Nduka Okafor [Nduka.Okafor@uni.edu] asked:
>I note that you intend to crush bones and add them to the compost. Is that not>wasteful? Since the compost is to be used by plants, is the intention to supply
>calcium to plants? Is there any evidence that the soil where the compost will
>be used lacks calcium? I would rather have thought that you would add the
>crushed bones in poultry feed to provide calcium to enable the birds produce
>well-formed shells.

bones often have fat, meat etc attached to it. Thus depending on how you want to use it, pre-treatment may be needed.

(a) as a calcium source to poultry, bones need to be heat dried to kill whatever bacteria it may carry and to keep it aseptic. Then they need to be powderised so that birds can take them. This route for bone utilisation will need high energy for drying + a dryer and then a machine to powderise it.

In Scenario 3, section 5.2.2 on Poultry, we are proposing a scavenging
poultry system. In such a proposed small scale system for broiler chickens
and maybe some quails for meat, we will not go for an elaborate setup for
bone recovery. At the Maya Farms (1979 when I visited them), they had a
rendering plant using biogas as the energy source. Blood and bones were recovered.

(b) In Bali at the proposed BIMPC (Bali Integrated Meat Processing Complex), the amount of bones generated per slaughter day is estimated to be 450 kg from 5 cattle and 10 pigs. This is an amount that also needs a programme for handling. The "meaty" bones can be sold to restaurants and are probably scavenged by the workers for their personal use. The unwanted remains need to be  sawn/crushed into smaller pieces (at the abattoir), then they can be added directly into the compost or let the maggotry sub-system clean them first and these "cleaned" bones can be used directly in the compost as bulking material for the compost. These are some ideas.

I welcome more ideas on how to use "unwanted" bones !

I have not read about pH control of compost using crushed bones, but it seems logical that they would. I dont think bones need to be added to a compost because they are needed.

Basically, the compost to me is a carbon sink. If adequate time is provided for maturity of a compost, it is also a process to decontaminate manure and other biodegradables.

My co-author, Simon, is the man at the site in Bali. The paper provides a few "academic" ideas for us to play with. As to the practicality and operations at the site, I let Simon comment on these and also look forward to comments from hands-on and experienced people.

regards
jacky