Range Cattle Improvement
Memoir Series Number 2John H. Knox, Professor Emeritus, Animal Science
College of Agriculture, Consumer and Environmental Sciences New Mexico State University
The purpose of cattle improvement is to increase profits. Through selective breeding, cattlemen can produce more beef per cow, step up the efficiency of their herds, and improve the selling price of their cattle. Improvement in any of these will increase profits. If all are raised together, even more profit may result.
Factors Influencing Production and Efficiency
Nothing influences the profits from a herd more than the size of the calf crop. Nutrition and management strongly affect the rate of reproduction, and heredity is less important. But a rancher can increase the reproduction rate by selecting cattle which do well on the range where they are raised, because cattle which do not do well, whatever the cause, will not produce well.
Milk supply is the greatest single factor determining weaning weight of range calves. It is most important when calves are slaughtered soon after weaning and least important when there is a prolonged period of growth between weaning and finishing. Perhaps this is why milk production was neglected in the early development of some beef breeds; cattle were older at slaughter than they are now.
Too much milk can be a problem when calves are young and range grass is plentiful. This is a price which must be paid if calves are to have enough milk when they are older or in unfavorable years. Culling cows with large teats and badly shaped udders will reduce this problem. Such culling is especially important in herds where range bulls are produced.
Growth rate, like milk production, is a heritable trait. It can be improved by selection. Cattle growth is beef production, and it is important in all stages of development. Nutrition largely determines growth attainment, but the capacity for rapid growth is inherent within the animal. A discussion of growth rate is complicated by concern about overly large cattle--those too large to do well on a rough or dry range, those with over-sized feed requirements and medium-sized calves, and those too heavy for the market.
It is true that some cattle may be too heavy to travel well on a rough range and some may require more feed than poor ranges can provide. But how can such animals come from breeding programs in which cattle care selected because they do well and produce well on the ranges where they were raised?
Currently there is much discussion about the correct size for mature cows. It is doubtful that the subject merits all the attention it receives. First, there is no right size for cows under all conditions. On any range, the correct size is that reached by the cattle which do best and produce best under existing conditions. Secondly, weight is a poor measure of a mature cow. A cow may be heavy because of a combination of good and bad; her weight may be due to growth capacity and adaptation, which are good, and it may be due to poor production, which is bad. Without rigorous culling, the heaviest cows are usually poor producers. They are shy breeders or poor milkers, or both.
Breeding small or medium-sized cows with good milk production to big bulls, preferably of another breed, may have merit. These cows may be efficient calf producers. But what about feedlot gains of their calves? Surely this is not the best way to produce reputation feeder cattle. And where are the small cows to come from after big bulls have been used for a few years? Certainly keeping the smaller, weaker heifers for replacements would be disastrous.
At times the market is depressed by too many heavy cattle. This is usually due to faulty management rather than to breeding. The cattle either were put on feed too late or, more likely, held too long. Cattle are too large to meet market requirements only when they cannot be finished to the desired degree by the time they reach the preferred weight. The objections to heavy carcasses are over-finish, over-age, and big retail cuts. The first two can be avoided with fast-growing cattle which reach the desired weight before they are over-finished and while they are still young enough to gain efficiently and produce tender beef. Besides, heifers from herds in which steers finish at 1100 pounds are well suited for slaughter at 950 to 1000 pounds. The problem of large retail cuts can be solved by proper merchandising.
Length of productive life also affects efficiency. It is influenced by vigor and adaptation. Some bulls are aging at seven years, and others are vigorous when they are nine years old. Some cows age by their eighth year, and others produce until they are 11 or older. Cattlemen can lengthen productive life in their herds by culling the weak animals early rather ran by giving them special care.
Unsoundness shortens the useful life of cattle. Unsoundness occurs most often in the eyes, limbs, and reproductive organs of both sexes and in the udders of cows. Eye cancer and vaginal prolapse are influenced by genetic factors. Injuries to the feet and legs and male organs are usually accidental. But some animals are predisposed to injuries because of weakness or structural defects. While spoiled udders may be caused by neglect, they occur most often in cows with poorly shaped udders and teats. Early culling of cows with these defects and using bulls from cows with well-shaped udders will reduce the trouble with spoiled udders.
