Selecting breeding stockStarting with and selecting the right breeding stock will go a long way towards ensuring a successful sheep enterprise, no matter what the production emphasis is or where the farm or ranch is located.
Breed selection is discussed in the Breed Selection chapter. It is very important that the appropriate breed(s) or type(s) be chosen and that they be well-adapted to the environment and production system in which they will be raised. It is almost always better to upgrade local breeds or stock than to introduce new breeds or genetics that may not be adapted to the local environment or producton system.
Most sheep selection is based on visual appraisal. Unfortunately, you can't tell much about the future productivity of an animal simply by looking at it. Ideally,sheep selection should be a combination of visual appraisal and evaluation of performance records.
You need to be careful when comparing sheep on one farm to sheep on another farm. Good management and nutrition can mask poor or mediocre genetics, while poor management and nutrition can mask good genetics. Sheep that look better aren't always better sheep. Nor should you rely soley on the information that the breeder gives you. You need to use your own observation and evaluation skills to make sound purchasing decisions.
A ram is "half the flock." His genetics will be spread over many more offspring than a ewe. Rams will be the primary means by which genetic imiprovement will be made in a flock. If the ram's daughters will be retained in the flock for breeding purposes, he should be born as a twin or triplet and/or come from a productive ewe or line. His dam should be one of the most productive members of the flock. Reproduction should always be maximized relative to the production environment. Multiple births may not be advisable in all production environments.
If the ram will be used to sire market lambs, he should be of adequate frame size (for his breed), well-grown for his age and diet, and well- muscled. You can tell how thickly muscled a ram is by feeling how wide and deep his loin is and by measuring the circumference of his lower leg with your hands. The forearm is another good indicator of muscling. Heavy-boned animals are usually more heavily muscled. Ultrasound can be used to more accurately predict carcass traits.
When visually appraising rams, you should be much more critical than you are with ewes. If a ram has has a serious jaw defect or other genetic flaw, many lambs will be potentially affected, including potential replacement lambs. Only the top five percent of rams in a flock should be used or sold for breeding. Just because a ram has testicles doesn't mean he should be allowed to mate with ewes.
Ideally, a breeding soundness exam (BSE) should be conducted on any ram that is purchased for breeding. A breeding soundness exam evaluate's the ram's breeding potential and includes a physical exam and semen test. A serving capacity test evaluates a ram's desire to mate with ewes. Some studies have found that more than 10 percent of rams are homosexual and will not mate with ewes. A mature ram will be able to service more ewes than a ram lamb.
If rams are not testing for fertility and will be used in single-sire mating systems, a marking harness should be used to monitor breeding activity or a clean-up ram should be put in with the flock. An alternative to a marking harness is to apply raddle to the ram's brisket (daily or as needed). The color of the raddle or marking harness crayon should be changed every approximately 17 days (the average length of the ewe's estrus cycle).
Producers should be willing to pay much more for breeding rams than ewes. The old rule of thumb is that a ram is worth five times the value of a market lamb. If market lambs are worth $100, you should be willing to pay $500 for a breeding ram. It is better to start with mediocre ewes (so long as they are healthy) and a superior ram rather than superior ewes and a mediocre ram.
MATERNAL FLOCK SELECTION
When starting a sheep enterprise, you can start with ewe lambs or yearlings that have never lambed and/or mature ewes that have produced offspringin the past -- or a combination of several. You can start with open or pregnant ewes. There are pros and cons to each purchase decision.
You are less likely to "purchase" problems if you purchase ewe lambs and yearlings that have never lambed. You are not likely to encounter any problems with their reproductive systems, especially their udders. Because young ewes have more productive years ahead of them, they usually sell for higher prices than mature ewes.
On the other hand, ewe lambs (bred to lamb at 12 to 14 months of age) are still growing and are more likely to experience dystocia (lambing difficulties) and other problems at lambing. Inexperienced shepherds may not want to purchase or breed ewe lambs. Ewe lambs will give birth to fewer lambs. Many ewe lambs give birth to single lambs.
