I can hear you say “Why would I want to waste my time painting the herd five weeks before mating start date (MSD) when I don’t want to use hormonal intervention?”. But just because you can’t see the non-cyclers doesn’t mean you don’t have any, and doesn’t mean they will all disappear.
Having a large number of non-cycling cows is one of the biggest contributors to a herd’s poor reproductive performance. A cow that hasn’t cycled before MSD will be less likely to submit in the first 3 weeks, less likely to conceive to AB, less likely to be in calf in 6 weeks and more likely to be empty. Therefore, we need to identify how many you have, in order to know if it’s worth worrying about them. We recommend that if 85% of whole herd (including late calvers) has cycled before MSD then the herd is on track to achieve a 90% submission rate without any intervention.
The cow-level management factors that increase the risk of a cow not-cycling before MSD include:
- Calving less than 6 weeks before MSD
- Undergrown first calvers at calving
- Mature cows in BCS under 5 at calving and first/second calvers under 5.5
- Animals that have lost more than 1 BCS between calving and MSD
- Animals that have had animal health issues at calving, specifically uterine infections (endometritis)
Also see http://bit.ly/IncalfBooklet (page 147)
Therefore, by the time you read this article most of the above management factors have already being determined leaving minimal options for dealing with your non-cycling cows. Preferential feeding, separation and once-a-day milking may speed up the post-calving recovery and may reduce the anoestrous period, however if the cow is still a non-cycler at MSD then she will benefit from being treated with hormonal intervention. If you want to use OAD to help improve the pre-mating cycling rate in your herd then the strategy needs to be implemented from much earlier in the season, which is well before you know if you have a non-cycling problem! The use of strategic OAD-milking is a bigger farm systems decision, rather than a knee-jerk reaction to a non-cycler problem.
Non-cycler treatment programmes (e.g. CIDRs) are nine days in length and treating cows nine days before the MSD will give you the best return on investment. Cows starting treatment before MSD will calve, on average, 16 days earlier than untreated non-cyclers. In addition, extra AB calves are born the following year and treated cows are less likely to be non-cyclers the following season.
I am well aware that sometimes the reason why you don’t want to identify your non-cyclers before MSD is because there are too many of them! We do understand! But there are always options – the simplest being – if you have previously had to treat 30 non-cyclers at the end of the first round of mating, then put your tail paint on and treat them MSD-9d. Of course you may have 60 non-cyclers at this earlier time, but pick the 30 best animals and treat those. These animals are far better off being treated before PSM than being left until the end of week 3.
Don’t stick your head in the sand this pre-mating period, get your pre-mating tail paint on and once you know how many non-cyclers you have, you can then decide if you need or want to take action
VET TIP: In the days leading up to MSD have a practice-run through with all staff; detect the heats, write the numbers down, draft the cows, put them on the yard etc. Use the pre-mating period as a training time to teach staff about the signs of a cow on heat and as a time to get your whole team ready for AB.