How to fix Quality Issues

Before you submit, compare your best shots with similar content in Stock inventory. 

To be accepted, it should be as good if not better than what Stock is selling. 

This is your competition:

https://stock.adobe.com/search?k="wild+reindeer"

https://stock.adobe.com/search?k="farm+horse"

https://stock.adobe.com/search?k="plow+horse"

https://stock.adobe.com/search?k="pony"

DSC_0127: There appears to be some competition here as to what is the main subject, the flowers or the mound, and neither are in focus as a result. 

DSC_0081_nef.jpeg - the bird is not sharply focused and the background is too dark. It appears that you have applied a vignette around the edges which is not permitted by Adobe Stock.

@Ricky336 is right, it's your lens that allows only for semisharp pictures. At the beginning, those kit lenses are great, as they allow you too start photographing easily, but at some time you should change to a better lens. But you should also learn the camera settings. Taking a picture at 1/1000s at probably the fastest aperture the lens can offer and at ISO400 is only a good idea, if you want to freeze a movement. Lenses tend to get softer, when pushed to the extremes, and higher ISO (at least on my Canon cameras) makes also my picture softer.

You should also work your framing (the pole should go away, either by changing the position, or by cropping or removing the pole in postproduction. The sharpest point of your picture seems to be, where I did put my circle, and that is more or less the middle point of the picture, where any lens is sharpest. Portraits need to have the eye the sharpest point of the picture.

DSC_0081: Too dark and not sharp.
DSC_1551: Not sharp, needs cropping and the deer should be on the other side facing inwards. 

I agree with @Ricky336 in that all of your photos are not focused well.
This is how your photo should look.

Hello,

Generally speaking, your focus is not good. E.g. the horse's head:

In all your shots, the focus is not good, which makes me wonder if you used the kit lens that came with the camera. 

The lenses that come with consumer models of cameras are generally cheap and nasty. It is to keep the price down. If you did use the kit lens, I would suggest getting a third-party lens, for example, Sigma, Tamron, etc, that have compatible mounts for your type of camera.