Egg Industry News and Commentary

  —  Apr 5

Justification for “Slow-Growing” Broilers?


Dr. Tatijana Fisher at the University of Kentucky reviewed Management of Slow-Growing Broilers for Profit at the 2017 Midwest Poultry Federation Convention.

Her paper noted the demand by boutique supermarkets and specific food service companies which have been active in promoting “welfare” for slow-growing broilers. 

Much of the publicity generated by these companies and their justification is not based on scientific fact and in many cases includes gross distortions. 

These include an exaggeration claiming a 90 percent plus prevalence rate of myodystrophy (“wooden breast”, “striped muscle”), and high levels of pododermatitis and locomotory dysfunction in commercial broilers.


At the outset it is clear that activists promoting slow-growing broilers appeal to emotion and in many cases have less concern over the well-being of flocks than in opposing and vilifying intensive broiler production.

Reviewing data documented by the National Chicken Council, in 1955 broilers required 70 days to achieve a weight of 3.6 pounds with a feed conversion of 3:1.  In December 2016, 145 complexes subscribing to an industry database collectively producing 649 million straight-run broilers achieved 6.6 pounds in 48 days with a feed conversion ratio of 1.85.  Selective breeding over successive generations has increased the proportion of breast meat in response to consumer demand.

Europe has seen an increase in demand for alternatives to conventional white-feathered high-yield broilers. Dr. Fisher estimates that 25 percent of production in the Netherlands involves slower growing breeds contrasted with slower adoption in the UK of less than 10 percent of broilers produced.  The EU has an affluent population which is reacting to misinformation but is apparently willing to pay for alternatives to conventional broilers.

A projection of the impact of converting 30 percent of current U.S. production of approximately 165 million birds per week to slow-growing broilers illustrates the sacrifices in sustainability which would occur with retrograde genetics.  An Elanco Animal Health simulation model estimated that the cost to the broiler industry would exceed $9 billion annually. This would require almost doubling available broiler housing and feed consumed relative to conventional birds.

Dr. Fisher presented data comparing trials conducted at the University of Kentucky on Cornish-cross male and Red-ranger male with respect to live bird parameters.  Cornish-cross males achieved an average daily gain of 58.3 g which exceeds the unrealistic standard of 50 g per day growth rate set by the Global Animal Partnership. In contrast Red-Ranger males attained an average growth rate of 40 g, which was very highly significantly less than the Cornish-cross males.  The feed conversion of the Cornish-cross males was 1.9 compared to 2.2 for the Red-Ranger males.  There were also very highly significant differences in carcass composition.  Chilled yield (without giblets) of Cornish-cross males was 74 percent compared to 68 percent for Red-Ranger males.  Boneless and skinless breast yield was 31 percent for Cornish-cross males compared to 20 percent for Red-Ranger males.  Cornish- cross males yielded 30 percent as whole legs compared to 34 percent from Red-Ranger males. Based on economic realities, Dr. Fisher appropriately concluded that slow-growing strains would only be suitable for specialized whole-bird markets. 

Cognizant of the demand, although limited for slow-growing strains, Aviagen has made available the Rowan Ranger™ based on their extensive gene pool.  Claimed specifications for the strain include 4.4 lb. live weight at 47 days for females and 44 days for males with respective feed conversion efficiencies of 1.90 and 1.85. Whole body yields (without giblets) average 66 percent for both males and females with males yielding 19 percent breast meat, 12 percent thighs and 10 percent drums.  These values exceed the data for the Red-Ranger male evaluated by Dr. Fisher.

Despite the initial publicity generated by Whole Foods Market which initiated and essentially motivates the Global Animal Partnership (See Commentary in April 5th Edition of CHICK-CITE) which has emerged as a certifying agency for alternative broilers, the cost of product will only be appropriate to an affluent demographic.  It appears that Panera Bread, Chipotle and some food service suppliers including Compass Group, Aramark and Sodexo which have all been prominent in promoting “welfare gimmicks” in the interest of image and product differentiation will be involved in promoting slow-growing broilers. On March 3rd West Liberty Foods a turkey producer purchased Crystal Lake Foods in Arkansas specifically to produce slow-growing broilers for the emerging but limited niche market.

Based on a differential in cost of production attributable to retrograde genetics, non-sustainability and suboptimal parts yield, slow-growing broilers will not be expected to displace any appreciable proportion of the conventional broiler industry in the U.S.

CHICK-CITE is of the opinion that producers should satisfy market demand wherever it exists provided that products are relatively sustainable and provide a margin. Choice is a cornerstone of a market economy. We take exception to those promoting alternatives to conventional product by dissemination of disinformation degrading the image of modern broilers and by extension their producers. We are also opposed to the principle of an affluent minority, irrespective of their motives, imposing their unsubstantiated and frequently erroneous views on the marketplace, resulting in increases in cost to middle and low-income consumers.