A comparative study of the characteristics of "mini" layers and a conventional layer

The poultry industry is a rapidly changing industry. In the past few years many changes in all phases of the industry, including breeding, management, processing and marketing have been made. One of the most significant changes has been the high density housing of layers. An important factor in determining optimum bird density in a house is body size. A hen of small body size offers several possible advantages. These include: a better feed efficiency, less space requirement per bird and less manure to dispose of. The main disadvantage is that small body size is generally associated with reduced egg production and reduced egg size. Another disadvantage is that the salvage value of the spent hen is less. In some cases processors do not like to handle the smaller birds because of the low yield. There are basically two ways of breeding a small hen that will lay an egg of acceptable size. One method involves selection of chickens that are small, but lay large eggs. The second method involves the use of a dwarf gene that is recessive and sex-linked. The dwarf gene, reduces body size by approximately 25 to 50 percent. Stocks that have been produced by these methods are considerably smaller in body size as compared to conventional stocks. They have been variously referred to as "mini", "midget" or "dwarf" chickens. Hutt's (1949) observations provided the stimulus for much of the earlier research with mini layers. Bernier and Arscott (i960) stimulated much of the present interest when they published a report of work done at Oregon State University. Since that time commercial poultry breeders have accepted the challenge of producing a marketable "mini" layer. At present there exists much interest and controversy about mini layers and their performance.