Chicken Growth Hormones

The Truth about “Hormone Free” Chickens

How many times have we gone to the grocery store to get food for dinner, and saw a label on our favorite protein, chicken, that stated “Hormone Free.” I hate to be the one to break it to you, but those labels are lying.

NO chicken, at all, no matter what, is completely “hormone free.” Chickens naturally produce growth hormones. Mississippi State University Extension explains this a little more when they said, “Progesterone, testosterone, and estrogen are naturally occurring hormones in both humans and animals. These hormones are necessary for normal development, growth, and reproduction.” As MSU Extension explains, hormones occur naturally in chickens so that is why the label, “hormone free” is incorrect.

Chickens Growth Hormones

Labels like these are misleading to consumers.

Another label that is misleading is “No Hormones Added.” Additive hormones are banned by the FDA and have been for the past 50 years. So no growth hormones are added to the chicken we eat, because they are illegal so when companies market their chicken as “No Added Hormones” just realize that this label applies to all chicken eaten in the United States.

This video from the USPoultry Association featuring interviews with professors and extension specialists from the University of Arkansas does a great job describing that hormones are not used in the poultry industry, and why they are not used. It also shows how chickens are raised, showing the housing, feeding operations, and overall care of poultry in the United States.

Chicken Growth Hormones

The left-hand chicken is a breed from 1957. The middle chicken is a breed from 1978. The right-hand one is a breed from 2005. They were all raised in the same manner for this paper and were photographed at the same age.

Poultry Science, a scientific journal, recently did a study on the effect of selective breeding on growth, efficiency, and yield of broilers, or chickens produced to be eaten. The study took mixed-sex chicks and grew them according to a current nutritional program to 56 days. They took front and side portraits of 8 birds per strains. They also measured growth rate, feed intake, and measures of feed efficiency including feed conversion ratio, residual feed intake, and residual maintenance energy requirements.

This study says that, “From 1957 to 2005, broiler growth increased by over 400%, with a concurrent 50% reduction in feed conversion ratio…” This study proves that the size of broilers has increased over time because of selective breeding that has consequently increased feed conversion ratios.

Another reason, besides legality that chickens are not given growth hormones is that they are not effective. Dr. Berry, a poultry science professor from Auburn University explains why, “Growth is complex; no one hormone can affect it. The hormone everyone considers a growth hormone is a protein hormone that is in all vertebrate. It cannot be taken orally, because it is digested normally, to be effective it would have to be injected. The injections would have to be given every 90 minutes to be in correlation with the pulses of the natural hormones in the chicken. We have 110-120 million birds growing in Alabama at any given moment, so 120 million birds would have to be given an injection every 90 minutes; obviously that is not economical at all.” This is a reason that surprises a lot of consumers, but it is another main reason that hormones are not used in the poultry industry.

So the next time that you hear that chickens are larger than in the past because they are fed growth hormones, just realize that is actually not true. Chickens are not fed or injected with growth hormones, they just have naturally increased size over time. So when you see a label that has “No hormones added” or “hormone free” just remember that NO chicken, at all is hormone free,  and no chickens have hormones added to them. So feel confident when buying chicken from the store or from Chick-Fil-A by realizing you are not eating something with growth hormones.