Nordic Total Merit Index

We are always talking about NTM, Nordic Total Merit –index. But what is NTM? What does it mean? What makes NTM one of the most progressive breeding value systems in the world? If these are questions you have been raising, you will get the answers as we are breaking down NTM and unlocking the figures for you.

NTM is a combined index of different genetic traits that are heritable through mating bulls with cows. The purpose, of course, is to develop the cattle’s ‘genetic capital’ to achieve higher profitability and functionality of the herd by breeding new generations of cows with higher capability e.g. for milk production and resistance to diseases. NTM comprises of more than 90 sub-traits combined into 15 main traits.

Different combined indices have different weights for different traits depending on the breeding goal. Some combined indices are more focused on developing the cows’ conformation (e.g. height, width), some have the main emphasis on production (i.e. how much milk the cow produces) and some are targeting the health traits (e.g. resistance to hoof and udder diseases). NTM is a balanced breeding tool – focusing on the improvement of the health traits and fertility, production and functional conformation.

NTM Breeding weights:

• Health and reproduction – 45%
• Production and efficiency – 40%
• Functional conformation – 15%

The ideology behind this weight distribution is that our breeding goal is to improve the health of cattle in each generation while increasing production as well. The heritability of health traits is a lot lower than production traits, so therefore we put more weight on the development of health traits to ensure balanced breeding outcome. Healthy cows have a long lifespan (i.e. longevity) and cost less, therefore improving the profitability of the herd. The weights vary a bit between breeds, but we’ll explain that later on in this series.

With NTM you are always breeding for better productivity, better health and good functional conformation.

It is actually not so difficult to understand NTM and the proofs in our system. Estimated breeding values (EBVs) for 15 different traits in NTM are shown in such a way that animals in the base population for the breed have an average index of 100. For NTM, our total merit index, the average is equal to 0.

You just need to remember that the average bull has

• NTM 0
• breeding values 100.

That would be the typical representative for the breed.

Using a statistical concept - Standard deviation - makes it possible to know what is normal, and what is extra good or what is not so good. Just relying on averages can be misleading. Without using standard deviation, you have no way of knowing how spread out the values are around the average.

Let’s see how the distribution of indices looks like. The bell-shaped curve shows a plot of normal distribution, and each band has a width of 1 standard deviation. In our system 1 standard deviation is equal to 10 units.

You can see from the distribution of indexes, 1 standard deviation (10 units) away from the mean to the left or right has 68% of the animals with breeding values between 90 and 110 and -10 to +10 for NTM. Moving further away from the mean – 2 standard deviations on each side, you have 95% of the animals being placed here, they have breeding values between 80 and 120. For NTM, our total merit index, that would include the animals with NTM from -20 to +20.

The animals with a proof over 120 and with NTM over +20 are actually the superior representatives of the breed, as these animals represent the best 2.5% of the breed. They are simply the elite specimens. If we compare with other international indices, a breeding value of 120 on the Nordic scale is comparable with a US bull at +2.00 (PTA Type) and 108 in the Dutch proofs.

NTM and breeding values for different traits is not just numbers but an important tool to compare the bulls. These numbers reveal what genetic potential is actually hidden in a bull. By looking at NTM and the estimated breeding values (EBV) for a specific bull, you could know what to expect from his daughters. The numbers will tell you all about their performance in your herd.

Everything is relative and we know there is a difference between bulls on the genetic level. In our total merit index – NTM, a bull with NTM 0 is an average bull. A bull with NTM +10 is labelled as Good, while a bull with NTM +20 is a Super bull. A bull with NTM +30 is even better, he is a Superior specimen and represents the top 0.1% (1 out of 1,000) of the bulls. Our top ranking genomic VikingHolstein bull – VH Bradoc has +40 in gNTM or 1 out of 30,000 bulls. Not hard to understand how rare and special that is!

If we take one of the most common problems in dairy herds – mastitis, what does the breeding value of 110 for Udder health in NTM mean in practice? For VikingHolstein bulls, if compared to an average bull with EBV 100 – the daughters of the bull with EBV 110 for Udder health will have 20% less incidences of mastitis. The daughters of the bull with EBV 120 for Udder health like our genomic bull VH Balzac (+34 gNTM) would mean 40% less mastitis.

Less incidences of mastitis means healthy cows, less money spent on treatments, less work on the farm, less milk that has to be thrown away. Numbers behind NTM and breeding values do make a difference. You can directly connect them to profitability of your dairy business!

As you can see, NTM and breeding values are not just numbers – they are tools that bring success to dairymen worldwide.

