Duck Poo?

[anniefish]

Hi all,

I can see that having ducks on inground ponds can be beneficial, I would be extremely wary of putting poultry pens over and letting fish eat the droppings. The chance of passing on diseases and worms as well as any medications fed to the poultry would far out weigh any benefits I think.

I recall an incident where a huge feedlot fed poultry manure in their rations. One batch wasn't treated properly and killed most of the cattle.

Our ideas with AP are to have the healthiest fish we can, I can't see this would be a good way to go. I think when you make any system intensive, problems become more likely.

That's my bit,

Annie

[Matt Trevatt]

Actually thats a good point, re disease being transfered form one species to another. I am not sure tho why ducks would get the nod but chickens wouldn't. I would be surprised that chicken manure fed to fish would be a higher risk to humans than using composted manure directly on plants as is done in organic farming.
There have been studies done on the effects of feeding manure to fish and seeing how much bacteria is taken up by the fish and the results were really positive. IE the flesh that was sampled past lab test with no problems. They showed that manure feed fish were much more healthy than with manufactured food.
I think some of the sites I posted will take you to some of the studies at least.

The issue that come to mind for me is the delicate balance of nutrient load and DO. I think I posted a link to a site here a year ago on manure teas and how they were being used as not only a fertilizer but a pest and fungicide. The highly oxygenated manure tea mixed with certain sugars to encourage good bacteria and fungi growth. These aerobic bacteria rich teas can have a positive health advantage for fish and plants because they fill that niche preventing bad bacteria from dominating. IE U need to keep your O2 levels high.
The 2nd would be the need for good quality feed but that also applies to the fish also.
This has been done in aquaculture commercially for ages, the online material starts in the 70s but I have no idea if its ever been done with aquaponics. Since what is happening in most cases is that the nutrient from the manure is being used to produce algae, which the fish feed on, the balance of bird : fish: growout area has just got a little more complicated.

The reason why this is so intriguing for me is that with duck or chickens you can have a year round harvest of meat. Ducks for instance can be harvested every 11 weeks. Fish on the other hand typically take 9 months before harvesting. Also the food requirement for fish is greatly reduced sometimes to almost nothing.

[Murray]

When comparing composted manures used on gardens and manures used as fish food remember that the composted manure goes through two stages of conversion.
First the composting processes and converts the matter, then the plant takes up and processes the proceeds of the composting step before human consumption of the vegetable.

In the direct use of duck or chook poo for fish food, any baddies in the poo are directly placed into the fish, and from there directly placed into the human.

The use of BSF as fish food is a good way to place a processing barrier between the waste material and the fish, and deliver to the fish only the good from our waste products.

"Food safety and bacteriological considerations in using manure fed Hermetia prepupae are favorable. Hermetia larval activity significantly reduced E. coli 0157:H7 and Salmonella enterica in hen manure (Erickson et al. 2004)" See additional material. (BSF are Hermetia larvae)

From Anniefish ...I recall an incident where a huge feedlot fed poultry manure in their rations

This is more common than most of us realise and is a disaster waiting to happen.

Not a good idea to directly feed something live that you intend to eat, animal poo, I feel. But to each his own.

[GaryD]

Hi,

I can see that having ducks on inground ponds can be beneficial, I would be extremely wary of putting poultry pens over and letting fish eat the droppings. The chance of passing on diseases and worms as well as any medications fed to the poultry would far out weigh any benefits I think.

There's two things I'd like to contribute to this discussion:

1. Rural Chinese (and various other Asian folks) have been doing exactly this for thousands of years.
2. Many large outbreaks of food-related diseases or poisoning...... Garibaldi smallgoods, Mad Cow, Melamine milk poisoning and now Swine Flu (?).....seem to emanate from large agribusiness operations.

Gary

[Matt Trevatt]

Ya Asian farmers have been doing this forever. Since coming to Bali I have had the opportunity to work with local farmers and NGOs. Its made me realize that I came with a fair amount of western baggage. I was shown how to make green manure no dig gardens, helped service biogas units.
( Biogass would be a great intermediate step as heaps of the baddies get killed in the proccess and the slurry that exits can then be heavily airated to kill of the rest!)

Particularly when it came to things like manure and what animals are for eating and what animals we play fetch with. :-) I understand that U guys have valid points so I plan to do a little more digging around to see what sort of health risks there are. Ill let U know what I find out!
If anyone has knowledge or expeiences from both sides of the argument please let me know.
Love the soldier fly larvae, I agree that thats a great way to go. Coz U are converting **** to high quality protien.

