Roots & Ridge Report

March in southwest Minnesota is rarely predictable, and this year has been no exception. With temperatures swinging up and down, producers are balancing late-winter chores while starting to think ahead to spring. Many are beginning indoor seedling starts, preparing equipment, and gearing up for a busy season ahead. At the same time, calving season is underway or just around the corner for many operations, keeping long days and late nights a part of the routine across the countryside.

As we move through the final stretch of winter, we also have several upcoming Extension programs you won’t want to miss, including BQA Certification in Pipestone, Tier 2 Cottage Foods Training in Pipestone and a Beef Dairy Short Course. These programs are great opportunities to stay current, earn certifications, and connect with local producers and educators.

This issue also features articles focused on stages of calving and how to manage each by Dr. Brett Kroeze from Windy Ridge Veterinary Service. We will also see a great article from Aaron Prunty from Chandler Coop, informing us about pre-emergence herbicides.

As always, please reach out if you have questions, would like to be featured, or have a topic you’d like to see covered in a future newsletter. We look forward to seeing many of you at upcoming events.

Matti Boomgaarden- Extension Educator

boomg022@umn.edu

MC:507-836-1143

PC:507-825-1193

Registration: https://extension.umn.edu/event/tier-2-cottage-food-producer-training-pipestone

Please contact Melissa Runck for the opportunity to sign up for the 2026 Dairy Beef Short Course. Spots are limited!

Melissa Runck

507-372-3900, ext. 3904 | mkrunck@umn.edu

Herbicides are a complicated topic. Effective, older herbicides have dozens of trade names. The scientific names are hard to pronounce. When you throw in the different combinations, ratios, safeners, and whether or not surfactants are preloaded, it can be a lot to process. With that in mind, I’ll try to focus on pre-emerge herbicides in this article to be more timely and keep things a little simpler.

Pre-emerge herbicides generally work by killing weeds before they come out of the ground. This is accomplished in a few different ways. One way is through imbibition. Imbibition is the process of a seed taking in water to start the germination process. Crop seeds and weed seeds all need to imbibe water to start the germination process. After herbicide is sprayed on the ground and gets rained on, it goes into solution in the top few inches of the soil profile. When weed seeds imbibe the herbicide/water combination, they die before they germinate. If the weed seeds do germinate and then come in contact with the herbicide/water mix as they grow up through the soil, they’ll often still die from that. If conditions happen to work out just perfectly, some pre-emerge herbicides have the ability to “reach back.” This means that after a weed emerges from the ground, a rainfall re-activates, or “re-dissolves” the herbicide back into a solution the weed can take up, and kills the weed after it emerges. Not many chemicals can do this effectively, and the weather has to cooperate.

With that in mind, when looking at pre-emerge herbicides, I generally try to get more than one effective mode of action. Having more than one way of killing a weed in the same tank increases overall effectiveness. I also like to include chemicals with different activation amounts, meaning some will only need ¼” of rain to work, some will need ½”, and some will need ¾” or more. The higher the activation amount required, generally the longer it will last in the soil. An example of this is Zidua Pro. It has Sharpen, Pursuit, and Zidua as active

ingredients. Sharpen takes very little rain to activate, Pursuit needs around a half inch, and Zidua needs ¾” to a full inch to activate.

If you’re curious about what you’re using and don’t want to deal with the scientific names, a good starting point is looking at your herbicide groups. Group 15 and 14 herbicides are usually solid for waterhemp control and generally have longer residual windows. Group 5 and 27 herbicides usually have lower activation amounts and are a good companion to 15’s and 14’s. There are a few group 2 and 4 herbicides that are still effective, but they’re generally strong only in certain situations, and can have spotty performance on waterhemp.

A few cautions: group 14’s can cause damage to soybeans in some situations. A lot of that depends on crop stage and rainfall/activation timing. It generally doesn’t affect yield, but can set back the plant’s growth. Also, MDA has noticed elevated levels of acetochlor (a group 15) in creeks in recent years, and would like for retailers and farmers to help mitigate the problem. MDA’s simplest solutions are to keep acetochlor off fields directly by creeks, and by using other group 15 or 14 herbicides. Fortunately there are other effective options, so if you have a field near a creek, don’t hesitate to reach out to your agronomist or extension specialist.

