Incubation Information

2007 prices and details:

ϖ Eggs cost $6 per fertile dozen
ϖ A small bag of feed for the chicks when they hatch is available for $2
ϖ Returning Chick fee is $1 per chick.(to offset brooding expenses and promote frugality)
ϖ Eggs should be ordered in advance to ensure availability
ϖ Return times must be pre-scheduled so that someone is available to help you*

*If you are returning chicks to us,
1. They must be less than 2 weeks old.
2. Chicks must remain in the class until being returned together to us. PLEASE do not send them home with students!

ϖ We have found our eggs to hatch at about a 70% success rate. (8 out of 12)

QUICK TIPS:

1. Run your incubator for a few days prior to starting eggs to ensure it is maintaining a steady temperature

2. Leave a note on the outlets you plug incubators into so that your custodians know not to unplug the machines

3. Remember to turn your eggs at least 3 times a day (until day 18) if your incubator doesn’t do this for you.

General information about CHICKENS and EGGS:

The eggs from our hens are very similar in structure and function to all other bird eggs in the world. Inside the hard shell are the yolk and the white. Several membranes keep various parts of the system separated from each other and from the environment. One additional structure in the egg is easily overlooked—a tiny white mass hardly larger than the head of a pin. This single cell, called the ovum, is the living part of the egg. The ovum will not develop in an egg unless the hen has mated with a rooster. Eggs purchased at the supermarket are by and large unfertilized eggs because egg farms keep their laying hens away from roosters. Our hen yard has several proud roosters and therefore our eggs are fertile. In a fertile egg as incubation begins the ovum will advance through a predictable sequence of dramatic changes that will eventually result in the emergence of a new live bird.

The egg yolk is stored food for the developing embryo and fetus. As the chick advances in size and complexity, the yolk is used up until it is almost totally consumed at hatching time. The egg white (albumen) is composed mostly of water with some dissolved protein (albumin). The primary function of the white is to keep the embryo moist and cushioned during the rigors of incubation.

A more detailed inquiry into the development of an egg and growth of the embryo reveals still more structures and features, all of which are exquisitely designed and complex in function. With amazing frequency they produce the expected outcome—a new chick.

Chickens are members of a clan of birds that have precocial chicks, meaning that the chicks are up and running in a matter of hours, covered with protective downy feathers, able to follow their mother, and capable of feeding themselves. Birds like robins have altricial chicks, meaning they are blind, naked, and helpless at the time of hatching. They must be fed, kept warm, and defended against predators, or they will perish. There are degrees of precocial and altricial chicks; chickens have chicks that exhibit the highest level of independence at hatching.

Chickens, like most birds, brood (sit on) their clutch of eggs to ensure that they develop properly. If the eggs are not maintained at 37°C (99°F*) for 21 days, they will fail. (*This temperature does vary slightly with different incubators, so follow your incubation instructions.)Chickens lay one egg a day. The hen will delay brooding her eggs until she has accumulated her whole clutch of perhaps ten eggs. The first-laid eggs stay alive but do not develop at the lower temperature. This ensures that all the eggs will hatch at about the same time, a tremendous advantage in the wild, where it is important to leave the nest soon after the chicks have hatched.

In the classroom an incubator will substitute for the warm underside of a hen. The eggs must be maintained at a constant temperature, the humidity must be high, and the eggs must be turned at least three times a day. Commercial incubators with egg turners generally minimize concerns related to temperature, humidity, and egg rotation.

Deciding to hatch chicks from eggs. Hatching eggs in your classroom is a wonderful activity that you and students will long remember. But there are several things to consider before doing this investigation.

Your first task of finding a source of fertile eggs at Benner’s farm is a good start. Getting eggs locally minimizes the risk of damage that can be incurred when eggs are ordered through the mail. We have been providing fertile eggs for incubation to educators for over 15 years, call in advance to reserve eggs.

Q: Can I hatch eggs from the store? No, the eggs bought at the store are not fertilized and only fertilized eggs will hatch.

