Welcome to the Spring 2000 Forager

Introduction

Rain that occurs between the time forage is cut and harvested causes both yield and quality losses that reduce the value of the crop as an animal feed and a marketable commodity. Weather-induced losses can be caused by:

· Increased and prolonged plant respiration that reduces soluble carbohydrates and the overall energy content of forage.

· Leaching of soluble carbohydrates, protein, and certain minerals.

· Leaf shattering and loss, removing the highly digestible and high protein portion of the forage.

· Microbial activity that metabolizes soluble carbohydrates, reduces forage energy content, and possibly produces harmful mycotoxins.

· Color bleaching.

How much does rainfall reduce yield?

Several research studies have addressed the effects of rainfall on cut alfalfa. In Wisconsin, Collins measured dry matter losses of 22% when alfalfa was exposed to 1-inch of rain after 1 day of curing. Similar hay cured without rain damage lost only 6.3% of the initial potential yield. Losses appear to be greatest after partial drying of the forage has occurred. In this same study, alfalfa exposed to 1.6 inches of rain over several days suffered a 44% loss in dry matter.

In Michigan, Rotz and co-workers conducted several different studies to examine the effects of rainfall on field cured alfalfa. The first study reported maximum DM losses of 34%. In a second study, rainfall intensity was kept constant at 0.7-in but spread over periods of 1 to 7 hours. Dry matter losses ranged from 4 to 13 percent with highest losses occurring when the rain was spread over a longer duration. Overall, dry matter losses were much lower than those found in Wisconsin experiments although rainfall amounts (in some cases) were nearly 2 inches.

How does rainfall reduce yield?

Three primary factors are involved: leaching, respiration, and leaf loss. Leaching is the movement of cell solubles out of the plant. Components of the plant that are very water-soluble are leached out of the forage and lost during a rain event. Unfortunately, most of these compounds are those highly digested by the animal. They include such things as readily available carbohydrates and soluble nitrogen, minerals, and lipids. About one-half of the dry matter leached by rain is soluble carbohydrate.

Excessive leaching of soluble carbohydrates by rainfall impacts its value to make good silage. Reduced soluble carbohydrates provide less substrate for bacteria involved in the fermentation process. In situations where soluble carbohydrates are in low concentrations, silage additives that provide fermentable substrate might provide some benefit to insure proper fermentation.

Respiration, the breakdown of soluble carbohydrates by plant enzymes, will cause dry matter losses regardless of whether wilted forage is subjected to rain or not. Respiration losses occur while crop moisture levels are above about 30 percent. These losses are reported to be about 3 to 4 percent of the potential DM harvest. Each time cut forages are wetted by rain, respiration is prolonged or begins again in cases where the cured forage is already below 30 percent moisture. In either situation, additional dry matter is lost.

Researchers disagree about the amount of leaf loss that occurs in cut alfalfa as a direct result of rainfall. In a Wisconsin study, leaf loss ranged from 8 to over 20 percent of the initial forage dry matter where rainfall amounts were from 1 to 2.5 inches. In a Michigan study, direct leaf loss was much lower ranging from 0.5 to 4.2%. For both of these experiments, the cut forage was physically picked-up and lost leaves underneath the swath were weighed. In an Ontario study where forage was not hand-manipulated, rain-induced leaf loss was determined to be minimal (less than 0.5%).

Experience and common sense tell us that rain damaged alfalfa is more susceptible to leaf shatter after it dries. Rainfall often means additional raking or tedding to speed up drying; hence, more lost leaves.

How does rainfall intensity and forage moisture affect losses?

Research is conclusive on these two points. Given the same amount of total rainfall, a low intensity rain will result in more leaching of soluble compounds than a high intensity rain. In addition, as forage moisture declines, it is more prone to DM loss from rain. In Wisconsin rainfall studies, the maximum loss in DM (54% DM loss) was a treatment where 2.5 inches of rain fell on hay that was nearly cured.

Does rainfall affect forage quality?

Perhaps nothing is more frustrating than to see excellent quality alfalfa turn into cordwood with each passing rainstorm and subsequent raking. Most rainfall studies agree that wetting of field cured alfalfa has little impact on crude protein concentration., In fact, it is common to see relatively high protein values in comparison to fiber concentrations. However, because rain leaches soluble carbohydrates, structural fibers (acid and neutral detergent fibers) comprise a greater percent of the forage dry matter. Depending on numerous factors previously discussed, the digestibility of rained-on hay may decline from 6 to 40 percent.

My hay is ready to cut but there’s rain in the forecast. Do I cut or not?

