There's reason to cry over spilled milk, researchers say.

They found that the discarded dairy product has a massive financial, environmental and nutritional impact.

"Systemic inefficiencies" in Canada’s supply management system have led to billions of litres of milk going to waste since 2012, according to a new study published in the journal Ecological Economics.

Costs of dumped milk

Between 6.8 billion and 10 billion litres of milk was discarded on Canadian dairy farms over 12 years, according to researchers based in Denmark, Michigan and Halifax's Dalhousie University. They found that the amount of tossed milk made up about seven per cent of milk produced on dairy farms over that time, and was valued at up to $14.9 billion.

In addition, researchers estimated that as much as 10 billion litres of milk was discarded, which contributed to "significant" land and water resource waste, and about 8.4 million tonnes of carbon dioxide-equivalent emissions, or the amount of emissions from 350,000 passenger vehicles each year.

Wasted milk also means Canadians are losing out on nutrition, the report's authors said in a news release Wednesday. The discarded milk could have fed more than 4.2 million Canadians each year, or 11 per cent of the Canadian population, according to the study.

Dairy Farmers of Canada, which represents nearly 10,000 Canadian dairy farms, questioned the accuracy of the findings.

"The authors of the study acknowledge that much of their conclusions are drawn from 'estimates' rather than a robust data set," Jacques Lefebvre, CEO of the industry group run and funded by farmers, said in an emailed statement to CTVNews.ca on Wednesday. "These data assumptions and calculations would need to be validated independently."

Recommendations

As a result of the findings, the study's researchers are calling for reforms in the dairy sector to reduce milk waste. They recommend penalties for overproduction and increasing transparency in milk production, such as by requiring the industry to report surplus milk production and waste.

They also propose revising dairy quotas to better fit with market demand and consumer preferences.

In response to the recommendations, Lefebvre told CTVNews.ca that supply management is aligned to the needs of the domestic market, and when there is a surplus of milk, it is often linked to supply chain issues.

“Milk disposal is not a unique issue to Canada,” he wrote. “Milk is disposed only as a last resort after exploring all other alternatives. This is done in accordance with regulations and the costs are borne by the dairy farmers."