Ram Breeding Soundness Examination
  • A breeding soundness examination is recommended for all rams immediately prior to breeding. 
  • The importance of this exam cannot be stressed too highly. 
  • An infertility problem in the ram can be very costly in a single-sire breeding group. (He must be considered as half the breeding flock). 
  • Rams may be classified as 
    • sound, 
    • questionable
    • unsound.
  • Occasionally we detect problems which are temporary or treatable.
This examination involves:
  • Body condition scoring and conformation
  • Good condition but not too fat (need to feel them)
  • Feet, legs and back should be sound
    • Check for foot rot
  • Testicular palpation and measurement
    • SC correlated with:
      • sperm production, 
      • age of puberty in offspring
  • Epididymitis may be detectable by palpation - check carefully that scrotum is full of testes
Semen collection and evaluation
  • Artificial Vagina can be used, hand held electroejaculator is the most common.

  • Rams usually all or none (good or azoospermic)
  • No WBC should be seen, as they are the first sign of B.ovis
  • The effects of the Louisiana summer can damage semen quality for up to 49 days (after last exposure to extreme heat). It is important to take this into account in this evaluation and also when selecting your breeding season.
  • Abnormal sperm cells seen.
  • < 5 WBC/High power field


  • Unsatisfactory in any - cull
  • Questionable in any - retest
  • Satisfactory in all - breed 50 ewes
  • Exceptional in all - breed 100 ewes

Ram Infertility
Brucella ovis #1 infertility problem
  • Transmission - venereal ram to ram
  • Ewe is mechanical vector
  • Generally older ram flock problem
  • Palpation
    • May miss carriers
  •  WBC in semen
    • See very early
  • Complement Fixation testing
  • Culture
    • Semen culture - not 100 % reliable
  • Brucellosis test - a simple inexpensive blood test will establish if your ram has brucellosis before you begin breeding. Cannot differentiate vaccination titers
Control recommendations
  • Cull palpably affected rams
  • Cullrams with WBC (PMN) in semen
  • Cull rams with > 30% detached heads
  • Cull all CF pos. rams (if not vaccinated)
  • Vaccination is questionable at controlling
  • B. ovis + Strain 19 used

Actinobacillus seminis
  • Seen in young rams
  • Spread by sodomy
  • See: epididymitis, orchitis, pus
  • Diagnosis - signs, culture
  • Control - cull affected
Breeding Management of rams
Puberty and Sperm Production
  • Puberty in the male is the time at which reproduction is first possible, that is when the testes begin to produce sperm cells. 
  • This time is governed by testicular size which in turn is a factor of the ram's body weight. 
  • Most rams will reach puberty between 5 and 9 months of age depending on body weight, nutrition, breed and various environmental factors. 
  • Although your rams have reached puberty by 9 months of age they may not be "successful" breeders until they have learnt correct sexual behavior.
Sexual Behavior
  • It is important to understand the ram's behavioral patterns in order to correctly choose a mating percentage (ie the ratio of rams to ewes).
  • Mature ewes in heat will form harem groups around rams. 
    • These groups will seek out the ram, maintain proximity to him and overtly solicit his attention. 
    • Younger ewe lambs in their first and second estrus (heat) will not form these groups. 
    • Thus ewe lambs require greater confinement and a higher mating ratio than adult ewes. 
    • Younger ewes are usually subordinate to adult ewes and this reduces their chance of being mated if run with adult ewes.
* separate maiden ewes from mature ewes for breeding
  • Ewes vary in their attractiveness to rams. 
    • In any group of estrus ewes, some will receive more attention than others. In turn some ewes will compete for proximity to a ram. 
    • Rams have a preference for ewes of their own breed or appearance.
  • The average ewe will be bred 2-4 times in one estrus period. Females may need to be inseminated more than once to achieve pregnancy.
  • Dominant rams will prevent submissive rams from breeding ewes. 
    • If a ram with poor semen or low libido (sex-drive) exhibits this "blocking" behavior in a multi-sire mating group, obviously poor lambing rates will result.
    • This stresses the need for breeding soundness examination (BSE) prior to breeding.  
    • Rams will form a pecking order for sexual competition which is identical to their feeding competition order. 
    • Subordinate rams will have decreased mounting and ejaculating frequency even if the dominant ram is in an adjacent pen.
* get a BSE on your rams before breeding
  • Ram lambs reared together exhibit homosexual behavior. As well as propagating epididymitis, this will have temporary effects on the mating behavior of these rams when exposed to ewes.
  • * raise ram lambs singly or at least in close proximity to ewes
Mating Ratio
  • The optimum ratio of rams to ewes vary with age of females, scrotal circumference of rams, age of rams and the size and terrain of the mating area. 
  • If rams are healthy and fertile, and if there are no geographical restrictions, then 1 ram can breed 100 females.
  • For maiden ewes this ratio should be reduced to 1:50. 
  • Likewise young rams (2-tooth) may not be active as mature rams and the ratio should be reduced.
  • The use of a harness with a colored crayon is now a standard technique to monitor mating patterns within a flock during the breeding season. 
  • The harness should be fitted carefully to the ram so that chafing does not occur and so that ewes are correctly marked. Harnesses and crayons should be checked regularly. 
  • The crayon color is changed every 15 days so that ewes which breed back can be detected.

For example:

  • yellow ochre for day 1-15
  • venetian red 15-30
  • lamp black 30-45
  • Obviously, ewes marked with more than one color are returning to the ram. 
  • This technique may also be used as an early pregnancy test. 
  • Some care must be taken in interpreting these results as very light marks may go undetected and not all ewes that are marked necessarily produce a lamb.
Heat Stress
  • By far the most common cause of problems we see in the breeding season is heat.
  • Hot weather (greater than 4 days at greater than 80 degrees) during breeding reduces libido, mounting frequency and semen production and quality, especially in European breeds. 
  • We advise:
    • don't begin breeding too soon, better to have late lambs than no lambs at all.
    • if the weather remains hot, house rams and breed only at night.
  • About 0.5 to 1 cm of wool is ideal for the breeding flock. 
  • Too much wool will make your rams susceptible to heat stress and reduce their efficiency. 
  • Feet trimming, if necessary, should be performed at this time.
  • Rams will eat less and lose condition during the breeding season. It is important that rams begin the season in good condition and that you maintain their condition (2-4 lbs/head/day).

contributed by Bruce E Eilts and modified on 22 October 2005

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contributed by Bruce E Eilts on 25 September 2012


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