A ewe lamb will not produce as much milk for her lamb(s) as a mature ewe. Sometimes, ewe lambs do not have enough milk for their lamb(s), especially if they have multiple lambs. Yearlings (bred to lamb for the first time as two year olds) will experience fewer problems than ewe lambs. They usually sell for higher prices than ewe lambs.
For people that are inexperienced raising sheep or have fewer dollars to spend, it may be a good idea to start with mature ewes (ewes that have previously raised lambs). Mature ewes give birth to more lambs, are better mothers, and produce more milk for their lambs. A ewe's performance usually peaks between 3 and 6 years of age. When purchasing mature ewes, it is especially important to make sure they are sound (udders and teeth).
If you purchase bred ewes, you don't have to purchase a ram right away. Bred ewes usually cost more than open ewes. It is best to purchase them at least a month before they are due to begin lambing, so that they can adjust to their new surroundings.
Aging (mouthing) sheep
The approximate age of sheep can be determined by examining their teeth. Young lambs have eight milk teeth or temporary incisors arranged in four pairs on their lower jaw. There are no teeth on the upper jaw, only a dental pad. At approximately one year of age, the middle pair of incisors is shed and replaced by permanent teeth (incisors).
Some breeds mature at a faster rate and their teeth will erupt at an earlier age. At approximately two years of age, the second pair of milk teeth is replaced by permanent incisor teeth. At three and four years of age, the third and fourth pair of permanent teeth appear.
At four years of age, the sheep has a "full" or "solid" mouth. As the sheep ages, the teeth will start to wear, spread, and eventually break off. When a sheep loses some of its teeth, it is called "broken" mouth. When it has no teeth (incisors) left, it is called a "gummer." A well-cared for sheep can manage without incisors, so long as its molars are still in good condition. As the condition of a sheep's teeth vary by its diet, it is difficult to accurately predict age once a sheep has a full mouth.
When examining the teeth of a sheep to determine its age, it is not necessary to pry open its mouth. Sheep will resist less, if you use your fingers to part their lips.
VISUAL APPRAISAL OF SHEEP FOR BREEDING
When selecting sheep for breeding, the most important criteria is health. Starting with unhealthy sheep dooms the shepherd to failure. A healthy sheep is bright and alert. It does not separate itself from the rest of the flock. It is in good body condition, relative to its stage of production and plane of nutrition. Sheep that limp, have abscesses, pink eye, or sore mouth lesions, show respiratory symptoms, or are in extremely poor body condition should not be purchased for breeding.
A sheep that is sound is in good physical condition and free from serious defects. A sound animal will survive and be productive for a longer time than an animal which has physical problems.
In a correct mouth, both the top and bottom jaws are aligned so the incisor teeth are flush with the pad on the upper jaw. Sheep with severe "undershot" or "overshot" jaws should be avoided, as this is an inherited defect. An undershot jaw, also called a "parrot mouth," is when the lower jaw is too short. Sheep with severe undershot parrot mouths may have difficulty grazing short pastures.
An overshot jaw, also called a "monkey mouth" is when the lower jaw is too long. Slight variations in jaw alignment are not a problem or inherited defect. The best way to observe jaw structure is to look at the sheep from the side.
The condition of a sheep's teeth depend upon its diet and the land where it lives. Animals on a rough, coarse diet will grind their teeth away faster than animals on an easily eaten diet. The molar teeth are far more important than the incisor teeth. They do the grinding of feed. To evaluate the molar teeth, you have to feel on the outside of the cheek and jaw.
Never put your fingers inside the animal's jaw. You are likely to get badly bitten. Bad breath can be a sign that there is something wrong with the molar teeth. Animals with teeth problems should be not selected for breeding.
