Back to basics: livefood
By Gary Fitt, Brisbane
Nutrition is perhaps the most important component of successful finch breeding. At least it is the main area where we as aviculturists can make a big difference by providing a appropriate, diverse and balanced diet. In earlier instalments of Back to Basics we have covered some aspects of nutrition through the basic seeds we provide either as dry mature seed or half ripe seed (Chapt 6, April Finch News) or greens (Chapt 7, June Finch News).
In this instalment I will deal with the various types of livefood that are readily available and are often essential for success. In Part 2 I will cover the multitude of other supplements and nutritional aids, some of which are essential while others are perhaps superfluous.
Many finches will take livefood when breeding and for some the nutritional boost provided by animal protein is absolutely essential. As finch breeders we may utilise three main types of livefood – termites, mealworms and bushfly maggots – although many other types are used. The more exotic livefoods include crickets, moths and grasshoppers but these are used more for softbills.
Termites are without doubt the best, nutritionally balanced livefood for finches. They are high in protein with an excellent balance of essential amino acids, high in calcium, iron and micronutrients and can also be high in fat (Table 1). Termites are utilised as food by many animals and birds in the wild and they also form an important part of human diets in Africa and South America.
Australia has many species of termites, some of which feed in dead wood, while many feed on dead grass. Some nest in trees and produce distinctive bulbous nests, while other species nest in the ground and produce a typical mounded nest, where most of the nest is underground. Termite nests need to be gathered and stored in containers which provide a suitable environment for the termites and which keep out black ants – the nemesis of termites. A large garbage bin or steel drum with grease around the rim to keep the termites in and black ants out is suitable. If stored properly nests will remain alive for months and if collected intact so that the queen is also present, the nest can even be fed with appropriate organic matter to ensure they continue to breed.
Most finch breeders simply break chunks from the nest each day and provide these to the birds. The termites will swarm out of the chunks of nest and be readily available. Again, however, the termites need to be provided in a tray which excludes ants or they will be quickly taken, especially in warmer months when ants are active. Some breeders extract the termites from the nest in various ways and some have constructed elaborate tumblers in which whole nests or substantial chunks can be tumbled to separate the termites. This produces huge volumes of termites which can be fed immediately, refrigerated for a short period or frozen. Some breeders are now finding success with frozen termites and this may well be a suitable option for long term storage given that collecting termite nests is often a real chore.
The biggest drawback with termites is the time required to gather nests, the storage requirements and the daily task of breaking up pieces of nest. We also need to be aware of environmental laws and restrictions on taking termite nests from public lands. Another drawback, if you want to look at it this way, is that birds who have become accustomed to feeding termites to their young can be very difficult to change onto other livefoods.
We are indeed fortunate to have Tenebrio molitor, the black meal beetle whose larvae we call mealworms. They are typical holometabolous insects with four life stages: egg, larvae, pupa and adult. It is of course the larva that is fed to birds.
Mealworms of varying sizes suitable for small waxbills (mini mealworms) or larger wavers and softbills (full size mealworms) can be purchased commercially through various outlets, including the QFS sales table (Australian Wildlife Supplies), but there are not many commercial breeders these days and supply is occasionally limited. Mealworms are quite straightforward to breed once you get into the routine, although the long life cycle (2 -3 months) means that if you have a problem it can take weeks to get back into production. Mealworms can be easily bred in large plastic containers in a dry mixture of pollard and bran (5-8 cm deep) covered with a few layers of hessian and with slices of carrot on top to provide moisture. Development from egg through larval stages to pupa is heavily dependant on temperature, but breeding success is also influenced by humidity. At low humidity females lay few eggs, whereas at higher humidities they are much more fecund and can produce 500-600 eggs each. Best results are obtained if you can separate the adult beetles from eggs and larvae. This can be achieved either by holding the adults in a smaller separate container with a gauze floor through which the eggs can fall into a larger container of bran/pollard mix below, or by simply catching up the adults and moving them on to a new box after 10 days or so of egg laying. By separating adults from eggs and larvae you can dramatically increase survival since the beetles will eat lots of eggs, Larvae can be separated from the bran matrix by sieving once they reach the desired size and then stored in a refrigerator.
One major disadvantage with mealworms is that they are high in fat and low in calcium, an essential nutrient for breeding birds (Table 1). It is possible to raise the calcium content by adding chick starter crumbles to the diet or by coating them with calcium powder prior to feeding out. However, the high fat content means that mealworms probably shouldn’t be used as the sole livefood. A valuable feature of mealworms is that they can be “gut loaded” with highly nutritious supplements and so help to deliver those supplements.
