Watch: Mating precision as 500 ewes serviced in Kilkenny
AI in sheep is uncommon, but farmers working with Sheep Ireland have just inseminated over 2,000 ewes. Peter Varley reports.

Artificial Insemination (AI) is commonplace in suckler and dairy herds, but its use is more limited in sheep flocks due primarily to prohibitive costs and variable success rates.

Last Saturday, the Irish Farmers Journal visited A Farmer Writes contributor Brian Nicholson to see laparoscopic AI in action. The farm, located in Johnstown, Co Kilkenny, is taking part in the central progeny test (CPT) programme run by Sheep Ireland.

The CPT programme is in its sixth year using AI, with in excess of 2,000 ewes inseminated per year. The process is no easy feat, especially when you take into account rams also have to be quarantined and trained to deliver semen for four weeks before inseminating.

As Eamon Wall from Sheep Ireland explains, the practice is worth the effort, as it delivers invaluable breeding information that is central to improving breeding in the national flock.

Background to CPT

The aim of the CPT programme is to improve the accuracy figures for the €uro-Star index and to help accelerate the rate at which top genetic sires are identified, based on performance data of a ram’s progeny on commercial farms.

Since 2009, the programme has used semen from rams on commercial flocks that have a very high standard of animal performance recording.

In the early years of CPT, the goal was slightly different to the current one. The primary aim was increasing the amount of information across all the bloodlines (high- and low-starred rams) in order to create genetic linkage across all the breeders in LambPlus. This goal was deemed to be at an acceptable level after 2013 and so the criteria was changed to try to identify the best bloodlines for breeding replacement ewe lambs.

Eamon says the reason behind using high-index rams is that their progeny’s performance can be scrutinised at a commercial level and the data obtained from these farms can be fed back to the animals’ indices. This increases the reliability of important production traits and identifies top-performing animals that will improve breeding in pedigree and commercial flocks.

“Our hope is that by proving the ram’s accuracies in the CPT, we can then go further down the line of promoting the use of those rams to pedigree breeders,” explains Eamon.

The main reasons AI is used for the programme are:

  • The number of progeny each ram produces is increased hugely compared with natural service, which means better data can be obtained.
  • Having ewes lambing down in a short period means the data selected for comparing progeny performance is much more accurate, as each lamb should be subjected to the exact same conditions (removes any environmental bias caused by a significant spread in lambing dates and aspects such as weather and grass availability).
  • Shared benefits

    Brian Nicholson says one of the main reasons he joined the CPT last year was because he likes the idea of a very condensed lambing period.

    This year, he is going to inseminate 500 ewes artificially and with an almost 80% fertilisation rate from the AI service in 2014, he expects over 400 ewes will be lambing over a 10-day period next spring.

    “Having a compact lambing period by synchronising the ewes means I can plan labour much better at lambing time,” Brian says.

    He also likes the fact that high replacement index rams are being used on his flock.

    “This should help increase the genetic merit of my own lambs that I will be keeping on the farm for breeding.”

    Brian keeps meticulous records at lambing time by electronically tagging lambs once they are born and matching these lambs to their mothers on a sheep management system.

    He records key data such as lambing difficulty, birth weight and weight at 40 days, 100 days and 150 days (unless already sold).

    By using electronic tags and a computer recording system, Brian knows the sires and dams of each lamb and he will base sire and dam selection the following year on the performance of those lambs.

    Brian’s recording skills in turn help the CPT programme because he will pass his lamb’s performance records on to Sheep Ireland. It will be able to see how each ram’s progeny performed and even more farmers will benefit from the data produced, as it will improve the accuracy of the €uro-Star indices.

    AI process

    There are various methods of AI available, with the most common being laparoscopic AI, with some cervical AI now being used. Laparoscopic AI is used for the CPT programme and is seen by Sheep Ireland as the most suitable practice to optimise fertilisation rates.

