Canada will soon be home to as many pigs as people as the hog production in industrial-scale barns grows by more than one million each year.

The exploding number of pig barns that hold several thousand hogs apiece has caused controversy across farming country, with disputes between factory farm operators and neighbours worried about pollution and the smell of multi-million-litre manure tanks.

Canada will produce an estimated 28.2 million pigs this year, the Manitoba Agriculture and Food ministry estimates. That's up 1.8 million from last year.

"I'd say it would probably hit 30 million in the next couple of years," added Manitoba's expert in pig numbers, Janet Honey. She is the manager of market analysis and statistics for Manitoba Agriculture and Food, but also tracks national figures and was asked to speak to the Ontario Pork Producers' Association last month in Toronto.

"That's dramatic," she said of the growth after running calculations yesterday. "I didn't know it had gone up that much."

Meanwhile, the human population of Canada is barely ahead of pig numbers at 30,007,094 people, according to the 2001 census, released this month. It's barely growing at all.

But pig numbers are booming, and may even leave the human population far behind.

"Ontario, Quebec and Manitoba will all be over seven million hogs this year. Saskatchewan has huge potential, so levelling off is hard to envisage if Saskatchewan continues to increase," Ms. Honey said.

"Manitoba alone increased 17 per cent last year. It was just unbelievable. I can't even keep up in Manitoba."

"The big question mark is how far Saskatchewan's going to go with this," she said. It's traditionally a grain-producing region.

"If they do (adapt to livestock farming) you could put 20 million hogs in Saskatchewan and not even notice."

The province is ideal because of its large farms and small population, she says. That means there's more room to spread manure than in Ontario.

Ontario's pig production was 6.7 million last year, "but they'll be lucky to get to 7.2 (million) this year," she added.

These pig numbers aren't quite like a human census, since many of the pigs are either slaughtered or exported during the year. The actual pig census -- the number sitting on farms at any given time -- was just over 13 million last year.

The rising pig numbers have alarmed many people who live near pig farms.

Environmental problems from factory hog farms include chemical and bacterial soil and water pollution and fumes that can harm the health of workers in the barns, according to Agriculture Canada documents released under access to information last week.

The documents were obtained by Ottawa researcher Ken Rubin.

The crucial problem is finding enough land to absorb the manure without having it run off into wells and rivers, and without having it build up in the soil faster than crops can absorb it.

Ms. Honey cautioned that future hog numbers depend on external factors such as prices -- which dropped dramatically in 1998 as Asian markets faltered -- and U.S. political trends. The U.S. Congress is now considering a bill that would restrict ownership of hog farms by meatpacking companies, which could drive more hog production north to Canada.

At the same time, many young weanlings are currently being shipped to the U.S. to grow, since corn prices are lower there.

Fluctuations in markets and political arenas could slow the expansion of Canada's hog industry, but only in the short term, Ms. Honey said.

In the global marketplace, Canada ranked seventh in terms of hog production in 2000. In that year, Canada had a hog inventory of 12.24 million.

Canada's hog production, however, fell fall behind the world's top 2 pork producers, China and the United States.

In 2000, China, which had a population of 1.26 billion people, produced 430.2 million hogs.

Hog production in the United States, with a population of 281.4 million, reached 59.34 million in 2000.