Table 1. Nutritional Analysis of some common livefoods for finches
|Fat||5.74||13.64||5.96||5 – 20 *|
|Vitamin C (Mg/kg)||105.9||38.1||9.8||32|
* There is huge variation in fat content between species and life stages of termites. Winged adults contain 3-4 times more fat than workers or soldiers in most species.
For many of us maggots are now the standard livefood due to the ease with which large quantities of high quality balanced nutrition can be generated (Table 1). Fly maggots, like termites, are high in protein, low in fat and high in calcium.
The best fly to use for livefood rearing is the bushfly – Musca vetussimma – which is a little smaller than the housefly and common in the Australian environment. It adapts well to culturing in cages and importantly can utilise simple protein-based diets without meat. Like mealworms, flies go through four basic stages – eggs, larvae [the maggot], pupae and the adult fly.
The first step is to obtain some bushfly pupae. It is better to obtain pupae from a fellow breeder rather than try to collect flies around your home or simply allow flies to “blow” some rearing food. You will likely get a variety of flies that way and probably not the ones you want.
For breeding the first requirement is a secure fly cage (see Image 1). This could be a simple box with gauze on the front, or a full wire gauze cage, or a plastic tub with a wire cover. Because you will need to be in and out of the cage regularly, a fly proof door is essential. I use an old section of stocking secured around the edges of the door opening and simply tied in a knot.
A second requirement is to control the temperature for the flies and maggots. Preferably they need a stable temperature of 26o to 27o, but they can certainly tolerate very cool temperatures and warm temperatures but development and survival will be compromised at the extremes. A 60W light bulb in the cage provides effective warmth in winter. During summer a lower wattage light [25W] is adequate. Some breeders use thermostats to regulate temperatures in their rearing cages. This is a great idea if you can afford the initial outlay.
Adult flies need access to water and they do better if provided with sugar as an energy source for flight and activity. A water container fitted with a dental wick through a hole in the lid is effective in providing water to the flies. Water is drawn up through the wick and the flies simply suck it out. I also add a “dash” of Aviclens to the water when I renew it each week. This keeps the water fresh and clean. The flies don’t require any protein – all the protein needed for a female to lay her lifetime of eggs is accumulated during the larval stage and carried through into the fly.
Rearing the maggots is straightforward once you get into a routine. The basic medium for collecting eggs and then rearing maggots is bran or pollard, mixed with milk powder. The bran provides a matrix for larvae to feed in and it contains 10-12% protein as well; the milk powder provides a liquid phase with readily digestible milk proteins. My mix is four parts bran/pollard to1 part full cream milk powder mixed with about 1.5 parts of water to produce a moist mix. Some breeders also add meatmeal and other additives to their mix, but provided the maggots have a readily digestible source of protein [like milk powder] and they grow rapidly their eventual nutritional quality will be much the same.
The bran and milk mix is placed in plastic butter containers (filled to the top) and then place these into the fly cage. Leave the mix there for 1 to 2 days then remove and replace with containers of fresh bran and milk mix. The containers will now be loaded with eggs and larvae, so I then tip them out into a larger plastic container, stir the mix around a bit and leave for another 24 or 48 hours after which they should be ready to feed. Sometimes when there are huge numbers of maggots they will rapidly consume all the food and still be quite small. So sometimes some additional food needs to be added.
When the maggots are still feeding they will have a clearly visible dark line of food in their gut. Don’t feed them at this stage. Maggots which are ready to feed to the birds should be pure milky white. When they have completed development and are ready to pupate the maggots will empty out any remaining gut content and that is when they are ready to feed out. The best way to pick this point is when a just a few have pupated.
It is critical that at least once a week one batch of maggots is allowed to complete development and pupate and then be placed back into the cage. This will ensure fresh flies are emerging regularly.
Maggots can be stored in the refrigerator for several days (but not for weeks like mealworms).
Livefood is essential for breeding many Australian and foreign finches and it can be provided quite readily once you get into a routine. I have given a brief overview of the three main styles of livefood that Australian breeders use – termites, mealworms and maggots. All have advantages and disadvantages. Termites are probably the best – all birds love them and do well on them, bushfly maggots are also readily taken by all birds and provide a balanced diet. Mealworms are readily available and valuable for softbills and finches, but are not a balanced livefood.
Back to Basics 2: Grits, minerals and vitamins
Gary Fitt, Brisbane
We owe it to our birds to provide the best possible range and quality of nutrition. This includes the basic staple items such as dry seeds, half ripe seeding grasses, sprouted seeds, water and various types of greens, plus an assortment of supplements that collectively provide a complete and balanced diet to support successful breeding. In Part 1 of this article (Finch News, August 2010) I covered the various forms of livefood available for finches. In this part I discuss a range of other supplements, such as grits and minerals, particularly calcium in various forms, and vitamin supplements.
