A Typical Sampling Visit

This is to give you an insight into what a 'typical' sampling trip involves when one is conducting a sheep genetics study for various traits! Usually I'm by myself so I don't have many photos to share, but will share what I do have. 

It first begins with an introductory email to a shepherd if I don't know them personally. I try to give an idea of the project without getting too technical so I don't scare potential shepherds away! Once I get a response, I plan a day and time for a farm visit. I usually try to cluster farms together that are geographically close to make my trips more efficient. I've had the opportunity to sample sheep across the Northeast & Great Lakes so far. I'm usually sampling on my own so I use a voice recorder to keep track of some the data I collect. 

Most of my sampling so far has been for out of season lambing and mature body size studies. The out of season lambing piece involves looking over lots of lambing records provided by the owner. The second piece is a lot more intensive. I have a series of 28 measurements that I take on mature ewes and rams shortly after shearing. These include various bone lengths, circumferences, and heights. Even though it is a lot of measures, it usually only takes 2-3 minutes to do all of the measurements on each ewe. So far I have measured about 560 sheep from about 20 or so different breeds ranging from Jacobs to Suffolks, this even includes some Dorsets from the UK!! With these measurements I'm hoping to identify the genes responsible for big vs little sheep.

 

Once I have the measurements on each sheep, I take a photo of the sheep for my records. Finally I collect a blood or hair sample to provide the DNA from each sheep. Depending on the number of sheep I am sampling from each farm, a visit can range from 15 minutes to a few hours, but on average it's about 10 sheep/hour if I'm sampling for everything.

Usually I start the DNA extraction and several of the undergraduates in the lab will help finish extracting the DNA when they are in the lab. 

 

Once we have the DNA and the phenotypes we can go several different paths. We can run a Polymerase Chain Reaction (PCR) to amplify a specific piece of the genome, run the DNA on a SNP chip which genotypes several hundred thousand markers at once, or sequence the entire genome! It all depends on the project and amount of funding we have. 

The long term goal of the research is to identify the causal mutations in the DNA that are responsible for the different phenotypes we see, such as large or little, black vs brown, or aseasonal or not. Once these mutations are identified we want to develop a cost-effective test that producers can use to test and select their sheep at a younger age. 

If you are interested in having your flock be a part of some of my studies please send me an email (cjp98@cornell.edu) and we'll discuss how you can be involved with this research even more!!