Commercial Chicken Breeds
Commercial chicken breeds are highly specialised, either producing lots of eggs or lots of meat, but not both. They are well suited for intensive production systems.
Commercial layers are typically sourced from breeders when they are 18 weeks old. Most of the commercially available breeds today have been developed out of White Leghorn and New Hampshire crosses, with Amberlink, Hyline and Lohmann being the most commonly used strains in South Africa. Each bird, depending on the line, has the potential to produce six to seven eggs a week from 18 weeks to 70 weeks of age.
While layers are kept longer in some other countries and sometimes even manipulated to go into another egg producing cycle, most South African egg producers sell their layers when the birds are 70 weeks old. Firstly, because it becomes too expensive to keep the birds for longer and secondly, because South Africa has a thriving informal market for live birds (spent hens). Producers use the money made from spent hen sales, to help subsidise new layer purchases.
Most of the commercially available broiler lines have been developed out of White Plymouth Rock and Indian Game crosses, with Ross, Cobb, Hubbard, Arbor Acres and Hybro being the most commonly used strains in South Africa. The birds are typically sourced as day-old chicks. Huge genetic progress has been made in broiler birds over the years.
Where it took 84 days to produce a 1,8 kg broiler from 3,25 kg feedback in the 1950s, modern commercial broilers have the ability to achieve this body weight after 33 to 35 days with less than half the volume of feed. New breeding strategies not only look at improved production in terms of egg or meat output, but also the breeding of more balanced and resilient birds.