Testing winter feed

Testing feed allows producers to develop a strategy that ensures all cattle in the herd are fed to meet their production goals while avoiding extra costs. Andrea Hanson, livestock extension specialist with Alberta Agriculture and Forestry (AF), outlines the importance of testing at the beginning of the feed season.
“Using higher quality feed early in the season could mean it is not available later in the season when the cows really need it,” explains Hanson. “It could get costly for the operation, either by increasing feed costs or reducing cow fertility.”

“Livestock feed supplies are going to be tight in some areas of Alberta, while in other areas, quality may be an issue,” says Hanson. “As such, testing feed stuffs is important to know what nutrients are available. When feed costs are the largest variable expense of overwintering a beef cow, overfeeding is wasting dollars. Conversely, if the animal’s nutrient requirements aren’t being met, it can negatively affect their immediate wellbeing and future reproductive efficiency.”

The formulation of a ration depends on the nutrient composition of the forage. The only way to accurately determine the forage’s nutrient composition is by sampling and testing the feed.

“Using last year’s feed tests or using a provincial average for a feed’s nutritional content, is not realistic or useful,” explains Hanson. “While physical attributes are part of feed quality, they don’t tell the whole story. A bright green colour does help indicate the feed was put up with little or no rain - and that the mould level is little to none - but it does not tell much more than that. Protein and energy content of the same hay field can vary greatly depending on when it was cut. Brome cut very early in the year could reach 18 per cent protein while that same forage may only be 5 to 6 per cent protein if cut late.”

AF’s beef and forage specialist Barry Yaremcio says that the protein requirements of a cow change depending on where she is in her pregnancy. “A minimum of seven per cent protein is needed in the second trimester while in the third trimester, nine per cent protein is needed. She requires 11 per cent protein when lactating.”

Hanson adds that the most important information in a feed test includes protein, energy, and fibre. “A basic forage analysis will list the moisture content of the feed stuff, energy as total digestible nutrients (TDN), net energy (NE) and/or digestible energy (DE), crude protein values as well as calcium, phosphorus, magnesium, and potassium. A basic analysis should cost less than $50, which is much less than the cost of a round bale of feed, let alone the possible savings from using fewer bales of hay mixed with lower quality forages. The more advanced analytical packages will provide more details about the feed depending on what is requested. If an early frost or crop stress has been experienced in the area and there are concerns, a nitrate test may be very beneficial as would a toxin test.”

Getting a representative sample of the feed to test is important in feeling confident with the analysis. Says Hanson, “If sampling bales, samples need to be taken from a number of bales - at least 15-20 - from different areas in the field and then mixed into one sample. Using a commercial forage sampler makes the process much easier, and often local agriculture service boards or forage associations have equipment available for loan.”

“Use plastic bags to ship the feed so that an accurate moisture level can be determined,” adds Hanson. “If sampling from a silage pit, rub the loose material off the face before taking the sample from packed material from the freshest part of the silage face, and from several locations in a ‘W’ or ‘M’ pattern. Mix the samples and pack tightly into a plastic bag with as little air as possible. If the samples aren’t going to the lab right away, freeze to prevent any change to the silage characteristics. Finally, if you want a sample of the swath grazing feed, take a tub and scissors out to the field and pull various samples from the swath from locations all over the field. As the samples are pulled, cut the feed into two inch lengths and mix in the tub. From the total sample, stuff a large zip-lock bag with a representative sample of the feed for analysis.”