K-State Research and Extension

“Supplementing Cows During Cold Weather”

By: Justin Waggoner, Ph.D., Beef Systems Specialist

The New Year often brings with it some of the coldest months of the year. Most cattle producers know and appreciate that cold weather increases nutrient requirements. However, the real question is what should producers feed or supplement when the wind blows and the mercury barely registers on the thermometer.

Cattle are most comfortable within the thermoneutral zone when temperatures are neither too warm nor cold. During the winter months, cattle experience cold stress anytime the effective ambient temperature, which takes into account wind chill, humidity, etc., drops below the lower critical temperature. The lower critical temperature is influenced by both environmental and animal factors including hair coat and tissue insulation (body condition). The table below lists the estimated lower critical temperatures of cattle in good body condition with different hair coats. In wet conditions, cattle can begin experiencing cold stress at 59°F, which would be a relatively mild winter day. However, if cattle have time to develop a sufficient winter coat, the estimated lower critical temperature under dry conditions is 18°F.

Cold stress increases maintenance energy requirements but does not impact protein, mineral or vitamin requirements. The general rule of thumb (for a cow in good body condition, BCS = 5 or greater) is to increase the energy density of the ration by 1% for each degree (Fahrenheit) below the lower critical temperature. The classic response to cold stress in confinement situations is an increase in voluntary intake. However, it has been documented that grazing beef cows may spend less time grazing as temperatures decline below freezing, which reduces forage intake, and makes the challenge of meeting the cow’s nutrient requirements even greater. In many cases, feeding a greater amount of low-quality hay will replace grazed forages but may not provide sufficient energy. Therefore, providing additional energy by feeding a relatively higher-quality hay or fiber-based supplement (DDGS, Corn gluten feed, or Soybean Hulls) may be required. If fiber-based energy sources are not available, small amounts (2-3 lbs) starch-based concentrates may also be used as energy supplements.

For more information, contact Justin Waggoner at jwaggon@ksu.edu.

“Forage Analysis: What Numbers Do I Need?”

By: Justin Waggoner, Ph.D., Beef Systems Specialist

One of the more common questions I receive with regard to analytical testing of forages and other feedstuffs is “I have the sample, now what do I test for or what analysis package should I select?”

The basic components that nutritionists need to evaluate a feedstuff or develop a ration are dry matter or moisture, crude protein, an estimate of the energy content of the feedstuff (Total Digestible Nutrients (TDN), Net Energy for Maintenance (NEm), Net Energy for gain (NEg), and the macro minerals, Calcium and Phosphorous. These are the most basic numbers that are required, but including some additional analyses in the report can give us additional insight into the quality of the feedstuff or improve our ability to predict animal performance, which is the primary reason we analyze feedstuffs. I recommend that the report include acid detergent fiber (ADF) and neutral detergent fiber (NDF). The amount of NDF in forage reflects the amount of cell wall contents (hemicellulose, cellulose, and lignin) within the sample. The NDF fraction is often associated with the respective bulkiness of forage and is correlated with dry matter intake of the forage or feedstuff. Therefore, the amount of NDF may be used to estimate the expected dry matter intake associated with the forage. The ADF number represents the amount of cellulose and lignin within the forage and is correlated with the respective digestibility of the forage. In general, a higher ADF value is associated with forage that has a greater proportion of cellulose and lignin and would likely be more mature. Additionally, the ADF fraction is used to calculate the energy estimates TDN, NEm, and NEg that appear on the report. There are a number of different mathematical equations that the testing laboratory may use to calculate these numbers, based on the type of sample (corn silage, alfalfa, grass hay, etc.). If the ADF is included in the report, the nutritionist can adjust or recalculate the energy estimates if necessary.

If the forage will be fed in combination with a byproduct feed, such as wet distiller’s grain, including an analysis for sulfur can be beneficial if the forage will be used in a growing or feedlot ration. Additionally, if the forage is a known nitrate accumulator (forage sorghums, sudangrass) or may have been stressed due to drought, including a nitrate analysis should always be considered, especially if the forage will be fed to pregnant cows.

Most analytical laboratories have a number of different analysis packages which encompass the most common procedures or numbers that a nutritionist or producer needs to know about their feeds. These packages will typically include the basic procedures (DM, CP, TDN) and then add on specific analyses such as NDF or the Macrominerals (Ca,P, Mg, K, Na, Cl, S). Some laboratories may group analysis packages by the type of sample (Forage vs. mixed ration) or production purposes (dairy vs. beef).