    Watch a step-by-step video of the process below:

    The timeline for synchronisation and laparoscopic AI on Brian’s farm is as follows:

  • 3 October: Approximatively 250 ewes were implanted with a progesterone sponge in the vagina (two weeks before AI took place). The sponges were inserted to synchronise cyclic activity of the flock. Brian inserted the sponges himself using a special tube and syringe.
  • 15 October: The sponges were removed by giving a firm and slow pull to the strings attached and the ewes were injected with PMSG at a rate of 400iu/ewe. The PMSG was used to increase ovulation rates and in turn hopefully increase the litter size of the ewe if she was successfully mated.
  • 16 October: The ewes were kept indoors and were given restricted access to forage and water for 24 hours to prepare for laparoscopic AI. Rams were in the shed next door to create the ram effect. The rams’ natural male pheromones help to set off the ewes’ reproductive systems and complements the effect of the removal of the progesterone sponges.
  • 17 October: Sheep Ireland transported rams rated as five-star on the replacement index to the farm (these rams were sourced from private breeders and put in quarantine for a month in advance). During this quarantine, rams were trained to produce semen for AI. Twelve rams were selected for breeding for Brian’s flock from the Texel, Belclare and Suffolk breeds.
  • On the day of AI, Ronan Gallagher from Prostar Genetics, Co Sligo, took fresh semen samples from the rams present. This semen was used to serve the 250 ewes that were brought into heat following sponge removal two days previously. A ram was selected from the six present and let into a pen with a ewe in heat. As the ram went to mount the ewe, an artificial vagina connected to a plastic collector and tube was used to collect the semen.

    Ronan says generally over one millilitre of semen collected from a ram is a good quantity in one jump.

    Once collected, he takes a small sample of the semen and puts it under the microscope. He grades the semen from one to five on factors such as motion, viability and vigour, with five being the best quality.

    Good-quality semen is diluted with a dilutant made up primarily of egg yolk to increase the amount of ewes the semen sample can cover. One millilitre of semen from the ram can be diluted to 10ml and this will easily cover 50 to 60 ewes.

    The semen and the dilutant were stored in a warm water bath at body temperature of 35°C.

    All the ewes were given a sedative to relax them before the procedure was carried out. Just before AI, the ewe was put up on a special trolly to keep her as steady as possible before work began and make her abdomen freely accessible.

    The ewe was clipped and surgically prepared. A small incision was made on the left and right hand side of her stomach. On the left, a 10mm trocar was used to make the incision a couple of centimetres in front of her udder and on the right, a 5mm trocar was used. On the left, the scope was put in and connected to a light source and acted as a mini camera.

    Gas was also pumped in this side to help displace the stomach, bladder and intestine so that it was easier for Ronan to see the womb.

    Once the way was clear, the AI gun was placed into the right-hand side and 0.1ml of semen was injected into each uterine horn. The two trocars were removed and there was no bleeding whatsoever.

    The insertion sites were tiny and there wasn’t any need for a stitch.

    Antibiotic spray was used on the sites and ewes were given an antibiotic injection to prevent any risk of infection. The remaining 250 ewes were serviced a few days later with the same procedure.

    Tullamore win a positive start to important week for Maam Cross Mule Group
    The group is hoping to build on last Sunday’s first prize win in the ewe lamb class by breeder Padraic Canny and record positive performance in Saturday’s annual ewe lamb sale in Maam Cross Mart.

    The Maam Cross Mule Group is looking forward to Saturday’s annual ewe lamb sale in Maam Cross Mart, Co Galway, with an optimistic outlook.

    Group member Stephen Joyce says the fact that fellow group member Padraic Canny claimed first prize in the Mule ewe lamb class at the Tullamore Show has started off the week’s preparations on a positive footing.

    “The level of competition in Mule classes has gone from strength to strength in recent years with more groups coming together to market lambs and continual improvements in breeding.

    ''The win by Padraic was great for the group as a whole and has lifted the spirits and gone some way to rewarding producers for their hard work in what has been a difficult start to the year. We hope now that the good fortune carries through for our sale on Saturday 18 August,” said Stephen.

