Hundreds of Hindus staged a protest over allegations that the RSPCA killed their 13-year-old sacred cow by lethal injection while they worshipped.
Gangotri was a 13-year-old Belgian blue-jersey cross
The group was accused of secretly putting down a Belgian blue-jersey cross, while Hindus at Bhaktivedanta Manor, Herts, were at prayer.
But the RSPCA denied the allegation, stating they informed staff on site "exactly" what would happen.
It added that it avoided killing the cow during prayer hours.
Some 200 delegates were sent to RSPCA headquarters in Horsham, West Sussex, on Wednesday after the cow called Gangotri was given a lethal injection. Another 700 Hindus held prayers at the Manor.
Vinay Tanna, temple spokesperson, said: "The RSPCA professes to be a compassionate organisation, but their starting point is to kill first. Ours is to tend the animal's needs and treat it to get better.
"Gangotri was taken care of by two herdsmen 24 hours a day, and was under the supervision of two vets, both of whom did not recommend the cow be euthanised."
Cows are sacred to Hindus, and the killing of one is considered sacrilege.
The temple runs The Cow Protection Project and allows old cows and bulls to die naturally.
Gangotri was described by Hindu community leader Gauri Das as being sick but not suffering from any disease.
The RSPCA said it was sympathetic towards to representatives of Bhaktivedanta Manor, but that it put animal welfare first.
'Put to sleep'
In a statement, it said: "It is sad we had to take this action, but the most important things was that this animal was suffering and to allow this situation to continue would have been wrong.
"The RSPCA acted on the advice of three competent veterinary surgeons, all of which concurred that the animal was suffering and should be euthanised immediately.
"The cow was put to sleep under veterinary supervision and the method used was completely humane, causing the cow no extra suffering.
"The allegation of a history of mercy killings is entirely unsubstantiated. The RSPCA puts animals to sleep only as a last resort and then only to prevent them suffering further."