Under the stiffened penalties passed by Gujarat's state assembly, anyone caught transporting cows for slaughter could also face up to 10 years in jail.
Cows are considered sacred in Hindu-majority India, and their slaughter is illegal in most states.
"A cow is not an animal. It is symbol of universal life," Gujarat law minister Pradipsinh Jadeja told the state's assembly.
"Anybody who does not spare the cow, the government will not spare him."
The amendment still needs the approval of the state governor -- a formality all but assured -- before becoming law.
Millions from India's huge minority populations -- including Muslims, Christians and lower-caste Hindus -- eat beef, although it is not widely available.
But Modi's ruling right-wing Bharatiya Janata Party, which recently won India's largest state Uttar Pradesh in a landslide, has long campaigned for the protection of cows.
The BJP's new chief minister in Uttar Pradesh, Yogi Adityanath, has launched a crackdown on abattoirs since taking office in March that has ground the state's meat industry to a halt.
Hindu activists have long accused the Muslim-dominated meat industry of covering up the slaughter of cows and passing off the meat as buffalo, which are not revered as holy.
Cow slaughter is a hot-button issue in India, where even rumours of cows being transported can spark murderous reprisals and religious riots.
Squads of "cow protection" vigilantes are known to roam highways inspecting livestock trucks for any trace of the animal.
In 2015 a 50-year-old Muslim man accused of eating beef was dragged from his home in 2015 and beaten to death by a mob. Police later said it was mutton.
