Parasites

Parasite resistance has been a major issue of late, especially the  barber pole worm (Haemonchus contortus). A multipronged approach works best for managing this devastating parasite. Pasture rotation, not allowing the grass to be grazed below four inches, and regular FAMACHA checks are baseline rules for managing this parasite. When a sheep or lamb starts recording higher FAMACHA scores, it's time to address the issue before clinical signs of anemia are noticeable.

Using multiple deworming products is a good approach. Parasite resistance to the dewormers available in the USA is widespread.

Most deworming products used produce some resistant worms. These resistant parasites breed with a nonresistant parasite to produce resistant offspring. And so the cycle continues until the product isn't effective at clearing the parasites from the sheep.

One product, levamisole hydrochloride (Prohibit), has a unique character. When a resistant parasite breeds with a nonresistant parasite, nonresistant offspring result. This makes it important to always have non-treated animals in the same pasture as the treated animals to ensure the breeding parasites are continuing to produce nonresistant offspring.

A new product on the market is BioWorma. It contains a fungus that consumes the worm larvae on pasture. It doesn't kill parasites already infecting the animals, only the pasture infection is affected.

The spring of 2019 Ponker Farm started using BioWorma and continued for four months. Lambs grew faster, less parasite loads based of FAMACHA scores for the entire flock, and less deworming chemicals were used overall. BioWorma is expensive and has palatability issues in some flocks. Feeding BioWorma also means feeding some grain to deliver the product. Reviews are mixed but Ponker Farm has had success and will invest in the product again next year primarily for lambing and the first four months of life for the lambs.

By using BioWorma, Prohibit as needed, FAMACHA, pasture rotation, and vigilant assessment of every sheep and lamb, parasites are manageable. The most important factor is to be aware of the potential for losses and recognize early signs of susceptibility. Those lambs that require frequent anthelmintic dosing should not be bred nor sold as breeding stock. Responsible stewardship begins with us, the breeders.

Scrapie Resistance - Does genetic testing matter?

There are several schools of thought about the scrapie situation in the USA. Some say that since there are fewer and fewer cases every year, it is inevitable that, over time, scrapie will become a non-issue. Others say that having a certified scrapie free flock is enough. Yet others test for genetic scrapie resistance. It could be said that everyone is right. A combination of these positions can offer the absolute best security for a shepherd’s flock and add value for a potential buyer. Every shepherd must judge for themselves what makes sense for their geographic location, market, and risk.

The United States Department of Agriculture (USDA) Animal Plant Health Inspection Service (APHIS) scrapie eradication program determines how animals, farms, and entire flocks are handled when scrapie is discovered.

A surveillance program managed with cooperation between the federal government, each state, and industry, monitors scrapie through testing at slaughter, on farms, and through the Scrapie Free Flock Certification Program. When an animal tests positive it is tracked back to the source (if possible) with the potential for any sheep having contact with the diseased animal to be euthanized (genetic testing aside). Heartbreaking, but tracing the disease back to the point of infection eliminates the source, thus making future positive scrapie from that flock unlikely. With this stance, the scrapie incidences will be reduced to a point of almost being a non-issue. Eventually, the goal being to eradicate scrapies from the USA.

Having a certified scrapie free flock takes time and adherence to the Scrapie Flock Certification Program Standards. Check the link for further information. https://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/downloads/standards_current.pdf

The caveat is that while the animal from a flock certified free of scrapies is indeed a safer alternative than a non-certified flock, the animal brings limited value to the new flock unless the genetic resistance of that animal is known. There is the peace of mind that certification brings to a flock owner and to buyers of those animals, especially buyers that already have certified flocks. To maintain the certification (there are two categories with three statuses) any additions to the flock must be the same level or higher certified. Co-mingling reduces all certifications to the lowest level animal in the flock.

Genetically testing sheep for Codon 171 can help determine which sheep carry lower susceptibility for scrapies. QQ sheep are at the lowest end of the scale and are most susceptible to scrapie infection. QR sheep are much less susceptible and RR sheep stand at the top with genetic resistance to scrapie. With the new regulations from United States Department of Agriculture (USDA) Animal Plant Health Inspection Service (APHIS), having tested valuable members of the flock can add a level of security especially if those sheep come in contact with other animals (such as shows or fairs). And in marketing lambs with genetic resistance a buyer is assured that those lambs will bring added value in the form of genes that will be passed on to their offspring.

By taking the steps of certification and genetic testing, scrapies incidences are decreasing every year. Protecting our flocks by adopting best practice biosecurity protocols can help but the long incubation time necessitates a multi-pronged approach. Genetic testing is a valuable tool in the ongoing fight to eradicate scrapies from the USA.

Breeding Plans

Dr. Phillip Sponenberg, Alison Martin, & Jeannette Beranger

As breeding season approaches, we turn our thoughts toward next year's lamb crop. Whether we're breeding for fiber, meat, breeding stock, or a combination of these, pairing our ewes and rams takes on renewed significance. A year of our hard work and dedication is invested in the end result. As responsible breeders, we need think of our own lambs and of the health of the breed as a whole in our strategies.

One part of the breeding puzzle is inbreeding or coefficient of inbreeding (COI). Going hand-in-hand with COI is the effective breeding population size. The simple definition of COI is the probability of inheriting two copies of the same allele from an ancestor that occurs on both sides of the pedigree. (2) (see definition below) Each animal has a COI and the COI of potential matings can be calculated as well.

As COI increases, the risks of inbreeding depression rises. A caveat is that linebreeding uses this method to consolidate genes for beneficial traits. As the percentage of COI increases, the risks increase. Overall vigor and reproductive success is depressed with increased inbreeding. Some breeds tolerate inbreeding better than others.