The objective of analytical testing of forages and feedstuffs is to improve our ability to meet the animal’s nutrient requirements and ultimately predict animal performance. The unequivocal best method of evaluating the quality of a feedstuff is feeding the feedstuff to an animal and evaluating performance over a set period of time, under a specific set of conditions. Since that would not be cost effective or timely, analytically evaluating feedstuffs in a laboratory is the next best thing and although it is not perfect, it is unequivocally better than the “this looks like really good stuff” method of evaluating feedstuffs.

For more information, contact Justin Waggoner at jwaggon@ksu.edu.

“Historical Perspective on Cull Cow Prices”

By: Justin Waggoner, Ph.D., Beef Systems Specialist

The sale of cull animals is one of the primary sources of revenue on a cow-calf operation, contributing 17- 24% of the gross income reported by cow-calf operators within the Kansas Farm Management Association from 2013-2017. The figure below offers some historical perspective on cull cow prices in Kansas (LMIC, compiled by Robin Reid). Cull cow prices are seasonal, being lowest in the months of October, November, December, and typically increase in March and then remain steady during the summer months.

The relative difference between the market low and high, based on the 5- and 15-year average prices illustrated in the graph is approximately $10-$15/cwt. Thus, the market value of a cull cow increases $10- $15/cwt. from November to March. A 1,300-lb. cow sold in November at $40/cwt. would generate $520 while the same cow, if sold in March at $55/cwt., would generate $715, a difference of $195.

Although, the cull cow market has been relatively soft in 2019 and we cannot foresee what the market will be in 2020, the historical data indicates that cull cow values typically increase over the winter. The question then becomes whether the increase in value is substantial enough to justify holding onto those cows for an additional 120 days.

For more information, contact Justin Waggoner at jwaggon@ksu.edu.

“Some Thoughts on Calf Revenue”

By: Justin Waggoner, Ph.D., Beef Systems Specialist

The air is now crisp in the morning and it won’t be long before we see the glimmer of ice crystals in the water tank. Many producers are weaning and will be marketing calves in the coming weeks and months. Margins in the cattle industry and agriculture in general are often unfortunately narrow and this year is no exception. Maximizing calf revenue is important for cow/calf producers every year, but is even more important in year’s where the probability of loss is greater than profit. Calf revenue from my academic perspective is driven by 3 factors, 1.) the number of calves sold, 2.) sale weight of calves and 3.) price received. Cow/calf producers to some extent have control over the number of calves sold and sale weight. The number of calves sold is essentially a function of stocking rate, cow fertility and/or reproduction on an operation. The sale weight of calves is more complex but is a multi-factorial combination of genetics, calving distribution, calf age, nutrition, management and technology use (implants). Price received is likely the most influential of the 3 factors that drive calf revenue and is the factor that cow/calf producers often believe they have the least ability to control. Once a set of calves, enters the sale ring, or appears on the video screen their value is determined by what 2 prospective buyers are willing to pay. Although it is impossible for producers to directly influence what buyers are willing to pay, I would argue that they are not completely helpless. Cow/calf producers directly control what they will sell (weaned calves, value-added calves or feeders), and determine when they will sell. These are difficult, complex decisions, that shouldn’t necessarily be made based upon weekly cattle sale reports or the thoughts of your favorite livestock market commentator. I am not saying that keeping informed about current market conditions isn’t important. However, that information when used with resources like Beef Basis (www.beefbasis.com) that use data to evaluate different market scenarios, from selling 6 weight calves the first week of December, to 7 weights in February helps producers make the best decision for their operations. Producers also control what information or data they pass along to the new owner. We all know that data has value in today’s world. I like to compare marketing calves to selling a beautifully restored pickup. If you were selling a pickup, you would share with a prospective buyer every bit of information you had and the details of the process, from the atmospheric conditions when the truck was painted to the actual sales invoice from 1972. Why should selling a set of calves be any different? Value added programs and certified sales provide potential buyers with some degree of assurance that your cattle were managed within the guidelines of the program. If you don’t participate in a defined program, providing the auctioneer or sales representative with as much information as possible about your cattle only helps them do their job better which is to get best price for your cattle.

For more information, contact Justin Waggoner at jwaggon@ksu.edu.

“Silage Harvest is Underway; Be Safe”

By: Justin Waggoner, Ph.D., Beef Systems Specialist

One of the busiest, most fast paced operations that occur this time of year is silage harvest. Cutters and choppers in the fields, trucks racing from the field to the pile or bunker, multiple tractors pushing and packing silage. The speed at which we can harvest silage today is amazing, but we should never allow the speed at which can accomplish a task to compromise safety. Below are a few things to think about during this year’s silage harvest.

