Boilies and the HNV Theory.

It was Fred Wilton who in the 1970's developed the "High Nutritional Value" bait theory, this is shortened to "HNV".  The original idea was that if you introduce a high protein bait on a regular basis, carp will learn to recognise the food value of the bait and see it as a preferred food source.  Because of this the bait would have a long life span on the water it was applied.   Milk proteins were used to make the bulk of the bait, which had protein levels up to 80% of the bait.

A label or flavour was added to the mix, this wasn't so much seen as an attractor, but as a point of reference for the carp to associate with the bait.  It was then found that some labels worked much better than others, so the concept of using liquid flavours and powders as attractors was developed.

When first introduced into waters these HNV baits could provide stunning results and everyone hailed the HNV theory as correct.  I would add a note of caution here, you can get stunning results when you introduce any radically different fishing method or bait to a water.

In the end all but the extreme HNV purists realised that very high protein baits made of milk proteins were not needed.  I think the price of milk proteins had something to do with it, as they soared sky high.  Also many people started catching carp on fishmeal baits.  So the term HNV lost it's high protein tag and we now had baits with a "balanced Nutritional profile".  This is the current state of affairs.  Baits with a protein value of between 35 to 45% are now advocated, with a spread of other nutrients such as carbohydrates, oils etc.

At the time that  high milk protein baits were in vogue, baits based on soya and semolina were termed "crap baits".  Even fishmeal was seen as an inferior form of protein, people might try to deny that now, but it was at the time.

What I would like to do is have a look at the makeup of a soya / semolina  boilie and it's nutritional value.   Lets take a look at a 50/50 mix consisting of 6oz Semolina, 4oz Soya Flour, 4oz Maize Meal, 2oz Ground Rice and not forgetting the 4 eggs.  Definitely a "crap bait" in some peoples eyes.

The following is a quote from Ben Helm B.Sc., from the Nishikoi Koi Information Centre on koi diets.  Koi are after all carp.  It deals with nutrient levels in koi diets.

• Protein. Levels of approximately 30% are typical but will be higher if a growth food and lower than this if a low temperature food. Protein is present for growth and repair and is the diet’s most costly ingredient. Sources of protein include both animal and plant derivatives and meals such as fishmeal, soya, wheat and egg.
  
  
• Carbohydrate.  These are the complex sugars such as starch and cellulose. They are all plant in origin and are included in high quantities in koi diets as a cheap source of energy. They are also included as a source of fibre to aid digestion. 
  
  
• Oils. Oils are included as fish or vegetable oils. Usually less than 10% in the diet they are used by koi in the production of new tissues etc. If too much oil is included then pellets appear greasy and oily as in a trout pellet. These tend to be too rich for koi and can cause water quality problems.
  
  
• Vitamins and Minerals. Manufactured diets often rely on the natural vitamin and mineral content included in the raw ingredients. More recently better quality brands have been including stable supplements of the notoriously unstable Vitamin C.

So lets have a look at how our 50/50 mix shapes up to the above.  Including the eggs it works out at about 18% protein.  This is lower than the average koi feed level suggested above, yet would fall within what is recommended for winter.  The main protein comes from the soya, maize and egg.  Lets have a look at a quote on egg protein:

Not only do eggs contain the highest quality source of protein available but they also contain almost every essential vitamin and mineral needed by humans. In fact, egg protein is of such high quality that it is used as the standard by which other proteins are compared. Eggs have a biological value (efficacy with which protein is used for growth) of 93.7%. Comparable values are 84.5% for milk, 76% for fish, and 74.3% for beef. They have valuable vitamins and minerals too" - National Nutrient Database.

It certainly looks like we have some good quality protein in there.  The make up of the bait looks like an ideal bait for winter.  It was not so long ago that some of the bait guru's  were telling us to still use high protein milk baits in winter.  Yet the nutrition boffins in the koi industry recommend feeding less protein?