Early maturity has been considered a desirable trait in beef cattle. Early maturity may be expressed as early reproductive maturity or early growth attainment. Breeds and individuals in the same breed vary in both. Probably early reproductive maturity should be considered an advantage unless it is associated with early aging, as it well may be. Early growth attainment is another matter. Cattle make cheap gains and produce tender beef in their youth. It seems more logical to prolong rather than shorten this period of efficiency. Too much importance has been attached to this trait. It should be re-evaluated and perhaps dropped as a consideration in cattle improvement, especially with the British beef breeds.
Factors Affecting Price
Relative prices of different lots of feeder steers of the same age depend on conformation, weight and condition, uniformity, and reputation of the herd from which they come.
Conformation is a major factor in determining price. It is the base on which the feeder must build to provide the kind of cattle the packer wants. The accepted ideas of correct conformation have changed in recent years. Now there is much talk about length or stretch. It is better to emphasize length than shortness, but pounds of beef have three dimensions. They cannot be measured by one alone. The most profitable kind of cattle for producers--growthy cattle which make good returns at each stage of their development--is also the most profitable kind for feeders and packers.
Light, thin feeder cattle sell for a premium when cattle prices are relatively higher than feed prices. Feeders can add the extra weight cheaper than they can buy it. Thin cattle are sought because they respond to improved feeding by making rapid and efficient gains. On the other hand, when feeder cattle are cheap and feed prices high, extra weight and condition may sell for a premium.
Uniformity in a lot of feeder cattle may bring a better price, especially from buyers of smaller lots. Buyers of large lots can shape up uniform groups after purchase. Color seldom, if ever, affects the price of slaughter cattle, but some feeder buyers consider color. Prices will be influenced less by factors not related to intrinsic value as more cattle are bought by large feeders who keep records of costs and returns. Feeder buyers are looking for cattle which consistently perform well in the feedlot and meet with packer approval. When they find a source of such cattle they usually pay a premium for them. These are call reputation cattle.
The Breeding Program
Improvement through breeding is accomplished by selecting the superior animals of the current generation as ancestors of coming generations. The selection takes two forms. Young animals are added to the breeding herd because of rapid growth and superior conformation. Older animals are removed from the herd because of age, poor production, or unsoundness. Both adding to the herd and culling from it are forms of selection. Both are required in a sound program.
Success depends on the standards for selection and the accuracy with which the work is done. Of the two, the selection standards are more vital. Selection should be for those traits which are directly related to profit. Standards of conformation which limit growth and production without improving carcass merit and emphasis on color or other fancy points which have no effect on production will yield little improvement. Bad results from selecting for traits opposed to production are obvious. Indulging oneís fancy by selecting for unproductive traits limits the amount of selection which can be made for important traits. The more traits selected for, the less improvement in any one trait.
Cattlemen make accurate selections by working carefully, by using scales, by working the calves from heifers separately from those from mature cows, and by having birth dates where practical. Careful work in making the selections is absolutely essential; using actual weights and working calves from heifers separately add materially to accuracy. Birth dates can improve selection, if used properly.
In registered herds, birth dates are required. In other herds obtaining usable birth dates may be fairly easy, if a herd is checked daily during calving. Each calf may be ear-tagged with a number which is then recorded in a day book. Calves born within a week or 10-day period may be moved to a corral and tagged with tags of distinctive color--blue, red, yellow, and so on--for all calves born in that period. Or numbered tags and estimated birth dates may be used. Errors in estimation should be too small to be important.
On large ranches or in rough country, any of these plans may seem to be impractical. Thus, many ranchers believe that a cattle improvement program is too difficult to carry out on their ranches. Birth dates are not that important. In fact, they may be misused. Where yearling heifers are bred, actual weights tempered with a little judgment may be better than weights adjusted for age. Small late calves are unsuitable for replacements regardless of their weight-for-age. Calves are weighed to evaluate their own performance or that of their dams. In either case and especially in the latter, adjusted weights which seem to say that a late calf is as good as an early one are misleading.