This dilemma has faced forage producers for years. Because the impact of rainfall on loss of forage yield and quality varies with timing, amount, and duration, there is no easy answer. The range in economic loss from rainfall for a particular hay crop can range from minimal to over 100 percent, if the forage has to be chopped back onto the field. However, based on previous research studies and applied management practices, we can categorize factors that increase our risk of cutting hay when the weather forecast is somewhat less than perfect. These are presented in Table 1 on page 4.

Finally, computer technology and the Internet now make it feasible for producers to have home access to up-to-date weather radar images. There are many excellent weather information web sites with both multiple radar image selections and updated forecasts. These help to take some of the "guess work" out of forage harvesting decisions.

New Forage Specialist at the University of Minnesota

The University of Minnesota has hired a new forage extension specialist to replace Neal Martin who left to become director of the USDA Dairy Forage Research Center. His name is Paul Peterson. Paul is a UW graduate that obtained his masters and Ph.D. at the University of Minnesota. He has since worked at McGill University in Montreal and Virginia Tech. Some of you may remember Paul's father Don Peterson who was with the UW-Extension for many years. Paul has a lot of Wisconsin ties, and we are looking forward to working with him.

Table 1. Relative Risk of Cutting Hay with Rain in the Forecast

Relative Risk		Explanation
Lower	Higher	Explanation
Forage can or will be ensiled	Forage will be baled	Fewer days needed for curing and swath is often narrower when forage is ensiled.
Small acreage of forage to harvest	Large acreage of forage to harvest	With many acres to harvest, delaying harvest puts more acres at risk of not being cut in a timely manner.
Rain is forecasted for early in the drying period	Rain is forecasted for late in the drying period	Quality losses are less if forage is rained-on while still relatively high in moisture. NOTE: weather forecasts are less reliable beyond two days.
Forecasted rain is short duration and/or scattered	Forecasted rain is "frontal" and/or long duration in nature	Less leaching of cell solubles occurs with short duration, high intensity rainfall than with long duration, low intensity rainfall.
Forage is pure grass or grass-legume mixture	Forage is a pure legume	Losses associated with leaf shattering are less of a concern with grass species.
Standing forage is beyond optimum maturity stage	Standing forage is still relatively high in quality	With advancing maturity, a smaller percentage of the plant is comprised of cell compounds that are most susceptible to leaching by rainfall.
A chemical drying agent and/or preservative is used	No chemical drying agent and/or preservative is used	Effective use of chemical hay drying agents and/or preservatives can speed drying time or allow for harvest at a slightly higher moisture level.
A market or feeding opportunity exists for lower quality forage	A market or feeding opportunity doesn’t exist for lower quality forage	In many situations there may actually be a need for a limited amount of lower quality forage
Lower quality forage can be stored (ensiled) separately from high quality forage	All forage must be stored (ensiled) in same structure	The ability to inventory forage by quality allows for more flexibility in ration formulation and doesn’t force the use of low quality forage for animals with high nutrient needs.

Check out the Wisconsin Forage Council on the Internet at:

http://www.uwex.edu/ces/forage/wfc.htm

AMERICAN FORAGE AND GRASSLAND COUNCIL

ANNUAL MEETING AND CONFERENCE

JULY 16-19, 2000

Schedule of Events:

