Handling non-cycling cows
Mating time is fast approaching with October just around the corner. Now is the time to start thinking about whether non-cyclers in your herd may impact your mating performance next month and your milk flow next season.
Drivers of an earlier, tighter calving pattern and more days in milk
A high submission rate is one of the key drivers of early milk production and more days in milk. Non-cycling cows pull down submission rates, and therefore affect the number of cows calving early and producing milk from the start of the season.
Do you think non-cyclers will impact your mating performance?
Premating heat detection for five weeks prior to the planned start of mating (PSM) will indicate whether non-cyclers will hamper your submission rate next month. To get the target of 90% of cows submitted in the first three weeks of mating, by 10 days before the PSM, more than 85% of the herd should have cycled.
What causes non-cyclers and what management tools are available to deal with them?
Risk factors for non-cyclers are:
- Poor body condition score at calving - cows should calve at condition score 5 and 1st and 2nd calvers at 5.5 to have adequate body reserves for good production and have a better chance at not dropping below condition score 4 for cows and 4.5 for younger cows before PSM
- Excessive condition score loss after calving – if cows and heifers drop below 4 and 4.5 before PSM, they are much more likely to be non-cyclers by PSM
- Poorly grown heifers – much as above, if heifers don’t reach condition score targets before mating, they are much more likely to be non-cyclers
- Late calvers – these cows don’t have as long to start cycling before PSM and often fall into the non-cycler group
- Dirty cows – endometritis can impact a cow’s ability to cycle
- Trace element deficiencies – low copper and low selenium in particular can affect a cow’s fertility
By September the options for preventing and dealing with a potential non-cycler problem are reduced
Once a day milking (OAD) and preferential feeding are effective tools for managing condition score loss in the run up to mating. However, for OAD milking to be effective, it ideally needs to run from calving until mating as four to five weeks of OAD prior to mating will have little effect on condition.
Pre-mating blood tests for trace element levels will tell you if selenium (and potentially copper) may impact mating performance. If you are concerned, book the tests in straight away so any deficiencies can be addressed as soon as possible.
Metricheck the cows. If this hasn’t been done already, get your herd metrichecked as soon as possible to find and treat infected cows so they have as long as possible to cure before mating.
Running a non-cycler mob with bulls may improve their submission rates as bulls have more time to spend on heat detection, but do not actually improve the number of cows cycling. Therefore, running bulls will only work if your non-cyclers are actually missed heats, and it will decrease your number of potential replacement calves next season.
Early CIDR treatments
The best option for dealing with non-cyclers this close to mating is to use the CIDR program before mating starts. On average CIDRs used before mating generate between $130 – 180 of profit through:
- Up to an extra 33kg MS of milk over an extra 16 to 21 days of lactation
- Additional AB heifer calves
- Reduced number of non-cyclers next season as there will be fewer late calvers
- More compact calving spread
Please contact your vet today to discuss your options for non-cyclers this coming mating.