Chicken Egg example essay topic

Experiment: Chicken Hatching Background Information Some facts about chickens A chicken is a bird. One of the features that differentiate it from most other birds is that it has a comb and two wattles. The comb is the red appendage atop the head, and the wattles are the two appendages under the chin. These are secondary sexual characteristics and are much more prominent in the male. The comb is the basis of the Latin name or classification of chickens. In Latin, gall us means comb, and the domestic chicken is Gallus domestic us.

The Red Jungle Fowl, ancestor of most domestic chickens, is Gallus bank iva. There are eight recognized kinds of combs: single, rose, pea, cushion, buttercup, strawberry, V-shaped, and silk ie. The chicken has two legs and two wings, a fact that influences housing and management. Heavy breeds used for meat production cannot do more than flap their wings and jump to a little higher level or move more rapidly along the ground. he chicken has pneumatic bones, making its body lighter for flying, although most domestic chickens have lost the ability to do so. The lighter-bodied birds can fly short distances, and some can fly over relatively high fences. The chicken's temperature is about 107 degrees to 107.5 degrees F. Chickens have comparatively short life spans.

Some live to be 10 to 15 years old, but they are an exception. In commercial egg production, birds are about 18 months old when they are replaced by new, young stock. It takes close to six months for a female chicken to mature sexually and start laying eggs. Then, they are kept for 12 to 14 months of egg production. After that their economic value declines rapidly, so they are disposed of when they are about 18 months old. Chickens and Eggs in the Economy Poultry and eggs are a comparatively cheap food of high nutritional quality.

One way is to include more eggs in the diet. Comparing protein foods on a pound-for-pound basis, eggs cost about 95 cents a pound when large eggs are selling for 64 cents a dozen. It is difficult to purchase any other high-protein food -- meat or fish -- for this low price. Essential nutrients Eggs are especially valuable as a source of protein. In fact, egg protein is used as the standard against which the quality of other food proteins is measured. One egg contains about 6 to 7 grams of protein.

People of all ages need adequate protein for building and repairing body tissues. The fat in the yolk is so fine that can be digested easily, even by infants. The ratio of unsaturated to saturated fats is about 2 to 1. This is considered very desirable. Oleic acid is the main unsaturated fat. It has no effect on blood cholesterol.

Eggs contain vitamin A, the B vitamins (thiamine, riboflavin, and niacin), and vitamin D. All are necessary during childhood and adolescence for growth. Eggs also contain an abundant supply of minerals, such as iron and phosphorus, that are essential for building and maintaining strong, healthy bodies. But eggs are low in calcium (it is in the shell), and contain little or no vitamin C. Individuals on weight-reducing programs find eggs beneficial. To lose weight, calorie intake must be reduced, while maintaining a well-balanced diet.

An egg provides good nutrition and contains only about 80 calories. Structure of the Egg The egg is a biological structure intended by nature for reproduction. It protects and provides a complete diet for the developing embryo, and serves as the principal source of food for the first few days of the chick's life. The egg is also one of the most nutritious and versatile of human foods. When the egg is freshly laid, the shell is completely filled. The air cell is formed by contraction of the contents during cooling and by the loss of moisture.

A high-quality egg has only a small air cell. The yolk is well-centered in the albumen and is surrounded by the vitelline membrane, which is colorless. The germinal disc, where fertilization takes place, is attached to the yolk. On opposite sides of the yolk are two, twisted, whitish cord-like objects known as chalaza e. Their function is to support the yolk in the center of the albumen. Chalaza may vary in size and density, but do not affect either cooking performance or nutritional value.

A large portion of the albumen is thick. Surrounding the albumen are two shell membranes and the shell itself. The shell contains several thousand pores that permit the egg to 'breathe. ' Composition An average-sized egg weighs approximately 57 grams (about 2 ounces). Of this weight, the shell constitutes 11 percent; the white, 58 percent; and the yolk, 31 percent. Normally, these proportions do not vary appreciably for small or large eggs.

