Rotational grazing helps producers boost pasture health

Producers can use a two-litre pop bottle to gauge when they should graze and when they should move cattle off a field

Rotational grazing is the key to building healthy pastures.

Producers may adopt intensive systems, mob grazing, adaptive grazing or cell grazing controlled with permanent and temporary fences, said pasture specialist Jack Kyle. A former pasture specialist with the Ontario ministry of agriculture, he now works with Gallagher Power Fencing Systems.

“Rest and recovery is the key to the whole system,” he said at the recent Canadian Forage and Grasslands Association conference held in Calgary.

Cutting plants for hay and silage may leave plants very short, but if animals are allowed to graze, it allows for better plant recovery because it leaves more plant material behind to cover the ground and allow photosynthesis to occur.

When a hay crop is harvested, it could take a week to get it off the fields and this could damage plants. With a rotational system, animals are in and out, causing less damage to the plants compared to machinery.

Ideally, cattle harvest forages when grasses are at the boot stage and legumes are at the early bud stage.

“The key is to avoid overgrazing. Don’t graze it down like the green on a golf course,” Kyle said.

There are simple techniques to estimate plant height.

“A two-litre pop bottle is my guideline. Start grazing when the plants are the height of a pop bottle. Quit grazing when the plants are the height of a two-litre pop bottle laid on its side, which is about four inches,” he said.

He recommends short grazing periods so cattle always have fresh forage that encourages them to eat more. If they are moved frequently, there is better manure distribution and they become quieter because they are used to people.

It is important to do a weekly or biweekly inventory to know what is available and evaluate the growth stage at any given time to create a feed budget. Regular pasture walks can help producers find underperforming paddocks and helps match the forage to the livestock. Cattle can be kept out of those poorer pastures to give them more recovery time.

A good grazing plan can drought proof pastures because a powerful root system develops.

Legumes have deep roots so whatever is growing above the ground is also growing below the ground. Remember that leaves stretch up to sunlight and roots reach down for moisture.

Pastures need fertility, and soil pH of six or higher is recommended.

Nitrogen, phosphorus, potassium, magnesium and sulfur are needed, especially on grass pastures.

Additional nitrogen can come from legumes.

Kyle recommends 50 percent legumes in a seeded pasture using alfalfa, sainfoin, clovers, trefoil or vetches. Alfalfa is the most productive legume available. It is a high-quality feed that provides energy and protein.

Grasses might include orchard grass, meadow brome, rye grasses or fescues.

Orchard grass grows fast with good recovery while rye grasses are the highest energy grasses and need lots of moisture.

Fescues sometimes have palatability issues but they are durable.

In the early spring or fall, annuals and winter cereals work well and provide fall rest for perennial pastures.

Swath grazing and bale grazing are popular in the West. These approaches keep nutrients in the fields as the cattle move through the fields.

Clean, fresh water needs to be available all the time. It should be within 225 metresof the grazing area if possible. Pumped water into a trough is better than surface water that could be dirty or contaminated. Clean water also increases feed intake.

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