Why a 6-week calving window is vital for this Co. Waterford farmer

Getting as many cows in calf within the six-week calving window is vital for Dungarvan dairy farmer Jamie Costin. His herd improvement programme is based on improving profitability and ensuring he breeds healthy and efficient animals.

“I need cows that efficiently convert feed to profit, stay healthy, remain in the herd for a long time, and leave daughters of even better generic merit to replace themselves,” he said.

“And to leave a legacy of strong cow families in a herd, I’ve seen that the cows need to calve consistently within the first six weeks of calving. This rate is a key measurement here at Cosfeirm Teoranta.”

According to LIC, the six-week in-calf rate indicates the combined effect of almost everything you do on farm.

When your herd is seen as the engine of your farm business, measuring milk production would be the equivalent of measuring speed, BW would be your engine’s horsepower, and the six-week in-calf rate your rev counter – showing how efficiently your engine is running.

As with any engine or system, small changes can have dramatic effects, so it’s vital you put your efforts into the right areas at the right time. Whether you are capturing more days in milk, more replacement calves, or improved herd quality through more culling options and more choice, lifting this in-calf rate will help you achieve your business goals.

Jamie’s six-week in-calf rate is 86% and, ideally, he wants to top 90%. At the same time, 96% of his heifers calved within 22 to 26 months, and he got 80% of his heifers in calf to their first insemination, despite a trying autumn and hard 2018 spring.

He recognises that there are eight key areas of impact on fertility and that they are all related to farm management. These are: calving pattern; heifer management; nutrition and body condition; heat detection; service bulls; AB practices and genetics; non-cycler issues; and cow health.

“Late calvers hold you back, and heifers below target liveweight calve slower, get back in calf worse, and produce less milk and milk solids in their first and second lactations,” he said.

A national herd fertility study in New Zealand has shown that the six-week in-calf rate delivers:

  • 15 more peak days in milk;
  • 20% more cows in calf to AB;
  • Three fewer days AB mating length;
  • 6% lower empty rate;
  • One week shorter total mating; and
  • The use of fewer CIDR treatments.

So key benefits include increased milk production, more AB replacements, fewer empties and decreased mating periods.

Confident in the future of dairying

Jamie milks 360 cows on his 130ha grazing platform and has expanded the herd rapidly since moving to LIC genetics in 2012.

He’s invested in the animals first and is now busy supporting the herd with capital investment, remaining confident in the future of dairying in Ireland.

The main bulls he used when he started his crossbreeding programme included Moodys Executive (YMD), Solaris (PSQ), Sierra (ZSP) and Integrity (OKT).


YMD was chosen to bring high kilos of milk solids, excellent fertility and health benefits such as low SCCs. He also offered good udders and capacity.

PSQ is an all-round excellent bull, with great fat and protein percentages of 4.9% and 4.0%, while also having excellent BCS and offering SCC reduction.

Solaris also has excellent capacity and fertility, allowing for efficient production of grass into milk solids. He has 60,000 daughters on the ground worldwide, with some 2,500 in Ireland.

OKT is a pure Jersey bull with excellent fat and protein components of 5.2% fat and 4.3% protein. His BCS and capacity is excellent.

“These were some of my foundation bulls which have allowed me to breed capacious, fertile, low SCC and high fat and protein percentage bulls,” he said.

For 2018 and 2019 he has chosen Sierra, Beaut, Epic, Spot-on, Misty and Dexter. All these bulls follow a similar trend – high fertility, high milk solids and fat and protein percentages, excellent capacity with good BCS and udders.

“I strongly believe that fertility and farm management go hand-in-hand and by concentrating on them both and having a positive herd improvement programme that I stick to, I will run a profitable dairy farm,” said Jamie.

“Once the animals are on the ground, we have to concentrate on having the right systems that manage these genetically advanced animals and allow them to produce to their maximum potential while getting them back in calf quickly each year,” he concluded.

Further information

For more information click here