Grazed forage may not be adequate to meet beef cattle’s nutritional needs this time of year, North Dakota State University Extension Service livestock experts warn.

“The nutritional quality of mature standing forage diminishes the further we get into winter through deterioration and selective grazing,” says John Dhuyvetter, area Extension livestock specialist at the North Central Research Extension Center near Minot. “Dormant pastures are likely low in vitamins and minerals, and lack adequate rumen-degraded protein to maximize fiber digestion.”

Inadequate nutrition can cause cows to lose weight and body condition. In cold weather, a cow’s energy demands increase as its body burns energy reserves to stay warm, and the cow can use up those fat reserves quickly.

“When this occurs, playing catch-up can be an uphill battle as it can take up to 45 days to regain one body condition score.” says Fara Brummer, area Extension livestock specialist at the Central Grasslands Research Extension Center near Streeter.

A longer-term effect of poor nutrition is that cows may not rebreed. This can occur when cows are underfed six months prior to breeding. The best time to make sure the cows are in adequate shape is during the middle trimester of pregnancy. In most North Dakota cow herds, that is November through February.

“So now is the time to feed the cow herd to good body condition, not lose weight,” says Karl Hoppe, area Extension livestock specialist at the Carrington Research Extension Center. “Feed the cows correctly right now so you don’t end wondering why there are so many open cows next fall.”

Dhuyvetter says that modest supplementation may be all that midgestation, dry, mature (moderate productivity) cows need if forage availability is high even though the quality is low. Periodically feeding high-protein hay, byproducts or commercial supplements that deliver 0.3 to 0.4 pound of crude protein per head per day will maximize intake and energy from low-quality forage.

Higher-need animals such as bred heifers and young cows, highly productive larger types (heavy milking, large frame) and less efficient grazers (old and broken mouth) need better feed than what late-season grazing provides. These animals likely will require daily feeding or access to good-quality hay, silage or grain and grain byproducts to meet their nutritional requirements.

“Abundant hay stocks and reasonably priced feeds makes it easy to justify providing cows what they need to stay in condition, deliver a healthy calf and rebreed in light of today’s record prices for calves and cows,” Dhuyvetter says.

Developing a feeding system that works for a cow herd is reasonably easy because of the supplements and coproduct feeds available in North Dakota, according to Hoppe.

“Practically a full feed of hay plus 5 to 7 pounds of coproducts can meet the needs of a gestating cow,” he says.

Knowing the energy content of feeds is the first step to a proper diet. Hay that is only 45 percent total digestible nutrients (TDN, an estimate of energy content in feeds) won’t be adequate to maintain weight when the weather drops below zero.

“Cows losing body fat may be all right if feed is short, the weather is particularly cold or cows are extremely fat,” Hoppe says. “A cow can easily handle one or two days of underfeeding, but a month of underfeeding can lead to one or two body condition score decreases. Two weeks of subzero weather can lead to weight loss if total cow feed intake isn’t increased or if the energy content isn’t increased.”

Brummer says that stockpiled winter grazing can provide effective manure and nutrient distribution, but a disadvantage is that it can damage the forage crop if the grazing isn’t managed properly. Grazing cattle can remove the snow cover and its insulating effect, exposing the plants to the cold. Green-up may be delayed the following spring if cattle remove the plants’ winter cover.

In addition to feeding cattle high-energy feeds with adequate nutrients, the animals need access to water to help keep their body temperature at the proper level, she says.

Cattle also need wind protection. For example, livestock protected by a windbreak can experience a 19-degree increase in temperature when the wind speed is 20 mph and the temperature is 20 degrees Fahrenheit, she notes.

Herd assessment is another important part of making sure cows receive adequate nutrition.

“It is easy to overlook individual animals in a herd situation,” Brummer says. “Thin females, as well as first- and second-calf heifers, should be sorted off and maintained separately with additional supplementation beyond the rest of the herd.”

For more information on winter feeding, check out the NDSU Extension publication “Alternative Winter Feeding Strategies for Beef Cattle Management” athttp://tinyurl.com/winterfeedingstrategies.