The average age that a suckler-bred heifer is calving down for the first time is now 31 months of age. Approximately 80% of suckler heifers that calved for the first time in 2014 have produced a second calf with an average calving interval of 364 days in 2015.
The information comes from data collated through ICBF’s HerdPlus and includes calving information on over 147,000 heifers in 2015.
Over the past five years, the average age at first calving has seen a small reduction from 32 to 31 months. While not a massive leap forward, it indicates a move in the right direction especially with fewer heifers calving between the ages of 31 and 36 months of age in 2015 compared with 2012.
In a suckler herd, there is one unit of output and that is the calf produced. To stand any prospect of generating a profit in suckling, breeding females need to wean as many kilos of calf liveweight as possible over their lifetime.
The earlier the heifer calves for the first time, the earlier she contributes to herd output and income by producing a calf that can be sold. Where heifers calve at a later age, then the longer it will be until these animals start to contribute to herd output or have a calf for sale.
Age at first calving
The graphs below outline the average age that suckler-bred heifers calved down for the first time in 2015. There are four age ranges used to categorise the heifers.
The most common age range for heifers to calve for the first time was 30 to 35 months of age at 32%. In 2012, there were 36% of heifers calving for the first time at this age range. On closer analysis, it appears that this 4% difference has moved into the 27- to 30-month age bracket when comparing national calving figures in 2015 to 2012.
On analysis of the data, it indicates that there are plenty of suckler farmers who operate a split-calving pattern. Split-calving between spring and autumn facilitates calving heifers down for the first time at around 30 months of age.
Suckler herd owners who buy in replacement heifers annually, either for breeding on farm or as in-calf animals, usually opt for an older animal that is well developed in terms of size, frame and liveweight. This would also see a lot of these animals calving between these two age ranges of 27 to 30 months and 31 to 35 months of age.
There were 27% of first-calving heifers in the 22- to 26-month age range, which has remained relatively static over the past number of years. In the dairy herd, this figure would be closer to 50%, which indicates that there is potential for more suckler-bred heifers to calve at a younger age than they currently are.
Calving at 24 months of age is the most profitable way to operate a suckler-breeding herd that breeds its own replacements. But it requires good management and herd genetics to have heifers properly developed, so that they can cope with the physical demands of calving, rearing a calf and getting back in calf again.
Many herd owners will be able to calve the heifer at 24 months, but getting the animal to produce a second calf by 36 months proves to be a stumbling block. This is where herd management comes into play by ensuring that the animal is correctly managed to meet weight targets at breeding and calving, as well as making sure the animal’s nutritional demand is being met.
Calving interval
One reason suckler herd owners will opt to calve heifers at an older age is down to the belief that they are easier to get back in calf again.
The graphs below outline the calving interval for each age bracket. Over the past three calving surveys, the heifers that calved down at 22 to 26 months have the shortest calving interval in each particular year.
In 2015, the calving interval for this group was 358 days compared with 374 days for heifers in the 31- to 35-month age range. In 2014, the calving intervals for the two groups were 389 and 402 days, respectively.
The data shows that in a well managed suckler herd with carefully selected female replacements, it is possible to calve heifers at 24 months every year and bring them through to produce a second and third calf.
While the average age at first calving may only show a slight reduction from 32 to 31 months, the calving interval for second-calving heifers has seen a massive reduction from 395 days in 2014 to 364 days in 2015.
Part of this will be driven by better grazing conditions during the breeding season of spring/summer 2014 when compared with the same period in 2013. Better grazing conditions will have had a positive effect on fertility and improved conception rates with breeding females on a more settled diet.
The calving interval for animals that go on to produce a third calf has a similar trend. Heifers that calved at a younger age still have a shorter calving interval by the time they are third-calving animals.
While this will still represent good management, it also indicates the effect of selecting replacements from the most fertile cows in the herd. It is likely that these herds are running in tight compact-calving patterns, which quickly identify fertile females for breeding with poor breeding females culled.
Breed effect
There is a higher percentage of continental beef-bred heifers calving for the first time between 31 and 35 months of age compared with 18% of continental-bred heifers calving at 22 to 26 months of age. While this might reflect later-maturing animals, it could be influenced by a large number of herdowners who buy in their replacements annually.
Continental beef breeds are normally later maturing than the native breeds which can have an effect on cow fertility. However, this is not always the case. Herd management will have a greater effect on fertility than the breed of the animal.
If it was purely down to breed, then there should be a higher number of native breeds calving at 22 to 26 months of age. However, there is an even spread across the age at first-calving for native breeds, which indicates a management influence or herdowners buying in-calf heifers each year.
Average age at first calving is 31 months.80% of suckler-bred heifers will produce a second calf.Calving interval for second calving heifers is 364 days.
