Wednesday, August 15, 2012

Eggs (and Biotin) for Mink

Eggs are the highest quality protein there is for mink and for people too. The trouble with eggs is that they contain a substance called avidin which binds to biotin making it unavailable to the mink. Symptoms of biotin deficiency start to show up fairly quickly in growing/ furring mink if there is insufficient biotin getting to them. The biggest issue is serious changes to the skin and hair: grey fur, banding of the fur, hair loss especially around the eyes “spectacle” eyes, dermatitis (scaly skin), eye infections, crusty feet, etc.

There was a feeding trial done at NSAC in 1995 looking at eggs- raw, cooked, fried and powdered, with and without egg shells. The results suggested 5-15% raw eggs with shells is acceptable. Other references I’ve found indicate much the same. However, when formulating mink rations with raw eggs, the diet requires 0.125 mg added biotin/kg of feed.

A typical bag of biotin premix has a concentration of 220 mg biotin/kg of premix. A feeding rate of 0.57 kg of premix per tonne of wet ration will give you the 0.125 mg biotin/kg wet feed that you are looking for. If you formulate based on pounds, that is 0.57 pounds of premix per 1000 pounds of wet feed. If your biotin premix is a higher or lower concentration (not 220 mg/kg) you will need to calculate accordingly.

Biotin premix is typically available from feed companies or farm supply stores. If you know you will need several bags to meet your requirements, it is best to order in advance, as it’s not a product often carried in large quantities. Because biotin premixes are so concentrated, I recommend that you first mix the 0.57 kg into a 5 -10 kg pail with cereal, and then blend that with the rest of your dry ingredients, to ensure an even distribution throughout the feed.

Offal from poultry breeders, especially turkeys, can have a similar affect on biotin. If you’re feeding spent hens in addition to eggs, you could really run into trouble. Turkeys are a much bigger issue than chickens though. On the other hand, liver is an excellent source of biotin, so if you’re feeding liver, it could help negate the effects of the eggs. Biotin is a B Vitamin, produced by bacteria in the digestive tract of the animal, so antibiotics can also interfere with biotin production. Cooked eggs do not create the same problem.

If eggs are boiled for 5 minutes at 91 ̊C, the cooking disrupts the avidin. Powdered eggs may or may not be problematic, depending on the process (temperature) used in drying.

Eggs are an excellent source of nutrients for mink. Used wisely, they make a great addition to growing and furring diets.

For further information on mink feeds/feeding be sure to visit Perennia's new website. Click here for the link to mink.