by: Stephen B. Blesinger
Ph.D., PAS

The start of the New Year lends itself to many things. For the cattle producer, one of these opportunities is evaluating his or her overall management program. Experienced and novice cattlemen alike sometime take for granted that no program is perfect and that every management program needs “tweeking” from time to time. In some cases more than just a little tweeking! In today's production environment with the rapid change in environment, commodity and cattle prices, economic issues, government and regulatory policy and politics in general, there is little constant except for change. Because of these circumstances the cattle producers (and just about ANYONE involved in agriculture) this requires constant vigilance and review of how we are doing things. So we're going to start off this year by reviewing some management concepts that every producer needs to keep in mind. To begin this article will discuss some issues related to calf health and performance. The calf is the foundation of the performance and productivity of the herd. If there are no calves or not as many as is feasible, overall productivity and profits will be limited. The initial conception of that calf and its development and birth begin before any of these events actually take place but we'll work our way around to that.

The management, nutrition and subsequent performance of calves is a topic of constant debate. Generally this discussion begins with that period immediately after birth through the growing animal's life. It's entire life – whether a feedlot steer or heifer or a bull or heifer selected to be used for breeding. It's interesting that how a young animal performs after birth, in most if not all cases, is tied directly to the dam carrying that calf. From conception on, the cow provides the nutritional needs and assists in growing and developing the fetus. Since this period of growth (from conception to birth) is the most rapid growth phase in the life cycle of the animal, this is also when genetic mapping takes place. So the groundwork or blueprint for that animal is being “laid down” during this critical period of time. Providing the nutritional needs of the cow is critical for the calf. Compromising nutrients to the cow at this stage of products will limit the young animal's performance, after birth and at all stages throughout its entire life. A great deal of work is being done at this time in this area and we are only now beginning to understand the greater implications of maternal health, nutrition and management on the offspring. We've known for a long time that the care given the cow directly affects the calf. Now we are learning to what extent.

For example, one very specific area of focus in recent years has been on the trace mineral (TM) status of the cow, the fetus and subsequently the newborn calf. This status can have significant long term effects on how the calf performs through life. A potential problem here is that mineral management for the cow herd, in many cases leaves a lot to be desired. The reasons for this include:

1) Failure by the producer to utilize any type of mineral program at all

2) The use of a poorly designed mineral supplement, focusing largely on cost or convenience. I.e., they are looking for something cheap or easy to use, not a supplement designed for the specific production environment

3) Use of a program that includes a properly formulated supplement but is management poorly applied, i.e., mineral supplement not kept out and available on an on-going basis, feeders placed poorly so that cattle do not readily visit the feeders to consistently consume supplement, etc.

4) Producer's “cutting” the mineral with loose salt which ultimately dilutes the mineral concentrations in the end product being provided.

5) Using feeders that are not well designed and that offer some protection from the elements.

6) Any combination of the factors listed above or others not listed.

Any of these factors will decrease the cow's ability to consume proper minerals and vitamins and subsequently compromise her mineral status as well as that of her unborn calf.

Both macro minerals and micro (trace) minerals are essential nutrients necessary to support nearly all physiologic, metabolic and structural functions of the body. Macrominerals such as calcium (Ca), phosphorus (P), potassium (K), etc. perform mostly structural, acid-base balance, nerve conduction and osmotic functions. Most macro-minerals are homeostaticly (actively controlled by the body) regulated to various degrees with extensive mechanisms existing in the body which regulate and maintain proper macromineral levels. Micro or trace minerals such as copper (Cu), iron (Fe), manganese (Mn), selenium (Se) and zinc (Zn) are involved in countless enzyme systems which facilitate and drive the various body processes. The TM levels are controlled predominantly through movement between storage, transport and biochemical functions in the body.

