ISU Extension
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Northwest Area Extension

February 2004

In this issue
Weed Thoughts for 2004
Beef News
Tips on Dips
4-State Dairy Management Seminar
Swine Production Analysis

Weed Thoughts for 2004
by Joel DeJong, ISUE Crops Field Specialist

The "Roundup Ready" system provides a lot of flexibility in weed management compared to conventional programs.  The large application window allows good weed control with simpler programs and fewer weed control passes through the field. It also allows you to control weeds in seasons when adverse weather conditions limit the appropriate time in the field.  

Most growers consider their weed management program a success if their field is relatively free of weeds at harvest.  However, this objective does not guarantee that weed-related yield losses were prevented.  Some research indicates that heavy weed competition in soybeans as early as the V-3 stage of growth (2 emerged trifoliate leaves) can reduce yields up to 1% per day under extreme situations.  Granted, if weather is great, and weed pressure is low, then yield losses likely start later.  But, early season weed control can be critical to maximizing yield - and income. 

Weeds that emerge after the soybeans are up cause less damage than weeds that emerge with or before the soybean.  Therefore, application timing should probably be based on the effects of early emerging weeds on crop yields.  The practice of waiting to apply these products so that only one application is needed can work for some (under good weather and low weed pressure), but in stressful times and heavy weed pressure situations, an earlier application might be warranted.  For a better discussion on this topic, see Extension Weed Specialist Bob Hartzler's article on the ISU Extension Weeds Page: http://www.weeds.iastate.edu/ , or look at this and other articles in the December 2003 edition of the ISU publication PM 1898 "Issues in Weed Management for 2004" available at your Extension office, or at this web site: http://www.extension.iastate.edu/Publications/PM1898.pdf

Dr. Hartzler also discusses the statement on many labels that says "Apply When Actively Growing" on the same web page and in the same publication.  Data from a Canadian study has shown that when growth of the crop studied was slow, the control level of weeds was reduced when treated with herbicides.  Each spring it seems there are time periods of reduced crop growth due to low temperature or moisture, frost, hail or herbicide injury.  In most cases weed control will be better if the crop, and therefore the weed, is healthy again before herbicides are applied.  Allow crops and weeds to recover before applying herbicides, if possible.  If not, then increase rates (if allowed by the label) to help boost herbicide performance.

Also in that publication are charts that rate a wide range of products for their effectiveness on several different types of weeds.  Selecting herbicides to match your weed pressure?  Use these tables to give some help.

Although weed management seems easier than it used to be, this issue still needs to be managed closely to be most profitable.  Spend a little time reviewing these topics in the publications mentioned above before the next growing season begins!

 

Beef News
by Beth Ellen Doran, ISUE Beef Field Specialist

Cow-Calf Refund - The Iowa Department of Revenue and Finance will be offering a refund to Iowa cow-calf producers.  The refund will apply to breeding bulls, bred cows and bred heifers in inventory on Dec. 31, 2003 and is computed on the basis of corn equivalents consumed.  All claims must be filed within 10 months of the end of 2003 with the taxpayer's income tax return.  Refunds for the year 2003 will be issued by February 2005.  To obtain a refund form (IA 132 2003) go to the web at http://www.state.ia.us/tax/forms/indinc.html and scroll down to IA 132, Cow-Calf Refund.  Select the 2003 form.

The Aftermath of BSE - Most of the news surrounding the first identified case of BSE in the U.S. has been factored into the market, and cattle prices have stabilized.  However, some important items have evolved. 

Agriculture Secretary Ann Veneman announced new rules to help safeguard the U.S. against BSE.  All beef processors will be required to identify and segregate animals by age to ensure that Specified Risk Materials (SRMs) from cattle 30 months of age or older do not enter the human food supply.  The Food Safety and Inspection Service is designating the brain, skull, eyes, trigeminal ganglia, spinal cord, vertebral column (excluding the vertebrae of the tail, the transverse processes of the thoracic and lumbar vertebrae, and the wings of the sacrum) and dorsal root ganglia of cattle 30 months of age and older as SRMs.  These SRMs are declared inedible and are prohibited in human food.  As confirmed by CSU Meat Scientists, this new rule applies to T-Bone steaks.  Thus, only T-Bone steaks from animals under 30 months of age can be sold for human consumption.

To ensure compliance with these new rules, packers, under USDA supervision, will be conducting dental checks to confirm the age of animals.  Because of the diminished value of animals older than 30 months, along with the costs associated with segregation and the devaluation of finished products, those animals will be discounted accordingly.

Additionally, all non-ambulatory animals presented for slaughter must be condemned.  This means that an animal with a broken leg that is not able to walk and is delivered to the local locker will not be able to be harvested and processed.

For up-to-date information on BSE and the cattle industry, please refer to the Iowa Beef Center website at <http://www.iowabeefcenter.org>.

 

Tips on Dips
by Chris Mondak, ISUE Dairy Field Specialist

Recommendations for Wintertime Teat and Udder Care for Dairy Cattle - As many dairy producers in the Upper Midwest know, teat end damage that occurs in the winter months can cause mastitis and high SCC problems into summer and fall. Leo Timms, ISU Extension Dairy Specialist, offers these research-based guidelines to reduce the chance of winter teat end damage:

1. There are many products on the market, each with their own selling points. The key ingredients that MUST be in your chosen teat dip include a good germicide and skin conditioner (10%).  Do not add extra glycerin or conditioner – it alters the formulation and makes the dip less effective!

