Dairy heifer fertility: Mary Cook, Taunton, Somerset

Mary Cook, Taunton, Somerset

Farmers struggling to rear their own replacements should consider using activity monitoring systems to boost efficient use of sexed semen, says Somerset dairy farmer Mary Cook. “When using sexed semen, you want to ensure you are using it as effectively as possible and picking up all heats. Before we used activity monitors the vet often said we’d missed some heats,” she says.

And this had meant sexed semen had only been used on some animals, with a sweeper bull used afterwards. So after installing the heat detection system in the main herd of 200 primarily Holstein Friesians, Ms Cook extended the system to her heifers.

Heatime is an activity monitor system that records cow activity 24 hours a day, working on the principle that a cow’s activity increases when in oestrus. The monitor is strapped to a cow’s neck and stores activity information until the cow walks under a reciever. The data are relayed to a display monitor in the parlour that flashes red when an animal is in oestrus.

The system proved excellent for cows and heifers, says herdsman Andrew Rich. “We used to have difficulty picking up animals bulling between 10pm and 5am and because heifers are housed in a separate shed, heats would often be missed. But the system now confirms heats for us.

“Now we know when heifers are bulling, eliminating some guessing that was going on before.”

Activity is usualy downloaded as cows pass through the parlour at milking. However, because heifers are not milked, a metre has been installed above the water trough in the heifer pen.

Improved heat detection has meant all heifers are served to sexed semen with 60% conception to first service.

“And because all heats are recorded and conception rates are improved, we hope to produce a surplus of heifers, providing an added income stream,” explains Ms Cook.

However, since using the computerised system, heifer management has had to change. “We used to put all heifers out in the summer, but now we house heifers until they are served as Heatime cannot be used outside.”