[Matt Trevatt]

This site has some info. See extracts for primer. In general the manure load that is optimal for growth for fish is way under the manure load required to overload the immune system of the stock fish to where bacteria is found in the organs and flesh. Note that bacteria loads were found in non manured ponds anyway.
This is just 1 site tho and I have a few more to investigate.

http://www.fao.org/DOCREP/006/Y5098E/y5098e07.htm

Whilst the levels of micro-organism in manure or pond water are important in understanding risks to the producer, the level of pathogens contained in the fish at harvest is of key importance in determining risk to those preparing and consuming the fish. Levels of microorganisms found in the digestive tract of fish are much higher than in the water illustrating a likely route to infection is via contamination of hands and surfaces during preparation and cooking of fish. Buras (1990) developed the concept of threshold concentration, defined as the total number of bacteria in the fish from inspection of blood, kidney, liver, spleen, bile and digestive tract that causes appearance in the muscle. This was developed after exposing various species of fish to different levels of microorganism in the water and then determining the levels present in various parts of the fish. Above a critical level, the immune system of the fish cannot cope with bacteria levels in the water, leading to their presence in various organs and, finally, muscle. Buras (1990) found that aggregate levels of total bacteria present of between 1.0-2.0 x 104 (Standard Plate Count, SPC) to be the threshold concentration for common carp. The concentration of bacteria in water that is required to reach these threshold values (critical concentration) varies between 1.0 and 5.0 x 104/ml, which would require loadings far in excess of that required for optimal fish growth.

At loading rates of manure investigated in the AIT trials which maintained good water quality and led to optimal fish yields, the threshold concentrations were clearly not exceeded as the indicator micro-organisms were rarely found in organs and were never found in muscle. Salmonella are commonly found in surface waters in nature, with contamination from wild birds a likely source. However, conditions are such in waste-fed ponds that even heavier microbial loads from introduction of livestock manure are rapidly attenuated. Salmonella has also been found in shrimp pond sediment and shrimp throughout Southeast Asia however, and the cause attributed to the use of large amounts of fresh chicken manure and supplementary feeds (Reilly and Twiddy, 1992).

Most of the parasites on this site are based on rural asian farms with pigs living close to humans an d that they have access to human fecal waste - not really an issue for the west.


Micro-algae and detrital bacteria that serve as food for cultured finfish and crustaceans produce most toxic compounds affecting aquaculture. The toxins produced by blue-green algae (cyanobacteria), microcystins, are particularly potent and widespread in fertilized freshwaters (Codd, 1995; Codd et al., 1999). The optimal environments for raising filter feeding Nile tilapia are known to be highly fertile water dominated by cyanobacteria such as Microcystis aeruginosa (Colman and Edwards, 1987). The evidence suggests that not all strains of cyanobacteria are toxic and that filter feeding fish avoid ingesting toxic cells (Beveridge et al., 1993; Keshavanath et al., 1994). When fish losses occur, often at the end of plankton blooms, it is unclear if mortalities are related to the depleted levels of DO levels that occur or the toxic effects of free microcystins released into the water. However, accumulation of microcystins has been demonstrated in the livers of freshwater fish under such conditions (Codd and Bell, 1995). It has been concluded that the risk to human health through eating farmed finfish and crustacea containing these toxins is very small (WHO, 1999).

The use of human and livestock waste in semi-intensive fish culture, subject to certain safeguards, can generally be considered positive in any holistic assessment of risk (Edwards, 1993). Semi-intensive systems fertilized within the carrying capacity of the system are healthy environments for fish. The fish production unit can act to ‘treat’ wastes that themselves may contain pathogens, provided certain precautionary steps are observed. Moreover, non-integrated intensive livestock and fish production carries its own risks to public health, which should be considered in any balanced comparison.

[Murray]

Threats to public health from both livestock and aquaculture are diverse. Recently, livestock and fish have been implicated in the irregular occurrence of influenza pandemics; the global impacts on public health of promoting livestock and fish integration are huge if these claims are substantiated. Certainly throughout history, infectious diseases have largely entered human populations through animals (Morse, 1990). It has been known for some time, that common pathogens of warm-blooded animals do not generally cause disease in fish (Guelin, 1962 cited by Buras, 1990), but the role of cultured fish in the possible transfer of pathogens between livestock and humans is important, particularly in less developed countries.

