Dairy Beef Index Series: Sexed semen key for genetic gain on Meath dairy farm

The ‘Dairy Beef Index Series’ is a collaboration between Agriland Media and the Teagasc DairyBeef 500 team.

The Mullen family are farming 158ha of good free draining land outside Kells, Co. Meath.

In 2023, they milked an average of 350 cows on a milking platform of 82ha. They are currently a monitor farm with the Teagasc / Tirlan programme and work closely with programme advisor, Sandra Hayes and local dairy advisor, Vincent Treacy.

They have a split calving herd with approximately 140 cows calving in the autumn. This system is typical in this part of the country.

The cow type on the farm would traditionally have been a strong Holstein cow, however cow size has reduced in recent years as more attention is placed on breeding a high economic breeding index (EBI) Holstein Friesian cow.

The current EBI of the herd is €185, which places the herd in the top third nationally.

The dairy replacement strategy going forward will be to produce a fertile cow that is capable of producing over 550kg of milk solids on a predominantly grass-based diet.

Sexed semen will be key in driving genetic gain in the dairy herd, with sexed semen being used on the heifers plus the highest EBI cows in the herd to get their desired amount of replacements each year.

All other cows in the herd that are not planned on being culled will receive a high merit beef AI straw to produce a quality calf sought after by calf to beef producers.

Up to now, the Mullen family sold their calves to local beef farmers and through the local mart in Carnaross.

They have always aimed at producing good beef calves and the proof of this is that they have repeat customers every year for their calves.

Dairy Beef Index

In recent years, they aimed to use bulls above €100 on the Dairy Beef Index (DBI).

Even though genetics is very important to beef farmers, Declan Mullen feels that the health of the calf is also key to getting repeat customers “every calf on the farm is treated the same in terms of receiving colostrum and getting well-fed, no matter whether that’s a Friesian heifer or bull calf”.

In the future, beef farmers will focus on purchasing calves that have a high Commercial Beef Value (CBV).

Calves that have a high CBV will, on average, be faster growing, grade better at slaughter, meet market specifications at a younger age and will not eat as much/kg live weight gained.

In order to produce these type of calves, dairy farmers need to drill into the DBI and examine the beef traits as well as calving difficulty and gestation length.

On this farm, it was decided to split the bull teams into two periods over the breeding season.

A team of bulls for the first four weeks and then a team of bulls for the remainder of the breeding season. Some of the bulls are in both teams.

This split meant that the gestation length of the bulls would not impact as much on the days in milk for the herd as compared to later on in the season.

It was also felt that the use of high carcass merit bulls at this stage would leave a more saleable calf in late February and early March, when a large number of calves comes on stream.

The Mullen’s requested that the bulls have a calving difficulty of less than 7%, but within the team the calving difficulty ranged from 2.6% to 6.1%.

This allows the Mullens to use easy calving bulls that they think are suitable for certain cows, e.g. easy calving bulls for first lactation cows and small framed cows.

The criteria that the bull needed to meet to get on the team for the early season was a calving difficulty of less than 7%, gestation length of less than three days, a beef sub index of no less than €80 and a carcass weight of greater than 12kg.

Table 1: 2024 bull team for first four weeks.

For the remainder of the breeding season, the use of short gestation bulls becomes more important to avoid an unnecessary extended calving period.

However, even within the shorter gestation bulls, we can identify bulls that exhibit good beef traits.

Again, the criteria that the Mullens required was that none of the bulls had a calving difficulty of greater than 7%.

There was a range from a low of 2.6% to 6.1% calving difficulty. All bulls for this period also had to be at -1 or less for gestation length and have a carcass weight of over 10kg.

Table 2: 2024 bull team for remainder of breeding season.

Finally, all the maiden heifers will receive sexed semen and on this farm a stock bull is used to mop up the heifers.

The current Angus stock bull has good figures with a calving difficulty of 2.7%, gestation length of -2 days, a carcass weight of 10kg and a beef sub index of €104.

These figures are a good guide of what a stock bull should be if using a stock bull. For many farmers, maiden heifer repeats will receive a beef AI straw.

The bulls used on heifers should have a calving difficulty of less than 2.5% and then look at beef traits. However, in this group of animals, calving difficulty takes precedence.

Table 3: Potential 2024 bull team for maiden heifers

Stay tuned to Agriland for more Dairy Beef Index Series articles over the coming weeks.