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By Katie Thear
It was the Cornish and the Barred Plymouth Rock that gave rise to the first of the modern, commercial breeds – the Cobb.
Initially, a genetically dominant, white Plymouth Rock was developed to meet the demand for a white-feathered bird that did not have dark stub feathers on the carcase.
This white male could be mated to different coloured females but the progeny would always be white.
Then, a Cornish (Indian Game) male was crossed with White Rock females and the progeny were subsequently selected for fast growth. An interesting aspect of this selection was the change in the frequency of pea combs.
A pea comb is a small comb with triple ridges. Initially, nearly 100% of the birds had such a comb. However, fast growth is associated with single combs, and selection produced birds that were 90-100% single-combed. It was this line that produced the Cobb 500, a white-feathered table bird that has dominated the broiler industry.
Developed for intensive, indoor production, the Cobb is certainly a fast grower and has been known to grow too quickly for its legs to cope with its weight. The males are particularly prone because of their even larger size. In intensive conditions, they achieve a weight of 1.8 to 2.3kg (4 to 5lb) in just five to six weeks.
In a free-range environment, where they are fed a lower protein ration, they achieve this weight in around 12 weeks. The exercise also helps to develop and strengthen their leg muscles. We often raised small batches of Cobbs on free-range and never experienced leg problems with them, although they were all females.
Ross is also a name associated with white-feathered broiler chicks. Again, although originally bred for indoor conditions, they adapt well to free-range conditions.
In recent years, slower-growing hybrids have been developed specifically for the free-range sector. The Hybro broiler from Euribrid is white-feathered and has a slower growing rate in its first four weeks of development, then accelerates after 28 days when its muscles have developed adequately.
Slower growing white-feathered birds are also available from other breeders. There is a Cotswold White (originally called Sherwood White) and a Devon White. There are also Devon Golds and Cotswold Golds, so called because, although the feathers are white, the skin is golden.
It is appropriate to ask why slower-growing birds are preferable to the fast-growing broiler hybrids. There are three reasons – avoiding leg problems as referred to earlier, a better textured meat with more flavour, and the humanitarian aspect of the birds being able to be outside. (In intensive houses, broilers are slaughtered so early that they are barely off heat in many cases).
Outdoor flocks often have access to woodland areas or to hedgerow strips where there are a range of wild plants such as bird’s foot trefoil and wild garlic, and where insects can be caught. All these add to the flavour of the meat, and in the case of the plants, there are elements of self-medication as well as the provision of extra minerals. Meat from very young birds tends to be very bland and relatively tasteless.
It was the French who pioneered the woodland method of managing free-range table birds, and also of introducing the designation Label Rouge, a description meaning that the birds had been raised outside and allowed to grow at a natural pace (not the name of a breed as some think). The French must also be credited for developing coloured hybrids for the table, and in so doing, helping to provide a commercial role for the traditional breeds. In the long term the future of any breed is linked to its economic interest.
The breeding firm Sasso, for example, has developed a range of traditional primary breeders that can be used to produce a wide range of coloured feather table birds to suit different markets. These include red, grey, black and other colours, catering for different areas that traditionally have had their own type of table bird. The breeders include Rhode Island Red, New Hampshire, Sussex, Plymouth Rock, Wyandotte, Gris d’Espagne, Marans Fauve, Marans Noir, Marans Gris, Faverolles, Ficchoise, Bourbonnais, Houdan and Taiwan Tou Dij (a Naked Neck type). However, these are not the table birds themselves, but the breeders that are used to produce them.
The way in which this is done is to cross these traditional males with small, prolific hybrid hens that have a recessive gene so that the progeny always resemble the fathers in feather colouring, and so also resemble the traditional table birds. However, the genetic input of the mothers ensures that the progeny have short legs and plump breast meat. They grow well, but at a natural pace and have a good feed conversion ratio. Sasso’s range of recessive females includes dwarf or compact strains, heavy, light and auto-sexing. They also have a good egg production rate, an essential requirement for the economic production of growing stock.
Hubbard-ISA has also developed colour feather table strains in a similar way. For example, the red-feathered ISA 457 is the result of a cross between the S44 male and the JA57 female. Also available in this country are JA 257 and 757, as well as Mastergris and Coloryield.
Local names are often given to some strains of table birds. Examples are Devon White, Devon Bronze or Devon Gold, Cotswold White, Cotswold Gold, Poulet Gaulois, etc.
|Traditional Utility Breeds||Modern Strains|
|Cornish (Indian Game)||Ross|
|Rhode Island Red||Euribrid Hybro|
|Plymouth Rock||Sasso breeds|
|Wyandotte||Hubbard ISA breeds|
|Dorking||(Sasso and Hubbard ISA|
|Marans||strains are available in the|
|Faverolles||UK under a range of names shown|
|Houdan||above, depending on the supplier)|
Copyright © Katie Thear 2005