There are an enormous range of commercially available additives and supplements for birds. If you Google “supplements for birds” on the internet you will get 1.45 million hits, so there is plenty of information and advertising of bird supplements out there. The trick is to wade through all the hype and identify what your birds really need. It is also important to realise that for many key nutrients eg. calcium, there is a range of concentrations where the supply is adequate, but above or below that range can be detrimental. In fact it is very easy to go overboard with some additives and supplements. Nutrition is about balance, not excess, and the best judge of what is needed is your bird. Hence it is important that birds can select what they need from a varied diet and not be forced to consume nutrients by having no choice as for example might happen if vitamins are routinely provided in water.
Grits and Minerals
We will start with grits. Beyond seeds and water a good quality fine grit is essential for finches. Grits come in two forms – insoluble and soluble. Insoluble hard grit can assist the action of the gizzard in grinding seeds, although it is not clear that this really occurs in finches. Soluble grits are largely calcium carbonate and come in several forms – crushed oyster shell, canunda shells, other crushed shells, cuttle fish bone, crushed coral, limestone and of course egg shells. Being made of calcium carbonate these all dissolve in the acid digestive tract to provide a useful source of calcium and other minerals. Egg shells, which have been dried and then oven baked or “cooked” in a microwave for 5 minutes, are a great source of calcium. They can be fed whole or in large chunks or crushed into small pieces and incorporated into a grit mix. Soluble grits should be available to your birds at all times and can form a useful matrix for providing other minerals and vitamins since birds will only consume what they need.
“Picking stones” and mineral bells are also a very useful source of minerals which finches can access as they need them. Picking stones are made of multiple grits set in a mineral matrix while most mineral bells have a bentonite clay matrix.
Some prepared mineral powders are also useful and can be mixed with grit. An example is PVM Powder (available from the Australian Pigeon Company), which contains all the minerals necessary for a balanced diet, in particular calcium, iron and iodine, and also vitamins A, B, D, E and K. BioCal, also from APC, is another useful product. It contains for different calcium sources – ground shell grit, ground cuttle fish bone, ground sea coral and calcite. It is naturally rich in calcium and iodine and also includes PVM. Marcus Pollard has developed some excellent recipes for fortified
grits using these products (see www.cliftonaviaries.org/cfa/shellgrit/grit.htm ), while Peter James’ new book “The Finch Keeper’s Recipe Book” [available from QFS] also contains some useful mineral grit blends. A blend that I use contains 1 part PVM powder, 1 part Biocal powder, to 8 parts fine shell grit. When feeding this out I add a small quantity of crushed mineral block (Australian Pigeon Company), plus crushed charcoal and crushed eggshells in separate dishes.
Charcoal is another highly beneficial supplement. In powder form or crushed to small pieces charcoal is readily eaten by many finches and is also placed in nests by some species. Masked finches have a legendary attraction to charcoal pieces. Charcoal acts in the intestine as a natural astringent and can deactivate a range of toxins which may be present. Powdered charcoal is easily produced by pulverising chunks of charcoal collected from charred trees or by putting chunks through a mincer. Charred pieces of timber can also be put into the aviary where the birds will pick at it with relish. It is critically important that the charcoal comes from timber which has not been treated with potentially toxic preservatives. Despite the above there are some information sources which claim that charcoal should not be fed because it may interfere with the absorption of certain vitamins such as A, B2, and K, resulting in deficiencies. On balance however, almost every article I have seen on charcoal indicates that it is highly beneficial.
Calcium, Phosphorus and Vitamin D3
This trio is worth discussing together since they interact greatly.
Calcium is the most abundant mineral in a bird’s body. Obviously it is a key component of bones (about one third of their weight is calcium phosphate) and is used in egg shells (in the form of calcium carbonate). However calcium is also important for muscle and nerve function, blood clotting and other enzymatic functions in the body.
Calcium is available in some foods, or in the soluble calcium grits and other forms already mentioned. Seeds, the staple component of most finch diets, and many vegetables, fruits and livefoods are usually calcium deficient and unbalanced in relation to other minerals (Mark Shephard – Aviculture in Australia). For example millets have a calcium/phosphorus ratio of 1:6, a long way off the 2:1 needed. More about that shortly. Table 1 shows the value of different sources of calcium, phosphorus and Vitamin D3 while Table 2 shows a range of plant sources of Ca and P and their ratio.
Phosphorus is perhaps more critical to biological systems than any other element. It is important in many body functions including bone formation, metabolism of fat and carbohydrates, egg formation and in the metabolism of proteins, carbohydrates and lipids (fats) used throughout the body.
