Esperance Fixed Time AI Project Proves Investing in Your Heifers Pays Big Dividends

Updated: Jun 23

Article by Dr Enoch Bergman, Swans Veterinary Services


The ASHEEP/Swans Veterinary Services Meat and Livestock Australia Producer Demonstration Site (ASHEEP/SVS/MLA PDS) is wrapping up. Our project was designed to demonstrate the value of integrating fixed time artificial insemination (FTAI) into the heifer breeding programs of commercial beef producers with the goal of improving conception rates, reducing dystocia, reducing calf mortality, reducing heifer mortality, improving calf weaning weights and improving heifer rebreeding rates. The project was secondarily designed to emphasize the value of both ensuring adequate heifer premating weights and of condensing the calving pattern of first-time calving heifers.

As we near the finish line, we have a significant amount of data collated that we can now share with you.

The setup of the PDS was fairly simple. We randomly hi-jacked approximately half of the heifers from a number of producers over three production years, synchronized them, and inseminated them on their traditional mating start date. Their sisters were put straight out with the bulls on the same day. The heifers which were enrolled in the AI program joined their naturally mated siblings ten days later for roughly an additional six weeks. We then measured the performance of the two groups in order to develop the potential value of integrating FTAI into commercial heifer mating programs.

Using the results from the PDS to date, each pregnancy returned an additional $64.76, after costs, per pregnancy to the producer, before factoring in genetic improvement or cow performance beyond her second pregnancy. Awesome stuff!

Having accounted for all AI mating costs to the producers for semen, pharmaceuticals, technician time, and travel, the average cost to each producer would have been $24.99 more to AI and back up at 2% bulls than to naturally join at 3%. Producer labour was estimated at 40 hours at $30 per hour per 100 heifers AI’d over the course of the AI program. Pregnant heifers were valued at an additional $100 per animal compared to empty heifers. Dystocia events were estimated to average $200 in labour and/or veterinary costs per case. Deceased calves were valued at $500 and deceased heifers at $1500. Kilograms of calf weaned were valued at $3.50 per kilo. Lastly, empty 2nd calvers were devalued by $1000 per animal should the be empty at their second pregnancy test.

Table 1: Economic estimate of the value of integrating FTAI per pregnancy.


Each of the parameters used for the financial analysis were collected from the PDS and the values associated with each difference were developed in consultation with groups of Esperance producers.


Conception Rate:

The final conception rate of the heifers which had been enrolled in the FTAI program were marginally better than the conception rate of their naturally mated sisters.Overall there was a measurable 0.8% improvement in conception rate overall for the FTAI groups, equating to a 4.6% reduction in the number of empty heifers.

Table 2: The number of heifers joined per farm per group over 3 years and the pregnancy rate statistics per farm between FTAI integrated and syndicate mated heifers.

Figure 1: The pregnancy rate statistics per farm between FTAI integrated and syndicate mated heifers over 3 years.


Dystocia Indicators:

Once calving commenced, some producers measured profound reductions in dystocia indicators whilst others saw little or no difference. We feel this was driven not only by bull selection each season but also by the maternal genetics on individual properties. The sires chosen for the AI program were significantly better calving ease sires as well as superior in growth characteristics.




Figure 2 and 3: EBV averages of AI vs. natural sires in 1st year from 3 farms.












Dystocia, calf mortality, and heifer mortality were reduced on most properties and overall in the trial. Year 3 statistics are still being compiled. Overall, dystocia was reduced by 1.3% for a reduction of 18.9% compared to naturally mated heifers; calf mortality was reduced by 1.9% for a reduction of 37.4%; and heifer mortality was reduced by 0.4% for a reduction of 40.7%.

Table 3: 2018 and 2019 combined dystocia statistics per property between FTAI integrated and syndicate mated heifers

Table 4: 2018 and 2019 combined calf mortality statistics per property between FTAI integrated and syndicate mated heifers

Table 5: 2018 and 2019 combined heifer mortality statistics per property between FTAI integrated and syndicate mated heifers.

Figure 4: 2018 and 2019 combined dystocia and mortality statistics per property between FTAI integrated and syndicate mated heifers.


Weaning Weights:

Whilst it wasn’t specifically part of the trial due to the logistics involved, we were able to collect weaning data from 5 sets of calves allowing us to estimate weaning weight advantages from the calves born from the heifers enrolled in the FTAI group w/ natural cover vs the calves born from the heifers which were only naturally mated. The average weaning weight advantage to the calves born from the FTAI group was 14.3 kilos, with a weighted average of 13.1 kilos.

Table 6: Weaning weight averages from calves born from 5 properties in Year 1 and 2.


Rebreeding Rates:

One of the most critical hurdles in a young cows life is getting back in calf the second time. The synchronization program associated with the FTAI groups brought the average calving date forward significantly. Close to 70% of the calves were born before the due date from the heifers enrolled in the FTAI program and backed up with bulls compared to those only naturally mated.

Figure 5: Combined calving distribution of the heifers enrolled in the FTAI program backed up by bulls vs. heifers mated exclusively to bulls over the same mating period from Year 1.


The subsequent conception rate of the heifers were significantly better amongst the FTAI integrated heifers vs. those naturally mated. 3.7% more of the 1st calvers which had been AI’d as heifers went on to get back in calf their second time for an overall improvement of 25.8% fewer empty heifers compared to those naturally mated as heifers.

Table 7: The number of 1st calvers joined per farm and the pregnancy rate statistics per farm between those in the FTAI integrated or syndicate mated group as heifers

Figure X: Pregnancy rates at second breeding opportunity as 1st calvers as a function of management strategy as heifers.


The PDS has been a great success here in Esperance. All producers involved in the PDS have expressed strong interest to continue integrating FTAI in their commercial heifer mating programs. In fact, many producers pulled out of the program, forgoing subsidies, in order to integrate FTAI over their entire heifer mating programs prior to the close of the PDS! The results of this PDS are already having a profound impact here in Esperance, but may influence beef producers across the entire country and possibly further! Good on ya Esperance Beef Producers!

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ASHEEP Esperance

PO Box 2445

Esperance WA 6450

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Disclaimer: The Association of Sheep Husbandry, Excellence, Evaluation and Production (ASHEEP) does not accept any liability whatsoever by reason of negligence or otherwise arising from use or release of this information or any part of it.