Stephen Moore, research technologist animal reproductive physiology with Teagasc, identified the key practices to achieve a 90% three-week submission rate to maximise a 6-week calving rate during spring 2022, on the Dairy Edge podcast hosted by Emma-Louise Coffey.
To achieve compact calving, farmers need to set high fertility during the breeding season.
Two factors Stephen highlighted are:
• The three-week submission rate, targeting 90%;
• The conception rate at first service.
“Typically, we are looking, for lactating cows, about 50-60% conception rates at the first service,” Stephen told Emma-Louise Coffey on Teagasc’s Dairy Edge podcast.
Gearing up for breeding
Stephen advises when trying to achieve high submission rates having a high 6-week calving rate is important.
“The longer the cows have calved, the higher their fertility performance is going to be. Within every herd, there are going to be some problem cows.”
How to identify problem cows:
- Cows that are not cycling: apply tail paint to monitor these. After three weeks, all these cows should be identified;
- Cows with an uterine disease.
“An option for cows that are not cycling is to put them on a synchronisation protocol if they are 30-days calved, for timing, AI which would be approximately 10-days before the mating start date.”
“With these types of protocols, because they are timed AI, we can ensure all the cows that go on these protocols are submitted for AI by mating start date.”
Stephen outlines that how many cows are metrichecked depends on the farm. He acknowledges that cows that had difficult calving, milk fever or ketosis, are most likely to have a uterine infection before breeding.
“In term of cows that may have a uterine disease, metrichecking them is the best option, over the next couple of weeks to identify these cows.”
“From work we have done in recent years when we metricheck cows anywhere from 30-days before the mating start date, we are looking at about 20% of the herd having some level of uterine infection.”
“The option for these cows would be in intrauterine antibiotics. Cows that receive this will have improved conceptions. There may be another group of cows that you might not have suspected of having an issue, but they would have a uterine infection.”
Stephen believes tail painting is slightly labour intensive before the breeding season but recommends once a farmer applies tail paint to check it once a week instead of daily.
The research technologist animal reproductive physiology believes a pre-breeding ultrasound is ideal for completing pre-breeding heat checks or metrichecking.
“One option is for the use of the tail painting and metrichecking to identify them problem cows that can then be examined by the vet for treatment.”
Low BCS cows
He outlined how to remedy low body condition score cows leading into the breeding season. While cows lose body condition after calving, there will be a proportion of the herd at a BSC less than 2.5 leading up to the breeding season.
“The cows we would deem to have a low BCS would be of 2.5 or less. Leading up to breeding, the ideal BCS target for these animals is 3-3.25, with a herd average of about 2.9 at the mating start date.”
Stephen advises farmers to practice once-a-day milking to improve BCS in thin cows, giving the cow time to put on condition, before the breeding season.
Minerals for the mating start date
The three main minerals Stephen advises to focus on, from a breeding perspective are as follow:
“We know that all of these minerals are naturally deficient in grass in Ireland. There are not enough of these minerals in grass to supply to requirements for lactating cows. That is the reason minerals are supplements in concentrate, through water or boluses.”
“One important aspect is knowing the situation on your farm. The best way to identify that is through either a grass mineral analysis or by identifying cows in the herd collecting blood from them to be tested, to get an idea of the overall herd mineral status.”
Synchronisation protocol for heifers
As heifers are the herd’s highest EBI animals, Stephen feels farmers should breed replaced from them using high-EBI sires.
He thinks generating the majority of replacements from heifers is a key step to maximising the herd’s rate of genetic gain.
“Synchronisation protocols available for heifers, there a couple of options. Some farmers prefer to breed off natural heats for the first week of the breeding season.”
“Then any heifers that have not been inseminated during the first week of the breeding season, can be administrated an injection of prostaglandin. This brings heifers that are cycling into heat within 2-5 days for AI. When relying on these approaches, heifers must be cycling, and it does require heat detection.”
“Any heifers that did not come into heat after the first 10-days of the breeding season, 10% of them will require a second injection of prostaglandin 11-days after their first injection. With this approach, the vast majority of heifers will be bred within 10-days.”
“Another option is to set the heifers up on a timed AI protocol. An advantage of this is there is no heat detection required; however, it does involve some labour in implementing this protocol. Basically, it is an 8-day protocol inserting a progesterone device 8-days before mating start date an injection of GnRH.”
“The 3-days before AI and two days before AI, each heifer, needs to get two injections of prostaglandin, and two days before AI, the device needs to be removed. When they are inseminated, that should get another injection of GnRH,” Stephen concluded.
According to Stephen, the first option using an injection of prostaglandin is the cheaper option.
The timed AI protocol will cost anywhere from €30-40 per animal, depending on the number of animals enrolled.
Stephen outlines that conception rates of 70% are being achieved with conventional and 60% with sexed semen in heifers.
Listen to the Dairy Edge Podcast here.
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