We have previously explained that in the NTM we are breeding for a balanced outcome combined of Production, Health & Fertility and Conformation & Workability to ensure the optimal economic outcome. The weights in NTM are:

• Health and reproduction – 45%
• Production and efficiency – 40%
• Functional conformation – 15%

The ideology behind this weight distribution is that our breeding goal is to improve the health and fertility of cattle in each generation while increasing production as well. The higher weight on health and fertility traits is due to its increasing importance for dairy farm’s profitability. Keeping the cost down per produced milk kg, ensured by good health and fertility, is just as important for profitability as focusing on improving the production capacity.

Why do we have different weights for different breeds? Bovine breeds are different from each other and therefore the weight distribution in the breeding goals for VikingHolstein, VikingRed and VikingJersey are a bit different. We want all the breeds to develop towards the optimal balanced breeding outcome while taking into consideration the genetic differences and the natural breed specific tendencies for certain traits. The weights for the different breeds are shown in the image.

VikingHolsteins are very high in production by their breed type and abilities, therefore, the weight for improving their Production capability is lower than for VikingRed and VikingJersey. As our breeding programs aim for a balanced breeding outcome, it is more important to focus on developing the health traits for VikingHolstein than production capacity that is developing well already for the breed.

Red breeds are naturally healthier breeds than Holstein so therefore the weight put for improving Health & Fertility is lower for VikingRed than for VikingHolstein. VikingJersey has a bit lower weight on the health traits in NTM than VikingHolstein, as Jerseys are better in reproduction traits, like daughter fertility and calving. Therefore, the focus can be moved to improving production instead. When looking at the NTM main traits - let’s take Hoof Health as an example - VikingHolstein has the highest weight of all breeds in improving that. The reason for this is that Holstein as a breed is more prone to hoof diseases than Reds and Jerseys.

The weight put on Conformation & Workability is lower compared to Health and Production, and is similar for all the breeds as all the breeds’ physical traits support efficient milk production equally.

The distribution of weights between the three groups – Production, Health & Fertility and Conformation & Workability is the result of thorough economic calculations. The goal is to ensure maximum profitability for dairy farms.

What is a correlation? Why is it important to talk about correlations in breeding?
Correlation is a measure for how things are related. When the connection between two things is close, we talk about a high correlation. On the contrary, when the connection is not clear, we talk about a low correlation or no correlation at all in some cases.

Why are correlations useful within breeding? Correlations are useful because if we find out what relationship exists between two things, we can make predictions about their future development. This way, we can calculate more precisely about the genetic progress that can be achieved. Understanding correlations is an important part of breeding programs.

A correlation coefficient, a number that indicates the strength and type of correlation, is a way to put a value to the relationship existing between two things. Correlation coefficient is a value of between -1 and 1. Number 0 means there is no relationship between the two variables at all. Perfect negative correlation has a value of -1 and perfect positive correlation is marked with 1. Negative correlation means that if one of the variables is increasing, the other variable is decreasing. For example, like the relationship between production index and health traits. In positive correlation, both variables are increasing.

We have talked in our earlier posts that there are 15 main traits in NTM. From the data we are collecting on all the different traits included in NTM, we can see that NTM has a strong positive correlation to Longevity, Production, General Health (trait that covers reproductive & metabolic disorders, feet & leg problems), Daughter Fertility and Udder Health.

The picture shows the five traits that you achieve most progress for, when you rely on NTM as your breeding tool for VikingHolstein. It’s important to remember that with NTM you are always breeding for improved profit as well. Data shows, that selecting bulls with high NTM, gives progress in all traits that have economic importance for a successful dairy business.

In a way, correlations are like ‘quality guarantee certificates’ that tell you what traits you improve in your herd, and in what traits you achieve genetic progress when you use NTM guiding your breeding strategy. Therefore, correlations are important to show and talk about.

In our next post, we will explain in more detail the trait correlations in relation to NTM.

In our previous post we explained the basic principle of correlation. Correlations are used as trait progress indicators in breeding programs throughout the world and it is very important to understand their meaning.

Dairy cow’s health and well-being is a sophisticated system where everything is interconnected. As an example, hoof health influences the longevity of the animal. Our breeding goal is a long-lasting cow that is healthy, trouble-free with high lifetime production. This means lower costs, less work, better profit and a better life for dairy farmers and the cows.

Using NTM as a breeding tool guarantees a good balance between the different included important traits. Our massive and unique data registrations behind NTM breeding values are a solid basis for building the optimal breeding program. Our goal is to breed a high producing cow that does not require too much attention – the invisible cow.