*Sunday - July 16*
All day registration
8:00am - Noon			- AFGC Board Meeting
10:00am - Noon			- Crop Germplasm Committee Meeting
1:00pm - 4:30pm			- NAAIC Biotechnology Symposium
4:30pm - 6:00pm			- NAAIC Executive Committee Meeting
Noon - 6:00pm			- AFGC Forage Utilization Tour
6:00pm - 9:00pm			- BBQ and Tour - UW Arlington Research Station
*Monday - July 17*
All day exhibits, National Hay Show, National Photo Contest
6:30am - 8:00am		- Industry/Affiliate Council Breakfast
8:00am - 9:00am		- Affiliate Council Meeting
9:00am - 10:00am		- AFGC Submitted Papers
8:00am - Noon		- NAAIC Breeding
10:00am - Noon		- Forage Spokesperson Contest
Noon - 1:00pm		- Luncheon
		FUTURE OF ALFALFA AS A GRAZING CROP		Speakers
1:00pm - 1:05 pm		-Welcome & Overview		Garry Lacefield, U of Kentucky
1:05pm - 1:25 pm		-Grazing Tolerance		Jim Moutray, ABI Alfalfa, Inc.
1:25pm - 1:45 pm		-Bloat		Bruce Coulman, Agri&AgFood Canada
1:45pm - 2:05 pm		-On-Farm Use of Alfalfa for Grazing		Jimmy Henning, U of Kentucky
		Panel Discussion - Future Of Alfalfa As A Grazing Crop In:
2:05pm - 2:20 pm		-Europe		Luciano Pecetti, ISCF, Lodi, Italy
2:20pm - 2:35 pm		-North America		Ray Smith, U of Manitoba
2:35pm - 2:50 pm		-South America		Daniel Basigalup, INTA, Argentina
2:50pm - 3:05 pm		-Discussion		Garry Lacefield
3:05pm - 3:35 pm		-Break
		ROUND-UP READY ALFALFA AND THE FUTURE OF BIOTECH TRAITS IN ALFALFA
3:35pm -3:55 pm		-Biotech Traits in Alfalfa - Overview		Edwin Bingham, U of Wisconsin
3:55pm - 4:15 pm		-Biotech Traits in Alfalfa - European Perspective		Fabio Veronesi, U of Perugia
4:15pm - 4:35 pm		-Round-Up Ready Alfalfa		Mark McCaslin, Forage Genetics
4:35pm - 4:55 pm		-Opportunities for Biotech Traits in Alfalfa Down on the Farm		Neal Martin, USDA-ARS
4:55pm - 5:10 pm		-Discussion		Garry Lacefield
5:10pm - 8:00 pm		-Authors with Posters, Cash bar & Wisconsin Cheese, Live auction-last 45min.
*Tuesday - July 18*
All day - exhibits, National Hay Show, National Photo Contest
6:30am - 8:00am	- AFGC Board Meeting
7:00am - 8:00am	- EFIC, CAIC, WAIC meetings
8:00am - 11:00am	- NAAIC Management & Physiology Symposium
8:00am - Noon	- AFGC Submitted Papers
11:00am - Noon	- NAAIC Business Meeting
Noon - 1:00pm	- Luncheon
1:00pm - 4:30pm	- The Grazing Lands Conservation Initiative
1:00pm - 4:30pm	- AFGC Submitted Papers
1:00pm - 5:30pm	- NAAIC Entomology & Pathology Symposium
4:30pm - 5:30pm	- AFGC Business Meeting
5:30pm - 6:00pm	- Mixer, cash bar
6:00pm - 9:00pm	- Joint AFGC/NAAIC Awards Banquet
*Wednesday - July 19*
6:30am - 8:00am	- AFGC Board Meeting
8:00am - 1:00pm	-Alfalfa/Forage Research Tour

AFGC/NAAIC Joint Meeting Registration

Marriott Madison West - Madison, Wisconsin – July 16-19, 2000

Name: __________________________________________________________

Spouse/Children: __________________________________________________________

Company: __________________________________________________________

Address: __________________________________________________________

City: ____________________State: ______ Zip/Postal Code: ___________

Telephone: ________________________ Fax: ___________________________

Email Address: __________________________________________________________

Membership (check all that apply): ____ AFGC ____ NAAIC

Registration *(all amounts in US dollars)*		Full	Producer	Spouse/Children (Sun/Mon only)
Number of persons		at $120 each	at $35 each	at $20 each
Total Registration
Sunday, July 16
Forage Utilization Tour & BBQ	$25
UW Arlington BBQ & Tour	$10
Monday, July 17
WI Dells Boat Tour	$50
Affiliate/Industry Breakfast	$15
Luncheon	$15	Included
Cash Bar/Cheese	$15	Included	Included	Included
Tuesday, July 18
House on the Rock & Taliesin	$50		N/A
Luncheon	$15	Included	N/A
Joint Awards banquet	$25		N/A
Wednesday, July 19
Alfalfa Research Tour	$15		N/A

Proceedings	$25	Included
Late Fee (after 6/15/00)	$30
Total $US

Please make all checks payable in U.S. funds to: AFGC 2000 Conference

Participants should return this form and registration fees to:

AFGC 2000 Conference, American Forage and Grassland Council, P.O. Box 94, Georgetown, TX 78627

Mastercard and VISA credit card payment will be accepted. Please indicate your credit card number and

expiration date below: If paying by Credit Card, form can be FAXed to 512-931-1166

Name as it appears on Credit Card: ____________________________________________

Credit Card # (Mastercard or VISA only): _______________________________________ Exp. Date ______

Call the AFGC headquarters at 800-944-2342 if you have questions

Upon payment of the registration fee, full registration participants will receive a complete registration

packet, lunch on Monday, lunch on Tuesday, ticket to Cash Bar/Wisconsin Cheese Event, a copy of

the Proceedings of the meeting, admittance to all meetings, exhibits and breaks. Producer registration

will include a registration packet, ticket to Cash Bar/Wisconsin Cheese Event, admittance to all meetings,

exhibits and breaks on Sunday and Monday only. Spouse/children registration will include a registration

packet and a ticket to Cash Bar/Wisconsin Cheese Event.

Accommodations are available at the Marriott Madison West by calling directly to 608/831-2000.

Mention you are with the AFGC/NAAIC Conference to receive the special rate of $89 plus tax for

single or double accommodations. Reservations should be made prior to 6/15/2000.

Volume 24, Number 2, June 2000