Improving Yak Artificial Insemination Conception Rate and Providing Data for Informed Decision-making for Improving Farm Sustainability

View the project final report

Commodities

• Animals: bovine, yaks

Practices

• Animal Production: genetics, livestock breeding

As of the completion of Project FS23-353 we initially bred ten yaks and one jersey cow in March 3^rd and 4th, 2025  at 70 and 96 hours after the CDR was removed. Four weeks later we pregnancy tested  those bred plus a yak which was thirty days pregnant in early February using ultrasound. Of those bred in March three yaks had conceived as well as the Jersey cow. Two of the yaks later aborted. In our second round of breeding done April 11^th and 12th, 2025 four of the yaks did not come into estrus within 96 hours: All of whom came in during the March breeding.   Eight yaks were bred: Seven previously artificially inseminated and the naturally bred yak who had aborted since the February testing.  These eight yaks were not pregnancy tested in the following months due to the physically stressful hot weather and fear of causing an abortion with the additional  stress of an ultrasound. Activity using Estrotech patches, visually monitoring bull activity, and the individual yak cow’s behaviors strongly indicates four pregnancies: This would yield five yak pregnancies for the overall breeding round (March-April) which involved twelve yak cows (40% conception ) and one Jersey cow (100% ). Calving is not until November and December. [Results will be added to this report at that time.]

The second major objective of this project beyond improving the artificial insemination process (from collection of semen through insemination) was to perform a comparative growth study between yak and yak x angus so that beef producers can make informed decisions about introducing yak genetics to their operation. Results from a fifteen week study on a typical Eastern Kentucky fescue and mixed grass pasture the average weight daily gain of four yaks bulls was 0.595 lbs/day. The average daily hybrid gain (two bulls and two female) was 1.365 lbs/day with the two female hybrids having an average gain of 1.49 lbs per day with the two hybrid bulls averaging 1.24 lbs daily.

We had intended on including a comparative meat analysis which compared  protein, fat content and taste of grass fed yak, grass fed angus and grass fed yak x angus sirloin to assist farmers in meat production decision making. However, because of the schedule of the University of Kentucky’s Angus breeding program, the angus cows to produce the hybrid could not be bred early enough in the overall study to have the hybrid calves at slaughter weight within the extended project period. This analysis will be completed during 2026 when the bull hybrids reach slaughter weight and the results will be provided to SSARE.

The final component of the project was to introduce existing and potential small acreage farmers, Black farmers and larger beef producer to yaks and yak genetics as a possible asset to their farm program. Over the two projects FS1-335 and FS23-352 we have held Yak conferences focusing on artificial insemination, yak husbandry and yak products (meat and fiber), run an article in a Cattleman’s Journal and even in Mother Earth News. In this project we have developed a self-run power-point:

"From the Himalayan Mountains to Eastern Kentucky

The Domestic Yak

An Introduction to Yaks and Yak Care'

which has been set up as a link through Google Documents. Information about the link and how to access it has been sent to Cooperative Extension Offices throughout the Southern Region, posted on the North American Yak Association’s website and Facebook, and sent to Historically Black College and University Agricultural Schools in the Southern Region.

The specific FS23-352 project objectives we worked on during this first year of the project are as follows:

• To successfully AI the angus at the University of Kentucky available for us use in this project as early as possible in the project so that we would be able to perform the comparative study described in the abstract.
• To review our semen collection protocol to determine where losses in sperm might be taking place before it is extended.
• Review our semen extending process to minimize the loss of motile sperm before freezing.
• To run side by side processing using several extenders to determine which extender yields the highest post thaw percent sperm motility.
• To determine if it is better fill straws before or after the initial cooling of the extended semen to 5C (41F) over 1.5 hours.
• To see where the freezing system used can be improved. This includes the actual freezing and going from having frozen straws in liquid nitrogen to having them in the LN storage tank.
• How to improve our actual insemination process to increase the conception rate.
• Participated in a SSARE sponsored Yak Conference, Project O522-157, held October 31, 2023. 

The Project objectives worked on during the second year of the Project were:

• Further collection, extending and freezing of yak semen to test the process finalized during the first year and to make improvements.
• Dr. J. W. Lehmkuhler obtained permission from the University of Tennessee Department of Agriculture to use their Computer Assisted Semen Analyzer to better evaluate the post-thaw motility of the extended yak semen we produced and then to evaluate its viability over time. 
• Perform at least one more round of artificial insemination using the Bos Indicus PG 5-Day + CIDR Fixed Time AI Protocol.
• Perform comparative weight gain study involving four yak bulls and the four hybrids produced during year 1 of the project.
• Develop an educational "product" which would be internet accessible to small acreage farmers, Black Farmers and larger beef producers to view on their own schedule which would serve as an introduction to the Domestic Yak, Yak products (meat and fiber) and basic husbandry required. The goal of this is to provide enough information for current and those interested in developing a farm to decide if the inclusion of yaks/yak genetics via AI is worth pursuing. 
• A basic comparative meat study between grass fed yak meat, the yak x angus hybrid yak meat and gras fed angus meat which would look at protein, overall fat, moisture content and have a comparative taste component by a chef(s).
• And finally to develop a guide for persons interested Yak Artificial Insemination (Collection Semen through Insemination) based on what we have learned through Projects FS1-335 and FS23-352.