• Don’t become complacent. Stay aware of your surroundings. Let’s face it: there are a lot of highly repetitive operations in putting up silage. One of the number one factors that lead up to an accident is complacency, or lack of situational awareness.
• Truck drivers should always slow down when approaching houses and intersections on all roads, every time. Those houses along the road belong to our neighbors and friends, some of which have children. The increased traffic on gravel roads creates dust, and the crops are tall, both of which reduce visibility at intersections. Our neighbors should not fear going to their mailbox due to our silage trucks.
• People (especially children) should never be allowed near a drive-over pile or bunker silo during filling. If people have to approach the area, get on the radio to inform the drivers/operators that people are on foot. Those on the ground in the area should always wear a bright colored safety vest.
• Never fill higher than the top of the bunker wall. This happens more than it should and creates a dangerous situation from the day the silage is packed until it is removed. The pack tractor cannot see the edge of the bunker well, if at all. The silage does not get packed well (which leads to poor silage) and the edge of the silage is unstable and more likely to collapse. Don’t do it.
• Be aware of steep slopes. To reduce the risk of tractor roll-over, a minimum slope of 1 in 3 on the sides and end of piles should be maintained.
• Never inspect or make repairs to equipment near the bunker or pile. Equipment should be removed from the area as soon as possible. Repairs almost always involve people on foot and potentially people who may not be familiar with silage activities and the associated risks.

For more information, contact Justin Waggoner at jwaggon@ksu.edu.

“Feedlot Steer Performance in 2018”

By: Justin Waggoner, Ph.D., Beef Systems Specialist

Each year I summarize the data from the K-State Focus on Feedlots in an effort to document annual trends in feed cattle performance. The Focus on Feedlot’s data for steers from 2018, 2017 and 2016 is summarized in the table below. In 2018, participating feedlots marketed 349,595 steers, 8497 fewer cattle than were marketed 2017. In weights remained steady, averaging 779 lbs. Final weights of steers increased slightly to 1398 lbs compared to 1387 lbs in 2017. Steers were on feed approximately 173 days, an increase of 9 days from 2017 and 14 days from 2016. Average daily gain and feed conversion were similar across years. Death loss remained steady at 1.58% compared to the 1.52% previously reported in 2017. Reported total cost of gain averaged $78.10/ Cwt. in 2018, an increase of $3.76/Cwt. from 2017.

For more information, contact Justin Waggoner at jwaggon@ksu.edu.

“Got Water…But How Much Do Those Cows Need?”

Most cattle producers fully understand the importance of water. After all, providing an adequate supply of clean, fresh, water is the cornerstone of animal husbandry and there are very few things that compare to the feeling of finding thirsty cows grouped around a dry tank on a hot day. Water is important, and in situations where the water supply is limited or we are forced to haul water one of the first questions we find ourselves asking is “how much water do those cows need?” The old rule of thumb is that cattle should consume 1-2 gallons of water per 100 lbs of bodyweight. Accurately determining the amount of water cows will voluntarily consume is difficult and is influenced by several factors (ambient temperature, moisture and salt content of the diet, body weight, lactation, etc.). Water consumption increases linearly as ambient temperature increases above 40° Fahrenheit such that cows require an additional gallon of water for every 10 degree increase in temperature. Additionally, lactation also directly increases the amount of water required by beef cows. The table below summarizes the daily water requirements of beef cows of several different body weights, milk production levels, and ambient temperatures.

The daily water requirements of beef cows represented are estimates and water consumption varies greatly during the summer months when temperatures exceed 90° Fahrenheit. Therefore, these recommendations should be regarded as minimum guidelines.

For more information contact Justin Waggoner at jwaggon@ksu.edu .

“Early Weaning: A Tool to Improve Cow Condition”

By: Justin Waggoner, Ph.D., Beef Systems Specialist

Early weaning may be one of the management tools that beef cattle producers should consider using this fall. The recent winter weather conditions have resulted in cows and replacement females that may be lacking body condition coming into the grazing season.

Yes, cows will likely pick up some body condition over the upcoming grazing season. However, it can be difficult to put condition on lactating cows, especially higher producing females, even under ideal grazing conditions. Therefore, some cows may still be lacking condition during the later months of the grazing season. One of the easiest ways to manage cow nutrient demands is by weaning the calf. This reduces the energy requirements of the cow by 25-30%. This effectively means that the nutrients consumed by the cow that were being used to sustain lactation may now be used to improve cow condition.  A study designed to evaluate preconditioning duration conducted at K-State documented that cow body condition scores improved as calf age at weaning decreased. The cows on this study remained on native grass pastures following weaning and the observed increase in body condition score in this study occurred over a 60 day period. The results of this study suggest that early weaning calves may improve body condition of cows grazing native pastures late in the grazing season.