Phosphorus in the diet is not always readily available to birds. While phosphorus derived from animal products or inorganic supplements is almost completely usable, only about 30% of phosphorus from plant sources is available. Plant derived phosphorus is often bound with phytin, and birds lack the enzyme phytase necessary to break the P-phytin complex and make the phosphorus available. Nonetheless phosphorus is so readily available in bird diets that it is unlikely to be limiting.
Vitamin D plays a critical role in maintaining health by regulating absorption and excretion of calcium and phosphorus. This is especially important when the ratios of calcium and phosphorus in the diet are unbalanced. For bone health, an adequate intake of vitamin D is no less important than calcium.
Vitamin D comes in two forms. Vitamin D2 comes mainly from plants. Vitamin D3 is produced exclusively in a bird’s body when the UV rays present in sunlight or an artificial UV light source react with Vitamin D precursors in the skin. Vitamin D3 is 30-40 times more potent than D2, and plant sources are generally considered insignificant as a source of Vitamin D for birds. As Table 1 shows cod liver oil is an excellent source and the use of oil fortified seed has been practiced for decades. Studies with poultry show that sufficient Vitamin D3 can be produced for growth of chicks with 11-45 minutes of direct sunshine each day. So any birds with direct access to sunshine will not suffer Vitamin D deficiency.
Too much calcium or phosphorus!!!
Birds which live in arid climates and eat mainly lower nutrient, seed diets (such as many of our finches) have evolved to efficiently conserve nutrients and water and thus they may be more sensitive to excessively high levels of calcium in their diets, as might arise when they have no choice but to consume calcium supplements in food. Once again allowing birds to make their own selection according to their varying needs is a better strategy. By contrast birds of tropical forests, with access to abundant, varied foods, have not needed to conserve nutrients in their body and may have higher daily dietary needs for calcium. Many softbills kept in other parts of the world fall into this category. Calcium supplements are important for them.
Similarly too high levels of phosphorus will interfere with absorption of calcium. Consequently much nutritional work (done essentially with poultry) indicate that diets with a ratio of 2:1 calcium to available phosphorus are optimal. As Table 2 shows many greens are close to this.
|Table 1. Sources of key nutrients relevant for birds|
(over 20 times requirement)
(over 2 times requirement)
(0.5-2 times requirement)
|Fish & meat meals
|Dried milk powder
|Fish & meat meals
Wheat Germ Meal
Most oil seeds
|Vitamin D3||Cod liver oil
|Dried milk powder|
|Table 2. Good Plant Sources of Ca and P|
|Food||CA (mg)||P (mg)||Ca:P Ratio
(2 : 1 optimal)
|Beet Greens||188||80||2 : 0.8|
|Broccoli Leaves||349||89||2 : 0.5|
|Broccoli Stem||111||47||2 : 0.8|
|Cabbage (outside green leaves)||429||72||2 : 0.3|
|Celery||44||32||2 : 1.4|
|Chinese Cabbage||400||72||2 : 0.4|
|Dandelion Greens||168||70||2 : 0.8|
|Endive||104||39||2 : 0.8|
|Kale||390||134||2 : 0.8|
|Kohlrabi||390||120||2 : 0.6|
|Lettuce Dark Green Leaf||25||14||2 : 1.1|
|Mustard Greens||582||168||2 : 0.6|
|Parsley||46||30||2 : 1.3|
|Spinach||156||92||2 : 1.2|
|Turnip Greens||694||98||2 : 0.3|
|Watercress||53||15||2 : 0.6|
|Source: The Midwest Bird & Exotic Animal Hospital, Westchester, Illinois. Calcium and Phosphorus contents are for 1 cup of food.|
Vitamins are nutrients that are required at only very low concentrations. Vitamin A, C, E and most of the B group vitamins are readily available in fruits, vegetables, greens and grains. Birds with access to a diverse high quality diet including seed, half ripe seeds, various greens and livefood when they need it should not suffer from vitamin deficiencies (Dr. David Shultz – Everybird). However for birds held in less than ideal conditions or with a poor diet a vitamin supplement will often be beneficial. There is a huge literature on vitamin supplements and many recommendations to provide vitamins in the water on a regular basis. As noted above with mineral supplements it is much better not to force birds to consume vitamins through the water, but to provide them in a varied and balanced diet. As Dr David Shultz says in the classic book on avian health, Everybird, “The practice of providing vitamins (on a routine basis) in the drinking water can be dangerous ….”. In part this is because overdosing of vitamins like Vitamin A can be detrimental, but also because such water provides an ideal environment for bacterial growth.
We have come a long way with finch nutrition and have a better understanding of how to provide a balanced diet to sustain growth and reproduction. There is still much to learn however. The key words with nutrition are variety, balance and choice. Balance and variety in what we provide across the spectrum of food types and supplements and choice in the opportunity for our birds to regulate their own intake through choice rather than be force fed with a plethora of superfluous additives.