Bulletin #2214, A Quick Guide to Raising Pastured Broilers in Maine
By Colt W. Knight, Ph.D., Assistant Extension Professor and State Livestock Specialist, University of Maine Cooperative Extension.
Note: As a member of the New England Poultry Extension group, Dr. Knight was asked to contribute to Penn State Extension Small and Backyard Poultry Flock Programming with this article and was originally published by Penn State.
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Introduction
In Maine, there is a tremendous amount of interest in raising pastured broilers, and this bulletin will attempt to clear up some misconceptions about raising chickens on pasture. Unfortunately, most science-based recommendations for raising poultry is geared towards large-scale production or raising chickens in barns. In the summer of 2017, the University of Maine Cooperative Extension began the Maine Pasture Poultry Project where we raised broilers on pasture and meticulously recorded feed intake, water intake, forage utilization, growth, carcass, and climate data to share with producers in New England.
What Chickens should I raise?
The most common broiler in the United States is the Cornish Cross, a hybrid of a commercial Cornish chicken and White Plymouth Rock chicken. These birds have been genetically selected for rapid growth and feed efficiency. These characteristics make the Cornish cross the most economical breed to raise. However, if the birds can grow too long (past 8 weeks) you may see issues with lameness due to their physical size, heat stress, and heart problems. I would recommend harvesting these birds between 6-8 weeks of age. Raising these birds longer than that is an invitation for sudden death loss. Cornish-cross chickens are unattractive white birds with spotty plumage. You will often see them with exposed skin towards their rear, belly, and underneath their wings. This exposed skin can be susceptible to insects leaving their skin a bright red color. Cornish Cross birds have a high dressing percentage of 75%.
Alternatively, there are slower-growing meat breeds that do not have the same issues as Cornish Cross. The most common include Freedom Rangers, Imperials, and Kosher Kings which are all derived from cross-breeding several heritage birds. These birds have a fuller and much more attractive plumage. Their feathers are often colored. These breeds appear to be more heat stress-tolerant. However, they will grow much slower than Cornish Cross, and often take 2-3 weeks longer to reach the same size. While they will consume approximately the same amount of feed, they will utilize more water than Cornish Cross birds. These factors increase the cost of production. Producers often choose these breeds over Cornish Cross citing ethical concerns over Cornish Cross growing too quickly or they want hardier birds that survive on pasture better. They also make a more appealing photograph for marketing opportunities. Slow growing birds have a lower dressing percentage of 67-69%.
Getting Started – what do you need?
First, you will need a brooder set up to get the chicks started off on the right track. You can learn more about brooders from the University of Maine Livestock website1.
Secondly, you will need a chicken tractor. A chicken tractor is a small and mobile structure that shades the chickens from the sun, keeps them dry in the rain, provides a windbreak, and protects them from predators while allowing them free access to the pasture. Chicken tractors come in many different styles. Two popular versions are the Salatin-style2 tractor which is a short cage approximately 10’ wide, 12’ long, and 2’ high and the taller A-frame Jon Suscovich-style3 tractor which is approximately 5.5’ wide, 10’ long, and 5.5’ tall. However, chicken tractor design comes in many forms and is only limited by your imagination. Pasture-based chickens require 1.5 square feet per bird, so a Salatin-style tractor could hold 80 birds, while a Suscovich-style tractor would hold 36. If you live in an area with a lot of predators, you should consider surrounding the chicken tractor field with electric net fencing. This prevents animals from burrowing under the tractor, reaching through the tractor fence wire, or tearing the tractor fence wire.
I prefer the A-frame style tractors for several reasons. I like to be able to walk into the tractor and get a good look at birds, feeders, waterers, etc. I also like to hang my feeders and waterers. Hanging feeders and waterers are a great way to reduce wastage and keep the chickens’ area cleaner. Plus, when I move the tractor, the feeders and waterer move right along with the tractor. Lastly, I can physically observe all the chickens while I move the chicken tractor so I can prevent accidentally running over the chickens with the tractor frame (a common problem).
Thirdly, you will need ample space to move the tractor around on pasture. For the first week, chickens are out on pasture, you will only need to move the tractor every few days. After that, you will need to move the tractor daily to prevent any damage to pasture health and keep the area clean from chicken manure.
Lastly, you need a plan for processing chickens. Currently, most processors are booked way in advance. I highly recommend finding a processor and booking a processing appointment before purchasing chicks. If you intend to sell your poultry meat, check with your area Extension service for help with rules, regulations, and permitting. Alternatively, you can process your own chickens with minimal equipment needs. However, if you plan on processing a lot of birds, you will probably want to invest in killing cones, a large scalding pot, plucker, and packaging for long term storage. Adam Danforth wrote an excellent book entitled Butchering with high-quality step-by-step color photographs. I recommend this book as a text for students enrolled in my meat cutting schools. For additional information see University of Maine Cooperative Extension bulletin #2235, Maine Poultry Facts: On-Farm Poultry Processing for Small Flocks in Maine.
