Guinea pigs kept in outdoor mobile tractors, free range and paddocking

I've been keeping guinea pigs in a mobile tractor outside going on 5 seasons, and I wanted to share experiences to interested permies and how I'm keeping these little critters outside all year in zone 7a. This herd started when living in an HOA community, as the organization made me get rid of my chickens that I kept in the tractor. I made a second tractor for the boars after getting my first batch of guinea pigs. They couldn't make me get rid of my 'pet' guinea pigs. My herd has several guinea pigs from the first litter, and the last one from my first batch has passed recently. I've had some ups and downs on how to care, as much of the inter-webs have information on how to keep guinea pigs as a pet, and certainly not outside all year. This thread should should help someone else start up a similar mobile guinea pig tractor with less of the learning curve I've had.

At first I thought my primary use for the critters were for meat, but that became a secondary use after seeing low little meat comes off of one, definitely need to source a Peruvian variety if this is your primary purpose, they are bred twice the size of guinea pigs commonly found around the US. You can find them, however, you need to search. My primary use for these critters are for creating garden compost, kitchen vegetable/fruit scraps, for cutting the lawn, and manuring the lawn. The tractor is just high enough for a typical lawn mowing, and in the summer, that is particularly all they eat aside from a vitamin c source, which was usually scrap item(s) from the kitchen like oranges, lemons, pineapple, peppers. They can go a week without an issue, but more than two weeks without a vitamin c might allow sickness, potentially a guinea pig scurvy. Two weeks has been my maximum, and don't try to wait that long. The grass has enough water content that they don't drink much water directly, as long as the tractor doesn't have much direct sunlight. Guinea pigs will eat just about any vegetation, and I'll supplement with what I have available. The only things I haven't seen them eat are certain vining species. I want to experiment with poison ivy - but haven't had the chance yet.

The picture I uploaded is of my herd free-ranging, and I did that often in my initial 1-2 seasons. In the first season the tractor was directly on the ground, this made free-ranging easy. But they would eat the grass bare where the tractor sat, and overgraze similar to other pasture raised scenarios. I raised the tractor to stop overgrazing. This made it great as a lawn mower. Because my tractor is slightly above the ground, they will hide underneath, and getting them out from underneath is a big hassle. I stopped free ranging for now. They are just fine in the tractors together. When there's plenty of grass, I can't move the tractors often enough it seems. About 4 times a day or every 2-3 hours is about the maximum they could be moved before seeing some patches of grass untouched. They are like little cows for the urban/suburban lawns, when my guinea pigs birthed early from summer heat, so did cows on the farm I was working at. There is slight resemblance in the grazing nature of the animals.

Once my raised beds are up, they will free range in the aisles for lawn mowing so I don't have to source wood chips. Also in the collage are pups, my sows eating kitchen snacks, and finally one cooked up on a dinner plate with a common sun-fish cooked next to it. I'd say the pigs give enough meat comparable to about 3 chicken wings. I stopped feeding pellets like the pellet feeder after season 2, and went to timothy bales that people usually buy for horses. This bale will last me about a month depending on the season. That's the only input for feed. It also serves as bedding if the guinea pigs don't eat all of it. When I take the bedding out to put into compost pile I will put a little bit of hay to get the bedding started and keep them from being in their manure, they will hang in their coop no matter how much manure there is, and will soil the coop readily.

I will share additional updates on specific care and lessons learned through-out the years. If you have questions and how to start an operation of your own, I will be happy to share my experience.

The tractor that I keep my sows in is based off this attached youtube video tutorial on building a rabbit hutch. I built it with chickens in mind, as well as other animals when the chickens had a better space, as there is no roost. When I had to get rid of them on HOA orders, I got guinea pigs for the tractor. Thinking it would be the best animal to keep in an HOA community at the time, and less diet requirements than rabbits. I was also recently with a PDC and we discussed the idea of guinea pigs for meat, and I wanted to give it a try.

My tractor is slightly modified from this tutorial, but very close. The tractor I made for the boars is even more modified, however based on this design as well.


The boar tractor is smaller in height, and uses less wood. The smaller height was supposed to save space and weight for the guinea pig smaller size. On a plus, the smaller tractor is easier to move. The smaller coop size backfired as I can't practice deep bedding easily, and as I open the tops the GPs can easily fall out when there is a lot of bedding. GPs falling out happens sometimes in the winter when the bedding is piled up and deep, and too high on the walls. The original I made can get really heavy. When there's 6+ inches of soiled hay/grass in the coop the tractor becomes nearly immobile with the little wheels. The tractor will dig into the ground. The wheels in the back require a good lift off the ground for both tractors to get moving. The original hits the shins really good. The use of hardware cloth for bottom and sides might give a good rusty scratch while moving too. If I were to make a better tractor for guinea pigs, I would try to make light weight as possible, and get big wheels to handle deep bedding. Not lawn mower wheels. The design doesn't allow for much space to grab onto and move around either. I would consider a run separated from the coop design as well, however, the run and coop in one does allow for little required attention other than feed and water routines. Certain GPs know who I am and know I bring snacks, so they will let me pet them, most are skittish. Maybe they remember their friend never came back and went to the frying pan. I would still consider having my tractor or run the height of a lawn mower to keep from over grazing.

I'll never forget the first season of having guinea pigs outside in the tractors. The first winter was very active, and brought several snow storms. We expected one snowstorm to bring more snow than the height of the tractors, and snow had indeed piled to the expectations of about 4ft. For the tractor preparation, I moved the tractors away from the house to ensure I had access, which I didn't expect a screen porch to be the justified reason they were moved in the center of the yard. A screened porch attached to the house I lived in at the time caved-in from the snow load. One preparation was I had to make pvc snorkels so I didn't have to stay up and dig out the tractors overnight. They were attached into the coop and stuck out another foot high from the tractors. By the next morning, all I could see were the snorkels I made, with a few inches to spare, and the tractors completely buried in snow. By the time I got to the tractors, the animals were perfectly fine with no snow in the run or coop areas and eating the extra grass and food I had for them. They likely ate the snow for water, but the main reason I had to dig out the tractors was to replace the water bottles, which froze overnight. If anything the snow acted as a insulator keeping the animals warm. I wish I was photo journaling this, but I regrettably didn't.

I am considering these as my next livestock (have chickens).  Reading this just got me wondering about mobile electric netting like for chooks to let the semi-free range.

How do they do in summer heat?  I would be a bit hotter here.  I know there are cavy species that live wild in heat, but seems the ones we see here are from Andes stock.

I have tried to set up non-electric netting to pasture range, but they slip under easily. Electric mobile netting may keep them in the pasture area, not sure how much shock the little cavy could take, but I’m sure one zap would keep them from testing the fence anymore. I haven’t tried electric mobile netting with my herd. Flying predators may have interest, I had a hawk attempt to strike into my tractor recently, but it’s fully enclosed.

In a hotter climate, your cavy herd may need more water and need consistent shade. My herd will lounge most of the day in full shade on hot 90 degree days, and will drink more water than normal. We had about 30 straight 90+ degree days this summer. They won’t be super active around noon, but will graze in the morning and evening when the temperature lowers and sun isn’t direct. No health issues with my herd in the heat. They will get up to eat if I move the tractors on a hot day, but lounge again not long after.