Sustained reports on Koi forums from across the world about the use of Garlic as a supplement to Koi food and the claims that were made by Koi food manufacturers regarding the benefits of this natural herb, has prompted this article. As stated numerous times on this web-site, there are always new things surfacing in fish keeping, so stay open for new ideas. Pablo Tepoot stated it so eloquently “only dead fish follow the current. Review the facts and think for yourself.”
When it comes to garlic as a supplement in Koi food, I must admit it become very hard to think for yourself. Just type “Health benefits of Garlic” on your internet search engine and you will realize that there is a tremendous debate amongst those for and against the use of garlic.
Few clinical trials have been conducted to determine the beneficial effects of garlic and its active ingredients on fish. One clinical trial suggested that even garlic extract injected into fish intentionally infected with Mycobacterium marinum, at most delayed the onset of the infection. It was interesting to note that the experiment revealed a statistically significant stronger immune response in the fish, but the disease could not be cured. The conclusion was that if even high dosages of garlic injected into fish could not cure diseased fish, how could the relative low dosages mixed into food have any impact on disease at all? Another study came to the conclusion that garlic possesses about 1% of the antibacterial properties of penicillin.
Garlic is a natural product and the belief in its properties dates back to even the earliest recorded times. It was used extensively in ancient Egypt, China and Greece. In 1858, Pasteur noted garlic's antibacterial activity, and it was used as an antiseptic to prevent gangrene during World War I and World War II. Garlic has been studied extensively in vitro, in animal and human clinical trials, and in epidemiologic evaluations for its multiple medicinal properties. Unfortunately the quality of human trials has been variable, making comparisons among the trials difficult. During these trials, many different garlic preparations have been used, with unpredictable release of active ingredients.
Garlic has a high concentration of sulphur-containing compounds. The thiosulfinates, including allicin, appear to be the active substances in garlic. The specific preparation of garlic when for instance preparing an extract, whether freshly chopped, dried etc. appears to change the active ingredients in that specific preparation.
It is however a well-known fact in horticulture and agriculture, that garlic is regarded as an effective repellent for a variety of disease causing agents. In the Koi industry, it is believed that garlic has parasite repellent properties which diffuse through the skin and into the mucus layer of the fish thus protecting it from infestation at the time when they are most vulnerable.
I would like to quote the following: “Over the years there have been a number of studies involving the use of garlic in fish food and the anecdotal evidence with regards to feeding fish allicin complex (the active ingredient in garlic) to rid them of parasites always appeared to be quite strong. As of 2006 there is now some recent science to back these earlier claims up, with one of the largest in-depth studies to date. In this particular study the inclusion of garlic at a rate of 3% was shown to increase the overall digestibility of protein, carbohydrates, and fat, as well as to lower the total bacteria count within the intestine, muscles, and water column. It was also found to enhance fish tolerance to environmental stress.” Read more here.
Pieter J De Villiers (SAKKS) (SAKoiIF) is an avid promoter of the use of garlic in Koi food. Although at the time, I have not tried the use of garlic as a supplement in Koi food myself, I became curious and wrote to Pieter and requested him to write an article on his experiences regarding garlic as a parasite repellant. He sent me the following notes:
"In 2005 I was having a conversation with Father-in law and the topic of garlic came up. He mentioned to me that he use to add some garlic into Dog food to keep the ticks away. Apparently ticks do not like the taste of garlic. What have ticks to do with Koi, maybe nothing, but what about garlic? This made me wonder, will garlic keep the parasites away?
What will happen if we feed our Koi garlic, mixed in food, about one month before the water temperature starts to rise? Will this stop the parasites from attacking the Koi, maybe they would, but will they keep feeding on the Koi?
I started to experiment with garlic by mixing;
1 kg Wheat-germ pellets
50 g Robertson’s Crushed Garlic
Ocean Gold Fish Oil ( 8000 units natural Vitamin A and 800 units Vitamin D per ml.
BaoBio Montmorillonite clay
It worked very well; the only problem was that an oily film appears on the water surface after each feeding, which was later trapped in the filters.
The oil at this stage was used to bind the garlic to the food, and the montmorillonite clay to soak up the excessive oil.
I later change the formula to;
1 kg Koi pellets or Floating Sticks
30 g Robertson Crushed Garlic
Manda Nishiki or Honey Propolis or Pure Honey
Bao Boi Montmorollonite Clay
Feeding it all year round.
Since using garlic I had no problems with parasites
Before & After Winter Treatment
I normally feed my Koi a mixture I called “Terramycin Treatment” before and after winter. This year I add garlic to the mix.
Recipe: Pellet Food
1 kg Koi Food Pellets (wheat germ or floating sticks)
5-10 gram Terramycin Powder (Oxytetracycline hydrochloride 55mg/gram)
30 gram Crushed Garlic (Robinson)
50 gram BaoBIO Montmorillonite Clay
80-100ml Ocean Gold Pure Fish liver oil (8000 units Vitamin A & 8000 units Vitamin D per ml)
Pure honey Propolis
Mix food with Fish liver oil or Propolis
Add Terramycin, Garlic and Clay and mix thoroughly.
Recipe: Paste Food
Mix Food with 150ml Fish liver oil or propolis
Add Terramycin, Garlic and Clay together until a dough-like consistency is achieved.
Roll and shape paste in hands to form pellets to suite the size Koi in your pond.
Keep food in a refrigerator.
Feed for 10 day at your normal feeding times.
Only feed above 16 degrees Celsius.”
Well that is what I could find regarding the use of garlic in Koi food. Human nature tends to resist change and this concept might not be widely accepted by the majority of hobbyists. Don’t be an expert too quickly, as many experts are people who simply know so much that they have no room left in their heads to learn anything new. Give it a chance and I would gladly ad your findings to this article!
Last Updated on Friday, 19 November 2010 23:12