A correlation of 0.5 between NTM and a single trait indicates that 50% out of the maximum progress is expected to be achieved for that trait if you use NTM as your selection tool rather than select only for a specific trait. Longevity has a strong positive correlation with NTM, equal to 0.64. So, if you rely on NTM, you are able to achieve 64% progress for longevity out of the maximum progress that you would achieve if you only selected for Longevity.

The picture shows the five traits that have the strongest correlation with Longevity. It is not surprising that you see the traits that are among the most common culling reasons for dairy cows. It is also interesting that longevity has a quite strong negative correlation to Frame (-0.35). This means larger cows tend to have more health problems, and do not stay long in the herd.

Correlations with longevity:

• Udder Health 36%
• Calving ease 21%
• Fertility 46%
• General Health 39%
• Hoof Health 38%

This means that improving longevity in your herd will also improve the above mentioned traits the percentage shown of the maximum improvement than can be done if only the mentioned trait was selected as a breeding goal.

Production for a dairy cow is one of the most important traits, if not the most important. Without the capability to produce a sufficient amount of milk, the cow is not supporting a sustainable and profitable dairy business. The production index describes the bull’s daughters’ genetic potential for milk, fat and protein production.

The overall breeding value for production is a combination of three components. Our production index includes breeding values for kg of milk, kg of fat and kg protein in the first three lactations. We also have breeding values for the fat and protein percentages.

We are using a specific formula for calculating the production index of the above mentioned three components. The formula is a bit different for VikingJersey than for VikingRed and VikingHolstein.

• VikingHolstein
  Milk x (-0.25) + Fat x (0.55) + Protein x (0.70)
• VikingRed
  Milk x (-0.25) + Fat x (0.55) + Protein x (0.70)
• VikingJersey:
  Milk x (-0.30) + Fat x (0.65) + Protein x (0.65)

Why do we have a negative weight for kg of milk? We are breeding for high fat and protein components, therefore, there is a negative weight on kilograms of milk. This way we can improve the overall production amount and the quality of the milk i.e. the amount of solids in an optimal way. In the modern dairy business, more and more importance is put on the substance of the milk than rather just the volume, and many of the dairy businesses are paying farmers by the solids.

A daughter of a bull with an estimated breeding value (EBV) of 120 will produce a lot more milk than a daughter of a bull with average 100 EBV for milk kg. As an example, the Nordic Holstein average milk production in 305 days (average of first three lactations) is 10,204 kg, in comparison a daughter of a bull with EBV 120 for milk kg the production amount average increases by 656 kg!

The Production index is based on reliable data with 95% of commercial dairy herds in Denmark, Sweden and Finland participating in milk recording.

In NTM, there are seven health-related traits – all these seven traits together have 45% weight in the total merit index (NTM). In the coming posts, we are going to talk about health and reproduction and we start with the Udder Health index. The Udder Health index has a weight of 19% for VikingJersey, 13% for VikingHolstein and 11% for VikingRed.

The Udder Health index is strongly correlated with NTM, for VikingHolstein that number is 41%, and it also has a strong correlation with Longevity (36%) and General Health (28%). The Udder Health index is a very important trait, both for dairy cows’ well-being and comfort but also for economic reasons. Mastitis is among the top culling reasons in dairy cows.

The Udder Health index describes the bull’s daughters’ genetic ability to resist mastitis and it includes breeding values for udder health in the first three lactations. The Data behind the Udder Health index is the records on clinical mastitis made by veterinarians. Cell count (first three lactations) and udder conformation (fore udder attachment and udder depth from the 1st lactation) are used as indicator traits for udder health.

What makes the Udder Health index unique is that in the Nordic countries, we register actual disease cases and don’t just rely on indicator traits, like Somatic cell count (SCC). SCC alone is not a good enough predictor for improving mastitis resistance. The Correlation between SCC and clinical mastitis is around 0.6, so it is not really the same trait. Therefore, registrations of clinical mastitis are a more accurate breeding value base. Official registrations are done for 90% of cows in Denmark, Sweden and Finland. That results in a high reliability of breeding values for udder health.

A daughter of a bull with an estimated breeding value (EBV) of 120 in Udder Health will have less mastitis than a daughter of a bull with 100 EBV which is the population average for the breed. There really is a difference between bulls! For example, VikingHolstein EBV 120 for Udder Health means 42% less cases of mastitis relative to population average.

