Agriland Media Group is delighted to collaborate with LIC Ireland to bring you the ‘Breeding For Efficiency Series’.
Dairy farmer David O’Leary has went from milking 48 black and white Friesian cows to milking 80 Jersey cross cows in Castleisland, Co. Kerry.
The dairy farmer is leasing 80ac of land and milking 80 cows on a 65ac milking platform, where he aims for high milk solids production and longevity in the herd.
O’Leary started off by using five sexed semen straws to now having the majority of his herd crossed with LIC pure Jersey semen and is reaping the benefits of heterosis now in terms of production.
O’Leary started leasing the land in 2018 and has rapidly progressed the herd and is aiming for his cows to do 5% fat and 4% protein.
The milking platform is averaging about 13.5-14t/ha of grass growth a year with overall grass growth on the milking platform in 2024 reaching 14.5t/ha.
The Kerry farmer will start calving down on February 5 and the cows will be let out to grass straight away where he finds the crossbred Jerseys to be very efficient in terms of grass utilisation and converting grass to milk.
Breeding
All sexed semen was used on cows last year to breed the replacements on the farm and all of O’Leary’s replacement heifers were bred to Aberdeen Angus bulls.
O’Leary first started cross breeding using pure Jersey semen in 2019 with a few cows, and has gone more intensive in his use of the semen in the last two to three years.
“I was happy with the litres and solids I was doing, but just wanted to increase the fat and protein percentages as quickly as I could, and I thought the easiest way was by putting Jersey on Friesian,” he said.
Breeding season starts on May 8 and they use sexed semen on about 20 to 30 cows and heifers within a week using a synchronisation programme.
Sexed semen is only used in the first six days of the breeding season, as he staggers his synchronisation programme having five to six cows coming into heat over the course of the six days.
Once the sexed semen is used up, O’Leary will use short gestation and good carcass weight Charolais or Angus bulls to put on the remainder of the herd up until the fourth week of breeding.
O’Leary said that the crossbred beef calves aren’t as difficult to sell as people believe, as they are all sold off the farm at three to four-weeks-of-age with no problem finding a buyer.
He said that once he was using a good quality beef bull, that there would be little difference in the calves from a Jersey cross cow from a Friesian cow.
Once the four weeks of artificial insemination (AI) is used, a few stock bulls will be let out to clean up anything that repeats.
The criteria for sexed semen is not based off economic breeding index (EBI), but rather based off milk recordings and milk solids production of the cow.
Jersey cross
“Over the seven years, we have been gradually building our numbers, as we went from having a herd of heifers to now having an average of about 3.9 lactations in the herd”, O’Leary told Agriland.
In terms of what cows O’Leary is choosing for sexed semen, he added: “I only choose cows in their first to fourth lactation and go off milk recording data and I don’t look at EBI (Economic Breeding Index).”
“I look at the fat and protein percentages on the EBI but other than that I’m not selecting cows from it.”
“The fertility in the herd is very good as we only had a 3% empty rate this year and the six week in-calf rate this was 89%”, according to the Kerry man.
O’Leary said that he would rather look at the cow’s breeding worth (BW) figures in New Zealand, as he feels it gives him the efficient cow he is looking for.
The farmer was originally breeding off low protein Friesian cows to try and “get a kick in protein” but is now breeding off Friesian cows that are doing 3.70 to 3.80% in protein.
O’Leary told Agriland that “The fat percentage of the herd has went from about 4.40% to 4.70% fat in the last couple of years and the protein percentage has been increasing gradually too”.
You can see from O’Leary’s co-op report below, just how much the Jersey cross cow has delivered for himself in terms of production, as his January to November co-op report for 2024 is as follows:
The replacement rate on the farm has been around 20% in the last couple of years, as he wants to increase the number of Jersey cross cows in the herd.
The main driver of the productivity and profiatbility of O’Leary’s herd is the fact that the Jersey cross cow is an “easy care cow who is fed only 800kg of meal”.
“I find the Jersey cross cow will put on more condition in the back end of the year compared to the Friesian and will produce more kgs of milk solids per kg of live weight”, the farmer added.
He admitted that the type of cow he has now takes little feeding and is a more efficient cow and once out grazing will “put their head down grazing and get on with it and is a hard working cow”.