Timeline
Once the chicks arrive, they will spend approximately 2 weeks in the brooder until they start to develop feathers. Then they can move outside to the chicken tractor with a heat lamp installed. After the chicks have had about a week to acclimate to their new environment, you can remove the heat lamp and begin rotating chickens through the pasture. The first week they are on pasture you will only have to move them every 2-3 days as their litter builds up. You will want help from one other person when you begin moving the tractor with the chicks. One person will move the tractor while a second person with a broom moves the chicks away from the tractor frame. This prevents the chicks from being run over by the tractor frame. Chicks learn quickly and will happily move on their own once trained. By the second week, they are on pasture, the tractor needs to be moved daily to prevent chickens from standing in their own litter and damaging the pasture. Our publication on pasture-raised broilers has an excellent description of forage utilization and pasture health. That manuscript can be found online at Journal of the NACCA online
Week 1 – Brooder
Week 2 – Brooder
Week 3 – Move to the chicken tractor with heat lamp installed
Week 4 – Remove Heat lamp, and place chickens on pasture. Move tractor every 2-3 days
Week 5 – Move Tractor Daily
Week 6 – Move Tractor Daily (Cornish Cross Should weigh ~ 5.25 lbs live weight, and produce 4 lbs carcass)
Week 7 – Move tractor 2x a day
Week 8 – Move tractor 2x a day (Freedom Rangers should weigh ~5.25 lbs, and produce a 4 lbs carcass)
How much food, water, and forage will the chickens consume?
The answer to this question depends on breed, sex, climate, diet, and the desired finish weight. However, I can give you a pretty decent estimate if we maintain a few constant variables. First, I like to raise chickens so that they will yield a 4 lbs carcass (the ideal size for a meal for the average American family size). Cornish Cross should reach this weight at 6 weeks of age, and slower-growing birds around 8-9 weeks when given a 20% crude protein starter/grower ration. Cornish Cross will consume about 15 lbs/bird of feed to reach harvest weight, and slow-growing birds will consume ~16 lbs/bird. Cornish Cross will use about 3.6 gallons/bird of water, and slower-growing birds will use slightly more (4-4.5 gallons/bird).
What about forage utilization? How much grass are the chickens eating? Shouldn’t this save me money on my feed bill? This seems to be somewhat of a controversial topic, but the science is clear. First, chickens raised on pasture will consume more feed than chickens raised in commercial chicken houses. They expend more energy walking around and staying warm/cool, so they need more energy to meet their demands. Secondly, chickens always look like they are eating a lot of forage because we can watch them pick at grass and we see the grass is gone when we go to move the tractor the next day. To be clear, chickens do not have the digestive anatomy to effectively break down and digest molecules like cellulose and other fiber constituents of plant cell walls like ruminants (cattle, sheep, deer) or hind-gut fermenters(horses, rabbits, elephants). Most of the forage disappearance is due to trampling, scratching, pecking, etc. In our 2017 pasture poultry study, we measured Forage Utilization (the amount of forage removed by the chickens) and estimated Forage Intake (amount of forage consumed by chickens). Measuring forage utilization provides us with a valuable grazing tool. In order to maintain healthy pasture, you do not want to remove more than 50% of the forage above group. Removing anymore and you begin to drastically reduce root structure as nutrients from the roots mobilize to restore the above-ground portion of the plant. Once the root structure is compromised, pasture health begins to decline. Therefore, once pasture utilization reaches 50%, you need to move the chicken tractor. With Cornish Cross, you only need to move the tractor 1x per today until they are 6 weeks old, but after that, tractors need to move more frequently. So how much of the chickens’ diet is forage? On a grass-based pasture, you can expect 3.6% of the chicken’s dry matter diet to be made up of forage. With a legume-based pasture, you could probably expect 5% of their diet to be made up of forage. That is about 1 pound of forage per bird.
How much pasture do I need?
| Chickens per tractor |
Tractor |
Days | Acres | Chicken capacity | Reps | Total Acreage |
|---|---|---|---|---|---|---|
| Cornish Cross | ||||||
| 36 | 1 | 21 | 0.16 | 216 | 1 | 0.16 |
| 36 | 1 | 21 | 0.16 | 432 | 2 | 0.32 |
| 36 | 1 | 21 | 0.16 | 648 | 3 | 0.48 |
| 36 | 3 | 21 | 0.16 | 216 | 1 | 0.48 |
| 36 | 3 | 21 | 0.16 | 432 | 2 | 0.95 |
| 36 | 3 | 21 | 0.16 | 648 | 3 | 1.43 |
| 36 | 6 | 21 | 0.16 | 216 | 1 | 0.95 |
| 36 | 6 | 21 | 0.16 | 432 | 2 | 1.91 |
| 36 | 6 | 21 | 0.16 | 648 | 3 | 2.86 |
| Slow growing | ||||||
| 36 | 1 | 35 | 0.27 | 216 | 1 | 0.27 |
| 36 | 1 | 35 | 0.27 | 432 | 2 | 0.53 |
| 36 | 1 | 35 | 0.27 | 648 | 3 | 0.80 |
| 36 | 3 | 35 | 0.27 | 216 | 1 | 0.80 |
| 36 | 3 | 35 | 0.27 | 432 | 2 | 1.59 |
| 36 | 3 | 35 | 0.27 | 648 | 3 | 2.39 |
| 36 | 6 | 35 | 0.27 | 216 | 1 | 1.59 |
| 36 | 6 | 35 | 0.27 | 432 | 2 | 3.18 |
| 36 | 6 | 35 | 0.27 | 648 | 3 | 4.77 |
References
- University of Maine Cooperative Extension: Livestock. Poultry.
- Salatin, J. Pastured Poultry Profits. 1993. Polyface.
- Suscovich, J. Stress-Free Chicken Tractor Plans: An Easy to Follow, Step-by-Step Guide to Building Your Own Chicken Tractors. 2016. Emerald Lake Books.
- Knight, C., G. Anderson, and J. Hatley. 2019. Generating Data-Based Recommendations for Pastured Broiler Producers. Journal of the NACAA. Volume 12.
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