Just a few reminders as we near the mating season...
The majority of ewes are looking better than ever this year leading up to tupping, but the tail-end ewes will need to gain weight pre-mating and over the mating period to increase their ovulation rates.
Avoid shearing ewes within a month prior to mating through to two weeks post-tupping, as the stress involved can have a detrimental effect on ovulation rates and embryonic survival.
It is advisable to run mobs of younger ewes separate to the main flock as they are less active seeking out the ram and their oestrus cycles are shorter than mixed-age (MA) ewes. For this reason, sexually-experienced rams should be used with the younger age groups.
The standard ram-to-ewe ratio is 1:50-1:100. This will depend on the topography of the land and paddock size, age of the ewes and rams and nutrition. Androvax®-plus (P.A.R. Class I, registered pursuant to the ACVM Act 1997, No A9927) or Ovastim® (P.A.R. Class I, registered pursuant to the ACVM Act 1997, No A8081) users should not use a ram-to-ewe ratio less than 1:100. Ewes should not be able to become separated from the ram by barriers in the topography e.g. creeks, deep gullies, scrub or bush.
Aim to give new teasers at least six weeks rest prior to use to prevent unplanned pregnancies. Ideally, teasers should be introduced 19 days prior to the ‘real' rams going out, and at a ratio of about one teaser ram to 300- 500 ewes. A prerequisite for a response is that the ewes must have been isolated from rams, teasers and bucks for at least 21 days prior to teaser introduction. Sudden teaser presence will then induce the ewes to have a ‘silent heat' prior to tupping so that they will be into their second, more fertile cycle soon after ram introduction. An important point to make is that the ‘ram (or teaser) effect' will have no bearing on ewes that have already started their normal cyclic activity. There is no need for teasers if ewes have been vaccinated with Androvax®-plus or Ovastim®.
If ram harnesses are to be used, change the colour of the crayon every 14-16 days so that ewes returning to the ram are marked with a different colour. Check the harnesses regularly to ensure they are not chaffing or slipping.
Brucella ovis outbreaks have become more frequent in recent years. This is a disease that causes an increase in dry/dry ewes and may produce a protracted lambing season. This may become more evident on those farms using lower ram:ewe ratios or those using single-sire mating. The disease is considered to be spread venereally, and by sodomy. Please consider getting your rams checked pre-tup for B.ovis and other reproductive anomalies.
The cost of detecting problems in the rams prior to tupping is far less than the cost involved if the rams don't work!