The average age that a suckler-bred heifer is calving down for the first time is now 31 months of age. Approximately 80% of suckler heifers that calved for the first time in 2014 have produced a second calf with an average calving interval of 364 days in 2015.
The information comes from data collated through ICBF’s HerdPlus and includes calving information on over 147,000 heifers in 2015.
Over the past five years, the average age at first calving has seen a small reduction from 32 to 31 months. While not a massive leap forward, it indicates a move in the right direction especially with fewer heifers calving between the ages of 31 and 36 months of age in 2015 compared with 2012.
In a suckler herd, there is one unit of output and that is the calf produced. To stand any prospect of generating a profit in suckling, breeding females need to wean as many kilos of calf liveweight as possible over their lifetime.
The earlier the heifer calves for the first time, the earlier she contributes to herd output and income by producing a calf that can be sold. Where heifers calve at a later age, then the longer it will be until these animals start to contribute to herd output or have a calf for sale.
Age at first calving
The graphs below outline the average age that suckler-bred heifers calved down for the first time in 2015. There are four age ranges used to categorise the heifers.
The most common age range for heifers to calve for the first time was 30 to 35 months of age at 32%. In 2012, there were 36% of heifers calving for the first time at this age range. On closer analysis, it appears that this 4% difference has moved into the 27- to 30-month age bracket when comparing national calving figures in 2015 to 2012.
On analysis of the data, it indicates that there are plenty of suckler farmers who operate a split-calving pattern. Split-calving between spring and autumn facilitates calving heifers down for the first time at around 30 months of age.
Suckler herd owners who buy in replacement heifers annually, either for breeding on farm or as in-calf animals, usually opt for an older animal that is well developed in terms of size, frame and liveweight. This would also see a lot of these animals calving between these two age ranges of 27 to 30 months and 31 to 35 months of age.
There were 27% of first-calving heifers in the 22- to 26-month age range, which has remained relatively static over the past number of years. In the dairy herd, this figure would be closer to 50%, which indicates that there is potential for more suckler-bred heifers to calve at a younger age than they currently are.
Calving at 24 months of age is the most profitable way to operate a suckler-breeding herd that breeds its own replacements. But it requires good management and herd genetics to have heifers properly developed, so that they can cope with the physical demands of calving, rearing a calf and getting back in calf again.
Many herd owners will be able to calve the heifer at 24 months, but getting the animal to produce a second calf by 36 months proves to be a stumbling block. This is where herd management comes into play by ensuring that the animal is correctly managed to meet weight targets at breeding and calving, as well as making sure the animal’s nutritional demand is being met.
Calving interval
One reason suckler herd owners will opt to calve heifers at an older age is down to the belief that they are easier to get back in calf again.
The graphs below outline the calving interval for each age bracket. Over the past three calving surveys, the heifers that calved down at 22 to 26 months have the shortest calving interval in each particular year.
In 2015, the calving interval for this group was 358 days compared with 374 days for heifers in the 31- to 35-month age range. In 2014, the calving intervals for the two groups were 389 and 402 days, respectively.
The data shows that in a well managed suckler herd with carefully selected female replacements, it is possible to calve heifers at 24 months every year and bring them through to produce a second and third calf.
While the average age at first calving may only show a slight reduction from 32 to 31 months, the calving interval for second-calving heifers has seen a massive reduction from 395 days in 2014 to 364 days in 2015.
Part of this will be driven by better grazing conditions during the breeding season of spring/summer 2014 when compared with the same period in 2013. Better grazing conditions will have had a positive effect on fertility and improved conception rates with breeding females on a more settled diet.
The calving interval for animals that go on to produce a third calf has a similar trend. Heifers that calved at a younger age still have a shorter calving interval by the time they are third-calving animals.
While this will still represent good management, it also indicates the effect of selecting replacements from the most fertile cows in the herd. It is likely that these herds are running in tight compact-calving patterns, which quickly identify fertile females for breeding with poor breeding females culled.
Breed effect
There is a higher percentage of continental beef-bred heifers calving for the first time between 31 and 35 months of age compared with 18% of continental-bred heifers calving at 22 to 26 months of age. While this might reflect later-maturing animals, it could be influenced by a large number of herdowners who buy in their replacements annually.
Continental beef breeds are normally later maturing than the native breeds which can have an effect on cow fertility. However, this is not always the case. Herd management will have a greater effect on fertility than the breed of the animal.
If it was purely down to breed, then there should be a higher number of native breeds calving at 22 to 26 months of age. However, there is an even spread across the age at first-calving for native breeds, which indicates a management influence or herdowners buying in-calf heifers each year.
Average age at first calving is 31 months.80% of suckler-bred heifers will produce a second calf.Calving interval for second calving heifers is 364 days. 
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