The Ram Effect
On exposure to the sight and scent of a ram, ewes will begin cycling. The first heat is usually short and silent. Multiple ovulation are much more likely in subsequent heats and follow the normal 17 day cycle. The ram effect can be used successfully to ensure more ewes have twins at the planned start of mating.
This is a key factor in achieving high scanning rates and overall ewe profitability. Some ewes will either stop cycling or have only single ovulation.
Teasers are used to synchronise ewes for a condensed lambing and to help start cycling activity in your or early bred hoggets and ewes. Teaser rams should have surgery at least two months before being joined with ewes to ensure all fertile sperm have left the reproductive tract because this avoids accidental early lambs.
There are many other advantages of using teaser rams:
- Rams don't wear themselves out for the first 17 days running around getting those ewes that are cycling in lamb to singles
- Ewes are mostly in lamb in the first planned cycle, making scanning, lambing, docking and even selling more compact
- Ewes get in lamb with twins before autumn dry or facial eczema takes hold
- To spread risk of poor weather affecting lambing survival, mobs can be stagger mated. eg old ewes with terminal sires targeting early lamb market.
Guidelines for using teaser rams
- Use at ratio of 1:200 mature ewes (1:100 hoggets)
- Join with ewes less than or equal to 17 days before planned start of mating (PSM). Swap with entire rams on PSM.
- Create teasers 60 days before using them
- Select appropriate rams. Dorset rams better than Romneys
- Use mature rams, crease as two tooths, will last 2-3 seasons
- Ensure rams and teasers are brucellosis free
- If mating hoggets, the same teasers can be re-used
Ram health is essential for achieving top lambing percentages. Ram soundness can be divided into two main areas. General health is ensuring the ram is in good body weight and condition, has no disease and is sound on all four feet.
Consider zinc bullets in terminal sires pre mating for FE protection. Sexual health is ensuring that the ram has normal sized and toned testes and epididymis.
Brucellosis is the most common cause of infertility in mature rams and will reduce ram effectiveness.
In 2008 there were many Brucellosis breakdowns in ram flocks.
Brucella Ovis causes abscesses to form in the lower, storage part of the testicles, thereby disrupting flow and causing infertility. If not removed from a flock it can be responsible for lower lambing percentages. Often, they can be palpated but many were diagnosed last year on blood test only.
It is wise to blood test a few rams as well as palpate if you are unsure of their status.
All rams with lumps in their testes need to be blood tested and new stud rams that are "free" should be kept separate until the ram team is cleared. Teaser rams can be vascetomised at the same time as the ram flock is palpated.