A man suffered a bleed on the brain after a colleague attacked him when the shooting event they were both working at went wrong.
Andrew Gardner, 53 , of Red Bank Farm Campsite, Bolton le Sands, was found guilty of causing actual bodily harm after jurors heard he straddled and pinned Michael Rollason down, clasped his hands together and swung his arms, striking him with his elbows.
Mr Rollason was kept in the Royal Lancaster Infirmary for two nights following the attack at High Snab Farm in Aughton, Lancaster, in December last year but was readmitted after a few days with headaches and dizziness.
Initially the victim had tried to cover for his friend by saying he had been hit by a falling dead pheasant and banged his head on a wall.
In a victim impact statement Mr Rollason, who lives on an isolated farm, said his injuries meant he had his driving licence taken away and had lost his HGV licence, which still has not been reinstated.
The trial was told Gardner was working as a manager in charge of the shoot that day, while Mr Rollason was assisting directing other people as part of the event.
Things were not going smoothly, and Gardner "started to get more worked up about things that weren't working out" and had a "melt down".
The two were trying to communicate by walkie talkie and the victim decided to go and speak to him, and had to walk across a field, cross a wall and go up another field.
He asked him: " What is your problem?"
The court was told Gardner grabbed him by the neck, threw him to the ground and pinned him there, "straddling" him.
He then struck him to the face repeatedly, with him unable to defend himself .
Gardner eventually he stopped and said: "I will let you up because I love you."
But Mr Rollason had suffered severe swelling and was taken to hospital where A CT scan showed the injury.
Gardner denied the offence and claimed he was defending himself from Mr Rollason.
In a victim impact statement Mr Rollason said after giving evidence at court he "felt sick" and had to go to bed for 15 hours.
He added: " I still can't believe that he made me go through all of that."
Gardener's defence lawyer said he was due to have surgery, and that his mother was in hospice care.
Imposing a curfew, and 100 hours unpaid work, Judge Andrew Woolman said he was sure they had both been in a temper with each other.
He added: " It caused more serious injuries than you obviously intended, but it shows the sustained nature of this assault."