The percentage composition of the edible portions is: Percent Water Protein Fat Ash Whole egg 74 13 11 1 White 88 11... Yolk 48 17 33 1 Our Project The plan Our project was based on the development of chicken eggs, in other words we really wanted to hatch a cute little chick. We decided that the best way to go about this task would be to incubate fertilized chicken eggs to full term and hope that they would hatch. In order to actually learn something from this we would need to crack open some of the eggs at different points in development to observe their growth. Materials Here is a list of the materials that helped us preform this experiment: ~six fertilized eggs~incubator~chicken food~glass dishes (to pour developing eggs into) ~tweezers (to pull apart shells) Procedure Once we relieved the fertilized eggs they were placed in an incubator at the heat of 105 degrees F. Every day the eggs needed to be turned once in the morning and once in the afternoon. This insured even heating for the developing chick.

Every few days we opened a chick egg and followed this procedure: We crack the chicken egg open pick away the egg shell carefully in order to not upset the insides. This is poured into a glass dish for observation. The Timing of Major Embryonic Developments This is a guild to the development of the egg. As you can see we followed our procedure on the first, third and sixth day. During Incubation Day 1 Development of area pellucid a and area of blastoderm. Major developments visible under microscope: .

18 hours, appearance of alimentary tract. 19 hours, beginning of brain crease. 20 hours, appearance of vertebral column. 21 hours, beginning of formation of brain and nervous system.

22 hours, beginning of formation of head. 23 hours, appearance of blood islands. 24 hours, beginning of formation of eyes Our observations: The egg shows no development yet. We can see the disk and chalaza e. Day 2 Embryo begins to turn on left side. Blood vessels appear in the yolk sac.

25 hours, beginning of formation of veins and heart. 30 hours, second, third and fourth vesicles of brain clearly defined, as is heart, which now starts to beat. 35 hours, beginning of formation of ear pits. 36 hours, first sign of amnion. 46 hours, formation of throat Day 3 Formation of nose, wings, legs, and allantois begins. Amnion completely surrounds embryo.

Our observations: There is a small red dot in the middle of the yolk that we think is the eye. Blood vessels have formed on the inside wall of the egg. Day 4 Formation of tongue begins. Embryo completely separate from yolk sac and turned on left side. Allantois breaks through amnion. Day 5 Pro ventriculus and gizzard formed.

Formation of reproductive organs and sex determined. Day 6 Formation of beak and egg-tooth begins. Main division of legs and wings. Voluntary movement begins. Our observations: We can now see the embryo very clearly. It seems able to move and the heart was beating for a while.

There was formation of the body, head, wings, feet and even the beak. Day 7 Indications of digits in legs and wings are visible. Abdomen more prominent due to development of viscera. Day 8 Formation of feathers begins. Day 9 Embryo begins to look bird-like. Mouth opening appears.

Day 10 Beak starts to harden. Skin pores visible to naked eye. Digits completely separated. Day 12 Toes fully formed. First feathers appear. Day 13 Scales and claws appear.

Body fairly well covered with feathers. Day 14 Embryo turns its head towards blunt end of egg. Day 15 Small intestines taken into body. Day 16 Scales, claws and beak becoming firm and horny. Embryo fully covered with feathers.

Albumen nearly gone and yolk increasingly important as nutrient. Day 17 Beak turns toward air cell, amniotic fluid decreases, and embryo begins preparation for hatching. Day 18 Growth of embryo nearly complete. Day 19 Yolk sac draws into body cavity through umbilicus. Embryo occupies most of space within egg except air cell. Day 20 Yolk sac completely drawn into body cavity.

Embryo becomes chick, breaks amnion, starts breathing air in air cell Allantois ceases to function and starts to dry up. Day 21 Chick hatches! Hatching day Two of our chicks hatched right on schedule. One seemed to be 'handicap ed. ' When it hatched we noticed that what we believe to be it's intestines were protruding from it's anus.

It died only a few hours after it hatched. We have just cause to think that this was due to the fact that some of our classmates were shaking the eggs. The other chick is healthy and we are continuing to raise it.

Bibliography

Actually this is just a list of the websites we used: web bonus (points, hint hint... ) The next 2 pages are just for fun! hint, hint.