Alan Willson was airlifted to hospital after he was found seriously injured in Whitebeam Road, Durrington, at just before 7.30pm on Easter Sunday.
It is believed he was assaulted in nearby Longcroft Park.
Police have confirmed he remains in a serious condition at the Royal Sussex County Hospital in Brighton.
Four boys were arrested on suspicion of attempted murder and grievous bodily harm with intent.
They were released on bail with conditions while police enquiries continue, a Sussex Police spokesman said.
These conditions include strict curfews, staying at a given address away from the local area and not associating with each other.
And police confirmed last night they arrested a fifth boy on suspicion of attempted murder on Monday (April 5).
He has also been released on bail with strict conditions, they said.
In the wake of the attack, there has been an outpouring of shock, love and support from the community.
Alan’s daughter, Becky Willson, said on Facebook: “Words can not describe how grateful I am of how much has been given to help my mum and family out at this time. I’m so so shocked – this will help my mum out so much while my dad is in hospital – thank you so so much every one xxxx”
Two crowdfunding pages have been set up to help Alan’s family.
A gofundme page set up by Rhiann Wiseman has raised more than £1,000, and reads: “We just want to take off any financial stress that is going to affect his wife and children. Anything will make a massive difference.”
Meanwhile, a JustGiving page set up by Cheryl Edwards and Tara Hobden has reached more than £3,600.
In response, Becky said: “Thank you so much to everyone who has made a donation. I wish he could know how much love and support there has been for him and his family – I know he would be so greatful.”
Police said they are treating it as an isolated incident, and officers will be conducting increased regular high-visibility patrols in the area to provide reassurance to the community, and to identify and deter any further criminal behaviour.
The investigation is ongoing and police are urging anyone who saw what happened, or who was in the park around that time and may have any relevant information, to get in touch.
Detective Inspector Simon Dunn, who is leading the investigation, said: “The assault and the build up to it occurred in a public park in daylight, so it was likely that other people would have witnessed the assault or the suspects running from the scene.
“I am keen to hear from anyone who has information but is yet to come forward.”
Members of the public can contact police online or by calling 101 quoting Operation Swallowtail.
Alternatively, information can be passed anonymously to police via the independent charity Crimestoppers online or by calling 0800 555 111.
To make a donation to either of the fundraising pages, visit https://uk.gofundme.com/f/help-a-family-after-the-dads-attacked?qid=14073615437092614af240010926e36b and https://www.justgiving.com/crowdfunding/cheryl-edwards?fbclid=IwAR3yP1TYoX1nEeUuDSRPGznucPTX9sUleE1F8enR5kuBSaraHglSGPiUqkE.