Beef Cattle Reproduction


Source: University of Arkansas

Generally success or failure in the cow/calf business depends to a large extent upon doing the right things at the right times. This is especially true when it comes to beef cattle reproduction management. Reproduction is the single most important factor in a cow/calf operation. After all, you can’t sell calves if you don’t produce them.

What is Reproduction Efficiency?

There are a number of different ways to calculate reproduction efficiency. The preferred way is to divide the number of calves weaned by the number of cows exposed to the bull times 100 called the net calf crop.

Net calf crop =          Number of calves weaned X 100
Number of cows exposed to the bull

The net calf crop calculation is preferred because a weaned calf is the goal of a cow/calf operation. There is no scientific research that documents the average net calf crop for Arkansas cow/calf producer but it’s estimated to be 72 to 76%.

Through management the net calf crop can be improved. The Arkansas Beef Improvement Program (ABIP) was designed to implement cost effective beef cattle and forage management practices on Arkansas cow/calf operations. While working with Arkansas cow/calf producers, net calf crop improved from 86% to 90% from year 1 to year 5.

Controlled Breeding Season

Managing the cow herd to calve in 90 days or less can be one of the most important steps toward increasing net calf percentage. The breeding season for replacement heifers should begin one month before the breeding season for the mature cow herd. Exposing replacement heifers to a bull one month before the cow herd breeding season allows an extra month for heifers to recover from calving before the second breeding season begins.

Advantages of a controlled breeding season include:

  • Reducing the number of times necessary to gather cattle for vaccinating and weaning.
  • Marketing a more uniform calf crop.
  • Optimizing the winter feeding program.
  • Allowing the use of cow herd performance records to select replacement heifers and identify cull cows.

Demonstrations across Arkansas have shown that reducing the breeding and calving season is the first step toward improving beef cattle management efficiency. Below are results from ABIP Breeding and Calving Season demonstrations:

  • The percentage of cows calving in the desired calving season improved from 36 to 100 percent.
  • Direct cost per animal unit decreased 32 percent.
  • Herd breakeven cost decreased 38 percent.
  • The gross margin (gross income minus direct cost) improved by 75 percent.

By shortening the breeding and calving season to 90 days, oftentimes average calf weaning weights increase. A short breeding and calving season helps produce a more uniform calf crop that can be sold at a higher price. In some situations, shortening the calving season to 90 days or less may take three to five years. Nevertheless, the breeding and calving season is a key element to improving efficiency and profits. For more information about a controlled calving season, click see the FSA 3011 publication..

 Artificial Insemination and Synchronization

Two Calves

The breeding and calving season is a key element to improving efficiency and profits.

Many producers of purebred and commercial beef cattle can profitably utilize artificial insemination (AI) on virgin heifers and/or on the cow herd. Success with AI requires attention to detail in all areas of herd management.

One of the most important factors affecting AI success is commitment. The manager must be dedicated to making AI work and instill this commitment into each link of the management decision chain. The weakest link sets the level of success of the operation. Should any aspect of management become substandard, AI conception rates will be reduced to the extent that they will cancel many of the benefits the technique offers.

Many managerial decisions relative to feeding, facilities, fences and corrals, equipment and sire selection will be necessary. Both a sound health program and good nutrition are requirements of any breeding program but become an absolute essential ingredient for artificial insemination. In addition, more labor and skill are needed, especially in the initial phases of the program. Form more information about AI, click see the FSA 3118 publication..

Estrous synchronization may not be for every producer. Use of this technology generally requires skilled management and adequate facilities. Cows will respond poorly if not fed properly or if body condition is less than adequate. Level of herd health is also a factor, as many diseases cause reproductive failure. For more information about estrous synchronization click see the MP 383 publication..

Estrous synchronization is the manipulation of the reproductive process so that females can be bred with normal fertility during a short, predefined interval. This control facilitates breeding in two important ways: it reduces and in some cases eliminates the labor of detecting estrus (heat), and it allows the producer to schedule the breeding. If the majority of a herd can be induced to exhibit estrus at about the same time, the producer can arrange for a few days of intensive insemination. Although the total amount of labor involved with insemination may not be reduced, it is concentrated into a shorter period. Other advantages of estrous synchronization include creating a more uniform calf crop, enabling more cows to be artificially inseminated (AI) to a genetically superior bull and reducing the length of the breeding season.

Body Condition

To optimize performance, body condition scores of cows should fall within a range of 5 to 7 (optimum condition) at the initiation of the calving season and remain in this range throughout the breeding season. To achieve this goal, cows should be condition scored when calves are weaned. Feeding programs should be planned for cows of varying condition so they will reach optimum body condition by the start of the calving season.

BCS are numbers used to suggest the relative fatness or body composition of the cow. Most published reports are using a range of 1 to 9, with a score of 1 representing very thin body condition and 9 representing extreme fatness.

Cows in body condition scores 4 or less have reproductive rates of 64% whereas cows in body condition scores 6 or more reproductive rates are 93%.


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