What does that 42% reduction mean in real life? Let’s take an example of two farms with Holstein cows; Farm A with 500 cows has 10% of cows with mastitis per year, so 50 cases of mastitis. Farm B with 500 cows has 40% of cows with mastitis per year, total of 200 cases of mastitis. A bull with EBV 120 for Udder Health can reduce the mastitis frequency so that farm A will go from 50 cases to 29 cases of mastitis per year and farm B will go from 200 cases to 116 cases per year.

In the Nordic countries, the frequency of clinical mastitis (average of first three lactations) for VikingHolstein is around 13%, and for VikingRed and VikingJersey is 8% and 15% respectively.

In this and our next post, we are going to talk about Hoof Health.

The Hoof Health index is strongly correlated with NTM, for VikingHolstein that number is 35%. It also has a strong correlation with Longevity (38%), General Health (25%) and Daughter Fertility (23%). The Hoof Health index is a very important trait, both for dairy cows’ well-being and comfort but also for economic reasons. Lameness is among the top culling reasons in dairy cows.

The Hoof Health index measures the bull’s daughters’ genetic ability to resist hoof diseases and it includes breeding values for 10 hoof disorders grouped into seven sub-traits. Sole ulcer as the most costly hoof disorder (a severe case is estimated to cost 1,300 € under Nordic conditions) has the highest weight in the index. Among other diseases included in this index are Digital dermatitis, Corkscrew claw and Sole Hemorrhage. The data behind the Hoof Health index is the records on hoof disorders collected by hoof trimers during the first three lactations.

What makes the Hoof Health index unique is that in the Nordic countries, we register actual disease cases and don’t just rely on correlated trait - like Feet & Leg conformation. The Feet & Leg index alone is not a good enough predictor for improving hoof health. The correlation between Feet & Leg index and Hoof Health index is around 25%. Only one out of four times, you would succeed in improving hoof health if you rely on Feet & Leg conformation. Therefore, registrations of actual diseases are a more accurate breeding value base. Electronic hoof trimmer data is collected for 40% of cows in Denmark, Sweden and Finland. That results in a high reliability of breeding value for hoof health.

In our next post, we will talk about how much improvement you can expect from a bull with high breeding values for Hoof Health sub-indices.

How much improvement in hoof disorders can you expect from a bull with high breeding values for Hoof Health sub-indices?

Let’s take the most costly hoof disorder – sole ulcer. A severe case of sole ulcer is estimated to cost 1300 € under the Nordic conditions. A daughter of a bull with an estimated breeding value (EBV) of 120 in Sole ulcer sub-trait under Hoof Health index will have less sole ulcer cases than a daughter of a bull with 100 EBV, which is the population average for the breed. There really is a difference between bulls! For example, VikingHolstein EBV 120 for Sole ulcer means 57% less cases of sole ulcer relative to population average.

What does that 57% reduction mean in real life? Let’s take an example of two farms with Holstein cows; Farm A with 500 cows has 10% of cows with sole ulcer per year, so 50 cases. Farm B with 500 cows has 40% of cows with sole ulcer per year, total of 200 cases. A bull with EBV 120 for Sole ulcer sub-trait can reduce the disease frequency so that farm A will go from 50 cases to 21 cases of sole ulcer per year and farm B will go from 200 cases to 86 cases per year.

Another common hoof disorder is digital dermatitis. EBV 120 for digital and interdigital dermatitis sub-trait means 24% less disease relative to the population average. One of the best performing VikingHolstein bulls VH Clark with 143 EBV for digital dermatitis will really make a difference in your herd! His daughters have 54% less digital dermatitis compared to population average. If you wish to improve hoof health in your herd, VikingHoofHealth is the solution you can trust!

Learn more about hoof health

How much improvement in health can you expect from a bull with high breeding values for General Health sub-indices?

Let’s take one of the most common metabolic diseases – ketosis. A daughter of a bull with an estimated breeding value (EBV) of 120 in Ketosis will have less ketosis cases than a daughter of a bull with 100 EBV, which is the population average for the breed. For example, a VikingHolstein bull with EBV 120 for Ketosis means 76% less cases of ketosis relative to population average!

What does this 76% reduction mean in real life? Let’s take an example of two farms with Holstein cows; Farm A with 500 cows has 2% of cows with ketosis per year - 10 cases. Farm B with 500 cows has 10% of cows with ketosis per year, total of 50 cases. A bull with EBV 120 for Ketosis sub-trait can reduce the disease frequency so that farm A will go from 10 cases to two cases of ketosis per year and farm B will go from 50 cases to just 12 cases per year.

