Producers Urged To Test Nutritional Quality Of Forage

Feed testing will be especially important this year as the quality of weather-damaged or mature forage may not be adequate to meet the nutritional requirements of livestock.

“With the amount of hay that has been cut late and is over-mature, or has been cut at the right time, turned twice, sat in the swath or rained on a number of times, forage quality will really be called into question,” says Barry Yaremcio, beef and forage specialist with Alberta Agriculture and Rural Development.

“This variable forage quality makes feed testing essential.”

A feed test requires a representational sample from the bales, silage or forage in the field. Hand samples always result in lower-quality results, so it is recommended to use a forage probe, take samples from at least 15 to 20 different bales, and send in a composite sample.

Sampling silage from an open pit is best done by taking samples from the face of the pit. If a proper silage probe is available, take samples from the top to the bottom.

It is more difficult to get a good representational sample from swath grazing material and perennial forage left in the field for winter grazing. Hand sampling is the only way to collect a sample in these situations, and it’s important to be sure to collect material from about 10 places throughout the field for the sample sent in for testing.

“Samples are primarily tested for energy and protein the two most critical factors in any ration,” says Yaremcio. “It’s also important to analyze feeds for energy, acid detergent fibre (ADF), calcium, phosphorus, magnesium, and potassium. If doing canola, it’s also important to test for sulphur. The main thing is to get the testing done, otherwise producers are feeding blind.

“This year, we are seeing higher-than-normal neutral detergent fibre levels in these rained-on and damaged forages. Neutral detergent fibre is what limits the intake of feed by cattle and other ruminants. Once an animal consumes over 1.2 per cent of its body weight in neutral detergent fibre, the animals will quit eating. In most years this isn’t an issue, but this year, with the forage being more mature and rain damaged, that value will be much higher making it more difficult to provide a balanced ration to cattle this winter.”



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