By Steve Blezinger, Ph.D.
Many cow/calf producers, whether they are commercial or purebred have begun to utilize either a split breeding season or a fall calving season. This allows them to produce weaned calves during times of the year when markets are somewhat stronger. This holds true not only for stocker steers and heifers heading to the feedyard and into the meat production pipeline but also for replacement heifers returning to the breeding herds. Breeding females which calve in the fall of the year face a certain set of challenges which may be more prevalent in the fall than in the spring. Before we discuss specific factors which must be overcome, let's examine some basic nutritional principles which affect the cow during those times just before calving, through the calving period and up until rebreeding.
Be it fall or spring, about one month before birth, the unborn calf is growing at a tremendous rate and is drawing heavily upon the nutrient supply taken in by the cow and found in her blood stream. At this point in the cow's production calendar her nutrient requirements are at about the second highest level they will be all year. At this time, her nutrient requirements are second only to the period just after calving and up to rebreeding. Her nutrient requirements are linked to the rapid growth rate of the unborn calf, the stress of pregnancy and the preparations her body is making for calving.
Upon calving, the cow's needs change somewhat in that she is no longer directly supporting the growth and development of the calf. Her support of the new born is less direct and less efficient since protein, energy and other nutrients are channeled to the milk gland for lactation. At the same time the reproductive system of the cow is repairing itself after the birthing process and preparing for rebreeding. Needless to say, the physiological demands during this time are substantial. This is compounded by environmental and management factors which may actually increase the demand for nutrients. It is also affected by breed type, body size and age of the female.
Fall calving and rebreeding is challenged by the fact that the nutrient availability from pastures and harvested forages (late season pastures, hays, silage, etc.) is not as plentiful or digestible as compared to spring forages. Early growth of warm season perennials such as bermudagrasses or winter pastures such as wheat, oats or ryegrass are normally high in available nutrients and quite digestible. Another factor affecting certain areas of the south this year is forage availability. In areas such as central Texas, months of drought conditions have left pastures all but non-existent. Similarly in these areas, hay is a rare commodity that must be shipped in from other areas, greatly increasing the cost. A problem with this is that much of the shipped-in forages are also low in quality and are not a good value. There are some better values available for cattlemen in these situations to utilize but they are somewhat unconventional when compared to the norm.
Under normal situations forage quality and nutrient density is not suitable to meet beef cow requirements by early to mid July and continues to decrease as the summer months proceed. This is even more true with fall calving cows which have higher requirements as discussed earlier.
So to this point we have established two basic facts: 1) Fall calving and rebreeding cows have higher nutrient requirements at this point in time compared to spring calving cows and 2) forages at this time of the year are poorly suited to meet these requirements. Once we have recognized these facts we can begin to plan how the problem should be addressed to best meet the needs of these cattle. This will help ensure that appropriate nutrients are available in order to have cows rebreed in a timely fashion.
Planning for how your cattle will be fed are decisions that are best made as far in advance as possible. This can be difficult when as much uncertainty exists in the market as does now. However, by determining what type of program will be used, whether it be hay or other roughage sources, winter pastures and supplementation methods, the cattleman can reduce some of the risk exposure he would experience if he manages his feeding program "by the seat of his pants." Some of this can be accomplished by contracting at least some of the feeds or feed ingredients necessary to provide supplemental nutrients for the herd. It is seldom recommended to contract all of your supplement needs in order to take advantage of any price breaks which might occur in the fall at or around harvest times. If prices do increase, however, since at least some of your needs have been contracted, you have significantly reduced the risk of having to pay full prices for all your supplements.
In developing your feeding and supplementation program for fall calving herds first you must determine what is available from your forages. These values can be obtained by forage testing your roughages whether it be pasture or hay sources. Samples of this nature can be properly analyzed through the extension service or any number of private feed and forage laboratories. It is best to check the cost and turn-around time of a number of labs before selecting one to use. Forages should be tested for dry matter, protein, fiber, TDN and the basic minerals. If forages such as sorghums are used, be sure to have a nitrate screening run to insure that nitrates are not out of line. Most labs can calculate net energy levels as well which indicate the overall energy level of the roughage and which are important values to know to determine how well a forage meets the energy needs of the cow.
Energy is normally the nutrient least available at this time of the year and tends to be the most expensive to supplement. We commonly hear about the protein needs of the cow and while there is a need to provide at least a small amount of supplemental protein, appropriate energy supplementation is the cattleman's greatest expense and is normally an area where the greatest amount of miscalculation takes place. In other words, energy will be commonly underfed or overfed. If underfed, cattle will not perform in terms of growth or reproduction in a cost effective manner. If overfed, cattle will tend to become excessively fat resulting in inefficiency and a waste of dollars.
Good sources of energy are grains such as corn or milo or by-products like corn hominy or whole cottonseed. Cottonseed tends to be one of the best energy supplements because it is high in protein (about 22%, dry matter basis) and fiber. Cottonseed has approximately 1.25 times the energy of corn due to it's high fat content. The fat level in whole cottonseed runs approximately 20% on a dry matter basis. This fat as an energy source tends to work well because when fed at a moderate level it will not have the negative effect on fiber digestion that feeding corn or other high starch grains can. Also when fed at two to four lbs. per head per day, whole cottonseed can supply most if not all of the protein needs of the cow at this time. Even at some of the prices noted for whole seed over the past year, it was still a better buy as a protein and energy supplement for breeding cattle than most cubes or other commercial supplements. Many other economical supplemental feeds are available in different areas and these will be covered in another article.
Finally, while protein and energy may be supplemented rather easily, it is important to remember that mineral and vitamins must also be supplemented for reproductive function to occur at it's ideal level. Phosphorus is vital for reproductive performance. Other major and minor minerals as well as Vitamins A and E play an important role in overall physiological function in the animal. In general a good quality, free-choice loose mineral containing no more than 5 to 6 percent salt should work well for cattle at this time. It is also beneficial that a mineral of this nature have at least some of it's trace minerals supplied as chelates or organic complexes. This improves the availability of trace minerals such as copper and zinc which is especially helpful at this time. A high quality, chelated breeder mineral should be made available 45 to 60 days pre-calving and continued until 30 days after breeding. This is a crucial period for these cows as it is for spring calving/breeding cattle but special attention must be paid to unsure adequate nutrition is supplied.
What are the benefits? First, we cannot discount the desirability of a moderate sized, vigorous, healthy calf. Low birth weight, weak calves suffer from higher levels of morbidity and mortality and tend to perform throughout their lifetime at a substandard level. Secondly, rebreeding with in a 90 or preferably a 60 day period post-calving has it's benefits of improving overall calving percentages, increased weaning weights and supplying replacement heifers that work more easily back into the herd. Having cows begin cycling earlier also allows a bit more time for breeding to take place, providing more room for error.
Of all the costs involved in a beef cattle operation, nutrition is the single highest input to be paid. Because of this it is important that feeding and supplementation be timed appropriately and appropriate forms and levels of feeds and commodities be utilized. In this day and time it is becoming ever more important to be creative in some of our feeding practices due to the high grain and commodity markets experienced recently and what may very well be repeated this coming fall and winter. Using a specific feeding program "because that's what we've always done" really does not have a place in today's beef production industry. Look at what's available to you, learn as much as you can about beef cattle nutrition and become a student of the grain markets and your level of production and profitability will improve nicely.
Dr. Steve Blezinger is a consulting nutritionist with an office in Longview, Texas.
Decide
where you would like to go and CLICK on one of
the signs below.
