Don’t Forget The Basics This Spring
DR. TERESA L. STECKLER
SIMPSON, ILL.
What a turn around! We have gone from subzero temperatures to almost 70 degrees F in a few weeks. Now the spring rains have begun, calves are dotting fields, and grass is greening up and growing. With the fast growing grasses there are several items you should keep in mind.
My colleague at the Orr Center, Travis Meteer has conducted research on the effects of washy grass and he reminds cattlemen each spring, when grasses are lush (washy), there are three primary challenges to meeting cattle nutritional requirements.
The first challenge is dry matter. Wet, washy grass can frequently be below 25 percent dry matter. This makes it hard for the cow to consume the enough dry matter (DM) to meet energy demands. During the rapid, spring growth most forage samples will be below 20 percent DM. This requires a lactating 1400lb. cow with average milk to consume 138 lbs. of fresh grass to meet her energy requirement. If that cow is a higher milking cow, she would need to eat 158 lbs. of fresh grass. In most cases, the cow fills up her rumen between 100 and 125 pounds. Physical fill can be a limiter on performance when grazing washy grass.
The second challenge is high protein content of lush forages coupled with moderate energy content. Excess protein can be a problem when energy supply is short. When rumen microbes are presented a diet that is excess in protein and deficient in energy (low in carbs, fats, and sugars), deamination of protein occurs. This process results in production of ammonia and a carbon skeleton that can enter the Krebs cycle for energy production. Ammonia produced from this process crosses into the blood via the rumen epithelium. Ammonia is then converted to Urea by the liver and excreted in the urine. Excess protein has been well documented by the dairy industry as a detriment to reproductive performance.
The third challenge is fiber. The low fiber content of immature forages results in very high passage rates and an unsatisfied cow. It seems odd that cows would be unsatisfied while knee-deep in green grass. However, I have observed this several times. Cows will readily consume a low level of dry grass hay with lush pasture. This can help the DM problem and add fiber.
Travis outlines several strategies that you can employ to get your cattle through the washy grass period. Some strategies may include delaying turnout until grass matures a bit more, supplying palatable dry baled forage that is low or moderate in protein (not alfalfa hay), supplementing with grains (not over 0.5 percent of body weight), or grazing only the top 1/3rd of the grass plant.
Also keep in mind that turnout frequently coincides with breeding season. Make sure you are balancing your pasture ration so cows breed- up quickly and don’t fall out of your breeding season. However, when balancing your ration it is also very important to include a high quality mineral program.
Proper mineral and vitamin nutrition contributes to strong immune systems, reproductive performance, and calf weight gain. Pasture forage is the most significant contributor to trace mineral nutrition of grazing beef cattle. Mineral supplementation in beef cattle can be divided into two broad categories, macrominerals and microminerals.
These categories are based on the amount of mineral required in the cow’s diet.
If several animals in a herd experience health problems, poor fertility, poor response to vaccination, low weight gains or other signs of poor performance, a trace mineral deficiency may be to blame.
Diarrhea, acidosis, stress, fever, trauma, etc. can alter the concentrations of certain minerals in body fluids and tissues.
There are several microminerals that beef cattle require; iron (Fe; primarily required for the formation of hemoglobin), manganese (Mn; required for normal reproduction, and fetal and udder development), copper (Cu; the most common micromineral deficiency in grazing cattle and is an important component of many enzyme systems essential for normal growth and development), zinc (Zn; a component of many enzymes and is important for immunity, male reproduction, and skin and hoof health), selenium (Se; deficiency causes white muscle disease (similar to muscular dystrophy) in newborn calves), cobalt (Co; functions as a component of vitamin B-12, which is synthesized in the rumen by bacteria), and iodine (I; an essential mineral for function of the thyroid hormones that regulate energy metabolism). Only three of the microminerals (Cu, Zn, and Se) are likely to be deficient in grazing beef cattle diets.
Micromineral nutrition is vital to overall herd health and reproductive efficiency. Supplementation of minerals can occur through a variety of means, including free-choice loose mineral mixes, trace mineral blocks, and fortified energy and/or protein supplements.
Controlling daily intake is a constant challenge, but management strategies can be used to ensure proper daily intake of minerals.
Associated with the rapidly increasing temperatures is an increase in insects especially flies. Flies will cost beef producers both in the cost of treatment as well as lost production. Discomfort to livestock and economic effects of heavy populations usually are apparent.
Economic losses occur because feeding by horn flies, stable flies, horse flies, and other bloodsucking flies mechanically transmits several disease organisms as well as causing irritation and physiological changes that decrease weight gains. Effective control measures will allow increases in profitability in beef cattle operations.
The two major species of flies that cause the most serious decreases in beef production and require the most control efforts are the horn fly and face fly. The horn fly alone is estimated to cause animal losses to the U.S. beef industry of between $700 million and $1 billion, while an additional $60 million is spent annually on insecticides to control infestation.
The adult horn fly, which is about one-half the size of a house fly, have brownish-gray or black bodies and are shiny, with slightly overlapping wings that are held flat over the abdomen. The thorax has two parallel stripes on the dorsal surface, just behind the head. They have piercing/ sucking mouth parts and feeds on blood and tissue fluids of cattle. They spend most of their adult life on cattle and feed 20 to 40 times a day. The crucial level of flies for losses to begin to occur is 200-250. If either young animals or cows have this many flies or more than treatment will result in increased weight gains.
The face fly is about the size of a house fly. They are non-biting and prefer to be on the face and consume the secretion form the eyes and nostrils. They avoid entering dark places, such as a barn, while on the animal. They are present on cattle only about 10 percent of the time and may be found resting on fence posts, trees, bushes and other objects the other 90 percent of the time. Because they spend so little time on the animal and do not feed on blood they are much harder to control than horn flies. They are particularly important because they serve as mechanical carriers of the causative agent of pinkeye in cattle (infectious bovine keratoconjunctivitis [IBK] caused by the bacterium Moraxella bovis) and because they damage the cornea of the eye during feeding and thus allow a port of entry for the pinkeye- causing organism.
When making decisions about fly control it is important to realize that there are many effective programs. Producers should develop a program for their operations which is cost effective and most convenient.
Here are several tips to keep in mind for fly control and pesticide use: 1) Plan ahead for insecticide and ear tag purchases; fly season always comes, even if delayed by cool weather or rain; 2) Consult with your herd veterinarian regarding active ingredient(s) in products and their record of effectiveness in your area; 3) Always follow instructions, warnings, and precautions: these products can be toxic to you, your children, pets, and others working with them around the chute; and 4) Follow label withdrawal times and keep records of treatment dates, products and lot numbers.
Cattle can tolerate low fly populations. When fly populations reach 100 to 200 per animal it is economically advantageous to begin a control program.There are several methods of fly control, such as insecticide sprays, dusts, pour-ons, oilers, dust bags, ear tags, oral larvicides in minerals and blocks and controlled release boluses. All of these methods are effective and have a place in the control program; however, the best fly control can most likely be obtained through an integrated fly control program.
As with any time of the year there are always numerous considerations livestock producers must make. During these interesting times, the cost of inputs weighs heavily. But weigh inputs costs with the cost of delayed reproductive efficiency. A modest input cost may ultimately result in better livestcok performance. ∆
DR.TERESA L. STECKLER: Extension Specialist, Animal Systems/Beef, Dixon Springs Agricultural Center, University of Illinois