“Variable moisture conditions throughout the province have made it difficult to make hay this year,” explains Karin Lindquist, forage and beef specialist at the Alberta Ag-Info Centre.
“However, using hay fields to extend the grazing season this fall is an option where stands in dry areas are too thin to take a second cut or too in wet areas where it is impossible to get into the fields.”
She says that forage quality is one factor to consider, as frequent rain and showers in parts of the province have made it difficult to bale dry hay.
“Many hay stands have been left standing much longer than normal. Some fields are too soft for equipment to get in. In other areas, not enough moisture has reduced yields and there is not enough present to cut for hay. Consequently, much of the harvested forage will not have the quality that younger, more vegetative stands have.”
She adds that fibre content is higher and digestible protein and energy content are lower when plants are more mature and are approaching dormancy, making those plants harder for ruminants to digest.
“Some hay stands may contain significant amounts of alfalfa,” she explains. “Higher quality hay typically has a legume component to provide sufficient protein and energy to meet animals’ needs. The grass component of a hay stand is more beneficial for grazing than a pure alfalfa stand due to the risk of bloat.”
“There is less risk for bloat in August than in June or July when the plants are growing rapidly. However, there is still some risk of bloat, so management practices to reduce incidents are still good to keep in mind.”
Lindquist says that roughly the best time to begin grazing an alfalfa-grass stands is after two light frosts when plants have gone dormant.
“If alfalfa is grazed within 45 days of going dormant, the plants are pulling food reserves out of the root system to initiate new growth. When this occurs, the lack of food reserves for the alfalfa to get through the winter increases the risk of winterkill. Alfalfa must be able to store energy in its crown and roots to survive winter and to use those energy stores for regrowth in the spring.”
She says to introduce animals to the hay stand in the mid to late afternoon. Cows have the largest meal of the day in the morning and additional meals mid-afternoon and in the evening. Lower feed intake in the afternoon reduces the amount of alfalfa the animal will eat and means less risk of a digestive upset.
“If you have access to some lesser quality hay or straw, leave a bale or two out for the cows to eat, and that will supply a long fibre feed. It helps move the rumen content and aids digestion. Moving the cattle between the stand that contains alfalfa and one that is mainly grass also provides long fibre. Check on them at least twice a day during this first week, as you may have some chronic bloaters that will need to be removed as soon as possible.”
She adds not to be too alarmed about nitrates if the herd is grazing on alfalfa and a frost hits.
“Nitrate toxicity with alfalfa and any legume crop is not an issue. Nodules in the root system only release as much nitrogen to the plant as is required daily, so there is a very low risk of excess nitrogen in the plant. Most hay stands are not usually fertilized heavily, so nitrogen levels in the soil at this time of year is minimal. Nitrates are more of a problem with annual cereals such as barley or oats.”
“However, a killing frost of -5 to -6 C for 4 to 5 hours tends to increase digestibility of the plant. These the cell walls rupture, making the contents immediately available to rumen microbes when consumed. It can increase the risk of bloat.”
Once animals adjust to the hay stand, Lindquist says that it is best not to remove them from it, even at night.
“Maintaining a constant feed supply is important to maintain healthy rumen function. Higher fibre content found in overly mature forages makes it more difficult for the animals to digest. Depending on weather damage, the stand’s content and its maturity may make it not much better than straw. Consider providing protein and energy supplementation to improve feed intake. It helps rumen microbes to break down the fibrous forage better, releasing much-needed nutrients for the cow to use.”
She says that options include free-choice protein tubs or feeding 3 to 4 pounds of peas per head every 2 or 3 days.
“Adding a non-protein nitrogen (NPN) source such as feed grade urea to barley will also help. Feed a mixture of barley and urea to cows every 2 or 3 days at 3 to 4 pounds per head, but be sure not to exceed 20 to 25% of the total protein in the ration from NPN sources.”
Connect with the Alberta Ag-Info Centre:
Hours: 8 am to 5 pm (open Monday to Friday, closed statutory holidays)
Toll free: 310-FARM (3276)