2. Before sending cows out of the milking area, take a second to dab or wick the teat dip droplet from the teat end. This greatly reduces the chance of teat end chapping and subsequent mastitis. This is especially important under the following conditions: cows directly exposed to the outside elements post milking, cows exposed to a wind chill outside or in the walkway back to their stalls, and days when the temperature is extremely cold (20 degrees or lower).

3. Comments on various formulations available:
   Barrier dips:  Not recommended in very cold weather or high exposure situations – since they take 20 minutes to dry, they increase the risk of chapping.
   High emollient dips (greater than 70% skin conditioner): – Minimize freezing risk post milking, but may cause teats to stay wetter and stickier longer, thus increasing risks for chapped or dirty teats.
   Powder based dips: - Newer formulations have good germicide and skin conditioner attributes. Stalls must be kept clean and dry to avoid wicking of moisture onto teats.
   Salves: Not the best choice because germicide and skin conditioner qualities are not proven, and tend to become contaminated with bacteria such as staph aureus. The greasy quality of salves tends to make dirt cling to the teats, and to make milking equipment surfaces greasy and dirty as well.

4. Is it best to just not dip teats in the winter?  To choose to not dip is the WORST DECISION! Teat skin is wet and unprotected when the milking units comes off. Sending cows out without a teat dip increases the risk of dehydration, teat chapping, and bacterial colonization on teat skin.

Coupling good decisions on teat dip choice and application with good management practices such as proper milking procedures, stall maintenance to achieve clean, dry stalls, and minimizing direct exposure to wind chills can greatly reduce the risk of wintertime teat end damage, and help you achieve your herd SCC and mastitis incidence goals. Questions? Call Chris Mondak, 712-737-4230 or Leo Timms, 515-294-4522.

4-State Dairy Management Seminar;  February 17, 2004 - NCC- Sheldon

Mark your calendar for this popular dairy program that ISU Extension hosts in NW Iowa every two years. This event is noted for its excellent speakers, research-based information, and good sponsor support.  The program this year features:

Mike Hutjens, Jeff Reneau, Leo Timms, and Paul Fricke.

Registration and exhibit-viewing start at 9:30 am, with the program starting at 10:30 am.  Pre-register by February 9 for the best rate ($35.00/person and $25.00 for 2^nd person from same farm or business).  Questions? Call Sioux County Extension, 712-737-4230.

Swine Production Analysis
by Dave Stender, ISUE Swine Field Specialist

Cost of production analysis can be deceptive and difficult to properly interpret.  Of course total sale weight produced in the operation has a huge impact on the bottom line, while margin per pound sold is also vital. The production characteristics that most influence profitability are growth rate, feed conversion, cost of feed ingredients, mortality, group variation and farrowing rate.  Listing the factors involved is the easy part, although some care and thought needs to go into picking the factors as well.  For example, average daily gain and days-to-250 measure the same thing.  Litters/sow/year and farrowing rate basically measure the same characteristic.  It is vitally important in the final analysis to pick only one measure for each important characteristic to avoid overestimates of financial impact.

Other factors need to be examined carefully as well, because some vary greatly in importance from farm to farm. Growth rate is huge on farms where the schedule is tight, but not as important if there is extra space in the grow-out facilities. 

Productivity is less important in a system that has extra gestation space.  Remember, the sow herd cost is a relatively small percentage of the total cost compared to finishing cost. Output and production flow on the whole operation basis is more important than individual sow productivity. 

For example, assume an operation has enough finishing space to sell up to 1000 head per year, yet only produces 750.  That operation loses the potential profit from 250 pigs or $7,500 on a $40/cwt market.  It also increases non-feed costs by 25% which results in about $10 per head higher production cost on 750 head or $7500.    Total loss in profit adds up to $15,000.  This operation has normal productivity of 20 pigs/sow/year for the 50 sows in the herd, and that productivity drops to 15.   In this case of a fixed number sow herd, every pig/sow/year is worth $3,000.   

Operation number two adds 17 more raised gilts to produce an extra 250 pigs per year. This operation then reaches 1000 head for every 67 sows which maximizes grow-out efficiency. The seventeen gilts would cost about $3000 per year. The three thousand dollars comes from an extra $1700 to feed, $1000 genetic and $900 yardage cost at $.15/day for a year, while subtracting 1700 pounds of sow weight gain worth $600 at $.35/lb. Each extra pig per sow per year is worth $600 in this operation. 

An extra pig per sow per year could be worth five times more than it is for a neighboring operation.  The same type of variation can occur in growth rate, variation and mortality.  Each individual operation needs to know their herd specific numbers and how to calculate the profit impact for each production trait in their operation. This is the best way to make consistently superior economic decisions. ISU Extension can run an analysis for your operation. Let us know if you are interested.

Hold February 17 for a regional swine conference at Cherokee WIT.   Topics include controlling feed cost, making health decisions, managing the sow herd and marketing.  Check with your county extension office or call Dave Stender 712-225-6196 for more information.

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