Frequently Asked Questions
The short answer is yes. Due to their dark pigmentation, Angus cattle do not show the physical signs of FE but it has been proven that beef cattle are highly affected by subclinical FE. A recent case study showed that FE impacted growth rates of beef animals by up to 70%. The impacts of FE are often more subtle in cattle than in sheep due to the timing of a cow’s breeding season, which is generally before the onset of an FE challenge. The main issue arises when the cow rebreeds the next season with liver damage affecting the cow’s ability to maintain condition, milk and ovulate. Often farmers overlook this impact and will attribute it to a more benign factor, but just like sheep it is lurking in the background and impacts on production.
At Piquet Hill we don’t treat any of our stud stock with preventative FE treatment. All stud stock is blood tested for FE and this data is kept and collated to help select bloodlines that are FE tolerant. We believe that producing a beef animal that has FE tolerance is a major step in locking in production gains for both beef and dairy beef producers. Analysis within our own herd has found significant variation in liver damage of different cohorts, with some cows and family lines showing up to 15 times more tolerance than others.
FE testing was developed in the 1980s at AgResearch to help identify individual animals that showed tolerance to facial eczema (FE), which is highly heritable (45%). Creating a measurable FE test enabled these animals to be identified.
The process works where the spore that causes FE is created in a lab and then induced into a potential sire in a controlled environment. Rams that show little or no elevated GGT levels in the liver after 21 days are termed to be tolerant and are, in turn, used as sires over candidates that have shown elevated GGT levels.
As you begin to test and select for the sire candidates that show nil reactions you are able to increase the dose rate. Over the last 20 years at Piquet Hill, we have been able to increase our dose rate from .45 to .72 in our Romney flock, effectively doubling the flock’s overall FE tolerance. This increase in tolerance gives farmers that use Piquet Hill sires greater and more immediate protection from facial eczema.
Facial Eczema testing in cattle is done in a similar way through natural challenge. Cows and Bulls are base line blood tested to create a baseline GGT level and are run in tight cohort groups where they are eating similar pasture preferably in a break feeding scenario without supplement. As the eczema season progresses, we take spore counts of the pasture and once we believe there has been adequate exposure, we then wait 21 days and then rebleed the cattle to get an elevated GGT level. Animals that show lower elevations than other members of the cohort are considered more FE tolerant. As more and more data is collected over years we believe family lines and patterns will emerge which will help in future breeding decisions.
Genomics is a modern technique used in animal breeding to help and assist in sourcing and identifying superior animals.
Genomics relies on a blood test, which identifies certain genetic markers that are associated with particular traits. Genomics enables a breeder to more accurately predict the make-up of a sire before he is used.
Two animals that are of the exactly the same pedigree and have similar raw data can have different genomic data. This means that one is more likely to pass on favourable genetic material to his offspring than the other. This enables you to better predict how an animal will breed before he has progeny on the ground. Genomics rely on a large reference population to validate the data. The more related that the gnomically tested animal is to the reference population, the more relevant the data produced.
Estimated breeding values (EBV) are produced by the conversion of phenotypical data into relevant breeding values that are comparable between animals. The more data that is collected on an animal and his relatives the more accurate the breeding values become. A sire with multiple progenies will have greater accuracy than an animal with none. The data becomes much more relevant when the animal is closely related to the reference population. This is why many breeders will use link sires every year to help connect their programmes with others. By linking their programmes, they are able to benchmark their animals against the rest of the industry. The use of link sires is less prevalent in the sheep industry as there is less artificial insemination, so rams need to be shared between partnered flocks in a short breeding season. Once an animal gets a genomic breeding value (GBV) the breeding value is then combined with its estimated breeding value and it is given an overall, or molecular, breeding value.
Line breeding is a system which concentrates the blood and influence of one or more ancestors to a level above that which would have existed had each of the ancestor’s names only appeared once in the pedigree of their descendants. Line breeding never introduces more than 50% of the blood of any ancestor into a descendant regardless of the number of times the ancestor’s name may appear in the pedigree of the descendant.
Prepotency is a term used to describe an ability for a singular animal to “stamp” certain characteristics on his or her progeny. Particular line bred or closely bred sires are known to be very prepotent due to the recurrence of the foundational sire in their pedigree. Hence, why some farmers choose to use them as an outcross to improve consistency in their herd or flock.
Outcrossing is the term used when a breeder sources genetics that are of no relation to their current herd or flock. Outcrossing is a way of injecting a portion of heterosis into the pedigree and increasing production. Outcrossing is more typically used when a breeder uses a terminal sire over their breeding females to get faster-growing, earlier-finishing animals. Heterosis typically halves with every cross.
Forming links is when breeders use sires from other flocks and herds in the same breeding seasons as their linking partners. Linkage helps benchmark breeding programmes with others in the industry. Sometimes a breeder has to use a sire that they wouldn’t normally just to help build linkage and data accuracy.