Q: Where should eggs be stored, if they cannot be set right away? If the eggs cannot be put in an incubator immediately, then they should be kept in a cool room at a temperature between 13 and 16 C (55-60 F). NOT REFRIGERATED! Do not hold eggs for more than 7 days.

Second, you need to purchase the equipment—it does not come in the kit. Delta Education is one source who carries all the equipment needed for this investigation (1-800-258-1302). Another option is Agway feed stores, Neptune Feed supply, or even some local pet stores. You will need to find an incubator, egg turner(unless you do this by hand), feeding tray, and water bottle. You can use your own desk lamp or clamp light once the chick is hatched. Feed can be found at the sources above or you can get a weeks worth of feed from us when you pick up your eggs.

Third, you have to be prepared to give yourself over to the chickens for 6 weeks—they demand time every day, including weekends and holidays.

Finally, and perhaps most important, you need to have a place for the chicks to go after they have spent a week or so in class. If you have purchased your eggs from Benner’s Farm you can return them at the cost of $1 per chick (fee to offset brooder costs and to encourage frugality in participants because of our limited space). Chicks must be returned prior to two weeks of age.

We encourage you to plunge in and have a chicken adventure with your class. The anticipation is palpable, the thrill of hearing soft peeps inside the shells is unparalleled, and seeing the chicks break out of the shells is magical. The soft peeping, the silly antics, and the sense of something important going on that will pervade your room will make for a memorable project. Do it—you'll be glad you did.

Setting up the equipment. A reliable incubator is of utmost importance for successful egg hatching. A still-air incubator will do the job; circulated-air incubators generally cost quite a bit more. Buy an incubator large enough to set at least a dozen eggs. A large picture window in the top of the incubator is especially nice, so a large number of students can gather around the incubator at one time to watch them hatch. To help your incubator maintain a constant temperature, place it where it will receive as little temperature fluctuation as possible. Do not place it near a window where it will be exposed to direct sunlight. The sun's heat can raise the temperature high enough to kill the developing embryos. Connect the unit to a dependable electrical source, and made sure the plug cannot be accidentally detached from the outlet.

Be sure the incubator you purchase has a thermostat so the temperature will be closely regulated. Set the incubator up a few days before you get your eggs to make sure that it is functioning properly. It should maintain a temperature of 37°C (99°F), give or take a degree, when the thermostat is operating. Usually a screw on the incubator adjusts the temperature. Always read the manufacturer's instructions that accompany the incubator you purchase and follow them to the letter for best results as certain types of incubators do vary a bit in temperature requirements.

Q: What temperature is required to hatch eggs? The circulated air incubator should run at a temperature of 37.5 C ( 99.5 F) with some exceptions as mentioned above.

It is essential to turn the eggs for successful hatching. Turn them an odd number of times so the position that is up the longest (at night) will be changed from day to day. Mark the date or an "X" on each egg so you can tell if the eggs have been turned. When you turn the eggs, move them to a different part of the tray to minimize the effects of temperature variation in the incubator. If the eggs are not placed on their sides, they should be placed at an angle so the small ends are in the downward position. Weekends often pose a problem for teachers incubating eggs at school. They sometimes take the incubators home (placing the eggs into egg cartons and wrapping them to keep them warm when traveling back and forth), especially the 1st weekend. Some teachers have found leaving incubators unattended during 2-day weekends has had little affect. Often the effect of not turning the eggs may be much less than that of the jostling, jarring, and possible temperature changes involved in taking the eggs home. We suggest making the trip in to school to turn the eggs, or, sweet-talking the weekend custodial staff with gifts and smiles in hopes they will turn them for you! If the eggs are not turned, the embryo will usually adhere to the wall of the egg, and development will fail. Automated egg turners are available. They slowly rotate the eggs throughout the day and night, and take care of the eggs on the weekends so you will not have to return to school. They usually give a higher rate of hatching—70% to 80%. The disadvantage is that students have less involvement with the eggs. Hatching rate should be at least 50% if you turn the eggs manually.

