Hundreds of fox hunting supporters gathered in a Leicestershire town for a demonstration on Saturday.
Hunts are vowing to put the new ban on hunting with dogs to the test
The Quorn, Belvoir, Cottesmore and Oakley Foot Beagle hunts staged a protest in Melton Mowbray before setting off to hunt within the new law.
Hunting events are also taking place in Notts, Derbys and Lincs.
Claire Bell, secretary of Cottesmore Hunt, said: "We intend to hunt to the letter of the law within this new law, however ridiculous it may be."
The hunts had planned to address the crowds in Melton town centre but were moved on back to the town's cattle market by the strong police presence.
The hundreds of people who witnessed the start of the procession swelled to thousands.
Police said the morning protest passed off peacefully.
Ms Bell, from the Cottesmore Hunt, said: "We want to show our strength and our force and... really to thank the town of Melton Mowbray because it is the centre of hunting and has been for 300 years.
"This is not good for the fox, it's not good for the countryside, it's not good for anything, it's a really bad and unjust law."
Unofficial estimates put the number of mounts at between 525 and 550, with
children as young as five on ponies and elderly men on large hunters.
The four hunts date from the mid-18th Century and are closely associated with hunting in its modern form, while the fox is the county emblem.
The South Notts hunt was holding a hound exercise at Screveton off the A46 on Saturday.
Hunt secretary Anne Jepson said: "We are doing it to show we are still there and have not disappeared and we will remain in existence.
"We will be seen every week in the normal hunting season and we will be doing activities which hopefully make people in this country - and particularly the government - realise that we are not going away."
Anti-hunting campaigners accused hunts of "recklessly going out with hounds" and asked the public to inform on them.
Douglas Batchelor of the League Against Cruel Sports, said: "They will need to exercise extreme caution if they are to avoid committing a criminal offence.
"The league has over 100 monitors out today, some in the fields, some operating undercover, and they will be videoing hunts, collecting evidence of any illegal hunting."