Trace mineral deficiency conditions affect almost every physiologic and metabolic function and include immune dysfunction (Cu, Zn, Se); developmental abnormalities (Cu, Mn, I); abortion (Cu, I, Se); retained placentas (Cu, Se, I); metabolic disturbances (Co, Fe, Zn, I); and poor growth (Co, Cu, Fe, Se, I, Zn).

The developing fetus is totally dependent upon the availability of essential nutrients through the placenta from the dam's blood. As a result, fetal nutrient status is reflective of maternal nutrient status. Maternal nutrients available to the fetus would include those from the cow's diet as well as reserves mobilized from the cow's body, if needed. Numerous studies have observed the fetus's liver concentrating ability for minerals, i.e., fetal liver mineral concentrations, to exceed maternal values. For example, a decline in the cow's liver copper concentration during late pregnancy would be consistent with her transfer of minerals to the fetus. As a result, if the cow is deficient in critical nutrients, it is likely the calf will be as well having no significant stores available to pull from.

During the early periods after calving, almost all essential nutrients are adequately provided by the calf's consumption of the cow's milk. However, a number of critical micronutrients, namely Cu, Fe, Mn and Zn are not provided effectively by milk consumption alone, thus requiring additional sources to meet daily needs.

Because of this, fetal liver nutrient reserves play an important role in maintaining adequate concentrations of these trace elements to support the daily requirements in the young animal. Survey data from bovine newborns ranging from birth to 3 months of age has shown significant declines in liver mineral concentrations during this time period. Figure 1 shows the changes of Cu, Zn and Fe status in the calf from birth through later stages of life (Figure 1, Branum 1999).

As the graph shows, calves are born with a given liver TM concentration and over time this concentration decreases, in many cases to the point where TM availability will not support many critical functions such as immune response or normal growth and development. If the situation exists where the cow has been inadequately supplemented during pregnancy, this initial status will be diminished and leading to even lower liver values over time, thus emphasizing the possibility of a variety of health and physiological problems.

Liver mineral reserves at birth are supported by consumption of colostrum, a highly concentrated source of most essential minerals. And, as would be expected, maternal mineral status will also influence mineral concentration in colostrum. As colostrum production declines and stops, the availability of the trace minerals from this source also ceases. The key point to remember is that colostrum production by the cow and absorption by the calf ceases after only a couple of days at the most. After this the calf relies on it's trace mineral stores to provide for it's physiological requirements, at least until the point in time where it begins consuming an appreciable amount of mineral supplement itself. This said, the calf is also subject to the same issues discussed previously, especially availability and palatability. One potential solution to this problem is the use of an injectable trace mineral such as MultiMin at or shortly after birth which can increase the stores of Zn, Cu, Mn and Se at least for a period of time.

The use of organic trace mineral sources in the oral mineral program can also increase the TM status of calves but it must be emphasized again that the mineral supplement itself must be properly formulated and palatable and mineral feeders must be managed properly in order to encourage consumption by calves.

So what is the message here? There are several:

1) Trace mineral status in calves significantly affect processes required for life, growth and development. Compromising this status is detrimental to the fetus and young calf.

2) During gestation and shortly after birth the calf is affected by the TM status of the cow. If the cow is deficient in TMs the calf probably will be deficient as well.

3) Proper TM supplementation of the cow can improve the TM status of the fetus and the young calf promoting proper development, health and growth.

4) Proper supplementation of the young calf is critical to the development and support of the immune system, as well as growth and development.

5) Use of products such as organic minerals in the oral supplement as well as injectable TMs can be very useful in building and maintaining the calf’s (and the cow’s) TM status.

Proper TM supplementation can be a deciding factor in the life of the fetus and young calf.  Use of a well designed TM program is critical for the cow AND the calf.  So take this opportunity to consider how your program is focused on the calves you are producing.  They are your bread and butter.

Dr. Steve Blezinger is a nutritional and management consultant with an office in Sulphur Springs, TX.  He can be reached by phone at (903) 352-3475 or by email at sblez@verizon.net.

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