Q:Why is it important to turn the eggs AND How often should we turn them? The eggs are turned to prevent the membranes from sticking to the shell, and is similar to what the mother hen does when she sets. The eggs should be turned at least three times daily.

Q: When do we stop turning the eggs? Stop turning the eggs on day 18.

(DAY 18 is a good time to make sure your brooder area is ready- See below)

Q:What happens if the eggs are not turned? If the eggs are not turned the embryo will die about day 11.

Eggs must incubate for 21 days. Eggs are rotated for the first 18 days, and lay still for the last 3 days. Perhaps the hen stops turning the eggs when she hears the chicks begin to peep inside the shell. When the eggs are last turned, 3 days before hatch, place a layer of crinoline or cheesecloth on the screen under the eggs. It will make cleaning the incubator easier after hatching. When the eggs are resting during the final 3 days, listen. A little hole or crack in the shell will be the first indicator of hatching. The process may take a day or more. Be patient. You may be tempted to help the chick cast off the shell, but resist the urge. Rule one: Don’t touch the eggs during the hatching process. The chicks have to do it all by themselves!

Basic handling of eggs. Always make sure that hands are clean before handling the eggs. The shell of the egg has many pores that allow gases and moisture in and out. Dirty, oily hands can block the pores and stop development of the chick.

If you want the eggs to start hatching on a Monday or Tuesday when students are in class, you should set them on a Tuesday (3 weeks before you want them to hatch). If the eggs arrive on a day other than Tuesday, keep them in a cool place—7° to 15°C (45° to 60°F)—until you are ready to put them in the incubator.

If you plan to turn the eggs yourself, use a pencil to mark each egg with an X on one side and an O on the other side to be sure you have turned all the eggs every time. The eggs should be placed on their side with the small end pointed slightly down. As the chick develops inside the egg, its head will be at the large end of the egg. If the large end is down and the developing chick is standing on its head, it will die. The eggs need to be turned through the 18th day. The last 3 days the eggs should not be turned.

If you are using an automatic turner, follow the manufacturer's instructions for installing it in the incubator. Be sure to place the eggs in the turner with the small end pointed down. Take the turner out of the incubator at the end of the 18th day. The eggs no longer need to be turned, and taking out the turner will prevent injury to the newly hatched chicks.

The amount of moisture in an incubator is also critical for a good hatch. Most incubators have a trough to keep filled with water to ensure enough moisture. If the incubator has vent holes, keep them plugged for the first few days. After that open the small vents to allow air circulation through the incubator. Monitor and correct (if necessary) the temperature throughout the whole process.

Q: Why is water added to the incubator? Water is needed to maintain proper relative humidity in the incubator. If the relative humidity is too low then the chick will stick to the shell and death will occur.

Candling. "Candling" is the examination of the contents of the eggs using a shielded light in a darkened area. WASH YOUR HANDS BEFORE TOUCHING THE EGGS! Checking the eggs for embryonic development will tell you if fertility is poor, air cell size can determine incubator humidity, and your students can observe the development of the embryo which will add to the excitement for the growing chicks. Eggs may be candled anytime between day 5 of incubation through to day 17 and it is a very exciting way for the students to see the progress first hand. Eggs should be kept out of the incubator no more than 5 to 10 minutes at a time when candling. If there is a clear egg (no sign of growth) by day 10 it will not hatch and should be removed from the incubator. There is generally a 60-80% success rate for hatching, so you should expect that not all the eggs will hatch—remember what they say: “Don’t count your chickens before they hatch!”

You can make an egg candler from a wood, metal, or thick cardboard box or container in which you mount a 40-watt light bulb. Make a 1-inch hole in the end near the bulb. For better viewing, place a felt or cloth cushion around the opening so an egg fits the opening better and so light does not leak around the egg.

