Fistulated/cannulated steer. The cattle are temporarily put to sleep and the plug is surgically implanted. It doesn't hurt them at all, and it allows researchers to study what happens in their stomachs when you feed them different diets. When scientists are done collecting their samples, they can plug the hole so their food doesn't fall out! Cattle have 4 stomach compartments - the rumen is the biggest! When cattle eat foods like hay and grass, the rumen helps them start to break down the starches thanks to helpful bacteria (humans don't have a rumen, that's why we can't eat hay). Then, cattle cough up the mush and "chew their cud" before digesting it a second time - using a stomach just like ours.

Fistulated/cannulated steer. The cattle are temporarily put to sleep and the plug is surgically implanted. It doesn't hurt them at all, and it allows researchers to study what happens in their stomachs when you feed them different diets. When scientists are done collecting their samples, they can plug the hole so their food doesn't fall out! Cattle have 4 stomach compartments - the rumen is the biggest! When cattle eat foods like hay and grass, the rumen helps them start to break down the starches thanks to helpful bacteria (humans don't have a rumen, that's why we can't eat hay). Then, cattle cough up the mush and "chew their cud" before digesting it a second time - using a stomach just like ours.

 A decomposed human rib after dissection. We collect these bones at many time points throughout human decomposition, sequence the DNA inside to look at the microbes, and we hope to use this information to estimate time since death. 

A decomposed human rib after dissection. We collect these bones at many time points throughout human decomposition, sequence the DNA inside to look at the microbes, and we hope to use this information to estimate time since death. 

 Collection of rumen from the fistulated/cannulated steer. This doesn't hurt the animal either! We can pull the contents out through the fistula to see what bacteria are inside the rumen. Yes, it does smell pretty bad :-).

Collection of rumen from the fistulated/cannulated steer. This doesn't hurt the animal either! We can pull the contents out through the fistula to see what bacteria are inside the rumen. Yes, it does smell pretty bad :-).

 How do you find out what mummies ate? You look at their poop, of course! In this picture, Dr. Metcalf is analyzing coprolite (well-preserved ancient poop) that was taken from the intestines of mummies from Sudan. Notice how much clothing she has to wear - that way she doesn't mix her own DNA and bacteria up with the mummy DNA.

How do you find out what mummies ate? You look at their poop, of course! In this picture, Dr. Metcalf is analyzing coprolite (well-preserved ancient poop) that was taken from the intestines of mummies from Sudan. Notice how much clothing she has to wear - that way she doesn't mix her own DNA and bacteria up with the mummy DNA.

 Squeezing out rumen fluid from cattle rumen using cheese cloth, which helps us catch any hay particles. We can put this fluid under a microscope to see bacteria swimming around, or we can sequence the DNA in the rumen fluid to figure out what those microbes are.  We can see how the microbes change based on what the animal eats. 

Squeezing out rumen fluid from cattle rumen using cheese cloth, which helps us catch any hay particles. We can put this fluid under a microscope to see bacteria swimming around, or we can sequence the DNA in the rumen fluid to figure out what those microbes are.  We can see how the microbes change based on what the animal eats. 

 The lab crew during our decomposed human rib dissections. We always wear proper personal protective equipment, including glasses, masks, gloves, and lab coats.

The lab crew during our decomposed human rib dissections. We always wear proper personal protective equipment, including glasses, masks, gloves, and lab coats.