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The first few weeks of the breeding season is often the busiest and most stressful period on dairy farms.
Cows will calve whether the farmer is there or not, but they won’t walk into the crush for AI on their own. Missed heats cost money.
Other than measuring grass, there are few things in dairy farming that give the same return as having good fertility.
The following steps will help to ensure a successful breeding season on your farm.
1 Pick AI bulls that are right for your herd
Daughters of the bulls being used this year won’t be in peak production until 2023. Breeding is a long-term game.
Be careful who you get advice from as the breeding industry is full of vested interests, both AI companies and farmers. I believe EBI with a strong weighting on milk and fertility sub-index is delivering for farmers.
Crossbreeding with Jersey or Norwegian Red is a quick fix for many of the milk solids and fertility problems associated with the average Irish cow. Only use enough dairy AI to breed as many replacements as you need and then use beef AI, if possible.
If you’re considering buying a black and white stock bull then reconsider and buy a beef bull instead. You can buy AI-bred replacement heifers from good herds. High-EBI AI-bred heifer calves are totally undervalued at present.
2 Get condition score right
Thin cows should have been put on once-a-day (OAD) milking three weeks ago. The next best time to do it is today. Cows calved in March and April that are thin (less than body condition score 2.75) should be put on OAD milking.
February calvers should be under less pressure at this stage. Make a judgement call on February calvers depending on whether you think they are starting to thrive. Putting late-calving cows on OAD will help to minimise BCS loss post-calving.
The effect on output of putting 5% of the herd on OAD milking is negligible. If the 5% on OAD produce 20% less milk solids, the overall effect on the herd will be just a 1% drop in total milk solids output. Leave the OAD milkers in the herd, just don’t milk them in the evening.
As soon as they come bulling, put them back on twice-a-day milking. Once-a-day milking is one of the most effective means we have of retaining cows in the herd.
3 Don’t sweat at pre-breeding heats
Pre-breeding heat detection will help to identify the non-cycling cows early. There are different variations of pre-breeding heat detection but the important thing to remember is that it is only a warm-up to the real thing, so don’t put too much effort into it, at the expense of getting burned out during the main breeding season.
Best policy is to tail-paint three weeks out from the start of breeding. If paint is rubbed off, leave it off. Top up the paint that is still on.
At the end of the three-week period, the cows with paint on should be looked at by a vet. About 55% of these cows will be fine and only require more time, but some will have cysts or require wash-outs or hormone treatment. Again, putting these cows on OAD milking will help to get them cycling.
Other farmers start pre-breeding closer to the start of AI, meaning the non-cycling cows aren’t identified until one or two weeks into breeding, which is better than nothing but the submission rate will be lower.
4 Use heat detection aids
Tail paint is a cheap and effective heat detection aid when used correctly. It needs to be topped up every four or five days, otherwise you won’t know if the paint is half gone because the cow is bulling, or if it’s half gone because it’s falling off naturally.
It should be applied in a 2in by 9in strip from the top of the tail head back. Some farmers switch to using scratch cards after using tail paint for the first few weeks. These are a bit more expensive than paint but require less maintenance and are sensitive to bulling activity.
Vasectomised bulls are useful after the first six weeks where all AI is practised and should be used in conjunction with other heat detection aids. Chin-ball markers can get confusing as cows served three or four days ago will still be marked.
5 To maximise heat detection rate, cows should be checked in the paddocks
New Zealand research says the best time to check cows is two hours after the morning and evening milking, when most of the grass has been eaten and cows coming into and out of heat are forming sexually active groups.
These checks must be carried out discretely, so no quad bikes or dogs. If you don’t carry out paddock checks, then the quality of the heat detection at milking times must be spot-on.
6 Whenever you inseminate a cow that you’re not sure is on heat, write a question mark after the service in the AI records
When deciding what to do, check the previous heats and services for the cow.
Inseminate if the cow has not been inseminated since calving and is showing reasonable signs of heat. If the cow’s previous insemination was more than 20 days ago, she should be inseminated.
If the cow’s previous insemination was less than 20 days ago, inseminate if the previous heat was weak. Identify the weak heats by marking them with a question mark.
Otherwise, look for more signs of heat. If these are seen, inseminate. If more than 10% of inseminations have weak heats, or if a high proportion of the interval between serves is long or short, then you need to review your heat detection practices.
7 Constantly review performance
Count how many cows have been served/repeat and compare to target. The target submission rate is 90% in the first three weeks, so 30% should be served per week, or 4.3% of cows per day on average.
However, it’s no good serving cows that aren’t in heat so be careful what targets you set and what targets you hit.
Identifying cows in heat is a skill and new employees or students will need upskilling and training to know the signs.
Don’t presume other people know how to identify cows in heat. The time spent on heat detection has a very high return, so it’s worth your while making sure it is done correctly.
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