Producers and consumers in developed countries are not immune, however, as the increasing number of food scares indicates and the global food trade continues to expand. Both the resurgence of ‘old’ risks, such as the recent outbreaks of anthrax in Australia and Thailand, and newly identified problems such as BSE in the UK show the interconnection between the health of humans and their food. The recently identified problem of Streptococcus iniae in tilapia in North America also raises the spectre of food hygiene becoming a major political issue, complicating the promotion of new aquaculture species by new producers.
Livestock and fish are involved in both passive and active transfer of a range of parasites and diseases to humans, broadening the need for risk assessment. The role of fish and warm-blooded livestock as intermediate hosts for a range of human parasites and control strategies are well known. However, the increasing use of a range of technologies, chemicals and feed ingredients in both livestock and fish production poses a relatively new set of risks. Products such as antimicrobials, pesticides and a range of chemotheropeutants are often used with little idea of either indirect or long-term risks. Prophylactic use of antibiotics and growth promoters in intensive fish feeds rival their use in the livestock industry. Similar problems, in terms of public health and consumer resistance, have arisen with legislation governing the use of these compounds in different countries threatening international trade. The development of genetically modified organisms, either as feeds of livestock and fish, or the animals themselves has been raised as both a moral and public health issue.

This is a quote from the same article that Matt quotes from above.

To me , it is just pushing your luck using duck and fish poo to feed fish.
There are many practices around the world that are very questionable. Just because they apparently "get away with it" does not mean that it is ok.
In PNG it is common to have pigs and chooks roaming in and out of the village houses and they "get away with it" most of the time. It is very efficient, there is no need to worry about a rubbish bin in the kitchen...the pigs just clean it up.
We now see "swine fever" coming out of Mexico. I wonder what kind of farming practices have "gone wrong" there to cause that transmission of an animal disease to humans.
There are some well established rules of hygiene, and one fundamental is that it is not good to eat your own or something elses excrement.
Wash your hands after going to the loo etc....

Personally, I will not eat scavenges......crustations, pigs, crows, eagles, roaches, mice, rats and definitely not something that has been fed some other animals excreta, or keeps their own excreta for a rainy day like oysters.....

But....to each his own.....

The more I look at this, becoming a vegetarian is making a lot of sense.....

[Matt Trevatt]

Also on the neg side of things re manuring ponds, from what I read the UK have banned it as a practice. But I haven't yet been able to find info or a study that directly links a substantial increase risk to health through eating fish that have been manured. Prawns Yes for sure. General concerns that bird flu may transfer but again nothing specific.

Personally I think I would consider the use of water fowl, primarily because this is how its working in nature anyway. I remember as a kid in New Zealand visiting a spring in Rotarua with amazingly clear water and heaps of trout and ducks and swans just everywhere. I am sure what we are talking about in this thread would be happening in this situation. I believe at least with the ducks I wouldnt be forcing nature to do something it wasn't doing anyway.
I would consider chickens after more study simply because how inefficient there gut is at processing food. I think at least 25% of protein remains undigested.
Any other farm animals I would not consider especially pigs!
I am a little surprised and the general negative reaction since aquaponics is all about utilizing fish poo,
but I realize that we are not feeding it to another animals.... each to his own convictions.

[GaryD]

Hi,

We now see "swine fever" coming out of Mexico. I wonder what kind of farming practices have "gone wrong" there to cause that transmission of an animal disease to humans.

And the initial indications suggest that it probably started in the huge piggery based in the village where the outbreak first happened. The piggery is apparently owned by a US agribusiness conglomerate. My point is that the questionable practices are increasingly happening in factory farming......not in the integrated farming systems that have been around for (in some cases) thousands of years.

Personally, I will not eat scavenges......crustations, pigs, crows, eagles, roaches, mice, rats and definitely not something that has been fed some other animals excreta, or keeps their own excreta for a rainy day like oysters.....

Most animals are opportunists (scavengers) left to their own devices.... including chickens.ducks and game birds.

Rabbits practice a unique habit called caprophagy where they eat their own faecal material. The rabbit passes particular 'pellets' the first time still containing nutrients and through ingesting this material, they are able to maximize all of the nutritional value from the food they consume.

I don't care whether you call it nature or God's design, rabbits are still good food and excellent micro-livestock for backyard farmers.

Crustaceans, oysters and pork/ham/bacon are three of my favourite things......and I'm much more fearful of what agribusiness will do to my food chain (anti-biotics, growth promotants, feed 'additives) than the thought of what they might eat in natural circumstances.

Gary

[anniefish]

Hi all,

I think the main point is that in this day and age, we all (humans and animals) are eating more and more unhealthy and far from natural foods than ever before. I feel it is this going away from nature that is a major cause of the diseases and health issues on our Earth.

Annie