Early weaning is a management tool, most often associated with drought. However, it may be an even more valuable management strategy to manage the nutrient demands associated with lactation and improve cow condition, especially on young cows. Additionally, early weaned calves may be managed to target a number of different value-added programs or sales.

“The Impacts of a Tough Winter”
By: Justin Waggoner

One of the common topics of discussion, regardless of what segment of the beef industry you operate in has been winter and the collective impacts of a winter that was wetter and colder than most of us in Kansas and to some extent the Central United States are accustomed to. Although, green is slowly replacing the brown in the pastures, the effects of this winter in the cattle industry may be felt for longer than many of us would like. The combination of wet and cold conditions increases energy expenditures and maintenance energy requirements of the animal.

In the feeding sector cattle performance, most notably feed conversion (lbs. feed: lbs. gain) increases. In the March Focus on Feedlot report, (February closeouts) the average steer feed conversion was 7.08 lbs. feed: lb. gain. In February 2018, the average steer feed conversion was 6.15, lbs. feed: lb. gain. Thus, 0.93 more lbs. of feed (15%) were required to produce a pound of live weight gain in steers marketed in February of 2019 versus 2018. More feed ultimately results in higher cost of gains and lower profit potential. Overall steer death loss was similar at 1.68% in February 2019 and 1.97 in 2018. Feed conversion will likely remain high for next two to three months and death losses could foreseeably trend upward as cattle placed on feed during the coldest months may have experienced greater health risk and cold stress early in the feeding period.

In the cow-calf sector, winter conditions have resulted in cows that may be lacking condition or replacement heifers that are lighter than they would normally be under normal conditions. Body condition and plane of nutrition drives reproductive performance, which is one, if not the, most important determinant of productivity/profitability on a cow-calf operation. It takes longer for thin cows to begin cycling, which means that thin cows are at greater risk of being open and if cows do begin cycling they will be bred toward the end of the 2019 breeding season and subsequently calve later in 2020. Later calving typically results in younger, lighter calves at weaning, which ultimately results in less pounds of sale weight and dollars being generated by those cows in the Fall of 2020.

A large part of managing cattle is responding to weather conditions be it a cold, wet winter or drought. Cattle feeders may adjust market endpoints and cow-calf producers may consider adjusting breeding seasons, early weaning, or other ways to add additional market value to calves. The good news is the days and nights are getting warmer, and every day brings us closer to summer.

For more information, contact Justin Waggoner at jwaggon@ksu.edu.

“The Basics of Mineral Nutrition”

By: Justin Waggoner, Ph.D., Beef Systems Specialist

Beef cattle producers recognize that mineral nutrition is important. However, a mineral program is only one component of an operation’s nutrition and management plan. An exceptional mineral program will not compensate for deficiencies in energy, protein or management. Additionally, the classic signs associated with clinical deficiency (wasting, hair loss, discoloration of hair coat, diarrhea, bone abnormalities, etc.) are not often or are rarely observed in production settings. The production and economic losses attributed to mineral nutrition in many situations are the result of sub-clinical deficiencies, toxicities and antagonisms between minerals which are often less obvious (reduced immune function, vaccine response, and sub-optimal fertility). The figure below, adapted from Wikse (1992), illustrates the effect of trace mineral deficiency on health and performance and the margin between adequate mineral status and clinical deficiency.

Seventeen minerals are required in the diets of beef cattle. However, no requirements have been established for several minerals that are considered essential (Chlorine, Chromium, Molybdenum, and Nickel). Minerals may be broken down into two categories. 1. The macrominerals whose requirements are expressed as a percent of the total diet (calcium, phosphorous, magnesium, potassium, sodium, chlorine and sulfur). 2. The microminerals or trace minerals (required in trace amounts) whose requirements are expressed as parts per million (ppm) or milligrams per kilogram of dry matter consumed (chromium, cobalt, copper, iodine, iron, manganese, molybdenum, nickel, selenium and zinc).

Mineral status of an animal is a function of the total diet (both water and feed) and stored mineral reserves within the body. Water may be a substantial source of minerals; however, the variation in water consumption makes estimating the contribution of mineral from water sources difficult. Mineral content of forages is influenced by several factors including plant species, soil, maturity, and growing conditions. These factors, and others not mentioned, makes estimating the dietary mineral content of grazing cattle challenging. Most commercial mineral supplements are formulated to meet or exceed the requirements for a given stage of production. This ensures that deficiencies are unlikely, but providing supra-optimal levels of minerals may be unnecessary unless specific production problems exist. A mineral program does not have to be complex or expensive to be successful.

For more information, contact Justin Waggoner at jwaggon@ksu.edu.