Commercial birds Shaver and Hyline hens look identical, unless you’re an expert.
The modern commercial hybrids available in NZ – Hyline Browns and Shaver Browns – could also be considered a light breed, although they are themselves a cross of several breeds, basically Leghorn with an infusion of a brown-egged heavy breed. Their mature bodyweight is much the same as a light breed, and in some cases considerably less.
Their nutritional needs are much the same and all are adequately catered for by the commercial feeds available, especially those with higher protein and energy specifications.
The commercial meat chicken is a hybrid cross of some of the traditional heavy breeds, including the White Plymouth Rock, Cornish, and others, and falls into the heavy breed category.
Prior to the 1940s, all the chicken breeds that we now call ‘heritage breeds’ (or a first cross developed from them) were all that was available, and originated mostly in Europe or North America.
By the 1950s, the strain cross hybrid became the breed of choice for commercial farmers. These were primarily developed by Hyline in North America, by Shaver (ISA Poultry) in Canada, and by Thornbers and Sykes in England.
These birds were either based on high-performing Leghorn strains or a light/heavy cross like the White Leghorn/ Rhode Island Red-cross or the heavier dual-purpose cross of Rhode Island Red/ Light Sussex. The RIR/LS cross had the benefit of being able to be colour-sexed at hatching, the brown-to-red feathered females entering the laying sheds and the white feathered cockerels being fattened for the table.
In New Zealand and Australia, the White Leghorn crossed with the Australorp hen was one of the most popular choices of poultry farmers producing eggs for sale up until the mid-1970s, when the first imports of Northern Hemisphere hybrids (Hylines and Shavers) were allowed into NZ.
The nutritional needs of egg-laying hybrids, with their smaller appetite and active character, is different compared to the more ponderous, heavy specialist meat birds. Specialist diets have been developed accordingly, and we’ll have more on that in next month’s column.