J. L. Goelz, D.V.M.
SheepLetter, Vol.26, No.7, September 2006
Once you turn the rams out into the ewe flock ram management is not done. If possible rams should be observed daily. I prefer observing rams in the evening as you are more likely to see them chasing ewes than during the heat of the day. Rams should be actively chasing ewes during the evening and sometimes you may even observe mounting. This confirms that the libido (desire to breed) is good in the ram. If the ram has a breeding harness new marks can be recorded and a reasonably accurate due date can be calculated. Marking crayons can be switched every two to three weeks (moving from light colors to darker) to help keep track of ewes that remark. Rams should also be observed for general health. Rams should be athletic and sound on their feet. Any lameness is cause to consider pulling a ram out of the breeding pasture. During the act of breeding a ram must be able to support nearly all his weight on both back legs. If one is painful he will not breed. When a ram dismounts half of his weight lands on both front feet; if one is sore he will not breed.
Back injuries are a common reason for pulling rams from the breeding pasture. Breeding requires both strength and flexibility in the spine. As rams age the spine becomes less flexible as calcium bridging starts to fuse the vertebrate. If this briging cracks the ram will experience intense pain and have no desire to breed. Intervertebral disks can also become compressed or inflamed and cause compression of the spinal cord. This is often evident as pain or hindlimb weakness or lameness. While lameness from a foot injury carries a good prognosis for recovery and a future as a breeding ram a back injury will nearly always reoccur the next time that a ram mounts a ewe.
Other reasons that rams may have to be pulled from the breeding pasture include pneumonia, rapid weight loss or testicular injury. Pneumonia or fever in general may cause temporary infertility if the testicles get too warm. Testicles are outside of the body for a reason. Sperm cannot be produced at body temperature. Therefore if body temperature increases 2-4 degrees the sperm in the testicles and epidiymis are at risk of being dead. It takes 60 days for a sperm cell to be produced so fever can cause 60 days of infertility. Testicular injury is not common but obviously ends the ram’s ability to breed ewes. After any insult to the testicle such as infection or trauma the first sign is swelling and heat. Heat will cause temporary infertility just like fever. After the swelling phase you may notice one or both testicles shrink in size. This is a poor prognostic indicator as it indicates that the sperm producing tissue is dead.
Rams will lose weight during breeding season, especially ram lambs as they are still growing and will not eat enough during breeding season to grow and maintain their weight Ram lambs may need to be pulled out of the breeding pasture if they get too thin. Often this is late in the breeding season when most of the ewes are bred and fewer rams are necessary to “clean-up” the remaining open ewes.
Treatment for rams that have to be pulled from the breeding pastures is aimed at 1) salvaging the ram to use later in the breeding season or for next year’s breeding season or 2) salvaging the ram for cull value. Number one is not a bad option if the reason for pulling is mild such as pneumonia, foot sprain, etc. Number two is a bad option as cull rams are never worth much. In most cases severe injury, weight loss, etc producers will be better off by culling the ram immediately. As far as we know treatment with Bamamine (flunixin), long-acting penicillin, Excenel, Naxcel or Nuflor is not detrimental to fertility. Treatment with dexamethasone or LA-200 can cause transient infertility for 60 days.