If we take early and late reproductive disorders, EBV 120 for these two sub-traits for VikingHolstein means 30% less disease cases relative to the population average.

Our General Health index covers important transition cow disorders like milk fever, metritis, ketosis among others. Health disorders in transition period cost a lot of time, money and productivity. Studies show that 75% of disease cases in dairy cows occur in the first 30 days in milk, transition cow disorders have a lot of influence on your bottom line. Preventing diseases through genetics will help you reduce many post-calving disorders.

One of our top performing VikingHolstein genomic bulls, VH Solvind, (+31 gNTM) with 121 EBV for General health will really make a difference in your herd! His daughters will have 28% less early reproductive diseases, 32% less metabolic disorders and 56% less ketosis compared to population average. If you struggle with a high level of diseases in transition period, choose the bulls that have high EBV for the General Health trait to enhance the transition health of your herd.

With the General Health index in NTM, you get the complete information on health covering more than 80 diagnoses.

In this and our next post, we are going to talk about Youngstock survival index in NTM. Youngstock survival index (YSS) was added to NTM in 2016. Youngstock survival index describes the genetic ability of the bulls’ offspring to survive from birth to maturity. Bulls with high indices for YSS breed offspring with good survival in the rearing period.

The correlation between YSS and NTM is 24% for VikingHolstein, 27% for VikingRed and 30% for VikingJersey. That means that when NTM is increased with 1 index unit, YSS is increased with 0,24 unit for Holstein.

Even though YSS was included in NTM only recently, we have been collecting data since 1998 in Denmark, 1999 in Sweden and 2004 in Finland. Thanks to the extensive data available in the Nordic countries, we are able to have a highly reliable index for youngstock survival. Breeding values for youngstock survival are based on farmer registrations on mortality of calves in rearing period.

Youngstock survival index includes breeding values for:

• Early rearing period (heifers), 1-30 days
• Late rearing period (heifers), 31-458 days
• Early rearing period (bulls), 1-30 days
• Late rearing period (bulls), 31-184 days

Survival traits in NTM, such as calving direct, longevity and youngstock survival have high economic importance and cover the whole life-time of animals. In order to improve survival of animals, it’s not efficient to just use longevity and calving direct as predictor traits. By adding YSS index to NTM, together by calving traits and longevity index, we have now a comprehensive and trustworthy breeding values for survival.

How much improvement in Youngstock survival can you expect from a bull with high breeding values for YSS?

As an example, for Holstein on average 4% of heifers are lost in late rearing period (1 to 15 months), and the costs to lose one Holstein heifer is about 405 euros. For a herd with 100 heifers, this would mean loss of 1,620 euros per year (4 calves). For a herd with 300 heifers, this would mean a loss of 4,860 euros (12 calves). One lost red calf costs about 415 euros and one lost Jersey calf 241 euros. Values are based on NAV calculations in the Nordic countries. So, improving the youngstock survival of your herd will save you money!

There are significant differences in youngstock survival between bulls. This means that it is possible to breed for better survival. A bull with 120 EBV would improve youngstock survival and help farmers reduce costs by 54%, relative to a bull with EBV 90.

What does this 54% reduction mean in real life? Let’s take an example of two farms with 300 Holstein heifers in the herd, one using a bull with EBV 90 for YSS and the other, a bull with EBV 120 for YSS. The farm using the bull with EBV 90 will lose 14 calves per year in the late rearing period, costing them 5,670 euros. The farm using a bull with EBV 120 for YSS will lose only 6 calves, costing them 2,430 euros. The farm using the bull with a higher EBV for YSS is saving 3,240 euros per year. Having a good survival rate in the herd makes the farmer’s job easier and more cost efficient. Having a high youngstock survival rate eases the herd planning and future plans as there are less un-expected losses in the herd and the farmer can rely on the herd’s progress.

Daughter fertility index describes the bull’s daughters’ genetic potential to start or resume heat cycle after calving, to show oestrus and to conceive at insemination. The higher the breeding values, the better fertility. Traits included in the combined index for daughter fertility index are:

• Days from calving to first insemination (cows)
• Days from first to last insemination (cows, heifers)
• Number of inseminations per pregnancy (cows, heifers)

Daughter fertility index is calculated on data based from insemination records on heifers and cows from first three lactations. Data is collected by farmers and AI technicians.

