Keith Midgley, 60, who owns a farm on Old Lane in Ovenden, admitted the incident has made him consider whether he wishes to continue a lifetime of farming.
No sheep were killed in the incident thanks to the fast work of the Fire Service and the bravery of Keith's son and wife, who ran into the flames in an attempt rescue the sheep at around 4.30pm yesterday afternoon.
The cost of the damage to the barn and equipment will run into the thousands.
Keith said: "It's just mindless. I despair.
"We've had incidents over the years, with dogs attack sheep, thefts and vandalism, but never anything as bad as this.
"It makes me want to say 'enough is enough, let's not bother any more'. I don't make a great living out of farming, I've always done it, I love it, but this feels like the last straw."
The sheep are well into lambing season and vets will visit the farm today to treat the sheep for smoke inhalation. There are concerns over the effect it will have on their pregnancies.
"The sheep are all coughing and spluttering," Keith said, "the straw gives off a very dense and dangerous smoke.
"The barn is designed in a way to allow ventilation through because its such a confined space. The smoke was just billowing straight at them, they had no escape."
Keith expressed his admiration for the work of the Fire Service.
"They were incredible," he said, "I cannot thank them enough. They ran into the flames and got all the sheep out. It was just heroic.
"Arson is becoming more and more common in the farming community.
"It's just knock after knock at the moment and it does knock you backwards. It's just mindless."
A spokesperson for the Fire Service said: "Fire crews were called at 16.09 yesterday to a barn fire in Old Lane Halifax.
"This was attended by Illingworth, Halifax, Rastrick crews.
"The barn was 50% involved in fire, one large jet, two hose reels and four breathing apparatus used to tackle the fire.
"By 16.56 hrs crews were damping down."