Hold the large end of the egg up to the candling light. You won't see much development until the 4th or 5th day of incubation. White or light-colored eggshells permit better viewing of embryo development. The contents of the egg have a pinkish color or cast when the embryo is developing properly. As the embryo grows, it occupies most of the space within the shell. Toward the end of incubation, the contents will appear dark except for the air cell.

Candling will not influence embryo development if you handle the eggs gently with clean hands! When eggs are removed from the incubator only a few times and are not allowed to cool to any extent, candling makes little difference in hatchability or the time required for hatching.

Q: How long should I leave the eggs in the incubator if they do not hatch on the twenty-first day? Leave the unhatched eggs until the twenty-third or twenty-fourth day. If they still have not hatched then dispose of them.

Q: Should I help the chick out of the shell? This is not recommended and is often painful for the chick

Basic care of chicks. The class may be able to focus on little else as the eggs begin to hatch. This will be a very exciting time! The chicks should stay in the incubator until they are completely dry and fluffy. It is also important to maintain a steady temperature in the incubator as the chicks hatch, so remove chicks to the brood pen only once a day. The newly hatched chicks will be tired from the hard work of breaking through the shell and probably won't eat for the first 24 hours.

Chicks instinctively begin pecking shortly after they hatch. Be prepared for some curious chick behaviors. For example, the first few days the chicks will be very active one moment, then fall in a heap with their heads on the ground as if they were taking their very last breath. A few moments later they'll be up and chirping once again.

Once the chicks have hatched, they need a brooding pen, food, and water. You can use a large cardboard box for a pen. The size of the box depends on how many chicks you are raising. They need plenty of room to grow. Put straw, wood shavings, or sawdust in the bottom to absorb droppings (Do not use cat litter or newspaper).

Provide a warm area in the pen, especially right after the chicks hatch. Heat a large area of the pen with a lamp, but keep part of the area cool for the chicks to exercise in. Buy an infrared lamp if you are heating a large pen. A 100-watt bulb in a short table lamp works fairly well in a smaller pen. Set up the pen and measure the temperature in several locations to be sure it is ready before the chicks hatch. The first week the chicks need the temperature at 37°C (99°F); you can reduce the temperature by 3°C (5°F) each week until it is down to 21°C (70°F).

Q: How do I adjust the temperature? By lowering the heat source you will increase the temperature and by raising it you will lower the temperature.

Food and water should be available to the chicks at all times. You may want to purchase a feeding tray designed to keep the chicks out and the feed in. You can also purchase a water bottle with a narrow tray that provides a constant supply of water. Chickens can be very messy, so purchase special feeding equipment if you do not want to be constantly cleaning the food and water containers.

Q: Do I need to teach the chicks to eat and drink? Yes, it is a good idea to dip the chick’s beak in the water and feed so that they know where it is.

CURRICULAR IDEAS:

Below you will find several activities and links for some great “EGG”splorations!

http://www.urbanext.uiuc.edu/eggs/lessonplan.html

http://www.atozteacherstuff.com/Themes/Life_Cycles/Chicken_Life_Cycle/index.shtml

http://www.geocities.com/sseagraves/fromeggtochick.htm

http://www.sciencenetlinks.org/lessons.cfm?BenchmarkID=1&DocID=394

If you do a google search, there are THOUSANDS of websites out there devoted to incubation!

Calendar Count

You will need the following materials:

Incubator, fertile chicken eggs, empty calendar grid, 8 1/2 X 11 paper calendar for each child to take home, construction paper eggs sized to fit empty calendar grid (put "Day 1" "Day 2", etc. on each egg, go to "Day 21") (Day 21 should show a crack in the egg)

1 Next to your regular calendar, hang another empty calendar grid.

2 As you show the children the fertilized eggs, tell them it takes 21 days to hatch.

3 Ask the children to help count out 21 Unifix cubes.

4 Ask the children to find the day on the blank calendar that is the same day as today.

5 Place the number one egg face down on the "today" space.

6 Ask your children to help figure which space will be used on day twenty-one.

7 Discuss different strategies that could be used to figure out day twenty-one.

8 After the discussion, choose some of their strategies and work together to find the space for day twenty-one.

9 Mark that space with the "Day 21" egg face down.

10 Check to see if the strategy worked by hanging up eggs "Day2" through "Day 20".

Weighing the Chicks

You will need the following materials:

