This fact sheet was developed by students enrolled in Purdue's ANSC 442 Sheep Management course in Spring 2004, as a semester project. These fact sheets provide useful information on various topics related to sheep. View the list of fact sheets.

Ram Selection

Jennifer Lowe
Ryan Blanch
Bryan Rodibaugh

Adapting your Ram selection to your operation

Selecting a ram is one of the most important aspects of your operation; it determines half of your genetics for a producer's entire flock in some cases. There are many things that go into selecting a stud buck. First you want to look at the operation you want to run, do you want to be a purebred operation or do you want to be a commercial operation? Do you want to sell breeding stock or just sell feeder/finish lambs? This plays a vital role in determining what ram you want to choose. If you want to be a purebred operation your choices are narrowed to the breed you are raising. If you want to raise commercial lambs, you can look at your ewe flock and determine the most productive cross (between all breeds). This will traditionally be one of the terminal ram species such as Suffolk or Hampshire.

If you are just starting your flock and want to know which direction to go there are some key things that you should look at in determining what breed/breeds you want to have in your pilot flock. First you want to take into account how much time you have and are willing to spend with your flock, if this is limited then you may consider getting a easy keeping breed, that is requires little maintenance. The Second thing you should consider is where you are at geographically and what is available to you in terms of feedstuffs. Do you have pasture and is it high quality? Are you in an area where feed grain is readily available? How much does hay cost around you, and how much of the year will you have to use it? What is your climate like, and do you have equipment and shelter to take care of your flock in adverse conditions? These are all things you should consider when looking at what breed(s) of sheep to raise.

In order to be a successful operation you must select rams that will compliment the environment that you are in. For instance you would probably want to select an easy doing ram that can be maintained primarily through grazing. Breeds that may fit this scenario would be the Ramboulliet, Columbia, and Dorset. If you are in a location where corn and other grains are readily available and cheap you may consider raising some of the breeds that traditionally require more supplement than just grass, these would be breeds like the Suffolk and Hampshire breeds.

Another important consideration in choosing a ram is what you have planned for your breeding program; do you plan to lamb once a year or to have an accelerated lambing program where you lamb three times a year? You need to select bucks that will work during all of your chosen breeding seasons. If you plan to develop an accelerated lambing program the breeds of choice are Rambouillet and Dorset. These breeds are proven to be out of season breeders and will likely increase the total number of lambs born outside of the traditional breeding season. If on the other hand you feel that you only want to lamb once a year (traditionally early in the calendar year) about any breed and buck will work for you.

Ram photo   Ram photo

Ram Selection

Ram selection is a very important decision for a sheep producer. Whether the ram is purchased or leased, there are many variables the producer should consider before investing his flock into the sire. The ram should be examined from a few different angles: phenotype, genotype and actual performance. Also, purchase from a reputable producer that you can trust and feel comfortable doing business with.


The ram should have certain desirable physical traits. Not all producers need to breed to similar rams. Each flock is strong in certain traits while other flocks needs improvement in those same traits. The producer should select rams that will progress their flock in those traits that need improvement. Some of these traits include but are not limited to:

  • Length of body
  • Length of neck
  • Length of loin and hind saddle
  • Angle to the shoulder
  • Depth of rib
  • Spring of rib
  • Squareness down their top
  • Square dock
  • Level dock
  • Muscle pattern
  • Firm handling
  • Big rack
  • Length, width, and depth of loin
  • Heavy muscled in terms of hip and hind leg (inside & out)
  • Feet and leg structure
  • Heavy bone
  • Temperament
  • Teeth & Mouth (overbite/under bite)
  • Scrotal circumference
  • Overall balance and Eye appeal
Ram photo


The genotype of the animal takes into account a few different things. The first is the parentage of the ram, his genes, and where they came from. Not only do are we interested in the genes that are passed on, we want to know whether the genes are expressed. We want to know if he is homozygous dominant, heterozygous, or homozygous recessive for certain genes of interest. These genes influence the performance of the animal and his offspring. Typically, a sire's projected impact on a flock is measured by his EPD's. EPD stands for Expected Progeny Difference. An EPD is an estimate of the genetic value that will be passed onto the progeny of that animal. Many EPDís represent various maternal and terminal traits. There are as follows:

  • # Born
  • # Weaned
  • Milk Growth
  • Maternal Milk
  • Birth Weight
  • Weaning Weight
  • Yearling Weight
Ram side photo   Ram back photo

Keep in mind that these are genetic traits and there is an environmental interaction that will alter expected impact of the ramís offspring.

Actual Performance

A prospective buyer must also examine the actual performance of the rams. Is he a single or twin? What is his birth weight? Weaning weight? Is his mother a good milker? What was his average daily gain? Is he scrapie free or a carrier? Is he spider free? These are the kinds of questions a buyer needs to be asking the producer.

Here is some information about a few of the more popular breeds in the U.S. It is important that you research information about the breed you are going to choose because it will better allow you to understand what to expect from your ram.


About half of the sheep registered in the U.S. are Suffolk. This is due to the breedís outstanding growth rate and carcass quality. The original Suffolkís were a cross of Southdown rams and Norfolk ewes and brought into the U.S. in 1888. Suffolks are considered a terminal breed. Suffolk rams usually weight between 250 and 350 pounds, and they are the most popular type of ram to be used in sire crossbred market lambs.



The Dorset is considered a dual-purpose breed, and it is the most popular white-faced breed and the second largest breed in total numbers in the U.S. One of the best qualities of this breed is its ability to breed and lamb almost any time of the year. They began as a cross between Merino and the horned sheep of Wales and were originally polled. Polled Dorsets originated at North Carolina State College in 1956. Dorset rams have a medium size build and usually weigh between 225-275 pounds.



The Hampshire breed originated in Southern England from the mingling of different strains of sheep. It is also a terminal breed and is similar to the Suffolk in size and growth. They have well-muscled carcasses and have a mild disposition. They are a popular sire breed, and rams usually weigh between 275 and 295.



The Katahdin are an American breed of hair sheep and are very popular because of their ease of care. They originated in Maine, and are adaptable, low maintenance sheep. They produce superior lamb crops and lean meaty carcasses. They donít produce fleece so they donít need to be sheared. They are also ideal for pasture lambing and grass/forage based management systems. Rams exhibit early puberty weighing between 180 and 250 pounds, and they are aggressive breeders.



Rambouillets are the most populous breed in the U.S, and they are considered a maternal breed. They are hardy, long-lived, and produce fine-wool fleeces. They originated from the Merino breed, and the rams usually weigh between 250 and 300 pounds.



The Cheviot originated in England, and it is considered a terminal breed. They are very hardy, and they can withstand harsh environmental conditions. The Cheviot is a long-wool type, and the wool has a distinctive helical crimp that gives resilience and durability. Their hard black feet make them less prone to footrot, and they also have a tendency for worm resistance.



The Columbia is a Lincoln-Rambouillet cross that originated in Wyoming in order to replace cross breeding on the range. They are a dual-purpose breed, and they are considered hardy, adaptable, easily handled, and fast growing. The Columbia rams are preferred for range and commercial cross breeding, and usually weigh between 225 to 300 pounds.