To evaluate any animal, you must compare it against another animal or a group of animals usually known as the base. At the moment, the base in the EBI system is split between two groups. For production (milk yield, fat and protein) the base is cows born in 1995 and milk recorded in 2000. For fertility, the current base is sires born between 1988 and 1992 with at least 90% reliability.
So currently, the average predicted transmitting ability (PTA) for these animals is zero and all other animals are either plus or minus depending on their performance.
But because of the genetic gain made since these base animals were in production, ICBF has decided to update the base to make it more relevant to the cows of today. The new base is coming in next week and the most obvious effect of it will be to reduce the EBI of every herd.
The new base population for milk and fertility is cows born in 2005 and calved and milk recorded in 2007, with at least two years out of five milk recorded. This pool of animals is also going to be used as the base for fertility, using their calving interval and survival percentages.
In Olympic parlance it’s a bit like instead of comparing the performance of the 100m sprinters at the Rio Olympics against the performance of the 100m sprinters in Atlanta 1996, you compare them against the sprinters in London 2012. The top sprinters in Rio will still be the top sprinters, but the difference in their average time will be less when you compare them against the more recent Olympics because performance, training, technique and so forth have improved.
In the same way, the top EBI animals now will still be the top EBI animals after the base change; it’s just that they will be compared against a genetically superior group of animals so their PTA, or differential with the base will have decreased and therefore so too will their EBI.
So what is the new base? The average 305-day milk yield of over 60,000 cows born in 2005 and milk recorded in 2007 is 5,743kg of milk, 224kg of fat and 195kg of protein or a fat percent of 3.9% and a protein percent of 3.39%. When compared to the old base, it represents an increase in milk solids of 52kg per cow. Of course, not all of this is due to genetics, with improved husbandry playing a part also. See Table 1 for the changes in production between the two base years.
When it comes to fertility, the new base cow has a calving interval 2.8 days shorter than the old base cow, and has a survival figure 0.65% higher than the old base.
The net effect of the change to the base is that the EBI for all animals will drop by €71. The EBI for milk sub-index will drop by €29 while the EBI for fertility sub-index will drop by €42. But this is the same for animals, so there is no re-ranking of bulls or cows within the EBI.
However, as the change to the base is happening at the same time as a genetic evaluation run, it is likely that the EBI of individual animals and herds will change by more or less than the €71 but this is because of new data emerging on their performance and this would be the case regardless of the base cow changing.
ICBF does an evaluation run three times per year and it just happens that the base change is coinciding with the September run.
According to Francis Kearney of ICBF, the base change will have very little impact on farmers:
“Every animal’s EBI is dropping by the same amount so every herd is being affected in the same way. It’s not as though some herds are going to be affected more than others. Changing the base herd isn’t a big deal. We could leave it as it is but then the EBIs would keep growing and the numbers would get very large over time. Changing the base probably does make the numbers that bit more relevant to the cows we have today,” Francis says.
“When looking at EBIs, the key thing is to select bulls that are going to improve your herd’s genetics, so only pick bulls that have higher PTA or EBI in each of the traits, that way you will maximise genetic gain quickly,” he says.
Because the PTA for milk volume has increased, some bulls that are currently less than +116kg for milk volume will now be negative for milk volume after the base changes, presuming their evaluation doesn’t change. But this is only a relative difference – their rank on EBI terms will still be the same.
COW Index
While the changes to the base cow are capturing the headlines, new developments in animal evaluations are emerging. The Cow Own Worth, or COW index, is currently being piloted on a number of herds and ICBF is currently evaluating feedback on it.
The COW index ranks cows within the herd based on current lactation performance but also on future lactations based on predicted fertility and SCC performance. While the EBI should be used to select your best cows for breeding, the COW index will be used to select the best cows for culling based on the cow’s ranking within the herd. Widespread rollout of the COW index for milk-recorded herds is expected to happen in the coming months.
Next Generation results
The latest results from the Kilworth farm trial in Moorepark with elite genetics have just been released. Based on the first nine weeks of breeding, much improved fertility and better milk solids are emerging between the Next Generation (Elite EBI genetics) and the national average cows on the research trial.
The latest results presented at an ICBF industry meeting show very good fertility performance for the Elite herd compared to much poorer performance for the average EBI herd. The scan results show a six-week pregnancy rate of 77% for the Elite herd compared with a fairly miserable 51% for the average EBI herd. Up to early August, the Elite herd have produced 16kg of milk solids more per cow which is worth another €50 per cow at current low prices. See Table 2 for a breakdown of the differences between the herds.
ICBF are changing the base cow from that born in 1995 to cows born in 2005.The EBI for all animals will decrease by €71 but no re-ranking of bulls will occur.The COW Index is expected to be released soon.The fertility performance of the Next Generation herd is looking good, with 77% scanned in-calf after six weeks of breeding compared with 51% of the national average cows.