Replacement heifers should be selected at weaning, before breeding, and when their first calves are weaned. Each of these steps in selection makes its own unique contribution to the final results. Selection at weaning emphasizes the mothering ability of the dams; poor milking cows do not raise heavy, bloomy calves. Selection before breeding stresses the ability of the individual to grow and do well under existing conditions. The third selection, when the first calf is weaned, measures the heiferís production. Records show that heifers which produce superior calves usually continue to produce calves that are above average. In other words, the repeatability of calf production is high.
A rancher could probably improve his herd most rapidly by keeping a large percentage of the heifer calves for heavy culling later. But the cost of growing heifers to breeding age and the higher price paid for heifer calves usually require that he select carefully at weaning. A part of the cost of growing out heifers may be recovered, because there is a tax advantage in selling breeding cattle instead of feeders.
If the cows in a herd are sold when they are 9 or 10 years old and the average annual death loss is about 2 percent, keeping heifer calves in a ratio of one calf to five cows provides a reasonable allowance for later selection and culling. Thus, in herds with an 80-percent calf crop, one-half of the heifers should be kept; with a 60-percent calf crop, two-thirds; and with a 90-percent calf crop, about 45 percent. Good calf crops are essential for much improvement through female selection.
Weighing the heifers improves the accuracy of the first and second selections. When each animal is identified by an ear tag or other means, individual weights can be recorded and a sort made by running the cattle through a chute. When the animals are not identified, the entire lot or a representative sample should be weighed and a dividing point chosen. This can be done quite accurately. If 45 percent of the heifer calves are to be kept, the point should be set close to the average to allow for the removal of heifers with unacceptable conformation. There will not be many of these. Most heifers with good weight have good conformation. In prebreeding selections, the cut usually will be from 10 to 20 percent, and adjustment in numbers can be made easily.
At the third selection, heifers with calves are usually preferred over those without calves. Placing a heifer which lost a calf depends on circumstances and the judgment of the owner or manager. When two-year-olds are calved or in drought years, the number of dry heifers may equal or exceed the planned discard. Then, dry heifers can be pregnancy tested in the fall, and those which are open can be removed. This problem should not arise in average years on a good range or when heifers calve first as three-year-olds. The weight of calves is more repeatable than the grade. Therefore, cattlemen should use care in discarding a heifer which raised a heavy plain calf or in keeping one which has a small high-grading one.
Culling the Cow Herd
After replacements are selected at weaning, before breeding, and when the first calves are weaned, culling consists principally of removing dry, unsound, and weak cows. Usually all dry cows should be culled in herds with calf crops 90 percent or more. If the calf crop is very much below 90 percent, good young cows may be given a second chance. Culling weak and unsound cows at the earliest practical time is good breeding practice and good herd management. Some ranchers sell old cows at a fixed age unless range conditions require an earlier sale. Others keep good old cows as long as they are sound and productive. Economics may favor the former plan, but the latter plan can aid herd improvement. These old cows are the cream of the crop, and good heifer from them are excellent replacements. This does not mean that poor heifers should be kept merely because they are from good cows.
The rancher should carefully consider his ultimate goal when choosing bulls. They, more than anything else, determine the growth rate and conformation of the cattle produced in his herd. Improvement of other important traits such as milking ability, soundness, and adaptation to the range is too often left to female selection alone. If this is done, little improvement of these important traits is made. About the most that can be expected is to hold the line. Some ranchers raise their own bulls to be sure of having bulls with these traits. However, it is not necessary to neglect them when bulls are bought. If bulls are selected from herds where conditions are similar to those where they will be used and where rigorous selection for production and soundness is practiced, they should help to improve these traits.
Age of Bulls to Buy
There are various advantages in buying bulls at different ages. Yearling or two-year-old bulls which have been grown out with plenty of exercise and without over-feeding are least likely to be disappointing. Their ultimate size and conformation can be judged better at this stage than when they are younger or overly fat. Long yearlings and two-year-olds which have been confined closely and over-fed are most risky unless they are carefully managed when put on the range.