Regarding the carbohydrates, we have certainly got plenty all of which are of plant origin.  Oil is provided by the soya flour, if you need more add a bit of flora or fish oil.  As for the vitamin and minerals, this is just a brake down of a single egg:

Protein (g) 6.29  Total lipid (g) 4.97  Total carbohydrate (g) 0.39  Fatty acids (g) 4.13  Saturated fat (g) 1.55  Monounsaturated fat (g) 1.91  Polyunsaturated fat (g) 0.68  Cholesterol (mg) 212  Thiamin (mg) 0.04  Riboflavin (mg) 0.24  Niacin (mg) 0.04  Vitamin B6 (mg) 0.07  Folate (mcg) 24  Vitamin B12 (mcg) 0.65  Vitamin A (IU) 244  Vitamin E (mg) 0.48  Vitamin D (IU) 18  Choline (mg) 125.6     Betaine (mg) 0.3     Calcium, Ca (mg) 27 2  Iron, Fe (mg) 0.92  Magnesium, Mg (mg) 6  Copper, Cu (mg) 0.05  Zinc, Zn (mg) 0.56  Sodium, Na (mg) 70  Manganese, Mn (mg) 0.02.

A lot of vitamins loose their potency with age.  Go buy your ingredients from the supermarket, pet shop or bird seed manufacturer and you will find that the products you are buying are fresh and have a sell by date.  Even semolina contains vitamins, don't take my word for it, do research on a search engine.  It's also worth a mention that cooking also destroys vitamins.

Just as an aside, it must be remembered that all koi carp feeds are produced at a trade of with quality and cost.  The best / cheapest source of protein is thought to be fishmeal.  Wheat germ is also thought of very highly especially in cold water.

Having a look at our 50/50 mix, it's not the nutritional disaster and crap bait it's made out to be.   Someone is going to say "Ah yes, but they crap a lot of that mix out.  I did read somewhere that carp pass about 50% of what goes in their mouth out of their back side.  Just think of all the debris of the bottom, snail shells etc that go in that have to come out.   So it is natural for a carp to pass a proportion of their intake out as waste.

Bear in mind also that if you feed carp to high a protein diet, some of that protein is used for energy instead of growth.  In that case the nitrogen in the protein is not used, but excreted as ammonia which is toxic.  Also protein requirements decrease with the age of carp.  young fish need it for growth, older fish don't.   This doesn't tie in with some of the bait guru's, who tell you that bigger fish feed on protein baits.

Of coarse it could be altered if we wanted to increase it's nutritional value.  A change to 6oz Semolina, 4oz Soya, 4oz Fishmeal, 2oz wheat germ and 2oz maize meal would produce a bait with a protein content of about 35%.  Wheat germ is very buoyant so you don't want to much in.   If you cant find wheat germ (which is sold by chemists and health food shops) leave it out and add another  2 ounces of maize meal.  Mind you we now have a recipe almost identical to that listed in the fishmeal basemix section.  Looks like were back where we started.

If you don't want to use fishmeal and want something simple and different, add 3oz or so of raw liver, squid or a tin of tuna (in brine or spring water) to your eggs and mix them up in a liquidiser before adding your base mix.   That will give you an HNV using a simple 50/50 soya and semolina type bait.  Of coarse you could add a bird food mix to this, or any other mix for that matter.  There again why stop at tuna?  There's tinned cat food, fish eggs, anchovies, anchovy extract etc. etc.  The list is almost as long as your imagination.

Or failing all that just add a couple of ounces of milk powder to your soya / semo bait.  It won't be the highest protein bait, but they will go on eating it, just keep the flavour level low or use a natural attractor.  Not only that, you will be able to afford to put plenty in.

So you see there really is no need to see a scientist to formulate a bait, like I read somewhere on the net.  Just pop down to the local supermarket or butcher.

Bear in mind that I see fishmeal being mentioned a lot as a way of increasing the protein value of baits.  I think a lot of bait companies baits with fancy names are actually fishmeal mixes.   Don't fall into the sheep trap.  Don't get me wrong, fishmeal is an excellent ingredient, but if everyone else and his dog is on it, a change could pay.

In my opinion the theory that carp can tell which baits are the most nutritionally beneficial is wrong.  I just think it's one of those things that's been accepted in to carp angling folklore.