Body condition is the single most important trait needed when breeding in an environment where there is variation in feed inputs throughout the year. A body condition score helps identify females that are able to hold and lay down fat in times of feed deficit, particularly in our dry summer months. Body condition is linked to fertility, lamb and calf survival, and mortality. It is the single most underrated trait to production. Our strict adherence to singular cohort groups means that females unable to thrive under selection pressure will not remain in the studs.
We have a unique herd composition at Piquet Hill. Half the herd is made up of what is commonly known as pure New Zealand genetics. These genetics are free of any North American bloodlines and trace their ancestry wholly back to Scotland. They are typically moderate-framed, fertile, easy-doing types with sound structure and disposition. There are only a handful of herds left in the country that have pure New Zealand bloodlines. Most recently outcross sires have been sourced from Pinebank , Glanworth, Kenhardt or Red Oak. herds follow similar breeding philosophies to our own, breeding to a stringent long-term goal of overall production gains in commercial environments that breed cattle in conjunction with high production sheep systems.
The other half of the herd is from more imported genetics with a focus on the same production goals. Typically, we see very little difference in the raw data output of the different lines, although we get slightly increased growth rates out of our composite cows with improved carcase data we also get a slight increase in weight and less FE tolerance.
Why do we do this? Firstly, it gives farmers a genuine industry outcross with a pure New Zealand (PNZ) bull that will lock in core traits of phenotypical consistency, fertility and Fleshing ability into their cattle. Secondly, we believe that the best bulls are produced with a portion of both imported and PNZ genetics in the first cross. That is why we embryo transfer our best performing PNZ cows to imported bulls, getting the best of both worlds.
Some of the standout bulls produced in the Waitawheta herd over the years had both PNZ and imported genetics.
Worm resistance is the trait that identifies sheep that produce less eggs per gram of faecal matter comparative to their cohort. A sheep that produces less eggs is deemed to be more resistant to parasites than one that produces more. It is best practice to weigh lambs when they are collected as this builds a picture of how different worm burdens have affected certain animals weight gain. Worm resilience doesn’t look at the worm burden of the animal, just their ability to thrive or not under challenge . This is measured in weight gain over time. There is a moderate link between the two traits.
A net efficient producing animal is generally termed as a cow or ewe’s weight of calf and lambs weaned compared to her bodyweight at weaning. This can be expressed as a percentage of body weight weaned. A highly efficient cow will generally wean above 50% of her body weight, while a highly efficient ewe will wean about her own body weight in lambs. This is quite different to feed conversion efficiency, which looks at the amount of feed required to produce a kg of carcase weight. Feed conversion efficacy measures inputs while net cow and ewe efficiency measures output without a full understanding of the feed requirements to reach those outputs.
Many people have different ideas on why some cow families are more dominant than others throughout different breeding programs. We at Piquet Hill term these cows at the base of these families as “Standout Cows”. The current Piquet Hill herd has around 130 females of which over 80% are descended from 6 cows. So, of the original cows purchased in 1984 to make up the Waitawheta herd only a small proportion of those cow families still exist. This has been done through basic natural selection.
Dr Percy Sharpe a highly respected embryologist, cattle breeder and Vet introduced a theory to me which I believe unlocks the answer to why some female lines are more dominant than others and why we should be more mindful of the dam line when making our breeding decisions.
What is a Standout Cow?
Any Beef farmer who knows his cows well will be able to show you the ones that are his star performers. More than likely, they will talk about cow families where it doesn’t matter what bull you mate to them the resulting progeny always seem to perform. These are the cows that we need to propagate and multiply.
What makes these cows star Performers?
Our theory is that these cows make better use of the feed that they consume giving them large energy resources which enable them to forage in times of feed deficit.
Biology tells us that all living cells ultimately rely for energy on the production of ATP (Adenosine Triphosphate) from whatever form of energy is supplied to them. A closer look tells us that this Kreb’s cycle takes place in the small organelles within the cell called the mitochondria. Our theory is that a cow with larger numbers of good mitochondria in her cells will have more energy to perform and make better use of the energy she consumes.
Cells have both Nuclear DNA and Mitochondrial DNA, this DNA is transferred through to progeny by the parents from one generation to the next. While nuclear DNA are passed evenly by both the sire and dam, Mitochondria DNA is only inherited from the Dam giving the dam an extremely important role in the development of the future progeny.
What does this mean for our breeding decisions?
We need to multiply our star performers if we are able to. The most effective way to do this is through embryo transfer. Every year at Piquet Hill we select a number of females who we believe carry these star attributes and try and multiply them.
With this information in mind, we need to take into account that the performance of certain animals can’t be solely determined by who their ancestors are and how their genes are inherited but also by where these ancestors are placed within their individual pedigree.
With this in mind we would also determine that the Sire contributes equally in the passing on of phenotype (physical characteristics such as conformation, growth, udder characteristics, feet and legs etc. but the sire contributes nothing to how the cells of their progeny make use of the energy they consume.
In conclusion not all cows are created equal and though huge emphasis is placed on sire selection. Dam selection is also a field that is extremely important.
Breeding structure and function without compromise, with a guarantee of performance; derived from years of selection pressure, to ensure the best genetic offering for your operation.
Director & Owner, Piquet Hill