riding for first time new yard-help me decide

[freshy]

so i moved my horse 10 days ago to a new yard much closer to home with great faciliites so i can get my butt in gear and start riding more.
previously he was prob being hacked out once a week in walk and that's about it due to various reasons. done nothing really for a couple of years due to injury then baby.
he is 9 but quite green and immature due to reasons above but gen always pretty good to ride. bit sharp sometimes but gen just gets on with it.
prev to leaving old yard he had become v sharp and rode last week in school at new yard for first time and he stood up and decked me. ouch.
he doesn't seem unsettled but long story short i had bought the wrong food last month and he effectively has been getting a competiton mix..think that goes a long way to explain behaviour.
he has been off that food for few days now and i really just want to hop on him today and hack him out but i am bit wary due to what happened. hacking is on a busy road (usually not an issue for him) and would have to go on my own(again not usually an issue ) as most school.
i am not sure whether just to do it or leave him another week and slowly start lunging him etc. how long does the effects of food take to leave there system??
i do not want to get decked like that again but large part of me thinks just get on with it.....

 

[suffolkmare]

Lunge first, if he seems settled then hop on for a short plod?
Did his diet change suddenly or gradually? I would think few days back on usual food should mean he's back to normal, but I'm no expert. Enjoy the sun.

 

[freshy]

diet changed suddenly ish.
picked up a bag of competition energy alfalfa genuinely not realising and he has been getting scoop and a half a day for about a month.
he was v sharp at old yard before i left but could deal with it there as knew the hacking/yard and just put it down to high spirits and lack of exercise.
he is used to going out on his own etc but i don't want a repeat of last weeks antics

 

[Love]

I'd also say either lunge or ride him in first to take away any initial freshness then go from there if you feel comfortable