Cow-Calf Corner | June 13, 2022
Beef Cow Slaughter Continues Unabated
Derrell S. Peel, Oklahoma State University Extension Livestock Marketing Specialist
Through the end of May, beef cow slaughter for the year-to-date is 15 percent higher year over year. With nearly half the year over, it is very likely that the annual beef cow slaughter total will be up by double-digits year over year. While some drought reduction regionally has improved pasture conditions (Oklahoma is a good example), range and pasture conditions nationally are still at the worst level ever for this time of year. In other areas drought continues to expand. Colder than normal weather in northern regions this spring and reduced fertilizer use everywhere are also contributing to delayed and reduced pasture and hay production. The most recent weeks of slaughter data have year over year beef cow slaughter increasing rather than decreasing as the reality of reduced pasture and hay production becomes clear moving into June.
All of this is in addition to a 9 percent increase in beef cow slaughter in 2021 over the previous year (the result of drought) and a net herd culling of 11.6 percent. Drought, which began regionally in 2020, expanded and accelerated herd liquidation in 2021, leading to a 2.33 percent decrease in the beef cow herd last year. The beef cow inventory peaked recently in 2019 at 31.69 million before declining to the January 1, 2022 level of 30.13 million head, a 4.9 percent decrease in three years.
What can we expect for the beef cow herd in 2022? The change in the beef cow herd each year depends on the net impact of heifer retention and cow culling. Heifer retention for 2022 is already determined at this point. We know that we started the year with 5.61 million beef replacement heifers, 18.6 percent of the Jan1 beef cow inventory. Of those, 3.41 million head are expected to calve in 2022. Cow culling relative to the available replacement heifers will determine the change in the herd inventory this year.
Given beef cow slaughter so far this year a significant level of culling is guaranteed. In order for the level of beef cow slaughter to just hold steady with last year, beef cow slaughter for the remainder of the year would have to drop 9.4 percent year over year. That is extremely unlikely. Note that beef cow slaughter in 2021 was 3.56 million head. A 2022 beef cow slaughter level equal to that implies herd liquidation given the 3.41 million heifers expected to calve this year, even if every one of those heifers actually entered the herd. Just holding cow slaughter for the remainder of this year equal to last year would still result in an annual increase in cow slaughter of 5.9 percent because of slaughter so far this year. That would result in a record herd culling level of 12.5 percent in 2022. That also seem unlikely at this point. The current level of beef cow slaughter suggests a culling rate in excess of 13 percent this year and a potential beef cow herd decline of one million head or more.
Is it too late for 2022? That point is rapidly approaching. Just a few more weeks of the current level of beef cow slaughter will seal the deal for this year. It is also not clear what is happening with the unbred replacement heifers from January 1. Those heifers should be getting bred this year to calve next year. However, drought may be shifting them into feeder markets with implications for a smaller inventory of heifers calving in 2023. Significantly improved conditions in the second half of 2022 could allow for more heifer calf retention this year, with implications for potential herd rebuilding in 2024.
Mark Z. Johnson, Oklahoma State University Extension Beef Cattle Breeding Specialist
One of the realities of beef production in Oklahoma is dealing with significant fly populations. The Oklahoma beef cattle industry loses millions of dollars each year due to external parasites. Blood loss, irritation and annoyance lead to reduced levels of performance due to flies. Horn flies, Stable Flies, house flies or horse flies must be controlled. With recent rains, humidity and warmer temperatures most of Oklahoma now serves as an ideal breeding ground for these annoying pests that rob profit potential from beef operations.
Horn flies are the most significant external parasites of cattle causing an estimated $1.8 billion impact on the cattle industry as a whole annually. Although this fly is small and feeds from the back down the side and onto the belly of cattle it is the sheer numbers of these flies on a per animal basis that cause stress to cattle. Considering the number of times an individual horn fly will feed on an animal throughout the day is 25 times per day then those numbers will certainly cause significant stress to cattle. In a cow – calf system the horn flies on the cow or heifer impact weaning weights in calves due to the impact of that stress causes decreased milk production but when combined with direct fly numbers on the calf then the impact can be greater.
Stable flies are usually a problem in cattle from March through early May and typically decrease when temperatures increase from June through August. The stable fly preferably feeds on the front legs of cattle and occasionally on the belly of animals. Their bite is very painful to cattle causing significant behavioral reactions such as leg stomping, bunching and standing in water for long periods to avoid the bites. One of the preferred breeding sites for stable flies are old hay feeding areas that never dry out or retain moisture for several months. In fact, a typical ring / round bale feeding area can provide sufficient habitat for approximately 60,000 stable flies per week. Treatment thresholds for stable flies are 10 flies per animal when observing just the front legs of animals. These numbers will cause significant stress to both the cow and calf but the stable fly populations will decrease if humidity levels begin to decline with consistent temperatures above 90°F. In a typical year, there are two distinct peaks of stable fly populations with one occurring in early April and another one occurring in late September.