Lets explain it this way.  If every time a animal goes towards a bright red light it gets a bang on the head, it will quickly learn to stay away from bright red lights.  Change the light colour to green and repeat the experiment.  At first it will go near the light, but will quickly learn again to avoid it.   Animals including carp learn to avoid danger and the stronger that signal is, which is associated with danger, the quicker they learn to avoid it.

Baits with a high danger stimulus, that is to say a high flavour level are learned to be avoided quickly.  Change the flavour (which is the same as changing the light colour) and you catch again, until the fish has again learned to avoid the new flavour.  I think it's also fair to say that the stronger the stimulus for the animal (the stronger the flavour), the quicker it learns to avoid that danger.  This is also true the other way around.  Therefore use a lower flavour level, which will reduce the strength of the danger signal and that bait will go on working longer.  This will have nothing to do with the nutritional value of the bait.  It all depends how much.

Bear in mind that the strength of the signal the flavour sends out depends on it's make up.  Some flavours can have a much greater inclusion rate in a bait than others.  A lot depends on what base they are on ie. the carrier for the flavours constituants.

People tend to use low levels of flavourings in HNV baits or natural attractors, they also pre-baited which helps to overcome the fishes fear of the bait.   I have said in another part of the site that I know of 4 lakes, where the carp have been eating bread thrown in for the ducks for years.  They haven't stopped eating bread because it was of so called low nutritional value.  I fished one lake with tigers for a couple of years and they kept coming back for more and more.  Not much of your balanced nutritional make up in a tiger nut.  Maybe they just liked them and it was an available food source.

Boilies have been catching fish for many years now.  The fact that they are still working is nothing to do with their Nutritional makeup.  It's to do with the fact that their are so many types and varieties available, we are able to temp fish with something slightly different.

One thing that fascinates me is anglers who apply the HNV theory when they are fishing busy waters.  You hear something like:
 "well I was on a HNV bait, but somebody came in on the same flavour with a rubbish bait and it ruined it"
Now come on, lets just apply a little common sense Here.  How the hell, with so many different coloured and smelling boilies going in the average carp water today, is Mr. Carp to tell which has a higher protein level and which hasn't, even if it could?  The carp must eat so many different smelling and tasting balls that is must think it's in a sweet shop.  Even in the old days when I've heard that saying also applied to high protein baits.  If the carp were eating just a mixture of low protein and high protein baits with the same flavour, then it was on a more balanced diet.  How can that put it off?   If you were on a low flavour level and someone came in on the same flavour but at a much higher level that's what would blow your bait.   Not the nutritional make up of the base.

As you may of gathered I don't believe that carp can learn over a period of time the the nutritional value of baits.  They are scavengers who will take advantage of a food source if it is there.  .There are so many different baits going into most waters these days, that the carp wouldn't have a clue where to start identifying which one did it the most good.  I also don't think that soya and semolina based baits are the crap they are supposed to be.

Fishmeal baits are the current "in thing".   They are recommended by the koi industry as a good protein source.  Because they are cheap, the bait companies can include them in their mixes at a very cheap price and still give their base mixes the "HNV" label.  As is said in the koi industry, aqua culture protein is best for aqua culture feed.  Fishmeal baits are very successful, because the fishmeal mimics the food signal given off by the carps natural diet.  It's animal based,  so is yeast, liver, squid, etc.,  they  can give off a similar scent and are also good attractors / ingredients.

Having said all that please remember that what ever you think about  the HNV theory, good food baits are good for carp, that part of the theory is very valid.    I think that on a lot of well stocked waters, the extra protein that baits provide, has helped to increase the growth rate of fish.

A lot depends on the water your fishing.  I fish a water that is very lightly fished for carp, but heavily pleasure fished.  The carp in that water just don't rely on boilies at all as part of their food chain.  One year I will fish a bright single semolina and soya hook bait, heavily flavoured.  The next year I use a fishmeal boilie with a more "laid back" flavour.  It smells different, tastes different, the colour and brightness are different and the baiting pattern is different.  I just don't worry about the nutritional make up of the bait on that water, I don't have to.

If I could recommend one book, it would be "Carp Sense" by Jim Gibbinson.  It really is a return to common sense, the book  unfortunately is now out of print.  It's  well worth a read for the rig section alone, where Jim strips away some of the crap that has crept in.