Ewe productivity is one of the key factors in flock profitability, as the number of lambs scanned and born dictates the yield.
Factors ranging from condition score at mating to parasite loads and disease can affect how ewes and rams perform at tupping.
Below, Cath Tudor and Abbie Dimelow from Prostock Vets offer advice on how breeders can boost herd performance this autumn.
“Having health checks prior to collection will ensure ewes and rams enter the breeding season in peak condition,” advises Ms Tudor.
See also: 5 tips from NZ to increase sheep income by 30%
1. Keep your body weight under control
The level of body reserves affects the hormones needed for reproduction, so a healthy body weight is very important for fertility.
Being too fat or thin can reduce conception rates, and it’s not a quick fix – it takes eight weeks of unlimited grazing for a sheep to score under condition.
Body condition goals:
- Aim for a body condition score (BCS) of 5 in lowland breeds, 3 in mountain flocks and 2.5 in hill sheep.
- The Rams will lose two conditional points during tupping, so aim for a BCS of 3.5
2. Parasite control
Ewes with high parasite loads will have poorer performance, but unless the animals appear thin or in poor condition, routine pre-watering tupping is not necessary.
A fecal egg count (FEC) should be done to determine if treatment is needed.
“A herd can struggle with different worms from one year to the next, especially if there are incoming stocks,” Ms Tudor warns.
Haemonchus is an increasingly common tropical/subtropical worm in England as the climate warms.
Filter incoming stock as different flocks will have different anthelmintic resistance and there is no guarantee that they have been treated.
Visit the Scops website (PDF) for advice on what to use.
Sheep and rams should be given a flucicide if your farm has wet soil, but blood and FEC tests with your vet will tell.
Around a quarter of all lamb losses on UK farms are due to abortion, but enzootic abortions of sheep (EAE) and toxoplasma can be effectively controlled by vaccination.
Farmers who note herd sterility greater than 2% should ask their veterinarian to investigate whether a potential infectious cause of abortion is the root cause.
“Take notes. More than two abortions per 100 sheep is not normal,” says Ms Dimelow.
Vaccination is key to preventing abortions from EAE and toxoplasmosis.
Protection against EAE from a vaccine administered at least four weeks before tupping lasts for three years, so for many flocks it is a “once in a lifetime” expense, immunity lasts for about 18 months in ewes vaccinated against toxoplasmosis before mating.
“It’s an investment worth making because heartache and hassle for lambs is not what you need at the busiest time of the year,” adds Ms Dimelow.
4. Quarantine incoming rams and replacements
The quarantine period should ideally be 28 days.
“The fact that the sale of rams is held so late in the year is a problem for veterinarians. Buying and selling should be in August to give incoming stocks a chance to settle in,” Ms Tudor explains.
Scabies is common in many areas and even an animal showing no symptoms may have picked it up from a sale – the parasite that causes it can live on surfaces such as doorposts for up to 17 days.
If the blood test and the result is positive, treatment before tupping, during tupping or after tupping, if necessary, will interfere with fertility.
5. Evaluate rams
One in five rams is subfertile or infertile, and heat stress is a factor – which reduces both sperm production and quality, and could be a problem for many flocks this fall.
If a ram has a high fever, it can affect sperm for up to eight weeks, so treat immediately if the ram is limping or coughing.
“Check the physical health of rams before mating,” Ms. Dimelow advises.
Check the teeth, toes, testicles and BCS and get a complete fertility check 10 weeks before tupping.
“If the ram requires treatment or needs to be improved, 10 weeks gives you time to do something about it,” Ms Tudor explains. “If it’s infinite, there’s still time to get another ram,” he said.
Flap rams should have two wide cutting teeth that meet the hard pad at right angles, not tipping forward. Cheek teeth can be felt from the outside of the jaw and should be regular.
See also: How to perform a dental examination in sheep
Feet should be healthy without digital growths.
Inspect the scrotum for two testicles that move freely and feel firm but not firm, without any hard lumps, and with an epididymis about the size of a ping-pong ball at the base.
Check everything again two weeks before the catch.
Using a teaser can promote breeding for up to two weeks and produce compact lambs, but if you are going to use it, keep the breeding rams out of sight, sound and smell of the ewes for 4-6 weeks beforehand – at least miles away.
One ram is enough for 100 sheep.
For breeding rams, assign one ram to every 40 ewes in the hill flock and one ram to every 30 lowland ewes.
Cath Tudor and Abbie Dimelow were speaking at a recent Farming Connect webinar