As we enter into the breeding season for the autumn calving herds, farmers should asking themselves whether a synchronisation programme is worthwhile for your farm.
For the spring calving herds, the selection of sires and breeding protocols will be entering he farmer’s mind in the next couple of weeks and a synchronisation programme might be on the cards.
The cost of a synchronisation programme could cost a farmer about €25-€30/cow plus a vet call out cost if needed, but the benefits of it outdo the cost.
With the recent surge in sexed semen uptake in the last couple of years, farmers have experienced poor conception rates with their herd of cows, as they are treating the product like a conventional straw.
Sexed semen is a tampered product and to achieve the same conception rates as conventional can be tough, but if it handled correctly and administered in the correct manner, conception rates can nearly match that of conventional.
The timing of insemination is paramount to the successful conception of sexed semen and it should ideally be used in the first three weeks of the breeding season or within the first 10 days, if possible.
Timing of artificial insemination (AI) is more critical for sexed semen compared to conventional and for maximum success, AI with sexed semen should take place 14-20 hours after the onset of heat.
For a lot of farmers, this timing can be hard to get right and conception rates are affected as a result, and so a synchronisation programme can solve this issue and eliminate the factor of poor timing.
Synchronisation
The problem with this is that, for farmers without collars or heat detection devices, it can be very difficult to pin-point the first onset of heat.
This challenge can be overcame by using fixed-time AI, as even though the initial cost of approximately €25 – €30/animal is often seen as prohibitive, it is counterbalanced by the compact calving and having cows more days in milk.
If you get a cow back in calf on the first few days of the breeding season, then she is going to be in milk earlier in the following lactation.
For instance, if you get a cow back in calf ten days earlier than her usual oestrus cycle, a cow giving 20L/day at a milk price of 55c/L, will earn the farmer €110 over those 10 days that she is in milk.
In extreme cases where a cow is missed or a straw is wasted on a cow due to poor timing, it would take the farmer another 21 days to have another chance at putting her back in calf, which means an extra 21 days without her milk in early spring or early autumn.
At a milk price of 55c/L, for a cow giving 20L in early lactation, would mean a loss of €231 if she slipped to her following oestrus cycle.
The likes of €231 might not seem like a lot but that’s only for one cow, if 10 cows are missed or their timing is poor, the farmer could lose out on €2,310 on milk sales in the early lactation.
Fixed-time AI eliminates any of the risk involved with sexed semen, and will ensure all sexed semen is used at the start of the breeding season, and mitigate any risk of reduced conception rate impacting on six-week calving rate the following season.
The following options are available: PG: Prostaglandin Injection; GnRH: Injection of Receptal, Ovarelin or Acegon; T. A.I: Timed AI
The following fixed-time AI eight-day protocol is recommended for dairy replacement heifers:
In order for fixed-time AI protocol to be successful, it is critically important that all interventions take place on the appropriate days and at the correct times.
The following 10-day fixed time AI protocol for dairy cows is recommended:
Any errors or non-compliance with the protocol can severely impact the fertility of the animal at the time of insemination, and so careful planning and organisation of the protocol is critical to its success.
Managing sexed semen
The handling of sexed semen straws is crucial to its success, as once the straws are thawed, they have to be used in a matter of minutes.
The recommendation is to organise sexed straws into one goblet for easy access and to only thaw two sexed semen straws at a time.
Straws should be thawed at 35-37℃ for 45 seconds and then loaded into a pre-warmed AI gun, which should be kept warm for the duration of AI.
Deposit the semen in the uterine body and make sure the inseminations are completed within five minutes to maximise the performance of sexed semen usage.
Overall, the interval from mating start date to first insemination can be shortened by using a synchronisation programme.
The use of synchrony treatments can also be targeted at anoestrous cows and late-calving cows to advance the time of re-breeding after calving.
The beneficial effects on subsequent calving pattern and the subsequent extra income will be maximised through early intervention.