So what does this mean in real life? Let’s take our VH Clark NTM +27 as an example. VH Clark has a high breeding value for Daughter Fertility EBV 130 and for sub-trait Days from 1st to last insemination the breeding value for him is EBV 135. The average number of days for VikingHolstein from 1st to last insemination is 49 days. For VH Clark daughters, this period is only 35 days, meaning you save 14 days! This is around 30% improvement compared to the population average.

For VH Clark the breeding value for Number of inseminations is EBV 130. The average number for the breed for inseminations in the insemination period is 2.0. VH Clark daughters have 1,79 inseminations – 10% better than average. Meaning that it is more likely to get VH Clark daughters pregnant on the first try than the average population cows.

Dairy cow’s fertility and health is a sophisticated system where everything is interconnected. To improve fertility in your herd, breeding only for better daughter fertility is just a piece of the whole puzzle. To improve the fertility performance, it is necessary to consider other correlated health traits as well.

Correlated health traits:

• Longevity 46%
• Calving ease 26%
• Udder health 15%
• Metabolic and reproductive diseases 32%
• Hoof Health 23%

With NTM you are always breeding for better complete health and all interconnected health factors are included in your breeding goal. This way you can be sure of the complete health improvement.

In this post, we are unlocking the Longevity index. Longevity is a very important trait for sustainable and profitable dairy business. With cows that last long in the herd and maintain good production levels, the farmer can trust his business.

Longevity index describes the bull’s daughter’s genetic potential for a long productive life. The index is calculated as days in production, and index calculations are based on data from first calving to the end of third lactation. Our production breeding values are very reliable with more than 90% of commercial dairy herds in Finland, Sweden and Denmark participating in the milk recording. Longevity is strongly correlated with fertility and all health traits. A healthy cow will last long in the herd and will maintain good production levels.

So what does better Longevity mean in practice? How does a bull with EBV 120 differ from a bull with EBV 100 for Longevity? A daughter from a Holstein bull with EBV 110 will stay in the herd up to 57 days longer and based on average production per breed, she can produce 1,591 kg more milk in her lifetime. Daughters from a Holstein bull with EBV 120 will stay in the herd up to 114 days longer and can produce 3,182 kg more milk in their lifetime!* This means better lifetime profitability for the farmer.

As mentioned above, it is very important to remember that Longevity is highly correlated with other health traits. Healthy cow = long production lifetime!

Correlated health traits:

• Udder Health 36%
• Calving ease 21%
• Fertility 46%
• General Health 39%
• Hoof Health 38%

With NTM you are always breeding for better complete health and all interconnected health factors are included in your breeding goal. This way you can be sure of the complete health improvement.

*The daily production calculation is based on the breed average production of milk kg for 305 days: 10,188 kg. We assume that not all the additional days will be average production days. In some cases, the cow might stay longer in an ongoing lactation and in that case her production can be expected to be lower. In some case the additional days might be days when the cow is dry and not in milk production. Therefore, we count the average daily production with full 365 days to get more realistic estimate: 10,188 / 365 = 27.91 kg per day. Average production values per breed; VikingHolstein 10,188 kg / 305 days, VikingRed 9,040 kg / 305 days, VikingJersey 6,998kg / 305 days.

In this post we are talking more about the workability traits in NTM: milkability and temperament. These traits measure how easy it is to milk the cows and how they are to handle.

Milkability index describes the bull’s daughters’ genetic potential for milking speed (expressed as flow of fat + protein). The higher the breeding value, the faster the milking speed. We also have breeding value for leakage (how easily bull’s daughters leak between milkings). The higher the breeding value, the less the leakage.

Milkability has a relative weight of 3% for VikingHolstein and VikingRed and 4% for VikingJersey in NTM. Registrations for milkability are collected by farmers and are based on herd owners’ assessment on cows’ milkability compared to other cows in the same herd on scale 1-5. Besides that, information from electronic milk recording from AMS and milking parlours is included, measured as gram of fat + protein per minute (if available this is used instead of the herd owners’ assessment).

Daughter of the bull with EBV 120 would milk 22 grams of fat + protein per minute more than daughters of the bull with EBV 100 that milk 181 grams of fat + protein per minute. For VikingHolstein, that is 2.4 litres milk per minute on average and 2.7 litres milk for daughters of the bull with EBV 120– 12% improvement.

Temperament

The index for Temperament describes the bull’s daughters’ genetic potential for temperament. The higher the breeding value, the better the temperament. Temperament has the weight of 1% in NTM. Data is based on herd owners’ assessment on cows’ temperament compared to other cows in the same herd on scale 1-5 (Finland) or 1-9 (Denmark and Sweden).

