SHEEP HEALTH - BREEDING

RAM PREPARATION GUIDELINES

The development of spermatozoa within a ram's testes takes 6-8 weeks. So for optimal spermatozoa production preparation should commence at least 2 months prior to using him for artificial insemination or in fact mating of any sort.
Check through the following list to ensure your ram is in good working order at the latest six weeks before he is expected to start work.

1. Mouth and Legs

   Check all his feet, if he has any foot rot, this must be treated so that he is clear of it by the time he has to start work. Check his joints and for warmth in the limbs and note any soft or hard swellings. Check his teeth and gums for wear and damage and the back of the mouth for any lumps or impacted feed.




2. Dietary Factors

   A ram should be in above average body score, but not "show" fat. He must be induced to take exercise by making him walk between food and water or some other ruse. Place him on a raising plane of nutrition of quality protein (Soybean/Fishmeal) and roughage. Any concentrate diet should avoid high levels of magnesium and calcium and should contain 1% Ammonium Chloride to assist in the prevention of urinary calculi. If there is any history of low copper and/or zinc, rams should be supplemented. Any danger of copper toxicity must be avoided at all costs.




3. Individual Penning

   Separating rams from each other a least 2 weeks prior to mating prevents inter-male aggression and homosexual behaviour. If you only have one ram, he can have the company of a yearling wether or he can become very aggressive and lonely.




4. Health Treatment

   At least 2 months before being required for Artificial Insemination or semen freezing it would be advisable that all potential sires are:
   • Treated for internal and external parasites
   • Foot trimmed
   • Shorn, if necessary
   • Given Multivitamins
   • Given Vitamin E Selenium
     ‘Vitesel' (Norbrook Laboratories) 2ml/45Kg intramuscularly. 2 treatments 2 weeks apart,
     OR ‘Vitenium' (C-Vet) 1ml/30Kg intramuscularly, 3 treatments at week intervals.




5. Health Testing

   Rams should be tested for Border Disease and Actinobacillus seminis before being used for AI. This especially applies to rams purchased from outside the farm whose health status is uncertain. In non MV Accredited flocks, bought in rams should be tested for MV.




6. Examination of genitalia

   Ask your Vet to show you how to check the ram's penis and testes. There should be no visible sores around the prepuce or on the scrotum. The testes should be firm and free of soft or hard swellings. Any abnormalities found should be reported to your Vet in plenty of time to find a replacement if necessary.




7. Libido

   One or two weeks prior to the AI or mating date, expose the ram to some ewes that are in oestrus and observe how keen he is likely to be to "work" when the day comes . If he has an old "sugar tail" ewe in with him all the better. If the ram is nervous or reluctant to mount in the presence of man this will give him confidence. It will also help to remove any degenerate spermatozoa from the epididymis and avoid the old theory that the first jump is always a blank.

   NB Two days before the due mating date, remove the ram from any direct contact with any ewes. This will ensure that he will produce good semen samples when required.

THE USE OF THE TEASER

When considering turning a ram into a teaser, it is very important to have the chosen male prepared well before the time he is needed. From the time of the vasectomy to the time he is likely to be needed and used safely is approximately eight weeks. It is well worth having your teaser ram fertility tested before use to make sure there are no live sperm left in the reproductive tract.

The ideal Teaser Ram

1. is healthy, free from any foot problems, arthritis, twisted joints etc
2. is in a good body condition, not over fat or lazy. Condition score 3.
3. has a good Libido
4. is from a suitable breed. Choose a ram of a breed that breeds naturally during the months to be used. Poll Dorset, Dorset Horn etc are ideal for early season work..
5. is aged from 18 months to 3 1/2 years

How to use Teaser Rams

Day 0. Teasers in
Days 6-7 Silent heat
Days 13-14 Teasers out. Entire rams in if using natural service or put in sponges.
Days 15-18 Early heats (short cycles)
Days 22-26 Late heats (normal cycles)

How it works

The onset of the flock's first heat can be manipulated using the effect of these substances. Usually the ewe has her first heat at a random time in the early season. If the ewe has been kept away from sexually active males, including billy goats, both sight and smell ( and the smell carries a long way down wind) for 6-8 weeks following weaning, but not necessarily following drying off from the parlour, she will tend to start to ovulate approximately 6 days after the introduction of a ram. This ovulation is often associated with a silent heat. The ewe will then either short cycle approximately 7-10 days later or more normally return into standing oestrus 17 days later.

Using Teasers in AI/ET programmes

The teaser can help to prevent this.

If you use the ram effect 2 weeks before sponging you ensure that you have increased the number of ewes that have started cycling naturally before AI. Ewes that do not hold to the AI should continue to cycle normally.

In addition there is evidence to suggest that ewes in their 2^nd or 3^rd oestrus cycle at AI synchronise for AI/ET more efficiently and therefore give you a higher conception rate, which is, of course, what is wanted. This is particularly true with shearling ewes

In AI Programmes

Where very large groups of ewes are to be inseminated, the ewes that the teaser has marked first should be drawn aside to be inseminated first. Similarly those marked last should be inseminated last.

It is believed that the teaser rams encourage ewes to show a good standing oestrus, this in turn helps to tighten up the synchronisation and increasing your conception rate to Artificial Insemination. This become even more important when using frozen semen where the better the synchronisation the better the results.

In an ET Programme

Using Teasers for Natural Mating

The vasectomised teaser rams are introduced 10-14 days before you want your fertile rams to join the ewes. One teaser per 50 ewes is enough for this.

Six to seven days after ram introduction, the ewes will ovulate and whilst some will show oestrus behaviour, others won't (silent heat). These ewes will then return to oestrus 7 days later ( a small proportion of ewes "short cycle" in their first cycle of the season) or 17 days later.

A fertile ram will need to be with the sheep at these return times, so the teaser should be replaced by the fertile rams not later than 14 days after turnout.

NOTE

For which ever reason you may be using a teaser, you must be aware of the following.

1. A teaser ram may become fertile, this is due to recanalisation
2. It is advisable to have your teaser ram retested before use each year
3. All teaser rams must be clearly identified to avoid any mistakes, especially the raddle colour.

(From Sheep Dairy News Vol 15, No.2).

GETTING YOUR EWES INTO SHAPE FOR BREEDING