Buying bull calves has some advantages. The buyer may have first choice, if he is lucky. He is assured of getting calves from good milking cows when he picks the bigger, fleshier calves. Even creep-fed calves show the effects of the damsí milking ability. However, better selections can be made when the calves have had only grass and their motherís milk. The calves can be developed on the range where they will be used. This may be important in rough country or on ranges where feed is scarce or distance to water is great. These considerable advantages may be offset somewhat by possible losses and a certainty that some of the calves will not develop as expected. Buying calves is more workable when large numbers are involved, because an allowance can be made for disappointments in groups of 10 or more better than in smaller groups.
The number of performance-tested bulls available to ranchers is increasing. Some are tested at official stations and others on the ranches where they are raised. These tests provide information on the capacity for growth. The faster-gaining bulls from the these tests should improve weights in most range herds. Even with performance-tested bulls, it is best to have information about the herds from which they came. Bulls are sent to testing stations in small numbers, making it difficult to buy many of uniform breeding from these sources.
Producing Bulls on the Ranch
A rancher may produce his own bulls either to obtain better bulls than he can buy or to save on the cost. He may produce his bulls at a lower cost, but unless he can produce bulls at least as good as he would buy, he may lose more than he gains.
A sound program for producing bulls may cost more than the rancher anticipates. Furthermore, if he selects bulls only for size and conformation, it would be more accurate to say that he is producing better bulls than he can afford to buy. Even this is open to some question. In spite of the difficulties, some such programs are successful.
The chances of success are better if the rancherís goal is to produce bulls not only with the best possible size and conformation but also with superior inherent milk production, soundness, and adaptation to the home range. To accomplish this, he must use care and give attention to details in his bull-producing program. He must also produce enough bull calves to permit a wide choice in selecting those to be used on the range. No good rancher would buy any bull he happens to see; neither should he accept all the bull calves dropped. A reasonable rule is to produce three times as many bull calves as the number of bulls needed. One-third of these may be castrated at weaning, and one-half the remainder chosen for use a year later. Scales should be used to improve accuracy at each selection. By consistently following such a plan for a period of years, a rancher should produce good bulls which are superior in some important traits to those usually available, at a cost no greater than he would pay should he buy the bulls.
Various plans are used for classifying individual breeding cattle. The most useful plan for commercial breeders classifies the herd so that the best females are bred to the best bulls. This may work better in fairly large herds, but it can be applied on a ranch with only two bulls and two pastures. Both theory and practice have demonstrated that classification of a breeding herd increases improvement. All cattle improvement is accomplished by breeding the best females to the best bulls available. Classification provides a plan by which this sound principle may be carried a step further at little additional expense by making best use of the animals in the herd.
The purpose of classification is to produce more superior animals for herd replacements. Even in the better herds there is a rather wide range from the best to the poorest animals. If random breeding is followed, only one-fourth of the calves would have two superior parents. When the herd is divided so that the better 50 percent of the cows are bred to the better 50 percent of the bulls, one-half of the calves will have two parents which are above average. Going a step further, if the best 25 percent are mated, one-fourth of the offsprings will have highly selected parents. With random mating, this would be true of only one calf in sixteen.
A herd may be divided into two or more classes. The most simple illustration is an equal division into A and B classes. Most, but no all, replacement heifers would come from the A herd. A highly selected group of AA cattle may be formed at the top end for even faster improvement. When this is done, it is usually for the purpose of producing bulls. If a C herd is formed from the poorer cattle, it may be done to have them ready for sale at the proper time.
Cattle should be classified according to the best available measures of production. These are weight and grade for heifers and bulls. For cows, they are the weight and grade of their calves. The original classification will take some time, may be an extra day for working 500 cows into three or four classes, less for two classes. The extra time needed to work 30 or 40 bulls or 100 replacement heifers should not be more than 2 or 3 hours. After the first year, even less time will be needed for the cow and bull herds.
