The effect of winter feeding systems: the study

Cattle producers can overwinter their herd using various feeding systems, and each system can affect the land, the animals, and the producer’s bottom line. Paul Jungnitsch, greenhouse gas offset agrologist with Alberta Agriculture and Forestry, explains his research that compared those different systems.
“Yard feeding has been the traditional method of feeding cattle in the winter in the prairies,” says Jungnitsch. “Feed is hauled in for the winter, and manure is hauled out in the spring or fall. Recently, winter pasture feeding has become popular. Cattle are left out on the pasture, and the feeding is done there. Machinery use is reduced, partly because the cattle spread the manure themselves.”

Jungnitsch says that little work had been done comparing the effect that winter feeding on pasture has on soil nutrients as compared to spreading manure from a corral with a machine. “Since is it not recommended to spread manure in the winter, there was concern that wintering cattle on pasture would result in nutrient losses compared to yard wintering.”

In the fall of 2003, two five acre winter feeding areas were laid out with electric fence in an old pasture of Russian wild-rye grass at the Western Beef Development Centre at Lanigan, Saskatchewan. Explains Jungnitsch, “Alternating hay and straw bales were set out in the west area, so the cattle could be winter fed by bale grazing. The east area was left empty in preparation for winter feeding with a bale processor. The area of the winter feeding areas was calculated to result in the cows applying 30 tons per acre of manure on the pasture over the winter. However, this turned out to be about 15 tons per acre at the same moisture level as the spread manure.”

Jungnitsch adds that a replicated site for spreading manure and compost was set up at the same time. All sites were sampled for background nutrient levels. Raw manure was then spread at 30 tons per acre while compost was spread at 10 tons per acre.

Sixty-four cattle were brought onto the pasture on November 22 after being weighed and condition scored. They were kept there until the end of March and were weighed each month. Feed use and the time and equipment used feeding were noted. Thirty-six cattle were also fed November to March in the intensive drylot in the farm yard, with the same measurements taken.

Jungnitsch found that nutrient retention of nitrogen and potassium was much better in winter pasture feeding compared to winter yard feeding. “One hundred and four lb. per acre of inorganic soil nitrogen was gained on the winterfeeding sites compared to the check, with areas ranging as high as 550 lb. per acre. No gain could be measured where manure or compost was spread.”

Soil Inorganic nitrogen in the 0 to 6 inch depth, lbs. per acre

“The efficiency of nutrient capture after a year and a half of harvesting was calculated as 34 per cent of the nitrogen hauled onto the winterfeeding sites in feed and bedding, or 38 per cent of that excreted by the animals. Phosphorus was 22 and 26 per cent. These figures approach or exceed that found in forage trials with the application of commercial fertilizer,” he says.

Jungnitsch adds that the efficiency of recovery of the spread manure nutrients was calculated as one per cent of the nitrogen hauled to the drylot animals in feed and bedding. Phosphorus recovery was calculated as three per cent.

“With ever increasing nutrient prices, this finding appears very significant, especially for cow-calf producers,” he notes. “The cattle concentration used of six cows per acre for four months appeared to give a reasonable inorganic nitrogen accumulation level.”

“Nutrient distribution of nitrogen and potassium was relative to the pattern of feeding and bedding of the cattle and showed large variation in soil test numbers. When winter feeding cattle on pasture, it appears to be important that cattle activity is as even as possible throughout the field,” says Jungnitsch.

He also found that forage growth and protein content was much greater from feeding in the field compared to spreading manure. “This was despite Russian wild rye - a bunchgrass - not being well suited to pasture feeding with straw, especially when bale grazing. A more aggressive creeping rooted grass would likely have performed better.”

“Hay and straw left by the cows when the field feeding ranged from four to eight per cent for the hay, and to 38 to 44 per cent for the straw – used for feed and bedding,” says Jungnitsch. “The penned cattle left about six per cent of the tubground feed and 70 per cent of the bedding straw.”

The research discovered cattle weight gain and condition showed little difference between bale processing, bale grazing, or drylot feeding.

“Economics favoured pasture feeding,” says Jungnitsch. “With savings in machine operation and manure handling, and gains in pasture growth. Machinery use was the least expensive and critical in the bale grazing system, next higher in the bale processing, and the most in the drylot system, especially using compost.”