Life cycle of beef cattle
After a calf is weaned from the cow at about 6 to 8 months of age, bull calves are typically castrated and ultimately, fed until market weight. Genetically superior bull calves are separated out for use in breeding programs. Heifers that will be kept in the herd reach sexual maturity by 15-months of age and are bred to deliver their first calf when they are 24-months of age. The gestation period for beef cattle is 9 months. Following the first calf, the female, now a cow, is rebred after a two to three month period and another calf delivered 9 months later. The goal is a 12-month calving interval. The average cow will stay productive in a breeding herd for 7 to 9 years if no disease or physical problems develop.
Feeding beef cattle
Beef cattle, like other ruminants, possess a digestive system that includes a multi-compartment stomach that can digest fibrous materials such as grass, corn stalks, cottonseeds, alfalfa and grass hays, etc. Bacteria and protozoa that reside in cattle's stomach make it possible to release nutrients from fibrous feeds that can be utilized by the animal. Unlike most other animals, cattle can consume byproduct feeds like corn gluten, distiller's grains, brewer's grains, potato chips, soybean hulls, citrus pulp and other products that are considered waste products. Cattle are also fed protein sources, such as soybean meal, canola meal, alfalfa and urea, and cereal grains such as corn, sorghum, barley, wheat, and oats. Generally, feedlot cattle are fed predominantly high quality fibrous diets early in their growth periods and high-energy cereal grain diets during the finishing periods. The breeding herd commonly grazes fibrous forages from pastureland, rangeland and from field residues, such as corn stalks. A mature cow consumes about 5 tons of fibrous feed (forages) per year.
Beef cattle consume feeds that range from high quality cereal grains such as corn, soybeans, wheat, barley, sorghum, etc. called concentrates to high and low quality fibrous feeds such as legume hays, i.e., alfalfa, clover, birdsfoot trefoil, soybeans, etc.; grass hays, i.e., brome, timothy, fescue, blue grass, coastal bermuda, etc.; mixtures of legumes and grasses; corn stalk residue, soybean residue, winter wheat, and other forages. The quality of forages can vary greatly depending upon the maturity and time of harvest, fertilization practices, method of harvest and preservation. Formulating a diet to meet specific animal needs requires knowing the nutrient content of the forage and balancing the diet with appropriate grains, minerals and vitamins. Forages can be preserved dry as hay in the form of large round bales or small rectangular bales, or fermented in the absence of oxygen by chopping the forage into smaller particle size and placed in storage structures called a silo. Silos can be upright above ground containers, horizontal concrete structures or horizontal plastic containers. All of these structures must be sealed for the anaerobic fermentation process to succeed in preserving the forage. Fermenting preserves the nutrient value of the feed so that it can be stored for a long time without spoilage. As mentioned before, beef cattle can consume fibrous feed sources and byproducts (waste products from other industries) that humans and non-ruminant animals (pigs and chickens) cannot consume. Thus, beef cattle provide a high quality, value-added protein source for humans from lower quality feed resources.
Feedlot cattle are commonly fed in open fence-line bunk feeders with the producer delivering the feed daily using a tractor and feed wagon, or by mechanical feed delivery systems to a stationary feed bunk. The cowherd normally obtains the majority of their diet from grazing, however, salt-mineral blocks (sometime fortified with protein and vitamins) and possibly a concentrate mix (predominantly cereal grains and protein) are fed during the winter or drought seasons when the quality of the pasture is poor. Generally, crop residues, such as corn stalks, require supplemental grains or protein and minerals at certain times of the life cycle (especially late in pregnancy and during early lactation) of the breeding herd.
Housing systems for beef cattle in confinement feedlots vary, depending on the climate in the area and topography of the site. They include total confinement buildings, open sheds and lots or open lots with windbreaks and/or shades. The lots are usually paved if located in humid climates to minimize mud problems. Beef cattle are hearty animals that tolerate a wide range of climatic conditions. Most buildings have open sidewalls and are naturally ventilated. Open sheds and lots are typically positioned to allow for protection from prevailing winds and maximize sun exposure during winter. In summer, shades and open areas allow for cooling and air movement. In arid climates, sprinkler systems are used in hot weather for cooling as well as for dust control.
In most confinement buildings or in a loafing sheds, with the shed and lot system, bedding on a solid floor is used to keep cattle dry. Some cattle are housed in a confinement building with total slotted floors where the manure drops into a storage container beneath the floor. However, this system in not commonly used today because of cost and potential feet and leg problems. In humid regions of the U.S. (Midwestern, Northeastern and Southeastern U.S.) cattle are often housed in a paved, or partially paved, feedlot with a loafing shed containing bedding for comfort of the cattle and a large fenced area for the cattle to use as an exercise area. In more arid areas (Western and Southwestern U.S.), cattle are reared in earthen lots with only windbreak fences and/or shades to protect the cattle during inclement weather.
The cowherd may also be housed in feedlots during the winter season or during calving season to facilitate closer observation of any calving problems. More typically, however, the breeding herd grazes pastures, rangeland or cornstalks and other crop residues after harvest. In most cases, the breeding herd is on the open range or pasture for 9 to 12 months of the year.