Last Update: June 2003
This worksheet identifies production areas in beef cattle operations.
Basic information for the calculations needed includes: cow numbers, breeding records, pregnancy test results (optional), calving records, death loss records, weaning and/or sales records (Table 2) These values cover an 18 to 20 month production period. By identifying these production points improvements in efficiency and profitability may be made.
Pregnancy Rate (Open Cow Percent)
Pregnancy rate or percentage of open cows is a key to productivity. If 10-15% open cows is average and the cost of keeping a cow for a year is $400, it does not take long to see total profitability decreases.
- Percentages; Pregnancy Rates
The percentage of open cows is possibly the most costly factor in beef production. The cow is expected to produce a calf each year given the inputs of feed, water, bull or semen and time. When she is open, she is still utilizing inputs and not providing production returns. The higher the percentage of open cows, the lower the returns from production.
Cows pregnant per cows exposed is a measurement that can be used to analyze the breeding program. The average of cows pregnant per cows exposed in Saskatchewan is 90%. There are several areas that may need to be analyzed if your numbers are not satisfactory. The first area is pre-breeding nutrition. If the cows or bulls are not conditioned enough to complete breeding, pregnancy rate will be lowered. Cows that had calving difficulty in the previous year may not be physically ready to rebreed. Bulls that are not in condition to breed, will not do an adequate job covering the herd.
The higher the percentage of open cows in the herd, the lower the returns from production.
Nutrition during the breeding season is also important to assure breeding. The bull-to-female ratio differs with pasture terrain and size, water and availability, bull ago, libido, fertility, social behaviour and condition.
The average bull-to-cow ratio in Saskatchewan is 1:25. All the above factors should be considered when analyzing the reasons for a lower percent of cows pregnant per cow exposed.
Other useful measurements include; calves born per cows exposed, per cows pregnant or at calving time. These are estimates of the efficiency of the entire herd management program, based on the actual number of cows at the different periods of production.
The three calculations take into account the breeding program, the culling program and death loss prior to calving. Calves born per cows exposed can identify cows with fertility problems. Infertility may be due to nutrition, maturity at breeding, disease or injury. Abortions or the skill of the pregnancy checker at the two causes reducing the number of calves born per cow pregnant. This number should be 100%. This identifies cows that are unable to carry a calf to full term. This type of problem may again be attributed to nutrition, disease or injury. The number of calves born at calving, identifies cows that have failed to deliver a calf and can be caused by all of the above factors as well as late term abortions or loss due to calving difficulty.
If all the information is recorded, each one measures a slightly different time period during the production cycle. The calculations for these measurements can be found in Table 3.
- Calving Season
A long calving season means a loss of production and therefore reduced profitability. The total length of the calving season is important as well as the percent of calves born early in the season. The later a calf if born in the calving season the lighter it will tend to be at weaning and when sold.
It is estimated that each additional heat cycle before conception reduces the weaning weight of a calf by 30 to 40 pounds. This means reduced income when the calf is sold. Also the later the calf is born, the less time a cow has to regain condition to breed back for the next year.
The calculations in Table 3 provide an estimate of the percent of calves conceived within the respective heat cycles of the previous breeding season. Although gestation lengths vary, calving dates do reflect the efficiency of breeding and conception rates.
Death loss impacts profits for beef producers. The loss of one calf reduces the productivity of the entire herd. The death loss in Saskatchewan is estimated to 6-7%. This is a concern for all producers and should be one of the areas examined to minimize losses.
The death loss can be broken down into two time periods. The first is calving to one month of age. Calf losses at this time may be due to calving difficulty, disease, deformation or weakness due to nutrition. In Oregon, the death loss during this period was about 81% of the total death loss.
This demonstrates that there are more calves lost at calving than during the post-calving period.
The second part of death loss is when the calves are one month to one year of age. Most calf losses during this period are due to accidents, disease or predation.
The Oregon death loss during this period in 1988 was about 19% of the total. When accurate records of calf deaths, including the cause, are kept, the calculations are much more meaningful and can be used to point out problem areas. The calculation to determine total death loss is in Table 3.
With the high cost of maintaining a cow herd, a culling program is essential to improve or maintain profitability. Most of the time culling is done once a year, after pregnancy checking. It should be a year round program.
Data from Miles City, Montana, showed that the largest number of cows were culled because they were open. This data was collected from 1965 to 1978 and showed that nearly 16% of the cows were culled because they were open, 1.5% because they were missing or had died, and 1.6% were culled because of other reasons. The total cull percent was 18.9% for the time period.
Reasons for culling vary, but all should include the following:
- unsoundness interfering with bearing or nursing a calf, and
- the weight and quality of the calf raised.
The calculations for culling percent can be found in Table 3.
- Death Loss
The death of a cow may be an indication of a problem area that needs prompt attention. Disease, predation or accidental losses are all areas that can be analyzed to reduce losses. When a cow dies, a post-mortem should be done to determine the exact cause of death. In most cases, this makes decisions much easier in preventing further losses due to the same cause.
The product sold on beef operations is growth. Weaning weights and selling weights of calves are measurements of growth for both individual cows and the entire herd.
By itself, growth has little meaning and should be considered over time. Total growth or production of the entire herd should be the first area of consideration. This is a composite of the growth of individual calves in the herd and includes two parts.
First is the environment that the calves are in after calving. The environment has a major impact on growth, when growth is expressed as pounds produced over a specific time period.
Maximum growth potential of individuals is determined by genetics, which is the second part of total herd growth. This involves the selection of individual cows that exhibit superior calf growth over time. These selections are the basis of growth potential for the next generation of cattle produced. Maximum genetic growth can only be reached when the environment is adequate. Management is combining the two parts.
- Weaning Weights
The weaning weights of calves is a combination of the genetic growth potential of the individual, the milk production of the cow and the environment. The genetic potential was determined upon conception and is based on herd genetics.
The milk production of the cow is a major portion of the growth of the calf for the first months of its life. A low milking cow will not generally wean a heavy calf.
The environment prior to weaning is also important to the calf as well as the cow. With good quality feed available, the cow can produce more milk and, therefore, provide more growth for the calf. Once the calf begins to graze, good quality feed helps to continue the growth that has been established by the milk of the cow.
- Selling Weights
The selling weight of calves takes into account the weaning weight as well as the growth post-weaning. Selling weights may be the same as weaning weights for some operations. However, for the operations that hold the calves for a time after weaning, the environment is a key factor. A clean sheltered area with good quality feed and water where calves start eating right away, thus keeping stress to a minimum allowing the calves to continue to gain.
The calculations for growth are in Table 3.
Key areas of production have been identified in this worksheet. If the numbers are not satisfactory on your operation, each should be examined to determine where profitability can be increased.
The management system is where the limits of tolerance for open cow percent, calving season length, death loss and minimum growth are set. This may be the place to begin the analysis and determine if realistic goals have been set for the conditions and environment of the operation. The parts of the management system included in the evaluation should be disease prevention, bull performance, nutrition, parasites, cow performance and the environment.
Prepared by Tom Dill, employed by Grazing and Pasture Technology Program, and
Jim Graham, Livestock Specialist with Saskatchewan Agriculture and Food, Swift Current.