Happily, there's an increase in the public's wish for the welfare of farmed animals - including chickens - to be less based in chemical "fixes" and "enhancers", and more concentrated on natural solutions.
That has led over a period of several years to two consequences:
Parsley has become one of those natural alternatives.
In this article, we'll look at what the benefits are, which type of parsley research shows is most effective, how to grow it in your own backyard (it's so easy!) and how to feed it to chickens.
Let's look at the basics first.
What is parsely?
Its botanical name is petroselinum crispum and it's a well known, very common herb used in cooking, particularly in Europe and Asia.
It's a biennial plant, but mostly grown as an annnual (that is, it needs replacing each year).
If allowed to grow for the second year it will produce flowers and seeds - more about that later.
There are more than thirty varieties of parsley. The two most well known are flat leaf, which is also called Italian (and sometimes French!) parsley, and curly leaf.
Flat leafed parsley (Petroselinum crispum var. neapolitanum) as the name suggests, has large, flat leaves with three "lobes", lighter green when they're young, darker as the plant gets older.
Curly leafed parsley (Petroselinum crispum var. crispum) tends to be bright green and has "ruffled" leaves.
Flat leafed is generally used for cooking as it has a stronger taste; curly, being more showy, for garnish.
There's a chemical difference between the two, as well.
Flat-leafed parsley is scientifically proven to have a much higher concentration of essential oils in its leaves. And it's that which makes it the type used in research about enhancing chicken health.
All the following information refers to flat leafed parsley.
Vitamin 'A': critical for keeping a chicken's respiratory and digestive tracts in good condition.
Vitamin 'K': important for bone health, and for ensuring blood clotting.
Iron: Particularly important for laying hens to ensure egg quality and the healthy development of chicks(3).
Calcium: contains around 4%. Critical for bone health and eggshell quality.
Essential oils: contains between 2% and 8%, including linoleic, myristolic, and other fatty acids known to be important for healthy eggs, and for producing healthy chicks from laying hens.
There are all kinds of claims made for parsley in terms of human health. It's said to treat everything from bad breath and skin blemishes to fevers, cancer and even the plague.
The three major proven benefits of parsley for human health(4) concern...
Please note: parsley is not recommended for pregnant women.
Very little parsley is needed to provide the necessary health benefits. Studies used parsley in two ways.
One of the easiest and low maintenance herbs, and with such high benefits for chickens, it's well worth growing your own.
Note that the plants bought from supermarkets generally do not do well as garden plants. It's best to buy from your local garden centre or nursery.
This is my favourite way of growing this herb. I let someone else do the hard part - germinating the seeds and growing the seedlings.
Grow small, starter plants in pots of into the large, lush bushes which will produce parsley all summer.
Use a mix of garden soil and compost to help with water retention.
When the root system has grown into the small pots, move the plants into their final place. I use three small plants to one large (35 cm, 14") ceramic pot.
If you don't have space on an external terrace or in your chicken run, keep your parsley in pots on a sunny windowsill.
A lot of "facts" you'll find on the internet are often people's individual views, based on inaccurate information repeated from poor quality sources.
The information I provide in this article and others is based not just on my own experience, but on evidenced facts from scientific, peer-reviewed research and books from highly respected and experienced poultry keepers such as Gail Damerow.
Some of the trusted sources I have used in this article are these.
1. Kumar, V: Petroselinum crispum. Pub. Encyclopedia of Food and Health, 2016.
2. Al-Quaisy, G. A et al: Effect of Additional Different Level of Parsley Leaves (petroselinum sativum) Powder to the Ration on Some Blood Serum Biochemical Traits of Broiler Ross. Published Journal of Natural Sciences Research, 2016.
3. Taschetto, D, et al: Iron requirements of broiler hens. Pub. Journal of Poultry Science, 2017.
4. Nielson et al: Effect of parsley intake on urinary apigenin excretion, blood antioxidant enzymes and biomarkers for oxidative stress in human subjects. Pub. British Journal of Nutrition, 1999.
5. Abbas, R. J: Effect of using fenugreek, parsley and sweet basil seeds as feed additives on the performance of broiler chickens. Pub. International Journal of Poultry Science, 2010.
6. Osman, M., Amber, K.H. and Mahmoud, M.A: Response of broiler chicks performance to partial dietary inclusion of radish, rocket and parsley cakes. Pub. Journal of Egyptian Poultry Science, 2004.
7. BBC Gardners' World: How to grow parsley. Pub. 2019.