Poultry Breeds

Poultry Breeds

Our livestock principles emphasize the use of breeds and strains well-suited and adapted to the prevailing conditions, and this should include their vitality and their relative resistance to disease. Ideally, breeds or strains of birds should be selected to avoid specific disease or health problems associated with intensive production. Indigenous breeds or strains should also be considered.

The ancestor of modern chicken breeds is the wild jungle fowl Gallus gallus (Wood-Gush, 1959; Moiseyeva et al., 2003). The breeds commonly used in commercial poultry are dominated by those supplied by large international, vertically integrated companies Hoffmann (2005). Hoffman describes the restricted access to pure parent line birds by selling F1 generation birds, and how this process allows the breeding company to remain the sole supplier of useful material. While patents do not yet play a role in poultry breeding, in the future an increasing interest in for disease resistance might change this situation (Hoffmann, 2005).

Which Layer Breeds?

A common practice in conventional egg production is the use of hens for only one laying period in conventional production. Pryce et al., (2004) highlight the potential for using hybrids that are selected for production over several seasons. Using these hybrids may be appropriate for free-range and organic laying units, not just because of the high price of new layers, but also because it is more in keeping with sustainable farming principles.

Laying breeds such as ISA Brown, Hyline and more traditional breeds such as Light Sussex and Rhode Island Red, are suitable for free-range systems. Other breeds popular in organic and other low-input, free-range systems are Black Rocks and Hebden Blacks. Also, the Bovan Goldline breed has a reputation of being docile and a non-feather-pecker.

A comparison of New Hampshire, White Leghorn and ISA-Brown under organic farming conditions showed the latter had the highest egg yield, although cannibalism was several fold higher (Sorensen and Kjaer., 1999 in Hermansen et al., 1999) and was hence seen as unacceptable for this type of system unless methods can be found to control their behavior. Rizzi and Chiericato (2005) compared egg production in two commercial hybrids (Hyline White and Hyline Brown) with two traditional Italian breeds (Ermellinata di Rovigo and Robusta Maculata) under organic conditions and found the hybrids had superior productivity.

Which Broiler Breeds?

There are various reasons why broiler breeds bred for intensive conventional production are not well suited to the very different conditions we see on low input, outdoor farms (Pryce et al., 2004).
• Genotypes that have been bred to suit intensive, indoor management systems focused on rapid growth, increased feed efficiency and increased processing yield.
• The high productivity of these strains depends on high levels of feed, health treatments and other inputs, the absence of which can result in disease and poor welfare.
• Most modern genotypes are bred to suit a specific market destination (e.g. well-fleshed birds processing and smaller birds roasting) within a short period of production, typically over 5-6 weeks and are thus not suited to low input and high welfare systems, where the period to slaughter should be much longer.
• Modern breeding has focused attention on the production of a single poultry product, either eggs or meat and hence the suitability of many hybrids for dual purpose production has been lost.
• Genetic selection for high productivity in conventional strains of broilers and layers has led to deterioration in animal health (Rauw et al., 1998).

There are many slow-growing genotypes available, and researchers have suggested that although the growth performance of slow-growing birds is less efficient than that of fast-growing birds, slow-growing birds are more adapted to natural systems, and the quality of their meat is more appropriate for a specialty or gourmet market (Fanatico et al, 2005). Nielsen et al. (2003) compared Ross 208 and Labresse cross broiler strains fattened outdoors from 42 to 84 days under low and moderate energy feeds. The Ross 208 strain was found to have a faster growth rate, poorer litter quality, more dermal lesions and impaired mobility, poorer gait score and pectoral myopathies and were considered unsuitable for 12 week growth in free range production systems. The Labresse crosses were observed to use outdoor areas more frequently and used more of the outside area. However, feather pecking and cannibalism only occurred in Labresse crosses and the suitability for free-range meat-type poultry production of that particular cross-breed is questionable. Interestingly, more birds on the moderate energy feed regime were observed outside.

A comparison of a commercial broiler breed with the Barred Plymouth Rock and Jaerhon breeds under intensive (ad libitum feeding) and extensive (restricted feeding) systems from 7 to 20 weeks (Ali and Brenøe., 2002) showed that while the commercial breed performed the best under intensive conditions, under the extensive regime it lost the greatest potential body weight. Interestingly, males expressed their growth capacity much less than females under extensive conditions. It was concluded that both genetic and underlying size differences should be considered in breed comparisons, particularly when chickens are subjected to different feeding regimens.

Fanatico et al. (2005a and 2005b) evaluated slow, medium and fast growing genotypes and showed meat quality, growth performance and yield differences exist among genotypes with different growth rates and reared with or without outdoor access. In the slow growing breed only, the effect of outdoor access was to make the meat more yellow. Slow growing genotype had the highest feed intake and hence the lowest feed efficiency. Birds given outdoor access had greater bone strength in the tibia, and the faster growing genotypes had the highest bone strength. Slow growing birds had the lowest feed efficiency, the lowest breast yield and the greatest leg quarter yield. The slower-growing genotypes showed a good adaptation to the extensive rearing conditions, while the fast-growing genotype showed unbalanced muscle response to the greater activity and the oxidative stability of the meat was reduced.

A comparison of three traditional Italian breeds Bianca Saluzzo, Bionda Piemontese and Valdarnese Bianca showed that the breed that the slowest growing breed and the one deemed best suited to organic rearing conditions (Valdarnese Bianca) also had a stronger anti-predator response and was therefore probably also better suited to free-range conditions (Ferrante et al., 2005). The characteristics of Polish breeds that would be suitable for organic production are described and efforts to conserve these breeds are discussed by Cywa-Benko (2000).

A German trial compared meat production from male brown layers hybrids (Meisterhybrid) with commercial fast growing broilers (Ross PM3) and found the costs and meat quality to be unacceptable (Damme and Ristic, 2003).