Storage of Hay Influences Quality
The hay is cut. Is it to be made into chopped / round bale silage or into dry hay? There are advantages and disadvantages of each system and associated costs. How the hay is baled and stored will also impact overall quality. This article discusses some of the factors to consider.
Chopped haylage or silage removes most of the uncertainty caused by weather because the crop is harvested within a couple days. Moisture content for chopped silage should be 60 to 65% and 45 to 55% for round bale silage. With limited time in the swath, dry matter losses caused by respiration are lower than for dry hay. Leaf loss is generally reduced to 10% compared to 25% with dry hay. This results in higher quality feed with higher amounts of soluble sugars and protein in the silage or haylage compared to dry hay. With lower leaf loss, yield per acre can be 5 to 10% higher than for dry hay. Also, protein and TDN can 1 – 3% and 2 -4% higher respectfully.
With any type of silage, excluding oxygen (air) from the pit, pile, tube or wrapped bale to minimize aerobic bacteria growth is key to having a high-quality end product. Cover the pile or pit as soon as possible. At the end of the day, cover the portion of the pile or pit that is completed. Do not wait until all the silage is harvested. Bales need to be wrapped or placed into a tube within 12 hours of being made. Again, minimizing exposure to air is key. Cover with a minimum of 6 ml plastic for pits and piles, or multiple layers of plastic to obtain a 6 ml thickness for wrapped bales.
The safe moisture content for making dry hay depending on the size and type of bale. Large square bales are vey dense and therefore moisture content above 12% can result in mold forming in the bale. Large hard core large round bales are less dense than the large squares, and large soft-core bales are less dense than the hard-core bales. Moisture content can be as high as 16 to 17% in the soft-core bales. The critical factor is that the hay must be cured before baling. This occurs when the moisture within the stem has evaporated and can take 5 to 8 days depending on weather conditions, crop yield, and field moisture.
Yield and quality losses occur when hay is cut, raked, baled and during storage. Cutting can result is a 2% yield loss. There is a 5% yield loss each time hay is turned. Baling losses increase in proportion to the time it takes to make a bale. A 12 foot windrow can have a 14% yield (shattering) loss. When 3 windrows are combined prior to baling, losses are reduced to 5%. It is the leaves and flowers that are lost. The parts of the plant that have the highest quality. Weather damage further reduces yield. One inch of rain on hay in the swath causes a 11.7% reduction in yield. It also reduces the digestibility of the hay by 6%.
Storing hay outdoors without any protection from the weather creates many problems. Dry matter losses due to shrink can be as high as 15 over the first winter. Bales made with sisal twine has double the loss than plastic twine (19 vs. 10%). Bales made with net wrap has a 7% loss compared to bales made with plastic twine. Having the net wrap cover the shoulder of the bale and 3 to 6 inches of the flat side of the bale helps to shed rain and reduces the losses to 4%. Wrapping dry hay in plastic or storing under a shed reduces shrink to 2%.
There are times when white mold is found in the silage or haylage or dry hay. This is caused by dirt contamination. Either the cutting bar or the pickup on the baler or silage cutter was set too low and this introduced dirt into the swath. Adjust the equipment so this does not occur.
Stacking does make a difference
Preventing moisture from migrating into the bales from rain or melting snow reduces bacteria, mold and fungi growth which reduces damage. Three common methods of stacking hay are compared
The pyramid stack creates the most damage. Moisture that runs down off the top bale migrates into the middle and bottom rows. Damage occurs where the bales touch.
The mushroom stack results in less damage than the pyramid style. Moisture that runs off the top bale migrates into the upper end of the bottom bale creating damage. Increased soil to bale contact allows more moisture to enter the bottom of the lower bale.
Individual bales stacked in a row with 4 to 6 inches space between the bales results in the least amount of damage. Any rain that falls or snow that melt can run off the bale surface minimizing damage
Hard core bales with a high density (made tight) are able to shed water better than soft core bales or bales with lower density
It may appear to the eye that three or four inches of damaged hay in a 5 foot bale is not significant. Work done by Buckmaster (1993) found that 3 inches of spoilage impacts 17% of the hay and 4 inches impacts 22% of the bale.
Improving the physical characteristics of a bale and reducing weathering damage to stored hay can reduce bale shrink, quality loss and the overall cost of feeding the cow herd over winter.
Yaremcio Ag Consulting Ltd.