Chick, pan, balance weights

1 When the eggs have hatched and the chicks have had a few days to rest and dry out, choose a chick to weigh.

2 Use a pan balance. Weigh the chick carefully in one side and place the washers in the other side.

3 Make a chart story about the weight of the chick.

4 Remove the chick.

5 Ask children to look around the room to find objects that may balance the chick.

6 Test these objects to see if they do, in fact, balance the chick.

7 Have a box labeled "weighs the same as the chick" in which they place all the objects that did balance.

8 After everyone has had a chance to explore the problem, take the box and share everyone's find with the class.

9 Begin a "Same Weight as the Chick" Big Book by writing on each page as articles are checked, for instance, "20 unifix cubes are the same as the chick".

10 Let the children illustrate the pages.

"Eggs"ploration

Comparing Eggs

You will need the following materials:

Raw egg, hard-boiled egg bowl questions below on a worksheet

1 Provide one egg for each child (plus a few extra eggs) and hard-boil half the eggs.

2 Use a pencil to write "1" on the raw eggs and "2" on the hard-boiled eggs. Do not tell the children what the numbers mean.

3 Have the students work in pairs. Give each pair one raw egg and one hard-boiled egg, a small bowl, two pencils, and two copies of the Egg Exploration worksheet.

4 Have the students use observation and deduction skills to complete the activity sheet. Caution the children to work carefully and gently with the eggs.

1. Does egg 1 look different from egg 2?

2. Does egg 1 feel different from egg 2?

3. Does egg 1 smell the same as egg 2?

4. Shake the eggs. Do you hear anything?

Egg 1?

Egg 2?

5. Roll the eggs on your paper. Do you hear anything?

6. Spin the eggs gently. Does egg 2 spin the same as egg 1?

7. Which egg do you think is raw? Why?

8. Crack the egg you think is cooked. Were you correct?

The Spin Test

A hard boiled egg will spin longer and faster than a raw egg because the loose liquid in the raw egg acts as a brake.

1 Make predictions about which will spin faster, a raw or hard-boiled egg.

2 Make a chart of the childrens responses. (I like to make this into a graph)

3 Check out the predictions.

The Floating Egg

A fresh raw egg will sink to the bottom of a cup. A very rotten egg will float.

1 Make predictions about which will float, a fresh raw or a rotten egg.

2 Make a chart of the childrens responses. (I like to make this into a graph)

3 Dissolve about ten teaspoons of salt in 1 1/2 - 2 cups of water.

4 Check out the predictions using the dissolved salt and water.

Dyeing Eggs

Use natural products to make egg dye. Beets-deep red, onions-yellow (add soda to make it bright yellow), cranberries-light red, spinach leaves-green, and blackberries-blue.

1 To make dyed eggs, pick two or three colors from the list. Boil the fruit or vegetable in small amounts of water.

2 Let the children put a cool har-boiled egg into a nylon stocking and dip it into the dye.

3 Keep the egg in the dye for several minutes.

4 Pull out the nylon and check the color.

5 If it is dark enough, place the egg on a paper towel to dry.

6 If children want to color the eggs before dyeing, show the children how wax keeps liquid from getting on the egg.

Rubber Eggs

Soak a raw egg in vinegar to take the calcium out of the eggshell. It will feel like rubber and you can see through it to the inside!

Great Egg Related Literature!

Chickens Aren't The Only Ones by Ruth Heller

From Egg to Chicken by Gerald Legg

The Chicken or the Egg? by Allan Fowler

Inside an Egg by Kiyoshi Shimizu

The Egg (First Discovery Book) by Gallimard Jeunesse

Egg to Chick by Millicent E. Selsam

The Chicken or the Egg? Big Book by Allan Fowler