Some cows in New Brunswick will be going for an unusual ride as flood waters force their evacuation from a dairy farm.

The Canadian military and the coast guard arrived in Maugerville, N.B., on Friday to help rescue 140 cows from rising flood waters.

The cows are in a desperate situation and stressed, said Robert Speer, a farmer from Hainesville helping out with the rescue.

The rescue is demanding a huge amount of resources, said Jody Price, fire chief in Oromocto, in an area where emergency officials are already on the water helping remove people from flooded homes.

The cows are stranded in a barn now flooded by the St. John River. If not milked, they run the risk of developing an infection, which can block milk production or even kill the animal, said dairy farmer Marco Boonstopple, who was helping with the rescue.

The cows are being loaded on to a type of barge known as a sea truck. Officials said they hoped to transport the cows across the river before midnight, but they were still preparing for the rescue on Friday evening.

Lt. Jamie Donovan at Canadian Forces Base Gagetown said the strong currents in the flooded river were making it dangerous for boats to manoeuvre.

If the cows are able to be taken across the river, they will be transported to a farm outside of the flood zone.

Boonstopple said that he knows the family that is trying to rescue the cows and that they had been trying to safeguard the animals on their own but had to ask for the extra help.

"It's real emotional. We're here for support," Boonstopple said.

The cows are like a family, and a herd grows with a farm through generations, he said. The stranded cows are at a seventh-generation farm, he told CBC News.

"It's genetics brought up over years. This is what you get up to do early in the morning until late at night.… You work with them every day and you can't replace that."

There are many dairy farmers in the low-lying area on the outskirts of Fredericton where flood waters of the St. John River are continuing to rise.

Families are struggling with leaving behind their cattle and horses, Oromocto Mayor Fay Tidd said.

More than 350 families in the area have had to leave their homes as waters reached 6.85 metres on Friday.

The deluge was expected to continue to rise to 6.9 metres on Saturday before beginning to slowly recede.

With files from the Canadian Press