    Variation

    The 12-member group has a strong association dating back over 30 years and this year will offer about 1,200 ewe lambs and in the region of 100 hoggets.

    Stephen explained that there is a good variation in sheep on offer for customers with flocks implementing varying breeding programmes and utilising different hill genetics.

    The 12-member group has a strong association dating back over 30 years and this year will offer about 1,200 ewe lambs and in the region of 100 hoggets

    “We have breeders working with the traditional Scottish Blackface ewe in the area while others have incorporated some Lanark genetics in recent years. The same can be said for the Bluefaced Leicester rams. Some are using the traditional Blue while others have gone for a crossing-type ram. All the sheep have the same characteristics though. They are bred on hard terrain, are hardy and will excel when transferred to better ground.“

    Strong link-up

    Stephen said that it will also be a sad day for the group in light of the passing of Maam Cross Mart manager Eoin Burke last November. “We had a fantastic relationship with Eoin and he was central to the success of the group. We are delighted to be continuing our long tradition of working with the Burke family and all farmers in the area are pleased to see the mart continuing to perform well.”

    The show and sale of ewe lambs takes place this Saturday 18 August starting at 11am in Maam Cross Mart, Maam Cross, Co Galway.

    Deciding what to include in a good quarantine protocol
    This week’s management notes touched on the topic of implementing a quarantine procedure for purchased sheep, this article goes into detail on the important aspects to include.

    Breeding sales of ewes and rams have kicked off, with a busy calendar of sales taking place over the next six to eight weeks. It is not the purchase of breeding sheep that presents a risk of introducing disease onto a farm, any animal coming onto the farm from an outside source presents a risk. Even where farms are operating a closed flock policy, there are very few operating a 100% closed flock policy, with rams purchased occasionally.

    Therefore, having a good quarantine protocol in place is a critical component of your farm’s flock health programme. This will differ between farms, but there are a number of variables that should be constant across each.

    Purchase in adequate time

    When it comes to the length of the quarantine period, the longer the better. As a general rule of thumb, animals should be quarantined for a minimum of 21 days and preferably 28 days before joining the rest of the flock.

    For ram lambs in particular, it is advisable to purchase well in advance of the breeding season, especially if rams have to change from an intensive, cereal-based diet to a grass-only diet or a grass diet with low levels of concentrate supplementation until mating.

    Purchased sheep should be quarantined on arrival to the farm and remain in quarantine until you are happy there are no risks of introducing disease to the rest of the flock.

    Safeguard against resistant worms

    Anthelmintic resistance is becoming a growing problem for sheep flocks, with resistance rising to varying degrees to benzimidazole, levamisole and avermectin – all active ingredients in commonly used products.

    To combat this risk, there are two approaches recommended. The more traditional approach used in recent years is to treat animals with a product containing levamisole (yellow drench) and avermectin, with a moxidectin-based product the drug of choice due to lower levels of resistance.

    A more modern approach, that is now regarded as the safest approach, is to treat animals with a moxidectin product and a new-generation wormer. There have been two new additions to this list in recent years – Zolvix, which contains the active ingredient monepantel, and Startect, which contains the new active ingredient derquantel and abamectin. Startect is experiencing supply issues, so it is likely that Zolvix will be the only option available. It is also worth noting that these products are prescription-only medicines, meaning they have to be provided by a veterinary practice.

    Sheep should be treated on arrival and kept off pasture for 24 to 48 hours, so that worm eggs present in the gut will not pass on to pasture.

    Following treatment, sheep should be turned out to pasture that is referred to as dirty; that is ground that has been previously grazed by sheep.

    Anthelmintic resistance is becoming a growing concern and as such sheep should receive a double treatment on arrival to the farm.

    Investigate presence of liver fluke

    Getting as much background information as possible from the owner of the sheep will help in strengthening the quarantine protocol.

