Alternative forage cropping recommendations outlined

Ray Mueller
With alternative forages, such as sorghum, be aware of how they fit the differing nutrient needs and health of milking cows, heifers, and dry cows.

REEDSVILLE – With an array of forage cropping challenges in 2019 and no guarantee of any improvement in 2020, how might alternative forages fit for harvesting, storing, and feeding?

That question was tackled by James Downey of CP Feeds at Valders and Bill Eberle of Chr. Hansen Labs in Milwaukee at the Manitowoc County Forage Council's annual dairy cattle feeding and management day.

Downey reviewed “the tough year” of 2019, asking if anyone was “ready for it to be over” as he noted how it started with widespread winterkill of perennial alfalfa stands followed by periods of excess rainfall that interfered with planting and harvesting as farmers tried to make up for the lost yields suffered earlier in the growing season.

Filling the forage pipeline

As a result, not only are forage supplies likely to run short on many farms before new crops can be grown and harvested locally but the autumn planting of forages for early spring harvest was prevented in many cases and manure application before the onset of winter was difficult, Downey observed. In addition, the occurrence of three or four ground freeze and thaw episodes already in the late autumn does not bode well for the winter survival for some of the remaining alfalfa acreage, he stated.

To fill in that potential gap on alfalfa forage again in the 2020 cropping year, there are dozens of alternative forages to chose from to boost the feed supplies, Downey noted. He listed opportunities such as double cropping, cover crops, breaking up of customary crop rotations, accommodating manure applications throughout the growing season, and obtaining good quality heifer and dry cow feed along with milking cow ration ingredients in some cases.

Alternative forage lineup

Among the forages which have crude protein and relative feed values (RFV) that are suitable for heifers, dry cows, and possible inclusion in milking cow rations are the rye, wheat, and triticale planted in the autumn and harvested in spring along with spring-planted barley, oats, spring wheat, triticale, and peas mixed with each of those except the wheat, Downey indicated.

For planting in June and July, the candidates are forage sorghum, rapeseed, soybeans for harvest as forage, sudangrass, the sorghum-sudangrass hybrid, and mixes of soybeans with grain sorghum and forage sorghum, Downey continued. He also suggested multiple planting dates for these and mentioned turnips for a planting during the first half of summer.

Following a winter wheat or vegetable crop harvest, the candidates for an August planting with an October harvest are the spring varieties of oats, barley, and triticale along with winter wheat and a mix of oats and winter wheat, Downey stated.

Alternative forage choices

With those alternative forages, be aware of how they fit the differing nutrient needs and health of milking cows, heifers, and dry cows, Downey stressed. If there's no alfalfa haylage and brown mid-rib corn silage is fed, forages such as forage sorghum, the high fiber sorghum sudan, hybrid sudan, and pearl millet would be a good combination for milking cows, he suggested.

With the milking herd, be sure to monitor the feed intake and efficiency, especially in how they convert into the pounds of solids in the milk that is shipped and how that affects the milk check, Downey stated. For boosting milk protein, supplement with methionine and look for results in about two weeks, he indicated.

High quality heifer feed can be obtained for forages up to 120 in RFV and close to 16% crude protein, Downey noted. For dry cows, a top concern is to limit the forages to those with low potassium and an RFV also below 120, he added.

The goal with heifers is to have them grow tall rather than wide with the approximately 15 to 16 protein ration while with dry cows the tasks are to provide well-processed feeds, to be aware of the feed hygiene and palatability (no butyric acid with forages that are too wet), to keep potassium at below 1.3% of the diet, to add anion salts as necessary, and to verify the nutrient values of the forages with a wet chemistry test only, Downey continued.

Experiences from 2019

Referring to the data from Dairyland Laboratories on thousands of forage samples of oat/pea, ryelage, triticale, and sorghum sudan, Downey and Eberle cited the great differences in the numerical values – two, three, and even four to one in some cases — on the contents of those forages. They called special attention to the values for protein, fiber digestibility, and potassium.

Based on the challenge from the loss of alfalfa acres at the start of the 2019 growing season, Eberle expected the possibility of “a seismic shift toward alternative forages” during the year in Wisconsin — as is already the case in states such as the Dakotas and Indiana.

But it didn't turn out that way and there are no more answers on growing alternative forages now than there were by May of 2019 because of variable results during the year, Eberle stated. In some cases, alternative forages saved the cropping year for farmers while for others the effort was a disaster, he reported.

In addition to the sorghum sudan and other crops that were harvested after they had frozen, Eberle held out the possibility of harvesting stalkage from some of the many thousands of acres of still standing corn as a source of bedding to replace the grain straw bedding that could become very expensive.

Harvesting challenges

One concern with forage (the sorghum crops) with a height/length of four feet or more is how to harvest them, Eberle pointed out. In addition to requiring slow field travel, he suggested cutting at a 45-degree angle to the planted rows, merging with a rotary rake, and realizing that the sorghum forage which is good feed for dry cows is wearing on choppers.

As a feed, Eberle observed that baleage has become quite popular in northeast Wisconsin in part because it allows for a wider harvest window. Depending on how it is to be fed, particle length can be a drawback with baleage as is the expense of the plastic wrap and the task of disposing of it, he said.

Putting weight in packing

Eberle, who had a management stint with Rosendale Dairy in western Fond du Lac County before joining Chr. Hansen Labs in 2018, is particularly concerned about inadequate packing of silage in bunkers and on piles. He believes there is a strong correlation between dairy profitability and the practices which would ideally pack 20 pounds of forage dry matter into a cubic foot, thereby enabling good fermentation and reducing the losses during storage.

Compared to the rush to get forage from the field to the storage unit, there is inadequate packing in too many cases, Eberle asserted. He subscribes to the 800-pound rule, meaning that there ought to be 800 pounds of tractor weight on the pile or bunker for every ton of forage that arrives. For example, a loading rate of five loads per hour at 25 tons per load would require 100,000 pounds of packing tractor weight, he noted.

To a question about tire size on the packing tractors, Eberle said the key is the amount of weight applied rather than tire width – “it's weight over time.” As the plastic cover begins to be placed, be sure to make final packing trip on the top, he advised.

Eberle also touted the value of inoculants with alternative forages, especially with high moisture content, to aid fermentation, lower pH, and reduce dry matter loss. An inoculant would cost about 70 cents per ton for a forage valued at $62 per ton as fed, he indicated.

Anti-nutritional factors

In addition to the positives with alternative forages, Downey reminded growers about the extreme dangers from the Prussic acid that develops in the wake of a freeze. He explained that the acid is a cyanide gas which blocks the flow of oxygen in blood, causing animal death from asphyxiation.

The potential for this poisoning is low with sudangrass, intermediate to high with sorghum-sudan hybrids and forage sorghum, and high to very high with grain sorghum, Downey pointed out. To avoid those risks, cut at a minimum height of 18 inches, allow at least three weeks for the gas to dissipate, and resolve any doubts with a laboratory test, he stated.

As farmers anticipate 2020, they need to determine their remaining feed inventories, be aware of the possibility of alfalfa winterkill again, and account for the appropriate feeds for dry cows and heifers, Downey advised.