The final episode of the March Animal Health Series, in association with MSD Animal Health Ireland, was broadcast on Agriland yesterday evening (Tuesday, March 29).

The broadcast brough to an end the highly informative series, which has been running for the last two weeks.

The episode saw Eleanor Kirwan, a ruminant veterinary manager with MSD Animal Health Ireland, speaking with Dennis Howard, technical manager with Munster Bovine, and farmer John Bourke, on the Tipperary farm that John runs in partnership with his brother Jimmy.

Their discussion tackled some of the main things farmers should watch out for when it comes to fertility.

Sexed semen took up a large part of the conversation, with Dennis highlighting that it’s a different product to conventional semen.

He explained that there is about 4 million sperm cells in a sexed artificial insemination (AI) straw, compared to 15 million in a conventional straw.

Dennis also outlined that the sexing process can be stressful on these cells, which may reduce their viability.

For that reason, if a farmer wants to achieve good results with sexed semen, there are some rules and procedures that should be followed regarding cow selection, timing of AI, and semen handling.

Farmer John Bourke agreed, saying that there are a lot of protocols in handling and timing to be aware of.

In terms of cow selection, Dennis advised selecting cows that have had no issue at or since calving, are in good body condition, are 50 or more days calved, and are cycling regularly.

He said that farmers and vets need to be more precise with the timing of AI. Cows should be bred 10 to 20 hours after the start of standing heat.

And in terms of semen handling, care is required when thawing out the straws.

Outside of those three main considerations, Dennis also advised selecting enough cows so farmers can give themselves a “buffer”, especially for once-a-day AI.

“So if you have 50 sexed straws to use, maybe don’t hold yourself to 50 cows. Maybe select 70 to 80. Give yourself a bit of leeway regarding timing,” he explained.

The Munster Bovine technical manager noted the benefit of technological solutions, including heat detection systems and drafting gates.

“The big benefit it labour saving. A very good person can do a very good job heat detecting, but if you combine it with drafting it just keeps working regardless of what day of the week it is,” he commented.

The discussion around sexed semen briefly touched on calves for the beef sector, with John highlighting: “In the dairy sector we have to produce a good beef calf”.

On that issue, Dennis remarked: “The big advantage with AI with those beef bulls is you can have your calving ease, you can have your calving length, but also you can have a very good calf with high beef sub-index and a good carcass value.”

Whether using sexed semen or not, the nutrition of cows was highlighted as a key component of fertility.

Dennis said: “You want to have cows arriving at breeding season in good body condition, but equally you want to keep them fed during the breeding season, and avoid them going into any negative energy balance, especially when the weather changes.

“Grass is going to get wetter, dry matter is going to drop, intake will probably drop, utilisation will drop.”

A good indicator of the nutritional status of the herd is simply the volume of milk in the bulk tank, as well as the percentage protein in the tank. If either of these metrics start to drop, then “you’re starting to worry”, Dennis said.

He added: “Try to know what grass is going in to them, if you’re measuring grass – how many kilos a day they’re getting and how much they should be getting, and you’re trying to make up the difference with concentrates.”

John, for his part, said that he and his brother Jimmy try to “get as much grass into the cows as we can”, and that they grass budget once a week.

In terms of knowing whether things are going right for fertility, Dennis outlined that submission rates are a key indicator, to “make sure you’re actually getting the cows bred”.

“It’s one thing to submit them, but you want to make sure your submitting them when they’re in heat, so accuracy of heat detection is important,” Dennis said.

He added: “If you have 100 cows in compact calving, you should have five cows coming in a day. If they’re not there’s two possibilities.

“Either they’re not coming into heat for whatever reason – maybe it’s nutrition – or maybe you’re missing them, you’re not picking them up. Maybe your heat detection aids aren’t working or you’re not observing them often enough.

“So the big thing is to investigate at that stage, if you’re not hitting your target as regard submission rate. So is it your heat detection or is it something else,” Dennis said.

He explained that, at that stage, it would be time to get the vet in to see what is going on.

“Cows you haven’t picked up after a week or certainly after the first three weeks, get them scanned and see if there is a reason behind it,” he said.

Dennis added: “If not, I think even at that stage there is merit in getting those cows treated, maybe putting them on fixed-time AI programme and making sure they’re going to be bred in 10 days after.”