Report by Chris Hall, ITV News Granada Reports
The trainer of Hill Sixteen, the horse which died after falling at the Grand National, has blamed the "ignorant" Animal Rising protesters for more deaths than usual at this year's event.
Sandy Thomson said the campaigners have "no idea about the welfare of horses" and defended the racing authorities as "continually moving forward to make the sport safer".
Hill Sixteen died after falling at the first fence - the second horse to die at Aintree on Saturday and the third at the three-day festival - prompting campaigners to call for jump racing to be banned.
The protesters breached security fences as National runners were in the parade ring, causing a delay of 12 minutes, although racegoers helped police and event organisers to stop some from reaching the track.
Sandy Thomson told Radio 4's Today programme: "If we look at the last nine years since the course has been modified, there's been an average of under two fallers at the first two fences and this year everybody got very uptight about it - horses, jockeys, starters - and there were eight fallers at those first two fences.
"This was all caused by these so-called animal lovers who actually are ignorant and have absolutely no idea about welfare of horses."
Mel spoke to Lydia Hislop, a journalist from Racing TV, and Robert Gordon from the Animal Rising group
Speaking about how the sport could become safer, Mr Thomson said: "Two of the considerations - a shorter run to the first fence and a few less horses - those are obvious things that may be considered.
"There have been huge changes in the whip rule, which has made a huge effect - last year's winner would have been disqualified under the new rules, so we as a sport are continually moving forward and trying to make the sport safer.
"The figures of people watching are surely a huge indication of where public perception is about the Grand National."
Meanwhile, the RSPCA is calling for the race to involve fewer horses and for jockeys to lose their whips.
The charity's policy director Emma Slawinski told Radio 4's Today programme: "One of the things we particularly see at the Grand National is a very big field, so lots of horses running together.
"That, of course, causes issues when horses fall and can get in the way of other horses, and cause accidents in that way.
"The other thing that we think needs to change very urgently is to see an end of the use of the whip for encouragement - hitting the horses to make them run faster.
"We know that that actually causes more accidents, it makes accidents more likely, makes injuries more likely, so we'd like to see that reform happen as well."
Nevin Truesdale, chief executive of The Jockey Club, which owns the Aintree racecourse in Merseyside, said measures including softer ground and smaller hurdles have been imposed in recent years.
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