The advantages of AI in the beef herd are well documented, but watching and serving beef cows when they come into heat naturally requires a considerable amount of time, and numerous handlings.
And this, according to Jonathan Chapman, beef farmer and director at Penbode Vets, is where synchronisation protocols can help.
Dr Chapman has developed various synchronisation protocols for his own 200-cow pedigree Angus suckler herd, which have minimised the number of handlings required and led to a focused one or two-day insemination period.
“With a full-time day job and a young family, it is harder to find the time needed to successfully AI the cows from spotting natural heats,” he says. “Suckler cows do not come through a parlour twice a day and it takes time and patience to get a cow into a yard, separate her from her calf and serve.
“Synchronisation greatly reduces the required number of times needed to handle the cattle and helps me to manage the workload at calving by knowing there is a group of cows calving in a tight window at the start of the calving period.
This year, Dr Chapman synchronised and artificially inseminated 130 cows and achieved an average conception rate of 64 per cent. “If all goes to plan, I expect to calve half the herd over the Easter weekend next year.”
Dr Chapman says over the years he has trialled many synchronisation protocols and he would advise speaking to your vet for a tailored solution to your situation.
“As an example, I am getting the most consistent results with a slightly modified seven-day progesterone synchronisation.
“I find this protocol gives me the best balance between minimising the number of handlings yet achieving a decent conception rate.”
However, Dr Chapman adds protocol choice is only part of the picture and attention to the details is required at all stages, from nutrition, crush and race setup, to the semen thawing and serving process.
“This year we achieved an average conception rate of 64 per cent, but this included a group of second calvers which averaged 56 per cent,” he says. “We made the mistake of grazing the second calvers too tight for the crucial six-week period around serving and they were in poorer condition than we would ideally have liked, which resulted in poorer conception rates.”
• Plan grazing so you have a field of good grass next to the handling facilities
• You want a rising plane of nutrition, especially for three weeks before and after service
• Heifers must be reaching target weights and size for a successful result. Dr Chapman synchronises heifers at 15 months old and a minimum of 390kg live weight
• A good race with good access will greatly speed up the process as a lot of the synchronisation procedure can be completed with a full race
• Good crush for the AI process
• To improve AI techniques try to minimise sideways movement in the handing system by tying a pallet inside the crush
• Pay attention to semen thawing and limit to a maximum of two straws thawed at a time
• Scratch cards work well at showing heats and are quick to apply, so minimise stress to the animal
• Beware of false positives if using heat detection aids in ‘frisky’ heifers
Day one – Insert progesterone releasing device (CIDR/PRID) alongside 2.5ml gonadotropin releasing hormone (GnRH) injection
Day seven – Inject prostaglandin, pull out progesterone device and apply scratch card
Day nine – Serve all cattle whose scratch cards have rubbed off
Day ten – Serve cattle not served on day 9. Inject only the cattle whose scratch card has not rubbed off with 2.5 ml GnRH