Stages and Processes of Parturition

There are three basic stages of the parturition process. These stages are separated by specific events during the process, however in reality the stages overlap and are one continuous process. The first stage starts with dilation of the cervix and relaxation of the pelvic ligaments. This process can start anywhere from 4 to 24hr before the completion of parturition. During this stage, the muscle of uterus become more sensitive to the natural hormones present during the birthing process causing the contractions of the uterus and dilation of the cervix. The contractions push the fetus up against the cervix helping to further dilate the cervix. This stage requires an active role from the fetus to proper position itself for expulsion. This stage can go unnoticed, but often there are some behavioral changes. These changes include the dam isolating herself from the other animals, signs of discomfort, elevation and switching of the tail, and/or increased clear mucus discharge from the vulva. These signs are usually more pronounced toward the end of stage one.

The second stage of parturition is usually labeled as the delivery of the fetus. It starts with the fetal membranes (water bag) and the fetus in the pelvic canal or breaking of the fetal membranes. The second stage is completed with the complete birth of the fetus. This stage has traditionally been thought to last 30min to 5 hrs. More recent data from Oklahoma State University and the USDA experiment station at Miles City, Montana show that stage two takes approximately 60 minutes for heifers and 30 minutes for cows. So, when should you give help to a calving cow or heifer? Give heifers a little more time as the process takes longer the first time around. If there is no progression for 30-60 min you should perform a vaginal exam. This means that after the point of seeing the water sack you should see a continuous progression of feet then head and so on. If there is a break in the progression, then she needs a little attention. There are a few signs that can key you into knowing if she is having trouble calving. If there is forceful straining and no progression, or she is up and down repeatedly it may be that there is fetopelvic disproportion (large calf size), malposition such as breech, head or leg back, fetal impaction, or uterine torsion. If the dam stands quietly after you know she was progressing and stops straining it can be a sign of uterine inertia, uterine rupture, or exhaustion.

When performing a vaginal exam, clean the vulva and the area around the vulva with soap and water to decrease the chance of introducing fecal contamination in the vaginal or uterine cavity. Use protective gloves as the uterine fluid may contain pathogens that can cause irritation to the skin or cause human disease. You should always use a lubricant to assist with easy entry of your gloved hands and expulsion of the calf. I prefer the chlorhexilube as it is a disinfectant and a lubricant at the same time. First, you should feel for the cervix to see if it is dilated. If it is fully dilated, you will not be able to easily feel it. The next thing is to feel for the calf. You should be able to have a straight line to the calf without any twists of folds in the cervix or vagina. If it is not a straight line, then the uterus is probably rotated, and you are dealing with a uterine torsion. The last part of the exam is to determine how the calf is positioned. It should be positioned with the front legs first and then the head in between them. If it is not, then some repositioning will be needed.

There are a few things that cannot be done with repositioning and pulling a calf. It does not work to change a posterior position where the back legs are coming first into an anterior position where the front legs and head are coming first. There is simply not enough room to accomplish this. You cannot deliver an anterior presentation unless both legs and head are through the cervix. It is important to make sure the head is coming with the front feet before you start pulling or you will cause the head to slip back and make the process much more difficult. You will have contraction and shrinking of the uterus on the calf making it hard to push the calf back to get the head repositioned. You cannot deliver three or more legs through the cervix. It may be three legs of the same calf or legs from two calves, either way it won’t work to pull three legs through. Very rarely can you deliver the calf with the headfirst without the front legs. It is much easier to push the calf back and retriever both front legs before proceeding. It is important to know what calving difficulties you are comfortable being able to do and when you should call your veterinarian for help. Time can be of the essence in these situations so knowing early when you need to call is beneficial.

The third and final stage of parturition is the expulsion of the placenta or fetal membranes. It normally takes less than 8-12 hours for these membranes to be shed. Do not attempt to manually remove these membranes as it is detrimental to the uterine health and future fertility of the cow. Antibiotics may need to be administered to guard against uterine infection if there is contamination into the uterus from going in and out or from retained placentas. The placenta will slough out in 4-7 days.

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