Volume 13, Number 8
||This Month in Ag Connection|
Brush Control for Forages and Pastures
occupied by a weed is a space where quality forage could be produced.
compete for sunlight, moisture and nutrition similarly to the way we think
of row crops.
To get your
copy of MP581, contact your local County Extension Office. This
32 page publication is a cost publication and it is a must for your
reference of good management practices.
Nitrogen Fertilization Strategies for Annual Ryegrass Pastures
Livestock operations as far north as southern Iowa are planting annual ryegrass pastures as an alternative to feeding hay in winter. Easy establishment, rapid autumn growth, and high forage quality are making annual ryegrass popular with dairy and beef farmers alike.
Annual ryegrass has several features that make it popular with livestock producers. When planted in late-summer, annual ryegrass can produce 2 to 3 tons of high-quality feed per acre before December and an additional 3 to 4 tons in the spring (Bishop-Hurley et al., 2001). Few other forage crops can produce this much forage for winter grazing. Annual ryegrass is able to achieve these yields in autumn because it continues to grow even after the first killing frost. Cold-tolerant cultivars can grow when average daily temperatures are below 39°F. In addition, the lack of true dormancy in annual ryegrass allows it to grow during warm spells in winter and to resume growth earlier in spring than many perennial cool-season grasses.
In addition to its rapid fall growth, the forage quality of annual ryegrass is outstanding. During vegetative growth, annual ryegrass has crude protein levels that exceed 20% and dry matter digestibility that approaches 75% (Dunavin, 1990). Because of its high quality, producers can successfully use annual ryegrass to feed both stocker cattle and lactating dairy cows. For example, stocker calf gains of 1.0 to 2.7 lb/day are common in the southern USA (Evers, 1995). In addition, milk yields of 85 lb/day have been reported for dairy cows grazing annual ryegrass pastures (Thom and Bryant, 1996).
Seed sales of cold-tolerant cultivars of annual ryegrass in Missouri have quadrupled over the past four years. However, we still have a lot to learn about the management of annual ryegrass for winter pasture in Missouri. There is little research about how to fertilize annual ryegrass that is grown outside the southern USA. Research from other regions suggests that annual ryegrass responds tremendously to N fertilizer, but proper fertilization rates and strategies for states outside the southern USA are lacking.
The overall objective is to determine the optimum rate and timing of N fertilizer for annual ryegrass in Missouri. Specific objectives are:
Objective 1: Determine the optimum N rate at planting to maximize fall growth of annual ryegrass for winter grazing.
Objective 2: Determine if N applications in late winter (March 1) are economical.
Materials and Methods
Forage quality samples showed that annual ryegrass is excellent forage. Samples for 2002-2003 showed that annual ryegrass averaged 24% crude protein and had acid detergent fiber values less than 22%. In short, few other forages can produce such excellent quality feed for winter and early spring grazing.
Soil samples taken to a 40 inch depth in June of 2003 showed that soil nitrate levels, 0 to 10 inches from the soil surface, were nearly 6 ppm when 150 lb/acre of N was applied in both autumn and spring, while all the other treatments had about 2 ppm of nitrate or less. At deeper depths, (10 to 20 and 20 to 40 inches from the surface) soil nitrate levels were less than 2 ppm for all treatments. This suggests that little N is lost due to leaching from annual ryegrass pastures at the rates of N we examined.
(Authors: Robert Kallenbach, State Forage Specialist, Matt Massie and Richard Crawford, Southwest Research Center, Mt. Vernon)
High Impact Forage Management Field Day Scheduled For August
Several state and regional specialists with University of Missouri Extension have collaborated in this research / demonstration effort to show the impact of various fertilization programs on forage yield, forage quality, animal productivity and the economic consequences of these forage fertility decisions. Nine different fertility treatments are being evaluated in this multi-year study.
The program on August 30 will give producers a chance to walk through the forage plots and view changes that occurred based on spring fertilization. Since this research project was initiated in the spring of 2007, limited information is available at this time. However, yield data and other pertinent topics will be discussed following a free evening meal.
The plots are located on Highway 135, just West of Clifton City. The meeting will be held at the community building on the south side of Highway 135 in Clifton City.
Registration for this program is requested. Please register by contacting one of the following MU Extension regional specialists:
This research project is being supported by the Fertilizer and Ag Lime retailers and University of Missouri Extension.
Controlling Intake of Pasture Supplements to Grazing Cattle
As many producers know, salt can be added to feed to limit supplemental feed intake of grazing cattle, but how much is the question?
This could be especially important in dry years or late summer when the pastures decline significantly in nutritional quality and supplementing is necessary.
The Salt Institute is the world’s foremost authority on salt and its more than 14,000 uses. Salt (Sodium Chloride- NaCl) is one of the few minerals cattle crave when it is in short supply: http://saltinstitute.org
Larry Berger, University of Illinois Professor of Animal Science wrote the booklet entitled “Salt and Trace Minerals for Livestock, Poultry and other Animals”. He suggests that the “science” of using salt to regulate intake has been adequately researched but, the “art” of using this technology is still developing, as many producers can attest.
The proportion of white salt in a self-fed mixture can vary from 5 to 40%, which is a huge variation. Do not use trace mineralized salt at greater than 0.05% of the mixture.
Berger suggests if producers want to limit intake from 1 to 2 pounds per day of supplement, they need to add between 30 to 40% salt in the mix, especially for mature grazing cows. For yearling cattle use 5% initially to limit intake to a pound a day. As cattle grow and the grass matures and becomes limited, 20 to 30% may have to be added to the supplement to maintain desired levels of intake.
Besides desired intake, producers also should factor in age and weight of the livestock, the quality and quantity of accessible forage, the grind of the salt (the finer the grind, the less salt needed in the mix), salinity of the water source (the higher the salinity of the water source the less salt that should be added to the feed). As weather becomes more severe, more salt is required because the livestock are less prone to graze. Also consider that if your livestock are really hungry, more salt is going to be required in the mix to keep them from over-eating. The Salt Institute recommends hand-feeding for a week before allowing free choice access to the supplement.
When using salt to restrict feed intake, water requirements can easily increase by 50 to 100%, so make sure your livestock have a plentiful water supply. Livestock can tolerate high amounts of salt in their diets, but they have to have access to water. When winter arrives and the snow starts flying and the temperatures are below freezing, this becomes even more important. Livestock tend to increase their consumption of the salt mixture during these times, so producers need to be aware that placing the salt mixture right by the water supply will restrict grazing distribution.
Another option producers can use to restrict feed intake is adding ionophores such as monesin (Rumensin) or lasalocid (Bovatec) to the supplement mix. Adding an ionophore, according to research, allows the use of a salt concentration that reduces the animal to animal variation in intake, increases average daily gain of grazing cattle and decreases the number of adjustments in salt concentration by half. Muller et al, showed that self-feeding a salt-monesin-supplement gave the same improvement in daily gain (0.2 pounds per day) as hand feeding the monesin supplement without salt. Salt is already a proven intake regulator and can be made even better with the addition of ionophores. Using salt as an intake regulator of self-fed supplements on grass is one management tool that can increase the bottom line of cattle producers.
(Author: Wendy Flatt, Livestock Specialist)
Ag Connection - Ag Connection Newsletter, August 2007
http://outreach.missouri.edu/agconnection/newsletters/is-07-08.htm -- Revised: August 28, 2007