Originally published in the June 24 edition of Agri-News
“A cool, dry spring this year did not allow pastures and hay lands in many parts of the province to grow as rapidly as they usually do,” says Barry Yaremcio, beef and forage specialist at the Alberta Ag-Info Centre. “Along with the weather, previous years’ stressors have resulted in pasture poor growth.”
Yaremcio says that in some situations, producers had no choice but to turn their cows out to graze three to four weeks earlier than normal because of short or exhausted stored feed supplies.
“Research has shown that for every day animals are turned out early in the spring, the grazing period in the fall is shortened by three days.”
He says that in some parts of the province, grasses have headed out early and alfalfa has gone to bloom.
“The plants are trying to complete their life cycle much earlier than normal, and that affects the overall yield and quality of forage available to livestock on pasture. If those pasture plants are not lightly grazed or clipped to remove the heads, they will go dormant for the remainder of this growing season. It is not likely that they will produce additional forage.”
Protein and energy are the top two nutrients to consider when feeding cattle. Yaremcio says that once grasses are pollinated and seed starts to form, protein content in the forage drops roughly 1% to 1.5% per week.
“Total digestible nutrients (TDN) or energy content will drop by 1.5% to 2.5% per week as well. Legumes will also experience a loss in quality once pod set occurs.”
He adds that under dry conditions, the loss of quality occurs three to four weeks sooner than in a normal year, but rotational grazing can help.
“It keeps plants in the vegetative state, prevents the deterioration of quality and entices the plants to continue growing. A minimum rest period of 30 days between grazing events is critical to allow the plants to recover. The longer the rest period, the better it is for the plants.”
Yaremcio adds that it is possible to extend the grazing period by supplementing with grain, milled or screening pellets, byproduct feeds, protein tubs or blocks.
“Availability, cost and nutritional content are all considerations when developing a program. Availability and cost are paramount.
He suggests trying to maintain a constant feeding program throughout the summer. “If supplies are tight, using a combination of two or three different products is advisable. Abrupt changes from one type of supplement to another could cause digestive upsets and animals going off feed for some time.”
“Feed grains such as barley, oats, triticale, wheat or rye are possible options, but each grain has a different limit of how much to feed per head per day. Screenings from seed cleaning plants or pelleted screening pellets fall into the same category as the feed grains mentioned above. It may take four to six pounds of supplemental grains, pellets or byproducts every two or three days to keep cows in good condition and maintain milk production. Calves that eat some eat some of the supplemental grain pellets or byproducts will improve their gains as well.”
Byproduct feeds such as distillers’ grains or malt sprouts are high in protein, phosphorus and sulphur. “A 1:1 or 2:1 mineral will not be suitable to use in this situation,” he explains. “It is necessary to feed a 3:1 mineral or feedlot type mineral with 3% to 4% magnesium to increase calcium and magnesium levels to prevent grass tetany or downer cows.”
Cutting a cereal crop for green chop silage is another option. The cut material is fed fresh to the grazing animals. It must be consumed the same day it is cut, otherwise the presence of aerobic bacteria will cause it to spoil.
Tubs and blocks are products are also available on the market, and there are two types – protein and energy.
With all the different products on the market, Yaremcio says it is best to read the tag to evaluate each product’s nutrients and compare that to the animals’ requirements. “Ask for help if you are not sure how to make the comparisons. The amount of product the animals need to consume may make the cost unreasonable.”
He notes that mineral products provide macro minerals, trace minerals and vitamins but do not supply any protein or energy. “They are essential for a balanced nutrition program, but they should be fed in conjunction with other feeds that supply energy or protein.”
“The biggest question to consider when using any supplemental product is cost,” he adds. “What is the cost per head per day? What advantage does the product provide? Is it feasible to use the supplemental product or is it costing more than the benefit that it provides? Take time to evaluate the costs and benefits before making any purchases.”