Having good-tempered cows makes the farmer’s life easier as the herd is easier to manage and safer for the farmer to work. Cows with good temperament are easy to milk and move around calmly in the barn.

The conformation traits have a weight of 13-15% in NTM depending on the breed. There are 22 conformation sub-traits, combined into Frame, Feet & legs and Udder. Breeding values for conformation traits are based on classification records in the first three lactations made by official independent classifiers and are scored from 1 to 9.

What are the weights of combined conformation traits? For Frame it is 0% for all three breeds, as the economic optimum has been already achieved. Due to correlations between Frame and other traits in NTM, the effect of Frame on economy is covered. For Feet and legs – the weights are as following – VikingHolstein (4%), VikingRed (3%) and VikingJersey (2%). Traits describing udder conformation have a relatively higher weight – VikingHolstein (9%), VikingRed (13%) and VikingJersey (14%). It is especially Udder depth and Fore udder attachment that are weighted more.

How to read breeding values for conformation traits?

For all other traits in NTM the higher the breeding value, the more beneficial it is for the economy of dairy business. However, conformation traits are the exception. Breeding values (EBVs) are simply meant to describe how the daughters of the bull would look like compared to average. The value below 100 is not necessarily a negative thing. Similar to other traits in NTM, EBV 100 corresponds to the breed population average.

However, it is important to keep in mind that the difference between a bull, for example, with EBV 80 and EBV 100 for conformation sub-traits is not that significant. So, if you see a bull with 80 in one of the conformation sub-traits that should not scare you away.

Let’s take chest width as an example. VikingHolstein breed population average is 5.2 on a scale 1-9. A bull with EBV 80 (two standard deviations from the mean) has 4.9 that is only 0.3 lower in classification score, while a bull with EBV 120, would have 5.5 or 0.3 higher. The genetic variation will always exist, but it is only a very small proportion of cows that get more extreme scores - less than 1% of cows are classified with 1, 2, 8 or 9.

In our previous post we talked about conformation in general, but in this one we will talk about the optimal conformation for commercial dairy herds in comparison to optimal conformation for show cows. It should be always kept in mind that the economic optimum for a good production dairy cow can be very different from a cow that is bred for show purposes.

A cow that wins the shows and a cow that has the conformation traits that are beneficial for commercial dairy production are not the same. Good-looking show cows have maximum scores for all sub-traits for Frame, as well as Feet & Legs and Udder traits. However, that is not the case for a good commercial dairy cow, especially when it comes to Frame sub-traits. Medium-sized cow (Stature 148 cm Holstein, 142cm Reds and 129cm Jersey) is more suitable for the modern dairy production. The average for VikingHolstein cows in 1st lactation is 148.6 cm. If we look at the average for VikingHolstein for sub-traits in Frame, the values are quite close to economic optimum. It is a cow with a more moderate classification (5-6) for Frame sub-traits that has the best profile for dairy production from the economic perspective.

For Feet & Legs sub-traits, for Rear legs side view the breed population average is quite close to economic optimum classification. However, for the other four sub-traits – Rear legs back view, Hock quality, Bone quality and Foot angle higher values are desirable, meaning as high EBV as possible.

As for Udder conformation – for udder balance, teat length and teat thickness should be classified 5 to 6 to fit economic optimum or EBV around 100. Teat placement back is the sub-trait for which bulls with EBV below 100 are desirable. For all other udder conformation sub-traits higher values are desirable - as much above 100 as possible.
Broad and high rear udders are good characteristics for show cows but that has no impact on economy, and that is why Rear Udder Depth & Height have low or no weight in NTM.

In this post, we are going to talk about the base population of cows that is used for estimating the breeding values in the Nordic system in comparison with the one used in the United States.

In the Nordic countries, the new breeding values are calculated and released four times a year. For each evaluation, the estimated breeding values for different traits in NTM, and NTM itself, are calculated and adjusted so that cows in the base population have an average EBV of 100.

Each time the breeding values are calculated, a new group of cows is added to the population. New younger animals added and older animals left out. The cows in that group must be 3-5 years of age at the date of publication of breeding values. With each new evaluation the cow base is adjusted in order to satisfy this condition. Meaning that each time the performance of bulls is compared to the most recent population of cows that are in their first to third lactations. The adjustment of the base population means that it is expected that there is a drop in bulls’ index levels on each index run. This happens because the bull’s performance is always compared to the latest genetic development of the population and the population improves by every generation of cows.

