Millions of devotees attended a mass animal sacrifice in Nepal on Friday, despite efforts by animal rights activists to end the practice.

The organisers of the Gadhimai festival, which is held in Bariyarpur, near the border with India, claimed about five million worshippers came to sacrifice tens of thousands of animals, including buffaloes, goats and birds, as an act of gratitude to the Hindu goddess.

However, in a sign that the campaign to end the practice may have had some impact, the number of buffaloes killed dropped to about 5,000, half the number slaughtered when the festival was last held five years ago.

“The numbers went down because the Indian court banned the ferrying of animals from India to Nepal,” said Ram Chandra Shah, chair of the Gadhimai temple management committee. “The animal rights activism has had some effect.” However, he said that although the numbers sacrificed have decreased, the worshippers are as enthusiastic as ever. “More people are still coming from India and Nepal, so the final numbers will be very high,” said Shah.

Thousands of buses, tractors and carts packed with families cradling goats and birds for the sacrifice blocked the small dusty road leading to the Gadhimai temple. Huge crowds massed around the temple to receive a blessing, while a constant stream of pleas from desperate parents who had lost their children blared out from the public address system.

Facebook Twitter Pinterest Hindu devotees at Gadhimai festival in Bariyarpur, Nepal. Photograph: Xinhua News Agency/Rex

For most festivalgoers the event is a special family occasion; a chance to thank the goddess, but also to shop for knick-knacks, enjoy the fairground rides and share a picnic.

“I promised the goddess that if I made good money in my business, I would sacrifice a goat for her,” said Rajesh Shah as he cooked the animal he had just killed. “I’ve heard of the complaints about this festival, but I had already prayed for my business to improve, so I had to keep my promise to the goddess.”

The climax of the day is the killing of thousands of buffaloes in a huge compound surrounded by a high wall. Hundreds of men, especially chosen for the task, walk among the animals, holding long curved machetes above their heads, and then decapitate the buffaloes with a blow to the back of the neck.

Joginder Patel, a veteran of five festivals, said the job of killing the buffaloes was a great honour. “I really look forward to this. God will bless me for it,” said the 44-year-old. “It is as easy as cutting vegetables. At the last festival I beheaded 300 buffaloes, but this year I killed only 175.”

That would come as little comfort to Shristi Singh Shrestha, an animal rights activist with Animal Welfare Network Nepal. “Today we are feeling sad because we were not able to stop the slaughter,” she said. “We feel we have been defeated. However, the positive thing is that the number of animals killed has come down … We hope there will be no killing of any animal at the next festival.”