Live food and supplements Part 1
Gary Fitt, Brisbane
Nutrition is perhaps the most important component of successful finch breeding. At least it is the main area we, the aviculturist, 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 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.
Tabel 1. Nutritional Analysis of some common live foods for finches.
|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. A full account of my approach to bushfly breeding was published in Finch News in ???
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.
image to come.
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