Precautions for Feeding Frosted and Drought-Stressed Forages

Hay bales in the field

Livestock owners feeding forage need to keep in mind the potential for some forage toxicities and other problems that can develop this fall. High nitrates and prussic acid poisoning are the main potential concerns. These are primarily an issue with annual forages and several weed species, but nitrates can be an issue even in drought-stressed perennial forages. There is also an increased risk of bloat when grazing legumes after a frost.

Nitrate Toxicity

Drought-stressed forages can accumulate toxic nitrate levels. This can occur in many different forage species, including both annuals and perennials. Several areas in Ohio have been dry of late. Corn, oat, and other small grains, sudangrass, and sorghum-sudangrass, and many weed species including johnsongrass can accumulate toxic levels of nitrates. Even alfalfa can accumulate toxic nitrate levels under severe drought stress.

Before feeding or grazing drought-stressed forage, send in a forage sample to be tested for nitrates. Most labs now offer nitrate tests, so it is likely that you can get a forage nitrate test by your favorite lab. Several labs are listed at the end of this article that does nitrate testing. This list is for your convenience and no labs are intentionally omitted. Check your chosen lab’s website or call them and follow their specific instructions about how to collect and handle the sample. The cost is well worth it against the risk of losing animals.

See the following references for more details:

Nitrates in Cattle Sheep and Goats (University of Wisconsin Extension) https://fyi.extension.wisc.edu/forage/nitrate-poisoning-in-cattle-sheep-and-goats/

Nitrates and Prussic Acid in Forages (Texas Cooperative Extension) http://forages.tamu.edu/PDF/Nitrate.pdf

Nitrate accumulation in frosted forages. Freezing damage slows down metabolism in all plants, and this might result in nitrate accumulation in plants that are still growing, especially grasses like oats and other small grains, millet, and sudangrass.  This build-up usually is not hazardous to grazing animals, but green chop or hay cut right after a freeze can be more dangerous. When in doubt, test the forage for nitrates before grazing or feeding it. Continue reading

Scout now for cressleaf groundsel in hayfields, or pay the price in May

Cressleaf GroundselBy Mark Sulc, OSU

Some hay producers have been unpleasantly surprised in the past when cressleaf groundsel infestations became evident in their hay fields in May prior to first cutting.  Cressleaf groundsel in hay or silage is toxic to animals, and infested areas of the field should not be harvested and fed.  Groundsel is a winter annual, emerging in late summer into fall when it develops into a rosette that overwinters.  Growth restarts in spring, with stem elongation and an eventual height of up to several feet tall.  The weed becomes evident in hayfields when it becomes taller than the alfalfa/grass and develops bright yellow flowers in May.  The problem with passively waiting until this point to discover that the hay is infested with groundsel is that: 1) it’s too late to control it with herbicides; and 2) hay from infested areas has to be discarded instead of sold or fed, and large plant skeletons are still toxic even if herbicides were effective on them.  Groundsel plants finish their life cycle in late spring, once they flower and go to seed, so it should not be a problem in subsequent cuttings. Continue reading

Fall Forage Management Tips

Alfalfa Field

By Mark Sulc, OSU Extension

Fall is a great time to take care of some very important aspects of managing forage hayfields and pastures. Below is a list of things that when done in the fall can help avoid big headaches this winter and next spring or even next summer.

  • One of the most important things to do now is to pull soil samples and get a soil test. Ask for the 2020 Tri-State Fertility Recommendations to be applied to the results. Apply fertilizer to correct any soil deficiencies and replace nutrients that were removed in hay and silage. Fall is a great time to apply both P and K to prepare established forage stands for winter. Soil sampling and testing are especially critical in preparation for making new forage seedings next spring or summer. Now is the time to apply lime to raise low soil pH levels for next year’s seedings. Soil preparation now will also help you be ready to plant when the first break in the weather comes next spring. Many headaches with forage stands can be greatly alleviated with proper fertility levels. Deficient fertility leads to weak forage stands that are susceptible to stresses (including winter injury) and especially weed invasion. Links to additional soil fertility resources can be found at https://forages.osu.edu/forage-management/soil-fertility-forages. Continue reading

Late Season Forage Harvest Management

Alfalfa Harvest

The best time to take the last harvest of alfalfa and other legumes is sometime in early September in Ohio, for the least risk to the long-term health of the stand. These forages need a fall period of rest to replenish carbohydrate and protein reserves in the taproots that are used for winter survival and regrowth next spring.

 

Many forage producers around the state have been cutting this past week and are continuing into this week. It will be ideal if this is indeed the last harvest of the season. But some growers might try to squeeze out another late cutting, and others have fields that are not quite ready for harvest right now. Like most farming decisions, there are trade-offs and risk factors to consider when making a fall harvest of forage legumes after the first week of September. This article reviews the best management practices and risk factors affecting fall cutting management. Continue reading

Short-Season Forages for Late Summer Planting

Figure 1. Early November growth of Italian ryegrass (left) and oat+winter rye (right) after mid-September planting in Ohio

By Mark Sulc, Bill Weiss

Short-season forages planted in late summer can be sources of highly digestible fiber in ruminant livestock rations. There are several excellent forage options that can be considered for no-till or conventional tillage plantings in the late summer or early fall planting window. These forages can be a planned component of the overall forage production plan. They can be utilized on land that would otherwise sit idle until next spring, such as following wheat or an early corn silage harvest.

Oat or Spring Triticale silage
These cereal forages can be planted for silage beginning the last week of July and into early September. Dry matter yields of 1.5 to 3 tons per acre (about 5 to 5.5 tons at 30 to 35% DM) of chopped silage are possible if planted in late July to early August. Harvesting between late boot, or early heading, will optimize quality. Yields will be lower for plantings made in early September, in which case late autumn grazing would be a more viable option.

The potential feed value of oat silage can be similar to mid-bloom alfalfa.  As a grass, maximum inclusion rates in diets for animals with high nutritional demand (e.g. lactating cows) are less than those for alfalfa, but it is a very acceptable feed.

Spring Triticale is the biotype of the hybrid cross between cereal rye and wheat (there is also a winter biotype that acts like winter wheat). In our research, oat averaged slightly higher fall yields than spring triticale, but this varied across years. If cut at the proper maturity, spring triticale forage has a higher feed value than oat, similar to early-bloom alfalfa. Seed cost for spring triticale is usually higher than oat, but it is later maturing than oat or barley and will maintain its forage quality for an extended harvest window. Continue reading

Late Summer Establishment of Perennial Forages

Preparing a firm seedbed for foragesBy Mark Sulc

The month of August provides the second window of opportunity for establishing perennial forage stands this year. The primary risk with late summer forage seedings is having sufficient moisture for seed germination and plant establishment, which is a significant risk this summer given the low soil moisture status across many areas.

The decision to plant or not will have to be made for each individual field, considering soil moisture and the rain forecast. Rainfall/soil moisture in the few weeks immediately after seeding is the primary factor affecting successful establishment.

No-till seeding in August is an excellent choice to conserve soil moisture for good germination. Make sure that the field surface is relatively level and smooth if you plan to no-till seed because you will have to live with any field roughness for several years of harvesting operations.

Sclerotinia crown and stem rot is a concern with no-till seedings of alfalfa in late summer and especially where clover has been present in the past. This pathogen causes white mold on alfalfa seedlings and infects plants during cooler rainy spells in late October and November. Early August plantings dramatically improve the alfalfa’s ability to resist the infection. Late August seedlings are very susceptible to this disease, with mid-August plantings being intermediate. Continue reading