Poultry eggs come in a variety of sizes and colors. Quayle and Partridge eggs are generally the smallest, usually about thumbnail in size. Bantam eggs are generally half the size of a chicken. Turkey and goose eggs are generally 2 1/2 to 3 times the size of a chicken egg . Chicken eggs come in small, medium, large, extra-large and every once in a while ouch, a double yolker. The following is an example of some of those eggs.Just as in humans chickens from time to time will have twins (double yolk egg). My father told me stories of living on the homestead and how some of these eggs would hatch out. On occasion Siamese twins were the result but that rarely did they survive more than a few hours. Most eggs simply did not hatch at all and generally were collected for eating. Oddities and defective eggs will occur, including eggs that have no yoke. Usually these eggs are about the size of a golf ball or smaller. There is no need to be concerned unless the oddities occur on a regular basis. In which case consulting with your local cooperative extension office http://www.csrees.usda.gov/Extension/ may be a good idea.
Something else that should be kept in mind is that eggs are good indicator of how healthy your poultry flock is. When I collect or eat eggs I make note of the condition and coloration. If eggs are being broken on the nest it is possible that the chickens are not getting enough calcium. A supplement to their diet can be oyster shell, which I buy in the large 50 pound bags. Oyster shell will keep for years and is cheaper in the larger bags (1lb bags can cost as much as a 50lb bag). You may also feed them the egg shells from the eggs that you eat. But it is extremely important that you crush the egg shells so they do not recognize the egg shells as eggs. This is to prevent the hens from cannibalizing their own eggs. If you start to get eggs that are difficult to break when cooking, it is possible that your hens are getting too much calcium. If you find blood spots in your eggs it is possible your hens are eating meat or something else. Also make sure that you're laying hens are not eating the baby chicken feed, as this usually has antibiotics in it and would make the eggs not safe to eat. Light-colored yokes are an indicator that the chicken is not getting enough greens or insect proteins. This is also why store-bought eggs are a very light yellow in color and free range chicken eggs are usually orange and have a better taste.