    Where previous liver fluke treatments are unknown, animals should be treated as potentially having liver fluke and dealt with accordingly. The advice is to use a product containing trichlabendazole and another product with an active ingredient, such as closantel, to safeguard against resistance to trichlabendazole.

    External parasites

    Dipping is the optimum method for controlling external parasite risks such as sheep scab, lice, ticks, etc. For complete control, sheep should be immersed for 60 seconds, with their head plunged under the solution two to three times.

    If dipping is not an option, an alternative is to treat sheep scab with the use of an avermectin product. However, be wary as there are no injectable products that cover all external parasites.

    In this scenario, treatment will need to be doubled up with suitable pour-ons that cover sucking and biting lice and other target external parasites.

    It is also important to read manufacturers’ product guidelines closely, as some products need repeat treatment seven to 14 days later to target parasites that have hatched from eggs and have not been covered by the initial treatment.

    Administering a clostridial disease vaccine boils down to personal preference and the history of disease on the farm, but is a small cost to safeguarding your investment.

    Early intervention critical with lameness

    Introducing serous lameness-causing ailments, such as CODD (contagious ovine digital dermatitis), is becoming a rising concern – with the disease growing in frequency in recent years. All sheep should be examined for any signs of the disease or for any other ailments causing lameness.

    Sheep should be footbathed as a precautionary measure and a treatment plan should be put in place for any lame sheep. The commonly used products are copper and zinc sulphate (10% solution) and formalin (3%), although other products are available on the market. Sheep should be monitored closely throughout the quarantine period and run through the footbath at any stage of handling.

    Dipping sheep is the ultimate treatment for addressing all forms of external parasites at the one time.

    What should be considered in vaccination?

    While vaccinations often contribute to the greatest cost of a quarantine health programme, they have an important role in reducing the risk of disease.

    Their use can be reduced in some cases by purchasing from known high-health status flocks. The three main ones to consider are clostridial disease, enzootic abortion and toxoplasmosis.

    The clostridial disease vaccine should be administered shortly after arrival, with a booster administered four to six weeks later to build animals to full immunity.

    Decisions will need to be taken on selecting a vaccine that covers the full range of clostridial diseases, or one that also provides protection for pasteurella pneumonia.

    Where replacements are concerned enzootic abortion or chylamdia abortus is a highly contagious disease of sheep that hits in late pregnancy.

    The only vaccine available is Enzovax, which is administered at least four weeks before the start of the breeding season. It can be administered at the same time as Toxovax, which prevents toxoplasmosis, and must be administered at least three weeks before the start of the breeding season.

    Purchased-in sheep can be especially at risk to toxoplasmosis, as they may not yet have developed an immunity resulting in high levels of barrenness, abortion and the birth of weak lambs.

    Read more

    All you need to know about abortion on sheep farms

    In pictures: sheep dipping on your doorstep

    Ewe and ram NCT at sheep 2018

    Ewe and ram NCT at sheep 2018
    Cathal McCauley discusses the importance of carrying out a ewe NCT well in advance of the breeding season, while James Kelly highlights the critical components of a ram NCT.

    Breeding may seem some distance away for mid-season lambing flocks but putting preparations in place at least 10 weeks before the start of the breeding season will provide a sufficient window for changes to be made.

    The importance is even greater this year given the difficult spring ewes in some part of the country endured, while drought-related difficulties are interfering with preparations on many farms in the east of the country.

    Carrying out a ewe NCT and a ram NCT were two popular demonstrations at the recent Sheep2018 Farm to Fork event held in mellows Campus, Athenry, Co Galway.

    In the ewe NCT, Cathal McCauley explains carrying out body condition scoring along with assessing ewes on feet, teeth and udder health. Meanwhile, James Kelly discusses the five Ts of a ram NCT – namely timing, tone, teeth, toes and testicles.

    Ewe pre-breeding NCT at Sheep 2018:

    Ram NCT demo at Sheep 2018: