Kean, who had been jeered throughout the game, turned in Rodrigo Bentancur's cross with five minutes left and then stood in front of the Cagliari fans behind the goal and opened his arms.
In response, Cagliari's supporters made the noise which is described by Italian media as "buu" and is regarded as a racist insult in Italian football, although some fans argue it is simply to annoy opposing players regardless of race.
Monkey noises could also be heard among the crowd.
Shortly after the goal, Juve's French midfielder Blaise Matuidi protested furiously to the referee and at one point appeared to threaten to walk off.
Matuidi complained last year that he was subject to racist abuse at the same stadium and Cagliari later apologised.
Play was halted on Tuesday and a warning was broadcast to the crowd -- the first step in the so-called three step procedure which ultimately leads to the teams being led off the field. Play resumed amid more booing and the referee blew the final whistle shortly afterwards.
Juventus defender Leonardo Bonucci, scorer of the opening goal in the 22nd minute, said Kean was partly to blame for the incident.
"You celebrate goals with your team mates," he said. "He could have done it differently... I think the blame is fifty-fifty. Moise should not have done that and the Curva should not have reacted in that way."
Juventus coach Massimiliano Allegri said he had been too immersed in the game to notice the abuse.
"As usual at the stadium there are idiots but also normal people," he said. "The uncivilised ones must be identified with the cameras and no longer allowed to enter."
Cagliari president Tommaso Giulini blamed Kean for his celebration.
"I heard mostly boos, if they started making animal noises then we were in the wrong," he said. "What happened at the end was because of a celebration which was wrong and it would have happened with any other player."
Kean, 19, has scored in each of his last four games -- two for Juventus and two for Italy.
The win took Juventus on to 81 points from 30 games with second-placed Napoli 18 points behind ahead of their game at Empoli on Wednesday.
Juventus were again without Cristiano Ronaldo who is recovering from a thigh injury he suffered playing for Portugal a week ago.
In December, Inter Milan were ordered to play two home games behind closed doors after Napoli defender Kalidou Koulibaly was racially insulted during a game at San Siro.
In 2017, there was an outcry after Ghanaian player Sulley Muntari was booked and sent off after complaining about racist abuse while playing for Pescara, also at Cagliari.
(Writing by Brian Homewood; Editing by Toby Davis)