Horn flies and stable flies are on cattle herds across Oklahoma. This means cattle are dealing with both fly pests and that rely on blood meals as their main food resource. Cattle will need some relief from the biting activity from these fly pests now and the quickest method are insecticides applied directly to the animals.
For stable flies, it is best to find their breeding habitats (hay feeding areas) and clean them up or pull some type of implement through those areas so they can dry out. Consider that a hay feeding area may not look conducive for fly development but if you walk on that area and there is moisture seen beneath your feet then it can support stable fly development.
For an insecticide application, the best method is to spray the legs, brisket and belly areas with a product that is labeled for on-animal use. Since cattle will get their legs wet from laying in pastures or walking through water then applying the insecticide with a diesel oil as the carrier will persist a little longer than one applied with water. Cattle producers will have to use a product that can be mixed with diesel and utilize a sprayer with pumps designed for diesel not water.
For horn flies, there are many different options to control this pest. One of the most popular applications for horn fly control are pour-on products. If using a pyrethroid pour-on be sure that it is synergized with piperonyl butoxide (PBO). The synergist inhibits enzymes that insecticide resistant flies can develop to detoxify the insecticidal compound. Insecticide impregnated ear tags are still a viable option for longer horn fly control but operators will need to rotate the type of product used every year to limit insecticide resistance. Rotating products is not based on trade names but by the chemical class the product belongs in. For instance, a product can be in three broad chemical classes based on its mode of action (the manner in how it kills the fly based on target site) and products labeled for on-animal applications are either pyrethroids, organophosphates, or macrocylic lactones. Veterinarians or country extension personnel can help identify which chemical class a product belongs based on the active ingredient listed on the product label if assistance is needed to identify the chemical class. Sprays are still a good option to provide some relief to cattle with heavy horn fly infestations and the spray should be applied as a course spray that is directed at the backs, sides and belly of the animal. Insect growth regulators (IGR) that are feed through mineral are a very good option when combined with other control applications whether it be ear tags, pour-ons or sprays but producers will need to monitor consumption to be sure that the herd is averaging ~4 oz. / hd/ day to prevent flies from developing from the manure pats. Self-application devices such as oilers can be effective if you make it a force use system or put multiple oilers out to ensure the whole herd is treated properly. A typical force use system is setting it up where cattle have to go under the oiler to get to water or a feed area. Regardless of the type of insecticide application chosen it important to get cattle treated to provide some relief from the biting flies so that cattle are not stressed especially when you add the additional heat stress that becomes a factor with high heat indices.
Effective Strategies to Control Internal Parasites
Paul Beck, Oklahoma State University Extension Beef Nutrition Specialist
Internal parasites impair production by increasing energy costs of maintenance and diet digestibility, reducing feed intake, and increasing activity of the immune system. They have a much greater impact on profitability of beef cattle operations than most of us really think. Research has shown weaning weights can be increased by over 30 pounds and pregnancy rates by over 10% by deworming cows in the spring and again in mid-summer.
There are 3 classes of dewormers in use today: imidazothiazoles (products such as levamisole), benzimidazoles (oral feed grade, white paste, or liquid products), and macrocyclic lactones (avermectin products such as the ivermectins).
Dewormer success and failure is measured by a Fecal Egg Count Reduction Test (FECRT), for a treatment to be considered effective this test much show over 90% reduction in post-treatment fecal egg count. Evaluations of FECRT have shown reduced effectiveness of many of our dewormer products, especially for pour-on products in operations that do not rotate among the different classes of dewormers. Research from 72 beef cow-calf operations across the U.S. evaluated multiple deworming strategies. Operations relying on pour-on macrocyclic lactones had 48% to 75% failure rate. Injectable products fared better with only a 15% failure rate, while oral benzimidazoles had 0% failure rate.
For cow-calf operations, the current recommendation is to 1) deworm after the first hard freeze, 2) check cows via fecal egg counts at spring green up and treat accordingly, and 3) re-evaluate and treat cows and calves in mid-summer.
Deworming is important for livestock productivity and profitability. There are no new dewormers coming out any time soon, so we need to manage the ones that are available the best possible way to keep them effective. If you are unable to conduct FECRT the best bet is to rotate to different classes of dewormers in each season. For instance, at weaning and preg check, you could use an oral benzimidazole product since cow will be caught in the headgate and follow up with a pour-on macrocyclic lactone product at spring green up. Be aware of the classes of dewormers you are using, just because they are different brands does not mean they have different activities, consult with your local veterinarian to design a deworming program that fits your operation.