Organic can mean two different things. Any thing that ever lived is organic. But it is also used to mean a specific type of cultivation without artificial pest and herbicides which, in some countries is certificated and has to reach certain standards.'

Under the latter meaning you cannot make organic compost out of materials which are not organic. But under the first meaning, any compost you make will be organic.

Furthermore you need something other than veg waste and manure to make compost. You need a source of carbon such as dead leaves, straw, paper or cardboard.

I have a hay barn where I keep my bails of hay, it provides plenty of straw that falls from the bails. I just scoop it up when I clean and put it into the pile. So, my compost is composed of the horse manure, veg waste, and hay, plus dead leaves as they fall off the trees.

That sounds fine. But my points about 'organic' stand. I don't really understand what you mean by "how can it (I?) compost my horse manure into organic uses?" You compost it into compost, not uses. Depending on which definition of 'organic' you choose it is or is not 'organic' compost. Once you have the compost you use it for whatever you like. I'm not clear what you mean by an 'organic use'.

You cannot get straw from bales of hay, any waste from hay bales will still be hay. Straw is the stems of grain plants such as wheat, oats, rye, etc.

What you are making is compost and all compost is organic, even if the plant material used to make it was not grown under organic conditions. Some people try to obfuscate this issue with a lot of blather about what is organic and what is not. All once living vegetable waste is acceptable as an ingredient in composting, although some hay, and maybe straw, should not be used if they have been sprayed with certain weed suppressing materials.

Kimmq, whether you consider it 'blather' or not there are two meanings to the term 'organic' as I tried to describe above. This forum is called 'organic gardening'. If it was simply discussing any living things what is the point of it?

Floral, I began studying organic growing back in the 1960's so I am quite well aware what organic growing is all about. I am also aware that there are two meanings to organic, one refers to a way of living, including gardening and farming, and the other refers to chemistry and materials that contain carbon.

Magic happens when herbivores eat and poop - what enters as intolerably "conventional" feed and forage emerges from the animal blessedly suitable for fertilizing "organic" crops.

You just gotta believe.

Certified organic growers in the UK are not allowed to use manure from non organically raised animals other than under exceptional circumstances with permission from the certification authority. There is a lot of paperwork involved in obtaining permission to use it. So it doesn't seem that over here conventional material is deemed to magically to become certified organic after passing through an animal. The aminopyralid disaster is proof of that. It would be helpful if berry could enlarge upon what his/her understanding of 'organic' is. Some definition of terms would aid the discussion.

My question is in connection to becoming USDA Organic Certified. From what I have gathered, its ok to use, just your carbon sources has to be picked carefully.

The USDA Certified Organic standards have been lowered so much as to make them almost meaningless. Some countries today will not allow foods to be labeled as Certified Organic from the USA.

Decades ago we used our horses' manure to fertilize our veggie garden every year. In the fall when we turned over the garden we covered the area with wheelbarrows of horse poop and covered that over with bags of limestone to mitigate the acidity and let the whole thing ferment all winter. However back in that era I had no worries about non-organic manure. The grain our horses ate was closer to organic that today's GMO, round-up laced horse grain.

The OP's questions occurred to me more recently while my last old pony was still living (she passed away about 6 years ago). The feed she ate in her last years was not the horse feed of yesteryear. It was now pelleted GMO alfalfa, almost certainly laced with round-up. This made me uncomfortable. However all our horses ate mixed pasture grass all summer long, and hay made from the same pasture grass/clover mix all winter long. This was their primary feed, and a horse's natural diet. Grain and pelleted feed was just an add-on, so I had to hope that the chemicals in that feed were not so significant in the long run. This is how I came to terms with it in my own mind. We all have to make our own choices and draw our own lines in the sand.

Now I am reduced to water from the goldfish pool, worm castings, and compost as fertilizer. I would estimate that 70 - 80% of the food we eat is organic, so that compost is the same percentage of organic. Also I wash all produce in a vinegar bath so I assume any pesticide residue goes down the drain rather than into the compost bin. However I miss the horse manure that our equine companions gifted us with. Few fertilizers work as well.