Classifying the Cow Herd
Her calf is the truest measure of the worth of a breeding cow. Both visual appraisal and weight are unreliable bases for selecting mature cows.
Classification is easier if cows are worked in bunches of 300 or less. Heifers should be worked separately from the mature cows because most heifers have lighter calves. The average weight of the calves is determined by weighing all or a sample. Usually there is about a 20-pound difference in the average weights of steer and heifer calves. If the over-all average is 400 pounds, and an even cut is to be made, 390 pounds may be taken as the dividing point for heifers and 410 pounds for steers. A little leeway may be allowed for borderline cases, and a few extras may be taken so that cows weigh bad eyes or udders will not go into the top herd.
If an AA herd is to be formed, the A calves can be run through again and re-divided. After the calves have been away from the cows most of the day, they pair up quite readily. The job goes faster when the smallest group of calves is paired up first. Of course the last group will not need to be paired. The job is easier after the first year. Then, only heifers and a few cows which are to be reclassified will need to be paired with their calves.
Classifying Heifers and Bulls
There are two plans for selecting replacement heifers. One is to classify them when their first calves are weaned. The other is to assign them to the different herds by weight and grade before they are bred and make the needed adjustments at the first weaning. Each plan has advantages. The first is preferred with yearling heifers to avoid breeding them to heavy bulls.
Bulls should be classified by grade and by weight, measured on scales if possible. Two-, three-, and probably four-year-olds should be weighed in separate groups. Bulls may be classified the first year they are used, or all young bulls may be run with heifers the first year and classified the second. If bulls are classified the first year, considerable shifting will be needed later. Changes will be required in any case, because some bulls become unsound or fail to develop properly, and their places are challenged by younger bulls coming on.
There is no doubt that competent herd classification speeds up improvement. It requires a little time, but it can be quite interesting to the owner or manger. He should not be deterred because the situation is not ideal. Sometimes pastures are not the right size for the herds recommended. Herds may be adjusted to fit the pastures without great loss in results. Even the lack of scales is not vital. They improve accuracy, which is important, but having the right standards is more important. A man with a practical goal in mind can do a good job until he gets scales. In fact, he will do better than a man with faulty standards and all the equipment he can use.
The Need for Records
Many range cattle breeders have not undertaken a cattle improvement program because they think that to many records are required. Most of the records suggested are important in research. Some of them are useful in improvement programs, if they can be obtained without too much effort. A brief look at some of these records will help put them in their proper place.
Birth dates, actual or approximate, are helpful if used properly. They are not vital and are sometimes misused.
Birth weights give no useful information that later weights do not provide better. Weights are important at weaning, yearling age, and before breeding; they provide the basis for making decisions at those times. When yearlings are bred, the yearling and prebreeding weights are the same. Individual weight records might be interesting, but they are of little practical use.
Some people say that a lifetime production record for each cow is necessary in cattle improvement programs. More important is to start with the right young cows. If these are selected first and then culled for production and soundness, little more information is needed. This is true especially when the herd is classified. Cows in the A herd are good or they wouldnít be there.
There is variation, of course, but more can be lost than gained if mediocre animals are kept because they are from good-producing dams, or superior animals discarded because they are from cows whose previous calves were below average. After all, the animal being considered is part of the record.
Progeny testing of sires is beyond the reach of most ranchers. The merit of a bullís offspring can be predicted more accurately from his own type and weight than can be done with a cow. A cowís mothering ability is important. This can be measured only after she produces a calf.
Ranchers should observe the performance of their cattle in the feedlot and in the packing plant when possible. If they compare favorably with other cattle, he is probably on the right track and should continue to do more of the same. If they do not compare well, he needs to make some major changes. Fortunately, the rancher, feeder, and packer all want cattle which makeófast and efficient gains and produce carcasses without excessive fat. If a breeder raises the kind of cattle which do well for him, he will go a long way toward producing cattle which will suit feeders and packers.
New Mexico State University is an equal opportunity/affirmative action employer and educator. NMSU and the U.S. Department of Agriculture cooperating.
Printed June 1968
Electronic Distribution January 2001