Another risk of inbreeding is the loss of genetic diversity in the breed as a whole. When bloodlines are crossed without preserving the integrity of the original bloodline, genetic variation decreases. While the decrease in genetic variation can improve the repeatability of phenotype, it depresses the genetic variability needed for population health and selection improvement. Protecting pure bloodlines from genetic dilution is healthy for the breed as a whole.

Two quotes are important for understanding effective population size. First, "Effective population size is a relative measure of the number of truly different genetic individuals in a population." and second, "Effective population size can be a useful estimate of future inevitable inbreeding trends, because low effective size indicates a future in which all animals will be related and therefore all matings will be inbred matings." (Sponenberg, Beranger, & Martin, 2017, p. 104)

The first step is knowing the COI of our own individual sheep which can be calculated by several different programs. Many Breed Associations offer some analytical tools as a part of the registry software unfortunately, at this time, the Finnsheep Breed Association registry does not have these tools available. Ponker Farm uses Kintraks. The problem with this route is the inevitable possibility of human error when transferring information from the online registry by hand into the Kintraks program. The second step is determining at what COI level risk outweighs reward. For Ponker Farm Finnsheep, we are targeting ≤5% COI for our lambs with an acceptable threshold of ≤10% COI. To ensure these are realistic targets moving forward, understanding the current effective breeding population size is important.

The census (or actual count of animals in the breed) is different than the effective breeding population size. A good example is Holstein dairy cattle. While there are vast numbers of Holstein cattle, the use of artificial insemination from related bulls drives the effective breeding population size down year on year. This makes significant inbreeding difficult to avoid. As inbreeding or COI increases, risks to depressed reproduction and reduced viability increase.  The overall low effective breeding population size coupled with the continued use of related bulls (sometimes producing over 10,000 calves a year) makes inbreeding inevitable with the result that viability and reproduction can suffer even if the actual number of animals is quite high.

Ensuring that our Finnsheep flocks and the Finnsheep breed are strong into the future requires foresight and planning.

 My rambling has come to a close.

“COI: The coefficient of inbreeding is the probability of inheriting two copies of the same allele from an ancestor that occurs on both sides of the pedigree. These alleles are "identical by descent". The inbreeding coefficient is also the fraction of all of the genes of an animal that are homozygous (two copies of the same allele). So, for a mating that would result in offspring with an inbreeding coefficient of 10%, there is a one in 10 chance that any particular locus would have two copies of the same allele, and 10% of all of the genes in an animal will be homozygous.” (Beuchat, "COI FAQS: Understanding the Coefficient of Inbreeding", 2015)

1. Sponenberg, D. P., Beranger, J., & Martin, A. (2017). Managing breeds for a secure future: Strategies for breeders and breed associations. Sheffield, UK: 5M Publishing.

2. Beuchat, C., Phd. (n.d.). COI FAQS: Understanding the Coefficient of Inbreeding. Retrieved from https://www.instituteofcaninebiology.org/

Marketing Finnsheep

Marketing Finnsheep for Ponker Farm was difficult at first but has become easier over the years. First, finding breeding quality lambs that have a suitable relationship to our flock (or line) is difficult. Finding additions to our flock that produce desirable and sound lambs is necessary. Second, the superior and delicate flavor of Finnsheep lamb was historically unknown in this area. It took effort to improve demand.

Our goal is to produce roughly 30% breeding quality stock in any given year. For a lamb to qualify as breeding stock it must meet our strict guidelines of wool quality, temperament, conformation (including well-formed, hard hooves), hardiness, and acceptable coefficient of inbreeding (COI) calculated out 10 generations. The breeding ewes and rams are all Codon 171 mapped. While the QR and RR designation can be desirable it is important to remember that a superior QQ animal can provide very good genes.

In the research of our own flock's genetics, we've found several ancestors that regularly appear in every pedigree. The goal we're working toward is to keep the COI of our lambs in the acceptable range with  ≤5% being optimal and  ≤10% being acceptable. Several of our breeding ewes carry much higher COI's so breeding them to an acceptable ram is necessary. While we'd like to find a completely unrelated line of Finns, we're also cognizant of the importance in overall breed health by keeping lines separate so the gene pool isn't completely diluted. It is a difficult balancing act. Having better analytical tools available on the Finnsheep Breeders Association website would be extremely helpful in this endeavor not just for Ponker Farm but for all breeders. This would help breeders find other breeders with complimentary stock.

It's taken us several years to develop a market for Finnsheep meat. We sell in bulk to a local sheep and goat buyer that transports the animals to large cities with demand that outpaces supply. We get a good market price for these lambs. On the local front, we sell 'on the hoof' via a small locker for individual sales. Every year, we have more local requests for our freezer lamb.

A very small percentage of our lamb crop is sold for non-breeding fiber pets. In a future blog post, we'll cover how we evaluate our potential buyers.

At Ponker Farm we believe that being an ethical breeder by treating people that adopt our beloved lambs as partners is the best practice. We don't believe in the 'buyer beware' mentality. That mentality allows breeders to sell any animal to anyone and claim anything leaving the buyer without recourse. It leaves me wondering why.  Encouraging people to invest in Finnsheep should be the goal. And to that end, breeders should be offering great lambs that they stand behind. There certainly needs to be breeder accountability if we're going to be good stewards of the breed.

It is our remit as a Finnsheep breeder to ensure we vet our potential buyers and enter into a fair two way agreement. We want our lambs to have the best home possible. This is one reason we'd like to see a 'pet' designation added to registrations of animals sold only for fiber or companions. Sometimes these lambs have great wool and temperaments so they are a good fit for that purpose but as breeding stock that are lacking. Adding a 'pet' designation keeps these animals from inadvertently ending up in the breeding pool.

My rambling has come to a close.