The 2013 weather continued the forage woes of U.S. dairy producers. The late-March warm-up in the upper Midwest, followed by freezing rain and then a major cold snap in early April, led to winterkill of alfalfa and ryegrass across large sections of central Iowa, through southern Minnesota, central Wisconsin and into central Michigan.
This area represents nearly 20 percent of the U.S. dairy cow numbers. Several areas in Pennsylvania and New York also experienced small pockets of winterkill of alfalfa in key dairy areas. This weather severely decreased the acres available for first-cutting haylages and lowered first-cutting yields.
Then this same area was inundated with rain through the spring months, resulting in delayed harvest and poorer-quality haylages. To add further insult to injury, these regions had a cold snap at the end of July, virtually stopping the growth of the next cutting.
I had a central Wisconsin dairyman tell me the temperature was 38ºF on Sunday, July 28, and they could not find enough clothes in the parlor that morning to keep warm. Tonnage suffered yet again following this cold snap.
ncreased overseas forage exports from California, Washington, Oregon, Kansas and Nebraska continued to cut into current U.S. forage inventories. All of these factors resulted in 2013 forage shortages and kept the price and demand for dairy-quality hay at 2012 levels.
However, all is not lost. The extremely mild fall that followed allowed producers to get an additional cutting of hay that they had not planned on with the late start to the season.
Those who planted a summer forage (such as sorghum-sudan or teff grass) were able to take an additional cutting well into the late fall, adding extra tonnage to their inventories. The mild fall also allowed many dairy producers to plant winter small-grain forage for early spring harvest that will add to their forage inventories.
These high-quality, highly digestible forages continue to make inroads into U.S. dairy diets and cut energy cost in rations. Many producers are considering planting spring forages (oats and barley) to add to forage inventories if they can find seed in a very tight seed market.
Then there are two corn silages
The 2013 corn silage harvest saw a tale of two fields. Those acreages that were late-planted saw decreased tonnage (20 to 24 tons as-fed), proper moisture, increased fiber digestion (4 to 5 points better than 2012), starch values close to last year’s drought-stressed corn silages and better starch digestion rates (80 to 85 percent on seven-hour IVSD) than last year.
The tonnage drag on the later-planted corn following the wet spring will hurt many farms’ total forage inventory and force dairy producers to sell cows, buy expensive hay or plant an early harvested forage.
While the quantity is not there, quality is. This corn silage is very good nutritionally, with above-average fiber (NDFD) and starch digestibility, and should allow for excellent milk production.
Much of this corn silage was put up at excellent moistures, resulting in good packing densities, which will lower the risk of yeast and molds forming while in storage.
Because of the late fall, this corn silage had time to grow tall but lacked ear fill. This resulted in the fodder diluting down the starch content of the forage with lower starch values than producers wanted (and very similar to 2012’s shortened plant with small-ear, drought-stressed corn silage).
I had many producers disappointed in their 22 to 25 percent starch corn silage when they saw the green fields as compared to the previous year.
I quickly reminded them that we plant corn silage for forage, and if we really wanted high-starch corn silage, we could simply leave 4 foot of it in the field and double the starch content.
They quickly realize that leaving half of the tonnage in the field is not a sound economic decision and figure they can buy a little energy to make up for the lower starch in the corn silage. Wise dairy producers.
The other corn silage
Then there are the other fields that were just slightly delayed getting the corn planted but got slapped by the weather in the fall. A warm front that marched across most of the U.S. in late August and early September 2013 hurt the U.S. dairy industry, not only with a major drop in milk production but also dried the standing corn at an alarming rate.
Most U.S. dairy producers were chopping corn or just about to start when the furnace-like warm-front blast spiked temperatures, and its accompanying high winds sucked the moisture out of the corn plant at a 2 or 3 percent point drop per day.
uddenly corn that was ready was too dry, corn that dairy producers thought was a week or two away was ready now, and guys that were chopping wished they were done.
Much of this corn silage is on the drier side and at an increased risk for molds and yeast. I have not seen or heard of issues yet, but I am worried about this spring when the temperatures warm up and the excess trapped air in the drier corn silage will allow the yeast to start to grow.
Yeast growth will raise the silage pH, allowing mold spores to grow. Certain molds will produce toxins as their defense mechanism and can be detrimental to cows.
Plastic maintenance needs to be a high priority on this type of drier corn silage. Holes, rips and tears need to be repaired quickly to prevent this chain reaction from starting.
The drier corn silage also saw a drop in starch digestion. This is showing up on forage lab tests with lower seven-hour IVSD (in vitro starch digestibility), with increased starch in manure analyses, increased MUNs in the tank and overall less milk production.
Adding a couple of pounds of pure corn starch, cookie meal, bakery byproducts, hominy, wheat or sugar will offset the slower starch digestion found in this drier corn silage.
As time goes along, the starch in the corn silage will become faster, and these faster-digesting feedstuffs may not be needed. The drier the corn silage is, the longer this time period will be.
Fiber digestion in this drier corn silage is about what we saw with 2012’s drought-stressed corn silages. A taller plant means more lignin to keep the plant upright. Lignin is indigestible but is part of NDF, so we saw lower NDFDs in 2013.
A taller plant also means higher tonnages, and most dairy producers would agree that they saw great yields last fall with 25 to 32 tons per acre. This tremendously helps corn silage inventories that had been depleted from feeding higher-corn silage diets over the winter to stretch existing haylage inventories.
Haylage inventories had to be stretched a month longer than expected with first-cutting delays. Corn silage inventories had to stretch a month longer than planned, with corn silage harvest delayed as a result of late corn planting.
Dairies that traditionally had two or three months’ extra corn silage inventories were back to the days of counting tons and days on a calendar to be sure they did not run out of corn silage inventory.
The forage crop of 2013 will continue to bring challenges to dairy producers. Inventory shortages and poor digestion of both starch and fiber will make it another year with feeding difficulties.
Dry corn silage could increase these challenges. A mild fall coupled with early spring forages could be the break dairy producers have been looking for. PD
Steve Massie
Western Field Nutritionist
Renaissance Nutrition Inc.
