The opportunity cost of owning land is next to nil since the government insists on stealing our savings by keeping interest rates near 0% and printing money (inflation), so the easiest way to determine the cost of the grass consumed is by using current pasture rental rates, which in north Missouri is about $60/acre.
Too many times I read (even from producers, sometimes!) that grass is free. Whoa, Nelly! It is not free and, in fact, the cost of grass has sharply increased due to so much of it being ploughed up to raise more corn and soybeans. Folks, that is not sweet corn nor edible soybeans. This is commodity, GMO crops raised to be fed to animals like cattle, chickens, pigs, fish, horses, buffalo, and even lambs and deer!
But I digress – how much grass do pastured hens eat and how does that relate to a dozen eggs? Hopefully, these questions can be answered at least for our management style.
By measuring the amount of forage in a small paddock before the chooks are moved in and then again after they are moved out in 3 days (during the growing season, it is imperative to move stock at least every 3 days to prevent removing too much forage, however, if you need to improve the diversity, overgrazing is a good tool to use for establishment, but it must be part of the plan). As with any research, there are variables that are hard to control. While we will measure the amount of feed we give them and report that, there is no way of knowing how many bugs they will eat. We plan three replications.
Trial 1 – Replication 1 – Day 1 cool, partly sunny weather (65-70F)
Day 1 – Fourteeen mature egg laying Barred Rock hens – .039 acres with mature fescue and about 40% red clover. Estimated forage available is 4 inches times 200 lbs of grazeable feed is 800 lbs per acre or 31.2 lbs (800 x .039). I’ll measure what is left when we move them in 3 days to obtain what they actually consume. Chooks will mash down a fair bit, but that is okay since that will feed the soil microbes and organisms. We are offering 1 lb of seed cleanout consisting of wheat screenings – unsprouted. Sprouted would be better, but for this trial, we want to know how much forage they are eating out of the pasture.
Results: Eggs laid: Day 1: 12 eggs, Day 2: 11 eggs Day 3: 7 eggs. Indications are that without more grain – production decreases markedly, this may not be a bad thing – pencil out the costs and needs.
Grazing equivalent: The 14 chooks grazed in 3 days what 1 cows would grazing in one day
Bear in mind, however, the trampling/mob effect would be entirely different since cows would likely trample more and certainly put more poop in large piles which will then cover up more grass. With so much rain, even more grass would be destroyed. There would also be a considerable difference in mob effect with 500 or 1000 chooks vs 14 as well. Chickens range only up to 250 feet (extreme outer limits) from their nesting boxes, so more trampling would occur due to concentration. I would think with that many – chooks would need moving everyday vs 3 days.
Chooks will eat far more bugs than cows.
There are several differences in the grazing impact, so just comparing the potential grazing is just for fun.
Neverthess, this experiment demonstrates that no matter the species – pastures MUST BE ALLOWED ADEQUATE REST PERIODS TO IMPROVE AND ALLOW FUTURE GRAZING! Animal movement must be controlled and their keepers must balance animal performance and pasture production effectively.