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Day has come for year round sheep breeding

Lamb demand has spiked in Canada over the last decade, thanks to a growing population of immigrants with an appetite for the meat.

However, sheep farmers have struggled to satisfy this increasing market.

The Canadian Sheep Federation estimates that Canadian farmers produce less than 50 percent of the lamb consumed in the country. The remaining lamb is imported, primarily from New Zealand and Australia.

However, the substantial gap between domestic supply and demand may soon be narrowed, thanks to research in Quebec on a sheep breeding system called photoperiod.

Nearly 200 of the 1,000 sheep producers in Quebec are now using the system, which uses light control to induce sheep to breed out of season, said Johanne Cameron, a breeding specialist with Centre D’expertise en Production Ovine du Quebec.

Photoperiod artificially alters the length of day with indoor lights to induce ewes into estrus.

Unlike cows and pigs, the length of day affects the reproductive cycle of sheep because ewes prefer to breed when days are shorter. This is known as in-season breeding.

The length of in-season breeding varies depending on the breed of sheep, said Delma Kennedy, a sheep specialist with the Ontario agriculture ministry.

“If the season for a breed is about 100 days long, the season will tend to start 50 days before the shortest day and end 50 days after the longest day,” Kennedy said.

“If the season is 70 days long, it will tend to start 35 days before the shortest day and end 35 days after the shortest day.”

Many Canadian producers have introduced less seasonal genes into their flock from breeds that originated near the equator.

However, Kennedy said even those animals don’t like to reproduce year round.

“A Barbados Black Belly … might have a (breeding) season of seven or eight months long, but it’s still not close to 12.”

Cameron said producers have adjusted flock genetics to achieve 60 to 65 percent conception rates during the longer day periods of the year.

However, she said the out-of-season breeding rate with the photoperiod system is significantly higher.

“With photoperiod, the result from our studies is 89 percent (conception rate) year round.”

Based on a farm with 500 ewes, Cameron estimated that photoperiod generates $50,000 more in annual profits than a conventional once-a-year lambing system.

However, those calculations are based on the operational costs of a barn, including light and ventilation, but not its capital cost.

She said the decision to adopt the photoperiod system was largely a byproduct of the decision to start moving sheep indoors.

“Most of the producers who use this protocol don’t put their sheep outside because of predators,” she said.

As well, new producers have decided to build barns rather than buy land.

“There are a lot of new sheep producers (in Quebec). They just have a small (piece) of land…. Some (don’t) have enough land, not enough pasture and not enough money to buy more land.”

However, Cameron said the high cost of building barns was an incentive for farmers to produce as many lambs as possible per sq. foot of building.

They turned to light control as a way to induce the sheep to breed year round.

“Under photoperiod, you produce 30 percent more (lambs) than the producers not using it,” she said.

This represents 150 more lambs a year in a flock of 500 ewes.

Kennedy said Ontario producers have been less willing to adopt the system.

“If you don’t already have buildings that are easily modified, they (sheep producers) aren’t willing to invest money to try it.”

Most Quebec sheep farmers who use photoperiod keep the animals inside for the entire year.

However, Cameron is studying the potential of a hybrid photoperiod system, in which sheep are kept inside during the winter and put on pasture during the summer.

This protocol, known as light extension, takes advantage of sheep’s response to relative amounts of light.

The lights inside the barn remain on for 22 hours during the winter months.

“Then when they move into natural lighting (in the summer), it’s considered, for the sheep, as short days,” and inspires them to breed.

Cameron said results from the light extension system are encouraging, but more research and data are required.

This hybrid photoperiod system could help prairie sheep farmers, who are looking for ways to produce lambs throughout the year.

“I think that’s a much bigger opportunity, especially for (western Canadian producers) who are used to doing mostly pasture,” Kennedy said.

Manitoba sheep producers could also think about moving sheep into abandoned hog barns, she added.

Regardless of how they do it, Cameron said Canadian sheep producers will need to find ways to breed sheep year round.

“If we want to keep our market, we must do something to produce (lamb) out of season.”

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