Feet and legs
A sound sheep has straight legs that are set squarely under the corners of the body. They are not too close at the hocks or knees. The pasterns are neither too straight nor too angled. Sheep with severe feet and leg problems may break down in difficult production situations. Sheep with slight structural defects usually do not have any problems.
Take a test on sheep feet and leg structure =>
Animals with abnormal or excessive hoof growth, cracked hooves, or extremely splayed hooves should be avoided as breeding stock. Animals with colored hooves are usually preferable to animals with light colored hooves.
Conformation is the body form of the animal. It varies by breed and breed type. Smooth shoulders and staight backs are desireable traits. A ram that will be used to sire market lambs should be thickly muscled, especially through the leg and loin.
Volume and capacity
A sheep should have a deep side, wide top, and "round" body, indicative of good spring of rib. Narrow, flat-sided, shallow-bodied animals are less likely to be productive.
Skeletal size (hip height) should be evaluated within breeds or breed types. Large-framed sheep tend to grow faster and finish at heavier weights than small-framed animals. A large-framed female tends to produce heavier lambs than a small-frame female. However, production efficiency tends to favor females of moderate body size. Selection should be for ewes of adequate frame. Extremes in frame size should be avoided.
Rams should appear rugged, stout and masculine. If they have horns, the horns should be growing away from the head. Ewes should be feminine and more refined in their features. Femininity is usually associated with a longer head and neck and a more angular body type.
If wool production is an important aspect of the sheep enterprise, breeding stock selection criteria should include fleece traits: fiber diameter, staple length, uniformity of length and diameter, and freedom from defects. White-wooled sheep should be free from colored fibers. Fleeces should be dense and free from kemp and medulated fibers.
Sheep that are wool blind or have excessive wrinkles should not be selected for breeding. If hair or shedding sheep are being selected, sheep with excessively woolly coats should be avoided.
A ewe without a sound udder has no value in a breeding program. The size of the sheep's udder will depend upon its age and stage of lactation. Ewes' udders should be palpated to determined that they are healthy and functional. Ewes with hard, lumpy udders should not be considered for breeding purposes.
The udder should have two functional teats that are free from defects. Ewes with pendulous udders and bulbous or oversized teats should be avoided. Rams should be evaluated to determine that they have two teats free of defects.
The ram's testicles should be palpated to determine that they are well-developed and normal. They should be firm, evenly sized, and move freely within the scrotum. Both the testicles and epididymitis should be free from lumps. A rams with a smaller than average scrotal circumference should not be selected for breeding.
Though scrotal size varies by breed, body condition, and season, ram lambs to be used for breeding should have a scrotal size of at least 30 centimeters; mature rams, 32 centimeters. Scrotal size affects a ram's semen output. There are also correlations between a ram's scrotal size and the reproductive performance of his daughters.
SELECTING SHEEP ON THE BASIS OF PERFORMANCE
When selecting sheep for breeding, performance records (if they are available) are usually more valuable than what an animal looks like. You can't tell much about a ewe's producing ability by looking at her.
There are three types of production records in sheep production: on-farm performance testing, central performance testing, and across-flock EPD's. Any sheep farm can keep on-farm performance records. All that's needed is some form of individual animal identification, a record book, and a scale. Birth dates and weaning weights should be recorded.
Weaning weights should be corrected to a common age and adjusted for birth type, type of rearing, and age of dam. Otherwise, lambs with an environmental advantage, not genetic superiority will be favored in the selection process: early-born lambs, single, and lambs reared by mature ewes.
Selection should favor the lambs with the heaviest adjusted weaning weights from dams with the heaviest litter weights. In the very least, twin and triplet-born ewe lambs should be saved for breeding, unless multiple births are a disadvantage in the production environment.
A central performance test is where males from different herds are brought to one central location to record performance. In a central performance test, observed differences between rams are more likely due to genetic differences, which will be passed onto the next generation of offspring, rather than environmental differences which will not be passed on. A central performance test is an ideal place to purchase a ram that will be used to sire market lambs. Maternal traits are much more difficult to assess and require years of performance record keeping.
