K-State Research and Extension

“How Much Water Do Those Cows Need?”

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

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. Water is important and, in situations where the water supply is limited or water is being hauled (i.e. grazing crop residues), 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. 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 (Adapted from Spencer, 2016).

Spencer, C., Lalman D. Rolf, M., Richards, C. 2016, Estimating water requirements for beef cows. Kansas State University MF3303. https://www.bookstore.ksre.ksu.edu/pubs/MF3303.pdf

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

“Feedlot Heifer Performance in 2019”

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 fed cattle performance. The Focus on Feedlots data for heifers from 2019, 2018 and 2017 is summarized in the table below. The number of heifers marketed decreased in 2019 with more than 26,900 fewer heifers being marketed in 2019 than 2018. Heifer in weights were slightly lower, averaging 704 lbs in 2019. Final weights of heifers were on average 7 lbs lower in 2019 at 1265 lbs, compared to 1272 lbs in 2018. Heifer days on feed increased to 175 days, an increase of 9 days relative to the 166 days reported in 2018. Heifer average daily gain was similar across years, but feed conversion increased relative to 2018 and 2017. Death loss increased to 2.01% relative to 1.75% and1.64% death losses reported in 2018 and 2017, respectively.

Total cost of gain increased in 2019 to $89.48/cwt. Heifer cost of gain was $5.11/cwt greater on average than that of steers, $84.37/cwt versus $89.48/cwt.

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

“Protein Sources for Growing Cattle”

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

One of the outcomes of the recent Coronavirus (COVID-19) situation that unexpectedly affected many cattle feeding operations throughout Kansas and the Midwest was a sudden reduction in the availability of distiller’s grains. As many Americans heeded “stay at home” orders, demand for fuel, oil, and ultimately ethanol fell resulting in price declines that forced many ethanol plants to scale back production. The cattle feeding industry has relied heavily on distiller’s grains as the primary source of protein in both growing and finishing rations for many years. Distiller’s grains comprise 10-30% of many cattle rations depending upon the nutrient composition and price of other commodities. The reduced supply of distiller’s grains forced many cattle producers to look at traditional sources of protein, such as soybean meal, cottonseed meal, alfalfa and urea that many producers had not used for at least a decade. The prices of several common commodity protein sources (central, KS; obtained 4/28/2020) on a per ton and a cost per unit of protein basis are shown below. It is essential that producers evaluate protein sources on a cost per unit of protein prior to making purchasing decision. All of the traditional protein sources in the table were comparably priced on a cost per unit of protein basis ($0.44-0.49 /lb CP) with the exception of urea. However, urea must be used with caution, should not comprise more than 0.5 to 1.0% of the total diet on a dry matter basis, and it is generally recommended that urea be added into the ration using a premix or liquid to ensure that urea is appropriately mixed in the ration.

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

“Body Condition Scoring: It’s About More than the Score”

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

Body condition scoring is one of the most valuable management tools at the disposal of the cattle manager. This one number gives us a direct indication of an individual cow’s previous plane of nutrition and future reproductive capability. Although the individual body condition scores are important, we do not necessarily manage individual cows, we manage groups of cows. Thus, it is important for us to look beyond the individual scores and look at the distribution of body condition scores within the herd.

If we have a herd (Herd 1) with an average body condition score of 5 that is essentially characterized by the classic bell curve, with a few thin cows (3.5’s), the bulk of cows in the middle (4’s and 5’s) and few overconditioned cows (7’s) everything is good. Alternatively, we could have a herd (Herd 2) with an average body condition score of 5 that is essentially the result of a few thin cows (3’s) and some over conditioned cows (6’s and 7’s). Body conditioning scoring also has more value when it is done on the same group of cows at multiple times during the production year. If Herd 2 was scored at calving and had been previously scored at weaning and had an essentially normal distribution (similar to Herd 1), we need to ask ourselves what happened. Did we change anything? Although these examples are somewhat extreme, they illustrate that we have to look beyond the individual body condition scores of cows at one point during the production year to get the most of body condition scoring.

A quick reference guide to body condition scoring may be accessed and downloaded at https://www.bookstore.ksre.ksu.edu/pubs/MF3230.pdf.

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

“Cow Nutrition: Protein, Energy and Forage Availability”

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

Protein supplementation is important, but there is more to cow nutrition than simply ensuring that the cow’s protein requirements are met and that we have supplied the rumen microbes with sufficient nitrogen to digest the low-quality forages that sustain our cows through the winter months. Most cattle producers know and appreciate the value of protein supplementation, but often overlook energy. Although, protein supplementation does impact energy status by enhancing digestibility and intake of low-quality forages.

The benefits of protein supplementation are not fully realized by the cow if forage availability (supply) is limited. Both protein and energy requirements steadily increase during gestation and post-calving. Thus, there are many production scenarios, where both protein and energy may become limiting or where energy becomes more limiting than protein, minerals or vitamins.

I have found that producers often attribute negative production outcomes, such as higher percentage of open cows, with their previous protein supplementation protocols or mineral and vitamin deficiencies. Protein, minerals and vitamins are important components of cow nutrition, but in many cases energy deficiency may be the more likely cause. Energy status of grazing beef cows is essentially a function of forage availability in most situations.

The most basic way to think about forage availability is to ask yourself “Does each cow have all she can eat in the pasture or field?” If the answer to that question is “No” then energy is likely the most limiting factor in your production system. There are many ways to address situations where energy has become limiting. Feeding hay to replace grazed forage, moving to a new pasture or field of stalks or feeding combination supplements that provide both protein and energy are all strategies that may used to increase energy status.

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