitate collaborations across states. Annual meeting report should only discuss multistate efforts. Collaborations are the basis for renewing projects.

Mike VandeHaar discussed that in the past part of the group meeting was designated for discussion of collaborations, and it was suggested that we incorporate that again.

Steve Smith gave updates on USDA/NIFA that was focused on a handout distributed prior to the meeting. There was some discussion of large, multi-agency awards.

Discussion of NASEM 8^th Edition (facilitated by Mark Hanigan, Mike VandeHaar, Ermias Kebreab)

• Years of the process consisted of expanding the data set and validating the data. Goal now is to find a place to store the data and there was a discussion about potentials (ADSA, USDA, CDCB, AFIA, DMI). Suggested that a government entity might not be a good choice due to budget fluctuations. A full-time person, at least for a couple of years, is probably needed to develop and maintain this database. If the position is maintained, the person could work on continuing to update the database.
  • Our group will continue to work on this database idea.
• Discussion about how incomplete data continues to be published in manuscripts. Could potentially have suggestions in JDS like they have the reporting checklist. There is a paper from McNamara a few years ago that includes some of this.
• Discussion about topics where there was not enough information available, and these should be areas of research prior to the next NASEM.
  • More work needed on endogenous flows, particularly of fatty acids. More data on fatty acid digestibility should be published.
  • Total amino acid digestibility should be published instead of selectively reporting individual amino acids.
  • Improved techniques to measure intestinal digestibility and rumen outflow are needed.
• Discussed that it could be useful to have a gethub or some other place for us to share techniques and problems. Troubleshooting procedures takes a long time and can be solved quickly if have the info from someone else who already solved it. Could also be good to have bovine standards. There is a NAMP gethub already set up.
• The model will be made available – so in future there will be potential to run datasets through it.

Planning of 2022 Meeting

• Tanya Gressley will be chair; Barry Bradford will be secretary
• For the Chicago area, consensus that DMI is much better than our previous venue. Discussed Cargill/Purina potentially hosting it (after 2022). Discussed perhaps using a rotating university venue.
• Discussed different timing options. The late October time conflicts with a few dairy conferences. Tanya will send out a poll to narrow down the month/time of year and then specific dates.
• Action items for 2022:
  • Devote time (1/2 day perhaps) to planning rewrite
  • Devote time (~45 minutes) with Juan Tricarico next year to discuss the database and potential collaborations between DMI and NC 2040

Accomplishments

OBJECTIVE 1: To quantify supply, availability, and interaction of nutrients and bioactive compounds utilized for efficient milk production while reducing environmental impact.

Virginia (Hanigan) and Tennessee (Rius) are collaborating on a project to assess the impact of heat stress on intestinal amino acid absorption in dairy calves. The animal experiment was conducted at Tennessee. Sample analyses and modeling work was completed at Virginia. Results interpretation and manuscript preparation were conducted in Tennessee.

Virginia (Hannigan) and Tennessee (Rius) are collaborating with Nebraska, Idaho, Select Sires, and Lely to develop and deploy a system to control grain mix composition fed to cows through automated feeders. The objective of the system is to use a combination of advanced modeling and machine learning approaches to discover the true energy, protein, and essential amino acid requirements for individual cows, and to control automated feeding to achieve diets just meeting those requirements. They have nearly completed initial development of the several software subcomponents of the system, and are working to integrate them into an overall working system.

An ongoing multi-institutional project examining feed efficiency includes NC2040 members from both Wisconsin (H. White) and Michigan (VandeHaar). Mike VandeHaar is the PI of the project with current funding from FFAR and matching funds from CDCB. The project also involves collaborators in Iowa and Florida who are not a part of NC2040.  All stations collect genotypes and phenotypes for feed efficiency, which are compiled into a combined dataset. Additionally, most of the cows studied are fitted with sensors for activity and feeding behavior and temporarily with vaginally indwelling iButtons to record temperature (Combs et al., 2021).  Milk spectra data are also being recorded.  A long-term goal to it estimate feed intake and feed efficiency to increase the pace of improvement in feed efficiency through culling and genetic selection through genomics.

OBJECTIVE 2: To identify and quantify molecular, cellular, and organismal signals that regulate intake, partitioning and efficient utilization of nutrients

Researchers within the feed efficiency collaboration between Wisconsin (H. White) and Michigan (VandeHaar) are taking samples of milk and tissues to elucidate the role of post-absorptive nutrient use efficiency in improving the feed efficiency of producing milk. 

OBJECTIVE 3: To use this knowledge of feed properties and metabolic and molecular quantitative relationships to challenge and refine nutrient requirement models leading to more accurate feeding systems for dairy cattle

The 8th revision of the National Academies of Science, Engineering, and Medicine Nutrient Requirement System for dairy cattle was completed in collaboration with NC2040 members from Virginia (Hanigan), California (Kebreab), Michigan (Allen, VandeHaar), Ohio (Firkins, Weiss), and Maryland (Erdman, retired). Thus the committee was comprised of over 50% NC2040 members. In addition to the publication, code was written in R for use in research and teaching, and it was transcribed into a piece of software for use by the industry. The R code will be distributed with the software and thus openly available. The meta data used for development has been transferred to the National Animal Nutrition Program and most of it has been uploaded to their database for public access. Code to read those data and undertake model simulations will be added to the NANP website in the future.

Combs, G. J., L. Cavani, F. S. Baier, M. J. Martin, S. J. Erb, M. J. VandeHaar, J. E. Koltes, K. A. Weigel, F. Peñagaricano, H. M. White. 2021. Evaluation of the use of intervaginal temperature monitors to assess postprandial body temperature changes. J. Dairy Sci. Accepted. (WI, MI)

Khanal, P., K. L. Parker Gaddis, P. M. VanRaden, K. A. Weigel, H. M. White, F. Peñagaricano, J. E. Koltes, J. E. P. Santos, R. L. Baldwin, J. F. Burchard, J. W. Dürr, M. J. VandeHaar, and R.J. Tempelman. 2021. Multiple trait random regression modelling of feed efficiency in dairy cattle. J. Dairy Sci. Accepted. (WI, MI)

Lui, E., M. D. Hanigan, and M. J. VandeHaar. 2021. Importance of Considering Body Weight Change in response to dietary protein deficiency in lactating dairy cows.  J. Dairy Sci. 2021. (VA, MI)

Tucker, H. A., V. M. R. Malacco, M. D. Hanigan, S. S. Donkin. 2021. Postruminal protein supply upregulates hepatic lysine oxidation and ornithine transcarbamoylase in lactating dairy cattle.  Journal of Dairy Science. 104(4):4251-4259. (VA, IN)