To evaluate any animal, you must compare it against another animal or a group of animals usually known as the base. At the moment, the base in the EBI system is split between two groups. For production (milk yield, fat and protein) the base is cows born in 1995 and milk recorded in 2000. For fertility, the current base is sires born between 1988 and 1992 with at least 90% reliability.
So currently, the average predicted transmitting ability (PTA) for these animals is zero and all other animals are either plus or minus depending on their performance.
But because of the genetic gain made since these base animals were in production, ICBF has decided to update the base to make it more relevant to the cows of today. The new base is coming in next week and the most obvious effect of it will be to reduce the EBI of every herd.
The new base population for milk and fertility is cows born in 2005 and calved and milk recorded in 2007, with at least two years out of five milk recorded. This pool of animals is also going to be used as the base for fertility, using their calving interval and survival percentages.
In Olympic parlance it’s a bit like instead of comparing the performance of the 100m sprinters at the Rio Olympics against the performance of the 100m sprinters in Atlanta 1996, you compare them against the sprinters in London 2012. The top sprinters in Rio will still be the top sprinters, but the difference in their average time will be less when you compare them against the more recent Olympics because performance, training, technique and so forth have improved.
In the same way, the top EBI animals now will still be the top EBI animals after the base change; it’s just that they will be compared against a genetically superior group of animals so their PTA, or differential with the base will have decreased and therefore so too will their EBI.
So what is the new base? The average 305-day milk yield of over 60,000 cows born in 2005 and milk recorded in 2007 is 5,743kg of milk, 224kg of fat and 195kg of protein or a fat percent of 3.9% and a protein percent of 3.39%. When compared to the old base, it represents an increase in milk solids of 52kg per cow. Of course, not all of this is due to genetics, with improved husbandry playing a part also. See Table 1 for the changes in production between the two base years.
When it comes to fertility, the new base cow has a calving interval 2.8 days shorter than the old base cow, and has a survival figure 0.65% higher than the old base.
The net effect of the change to the base is that the EBI for all animals will drop by €71. The EBI for milk sub-index will drop by €29 while the EBI for fertility sub-index will drop by €42. But this is the same for animals, so there is no re-ranking of bulls or cows within the EBI.
However, as the change to the base is happening at the same time as a genetic evaluation run, it is likely that the EBI of individual animals and herds will change by more or less than the €71 but this is because of new data emerging on their performance and this would be the case regardless of the base cow changing.
ICBF does an evaluation run three times per year and it just happens that the base change is coinciding with the September run.
According to Francis Kearney of ICBF, the base change will have very little impact on farmers:
“Every animal’s EBI is dropping by the same amount so every herd is being affected in the same way. It’s not as though some herds are going to be affected more than others. Changing the base herd isn’t a big deal. We could leave it as it is but then the EBIs would keep growing and the numbers would get very large over time. Changing the base probably does make the numbers that bit more relevant to the cows we have today,” Francis says.
“When looking at EBIs, the key thing is to select bulls that are going to improve your herd’s genetics, so only pick bulls that have higher PTA or EBI in each of the traits, that way you will maximise genetic gain quickly,” he says.
Because the PTA for milk volume has increased, some bulls that are currently less than +116kg for milk volume will now be negative for milk volume after the base changes, presuming their evaluation doesn’t change. But this is only a relative difference – their rank on EBI terms will still be the same.
COW Index
While the changes to the base cow are capturing the headlines, new developments in animal evaluations are emerging. The Cow Own Worth, or COW index, is currently being piloted on a number of herds and ICBF is currently evaluating feedback on it.
The COW index ranks cows within the herd based on current lactation performance but also on future lactations based on predicted fertility and SCC performance. While the EBI should be used to select your best cows for breeding, the COW index will be used to select the best cows for culling based on the cow’s ranking within the herd. Widespread rollout of the COW index for milk-recorded herds is expected to happen in the coming months.
Next Generation results
The latest results from the Kilworth farm trial in Moorepark with elite genetics have just been released. Based on the first nine weeks of breeding, much improved fertility and better milk solids are emerging between the Next Generation (Elite EBI genetics) and the national average cows on the research trial.
The latest results presented at an ICBF industry meeting show very good fertility performance for the Elite herd compared to much poorer performance for the average EBI herd. The scan results show a six-week pregnancy rate of 77% for the Elite herd compared with a fairly miserable 51% for the average EBI herd. Up to early August, the Elite herd have produced 16kg of milk solids more per cow which is worth another €50 per cow at current low prices. See Table 2 for a breakdown of the differences between the herds.
ICBF are changing the base cow from that born in 1995 to cows born in 2005.The EBI for all animals will decrease by €71 but no re-ranking of bulls will occur.The COW Index is expected to be released soon.The fertility performance of the Next Generation herd is looking good, with 77% scanned in-calf after six weeks of breeding compared with 51% of the national average cows. 
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