Protecting hay from weather damage can significantly reduce the cost of wintering cows.
Adequate moisture conditions in most of the province have resulted in larger-than-normal yields resulting in bigger stacks and rows of hay bales. If the winter is normal and cow numbers remain static, there could be a large surplus of hay carried over into the summer of 2017 and fed in the winter of 2017-18.
“When hay is carried over the course of a winter, bales weather and lose both weight and quality,” said provincial beef and forage specialist Barry Yaremcio. “This poses the key question of what kind of value losses occur when storing the bales outside unprotected from the elements?”
Research on over-winter outdoor bale storage done in the Westlock area found a 5.7 per cent reduction in bale weight over the first winter. A 1,400-pound bale in July would weigh 1,320 pounds the following spring. (The bales were stored in an area that was higher in elevation compared to the surrounding area and the grass was mowed prior to bringing the bales onto the site.)
Other research reports indicated that weight loss can be as high as 15 per cent (210 pounds for a 1,400-pound bale). If snow is trapped between the bales and if the water does not run off during spring melt, there can also be significant water damage.
“Weathering also affects the acceptability of hay to livestock,” says Yaremcio. “Cows will reject or waste up to eight per cent more feed from bales stored unprotected outdoors as compared to bales placed under a tarp or stored under a shed.”
Bales stored outdoors tend to squat or flatten out during storage. The total surface area of the bale in contact with the ground and exposed to rain increases, adding to the weather damage over time. Digestibility of the weathered hay can drop 10 per cent compared to hay protected from the elements.
This loss in consumption and digestibility is further compounded by leaching losses of protein and soluble sugars (energy).
“Nutrient losses are greater from the leaf portion of the plant compared to the stems,” said Yaremcio. “Weathered hay can test two to three per cent lower in protein (hay that tested 14 per cent after baling can be 10 to 11 per cent the following spring), and energy 20 to 50 per cent lower (TDN value of 63 per cent after baling can be as low as 45 to 55 per cent).
“If the winter is variable with many freeze/thaw cycles, damage will be greater than in winters that are constantly cold.”
Bales made with net wrap withstand weather better than those made with twine. Net-wrapped bales can have 10 per cent damage whereas bales made with twine can have 18 per cent damage. Hard core bales with high density (heavier bales) are packed tighter and shed water better than bales with lower density (lighter bales). Soft core bales sustain more damage than hard core bales.
Weather damage to the outer layers of the bale significantly impacts overall bale quality. A five-foot-diameter bale with four inches of deterioration affects 23 per cent of the total bale weight. Overall quality is reduced significantly even if it appears that a small layer of the bale is damaged.
“Spending time to prepare a bale storage site, covering the bales with a tarp or plastic, or placing bales under a shed will provide an economic advantage especially if a portion of this year’s crop will be carried over into next winter’s feeding period,” said Yaremcio. “If a 1,400-pound bale is valued at five cents a pound or $70 per ton, weight loss of 5.7 per cent, a reduction in acceptance (increased waste) by eight per cent, and a 10 per cent loss in digestibility increases the ‘cost’ of providing the same amount of nutrients to the cow at $89.65 per bale.”
If a 1,400-pound cow is fed 40 pounds of hay for 125 days it requires 5,000 pounds (3.6 bales) of “non-damaged/protected” hay for the wintering period. The cost of the undamaged hay at $70 per bale is $252 per head for the 125 days.
“Using the values mentioned above, unprotected hay with the associated weight loss, reduction in quality and increased waste, the cost of providing the equivalent amount of nutrients from the hay and accounting for the losses increases the cost to $322.74 per head,” said Yaremcio.
“The difference in feeding cost is $70 per cow when associated quality and yield losses are considered when storing hay outdoors unprotected from the weather. Harlan Hughes from North Dakota State University calculated that a $1 reduction in winter feeding costs would improve overall profitability of the operation by $2.48.”