EPD is the acronym for Expected Progeny Difference. An EPD is an estimate of the genetic value of an animal that will be passed onto its progeny. For example, if a ram has an EPD of +2 lbs. for weaning weight, this means that his offspring will be 2 lbs. (on-average) heavier than the average of the breed. EPD's are calculated for various growth, maternal, fitness, fleece, and carcass traits. They are the only way to make accurate across-flock comparisons.
In the United States, EPDs are calculated for numerous breeds by the National Sheep Improvement Program (NSIP). Equivalent programs in Australia and New Zealand are Lambplan and Sheep Improvement Ltd (SIL), respectively. Canada and the United Kingdom have similar performance-testing and sire referencing schemes.
Sheep with performance records are more valuable than those without. Every effort should be made to purchase sheep, especially rams, with some type of performance records. Higher prices should be expected for performance tested animals.
WHERE TO BUY SHEEP BREEDING STOCK
There are many places to buy breeding stock: consignment or production sales, performance-tested sales, dispersal or reduction sales, sale barns, and breeders. With the exception of private treaty sales, livestock are usually sold via public auction: live, silent, or sealed bid, with live auctions being the most common. Telephone, internet, and mailed bids are often accepted.
A central performance test can be a good place to purchase rams. Many performance tests have sales at the end of their tests. Only the top-performing rams are sold. Sometimes, ewes are included in the sales. All animals have health papers.
A consignment sale is one in which breeders consign one or more of their animals to the sale. Some consignment sales are for registered sheep, while others cator to the needs of commercial breeders. Sheep sold at consignment sales are required to have health papers.
Some farms or ranches have their own production sales or several breeders work together to hold a production sale. A dispersal sale would be a production sale of a breeder that is reducing or dispersing his herd. Sheep sold at production and dispersal sales are required to have health papers.
A sale barn or public livestock auction (or stockyard) is usuallly not the best place to purchase breeding livestock. This is because many producers take their cull livestock to salebarns. There are no health requirements when selling livestock at salebarns. While animals tend to sell for cheaper prices at salebarns than at other sales or via private treaty, the health risks are usually not worth the savings.
Even if healthy animals are brought to a sale barn, they are exposed to other animals that may be infected with or carriers of contagious diseases. Diseases common to sale barn animals include foot rot, pink eye, and soremouth. Cull stock may have chronic diseases or reproductive problems.
If breeding stock are purchased from a salebarn or similar venue, care should be taken to isolate them from the rest of the herd for at least 30 days. Lambs are the safest to buy for breeding, as they are not likely to have any reproductive problems.
The best place to purchase breeding stock is from a reputable breeder that will guarantee his or her breeding stock. Most breed associations have directories of breeders that usually have stock for sale. Many states have clearing house lists of breeding stock for sale. Various web sites list breeding stock for sale.
Sheepgoatmarketing.info is a national directory of sheep and goat producers. Another place to locate breeders is Nebraska's U.S. Sheep Breeders Online Directory. Never overlook classified ads in agricultural publications and local media as a potential source of breeding stock. These days you're liable to find sheep advertised on Craig's List and E-bay.
Regardless of where or from whom breeding stock are purchased, the animals should be isolated for at least 30 days with no fenceline contact with the existing flock. Ideally, breeding stock should be purchased from as few places as possible. Once the starter flock has been acquired, it is best to close the flock to outside purhcased, except for males. It is usually necessary to purchase outside males to prevent excessive levels of inbreeding. Unfortunately, artificial insemination is not a viable option for most sheep producers.
National (state) identification requirements
In the United States, all breeding sheep are required to have official USDA scrapie identification, usually ear tags. The identification should be applied on the farm where the animal was born. In some countries, national animal ID may be required. When purchasing breeding stock, make sure they are carrying appropriate ID.
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Late updated 07-Sep-2011 by Susan Schoenian.
Copyright© 2011. Sheep 101 and 201.