Many pasture-based poultry producers raise Cornish Rocks, the same bird raised in confinement and bred for rapid growth, a double breast, easy cleaning and other traits important to that production system. But are these the best birds for pasture? Does their lethargy, weak legs, sensitivity to heat, and potential for heart attack reduce their performance? Would other breeds be better? Those are some of the questions Kim Cassano hoped to answer with her 2010 Sustainable Agriculture Research and Education project.
She looked at the performance and behavior of six hybrid breeds of broiler chickens on three farms with three common production systems:
Free Range as promoted by Herman Beck-Chenowith
Birds range freely during the day and are secured in houses at night.
Day Range, using the pen style developed by Andy Lee
Birds are housed in a coop and rotated through chicken netting fenced pastures radiating from the coop like daisy petals.
Joel Salatin’s “chicken tractor”
This is a movable, floorless pen dragged through pasture
Cassano measured growth rate, feed consumption, carcass yield, mortality rate, activity level, and overall profitability potential for six breeds of meat chickens:
Cornish X Rock
This is the standard production chicken.
This hybrid also goes by the name Hubbard Redbro. It was developed in Franc for their “Label Rouge” program and has been a popular alternative to the Cornish X Rock in pasture systems.
A hybrid that originated in Italy
Silver Cross aka Kosher King
This is a barred hybrid that has been available for a number of years
Red Ranger and Super Dixie
Both developed from American genetics by a family owned hatcher in Alabama.
The Answer Is….
While the Cornish X Rock was the least expensive and most profitable overall, Cassano was still unhappy with the breed’s other characteristics. She believes that their mortality rates, lethargy and limited genetic diversity didn’t fit with the other goals she had for sustainability and the quality of life for animals on her farm. Since completing the project, she has continued to raise Freedom Rangers and Red Rangers. Here’s what Kim says about raising chickens:
Our motivation to farm and to provide good meat for our CSA members stemmed largely from the desire to provide farm animals with a good life that benefited our pasture ecosystem. I worked hard to design and implement systems that would allow the animals to go about their daily lives in as naturally and humanely as possible. I wanted to let pigs be pigs, and chickens be chickens with as little restriction and intervention as I could.
We built a floored shelter for the chickens instead of using the standard smaller, floorless, manually moved shelters because we wanted to give our chickens as much room to run around as they wanted. We put an electric net fence as far from the shelter as they would roam–strictly to keep ground predators out, not to keep the chickens in.
All of this effort to let a chicken be a chicken seem to fall flat with the Cornish Cross. They preferred to stay close to the feeders rather than roam the pasture hunting up bugs. It was almost as if they were already not quite chickens when they hatched regardless of the environment I could provide them. I came across a quote from Temple Grandin describing the breed’s genetics as being inhumane that summed up the general sense of unease I felt raising those birds.
In the end I decided that I couldn’t improve the situation for those chickens enough to provide them with a humane life and I wasn’t really providing my CSA members with a better product, a chicken that got to live its life as a chicken, if I stuck with the Cornish Cross. I chose the two top performing breeds that were not Cornish. It sounds like your experience with them was similar to mine.
Data For Your Decisions
To help you make your own decisions, here are the graphs Kim created with the data from her project. Note that there are only three bars for the farm raising chickens using the Salatin chicken tractor. That’s because it was hard to keep the red breeds separate from each other. So many switched pens in the chicken tractor groups that she wasn’t able to track them as individual breeds. So she combined them into one group she called “red broilers.”
How Much Do Chickens Eat?
While the Cornish X Rock ate the least amount of feed overall, the amount it ate is different depending on how it was raised. It required the least about of feed in the Free Range setting and the most when raised in the chicken tractor. This could be due to differences among the people feeding the birds, but I have read that other producers have had similar results.
Mortality Rates Among Different Chicken Breeds
Kim adjusted the results because some chicks died as a result of flooding on the day range farm.
Health Issue Differences Among Chicken Breeds
Cassano notes that “Other non-fatal health issues were low overall. The Free Range farm had one Red Ranger with a deformed leg (2%) and one Freedom Ranger with a distended crop (2%). The Day Range farm had 2 deformed legs: 1 Red Ranger (2%) and 1 Super Dixie (2%). Five birds on the Salatin style farm had deformed legs: all of them Cornish Rock Crosses (10%).”
Cost Per Pound and Days to Market Comparison Among Chicken Breeds
Just as interesting as the cost per bird are the differences among the farms. I will be looking for more information that will help us figure out whether these differences are a result of the method of production, or simply a function of the people involved.
Differences in Behavior Among Chicken Breeds
It’s hard to gather data on behavior. Chickens may be moving too much or be too close together to be able to tell what they’re doing. The weather also has a large impact on how active they are. This is the data that Kim gathered when she visited them within 30 minutes of sunrise and 45 minutes after sunrise. In the end, she felt that she didn’t really have enough information to make a judgement on behavior.
Thanks to Kim and everyone who worked with her on this project for gathering this very useful information. It’s information that folks have specifically asked us to find, and her attention to the details of on-farm research makes it very valuable. If you have other questions, observations or data to add, please share them in the comments below or get in touch with me.