I’m now seeing two parts to your story and question.
The grain question is easy to answer.
The second half of your question is a common enough one here too. It is: I thought my BO/coach/trainer was my friend but now that circumstances have changed, I realize they arent really. I am starting to resent this. Is it time to move barns? If not, how do I recalibrate the relationship given my feelings of hurt?
You have a baby and a new horse. You are no longer doing so much work for the BO and are at the barn less. Were you cleaning multiple stalls to get the ride on the horse, or for pay, or just out of the goodness of your heart? In any case, when you stop all this you move from being part of the barn staff and volunteer crew, who need jollying along, and become a background boarder who doesn’t need any emotional energy.
I have a couple of trainers who I consider friends but I am also well aware that because we have long standing relationships, they are always going to be putting more energy into flirting with, chatting up, selling themselves to new clients and I need to let them do that as part of their business model. However I am also happy to be able to do my own thing.
As long as they are not snapping at me I am fine with benign neglect. I’m actually happy to overhear my main coach having productive lessons and conversations with her students. I don’t feel excluded or hurt. After all I am on her jobsite. Our closeness waxes and wanes depending on whether we are doing things together like camping or shows. There are things she still comps me for, but I make an effort to thrust a cheque at her for other things.
Obviously it’s impossible for anyone outside the situation to say what’s going on and how you should feel about it. I have no idea if your BO is being passive aggressive because they lost your free labor, or if they are just on to the next shiny thing because you are spending less time at the barn, or less work, or if they backed off because of your problems with your OTTB.
Adult relationships wax and wane, they aren’t always BFF, often they are contingent on shared interests like jobs or hobbies.