Not all breeding programmes advance in the same way. For example, in the United States the base population is adjusted only once every five years. As the cow population base changes so rarely, the EBVs for bulls in the US system will experience a big and sudden drop when the base changes. The longer time passes since the last time the base has been adjusted, the breeding values of the bulls move further and further away from the population average.

In the Nordic system, the cow base is adjusted 20 times in five years of time, while in the US system it changes only once in that period. We find it very useful the way it's set up in the Nordic system as we are able to compare the bulls against the most recent population of cows in production. In that way, we always have the most up-to-date information on the average performance of the population, and farmers also use that as the best way to benchmark their own herd's performance to pinpoint the areas for improvement.

We place great trust in genomic breeding values in NTM. The genetic progress is much faster today, and currently close to 100% of services in our home countries are made with semen from young bulls with genomic breeding values. Genomic testing on females is increasing and is boosting the profitability on herd level for dairy farmers. Our farmers believe in genomic breeding values and that it will benefit the dairy business development.

Genomic selection has truly changed cattle breeding. Instead of waiting five years to get breeding values from daughter performance, we now know from a newborn bull calf what kind of daughters to expect this bull to breed in the future. Also, the sire selection to our breeding programme is more secure – we can be sure that all bulls we use in the breeding programme are the best bulls from the Nordic population.

What about the reliability of the breeding values for genomic bulls? Genomic selection reliability is getting closer and closer to the reliability of daughter information. The reliability for genomic breeding values for production is 75% whereas the reliability for the daughter proven bulls is 90%. For health traits, the reliability for genomic and proven breeding values are closer: genomic 50% and proven 63%. For conformation, the reliability rates are 65% for genomic and 80% for proven. So, there is still the benefit of higher reliability for breeding values of daughter proven bulls, but the benefit of using genomic bulls is that genetic progress makes the young bulls far better than the older proven bulls.

Why is this? There is genetic progress in NTM for all breeds, meaning that the genetic capacity of the animals is improved year by year. By using young genomic bulls, this genetic progress will go faster. Therefore, using the genomic bulls will advance the farmer’s herd’s development and at the same time produce more quality individuals for the breeding programme too.

Farmers use the genomic information on their heifers as a management tool too. Genomic testing is used to identify the best females within the herd. When farmers inseminate the best performing high NTM females with sexed semen and the lower NTM females with beef semen - the average NTM in the herd will increase. This increases the profitability of the dairy farm as the best females are producing even better daughters for the herd and the poorer performing cows are dedicated to beef production.

Genomic selection is contributing to having a balanced breeding goal that produces profitable, healthy and long-lasting cows!

In this post, we will talk about why you should not compare breeding values (EBVs) for the different traits in NTM between the three breeds.

We have previously explained that we have breed-specific weights for the traits in NTM. Bovine breeds are different from each other and therefore the weight distribution in the breeding goals for VikingHolstein, VikingRed and VikingJersey are a bit different. Each of them has its own strengths and weaknesses. We want all the breeds to develop towards the optimal balanced breeding outcome while taking into consideration the genetic differences and the natural breed specific tendencies for certain traits.

The development of genetic trend depends on how much weight is allocated to the specific trait. For traits with higher weights, the genetic progress would go faster. On the contrary, the traits that have little genetic progress have small or no weight in NTM, because it is less valuable to improve the breed for that specific trait.

When we look at NTM and the genetic trend, the figures can be comparable between different breeds.

However, if we look at the individual traits, we should look at each breed separately and not compare the genetic levels between the breeds, as the three breeds have different starting points in terms of genetic level for various traits and different development of the genetic trend over time.

VikingHolsteins are very high in production by their breed type and abilities, therefore, the weight for improving their Production (27.7%) capability is lower than for VikingRed (36.0%) and VikingJersey (37.0%). As our breeding programmes aim for a balanced breeding outcome, it is more important to focus on developing the health traits for VikingHolstein than production capacity that is developing well already for the breed.

Red breeds and Jersey are better in reproduction traits than Holstein so therefore the weight put for improving daughter fertility and calving is lower for VikingRed and VikingJersey than for VikingHolstein. When looking at the NTM main traits - let’s take Udder Health as an example. VikingJersey has higher weight than VikingHolstein and VikingRed. And that makes good sense, if we look at the phenotypic values for udder health, the population average for mastitis frequency in the first three lactations is 14.4% for VikingJersey; 11.7% for VikingHolstein and 7.4% for VikingRed. For VikingJersey, Udder health is the trait that requires more focus in the breeding programme and we see a significant improvement in that trait for VikingJersey +17.4 index units during the last 15 years.