Author: Annica Hansson (Växa) - Date: February 7, 2019
Rolf and his son Emil run a dairy farm at Edenberga in the southern part of Sweden. It consists of 100 dairy cows, a mix of two thirds of Swedish Holstein cow and one third Swedish red. The work regarding heat detection is all done manually during heat observations. Statistics from the Swedish cow data base show potential of improvement regarding fertility result.
In January 2017, a thorough examination of statistics and potential of improving fertility results were conducted. Average herd size during the last three years has been 98 cows and on average they have delivered 104 calves per year. The cows have produced on average 9400 kg milk per year. Calving interval has been 13 months with big individual variation, see Figure 1. During summer less animals are being inseminated according to Figure 2. From this patterns follow an unevenly number of pregnant cows between months, see Figure 3, as well as an un-preferably big variation in number of calves per months.
Figure 1. Number of cows at different calving interval (days) at Edenberga in January 2017. Blue represent pregnant cows and their predicted calving interval during the coming 7,5 months. Yellow represents calving interval among cows that calved during the latest 12 months.
Figure 2. Inseminations conducted at Edenberga. View from Swedish Instrumentpanelen (Dashboard) the last two years. Blue represent latest 12 months, 2016, and yellow 12 months before that, 2015.
Figure 3. Number of generated pregnant cows, green, and heifers, yellow, 2016 at Edenberga.
Key performance indicators (KPI) regarding insemination show 41 days in milk (DIM) for the 10 % earliest inseminations referred to as voluntary waiting period (VWP). Average time from calving to first insemination (CFI) was 69 days. 13 % of the cows were started later than DIM 110 (9 of 69). Submission rate (SR) in first lactation was 51 % and for elder cows 47 %. Conception rate (CR) in first lactation is 50 % and among elder cows 40 %. In the Swedish cow database SR is measured for animals with more than one insemination. SR average is between 40-50 % depending on breed and milk yield. Pregnancy rate (PR) defined as the product of SR and CR is 25 % in first lactation and 19 % among elder cows. Ordinary heat detection routines in the herd is to observe cows during milking plus one thorough round per day, which takes approximately one hour per day.
Investments & goals
Being aware of the potential for improvement regarding fertility, Rolf and Emil looked for a solution. It ended up with an investment in Heatime®, an activity meter. They bought equipment for about 100 000 SEK; a computer box, cables and antenna plus 50 collars and necklaces. It was installed in May 2017. Their goals were as follows: A SR above 70 %, concentrated CI around 12 months, 9 +/- 2 calving’s per month, more than 115 calves born per year and more than 10000 kg milk per cow per year. Time to be saved is about one hour heat detection per day.
In July 2018 the results, including CR was measured. SR for first lactation cows was 77 % and elder cows had 74 %. CI is now 12,2 months and more concentrated , with prognosis 11,7 months. Figure 1 and 4 show CI before and after fully one year with Heatime®. Average number of generated pregnant animals during the first 12 months with Heatime® is 10,5 animals per months. The pattern shows a dip in August with 3 pregnant animals and a peak in December with 17 pregnant animals, see Figure 5. Number of calves born, between February 2018 and January 2019, first 12 months as an effect of Heatime®, was 123. Milk yield is now 9650 kg per cow. Heat detection is now 100 % relying on Heatime® heat alarm. No manual heat detection work is conducted. To check the screen takes a couple of minutes. All set goals are reached except for milk yield, which will be reached within a year. KPI for insemination strategy show VWP 40, CFI 60 and 4,5 % of the cows got their first insemination later than DIM 110 (4 of 89).
Figure 4. Calving interval at Edenberga in July 2018. Yellow represent calving interval last 12 months. Blue represent pregnant cows predicted calving interval, equals 7,5 months.
Figure 5. Generated pregnant animals per months at Edenberga from a report in July 2018. Green represent older cows and yellow represent heifers.
CR for first lactation is now averaging 46 % and elder cows 51 %. PR for first lactation cows is 35 % and for elder cows 38 %. During the first year with Heatime® it has been a continuous work to maximize positive output from the Heatime® investment. The installation was done in May, which was the perfect timing to meet earlier seasonal decrease in number of inseminations, see Figure 2 . The gap was now, instead filled up with late lactation cows with silent heats, see Figure 6.
Figure 6. Inseminations at Edenberga, view from Instrumentpanelen (Dashboard) in February 2018. Blue line represents 2017, first year with Heatime®, and yellow line represent 2016, the year before Heatime®.
In October the number of inseminations and pregnant cows arose which gave the owner much more confidence in the technology. It therefore opened up for working strategically with insemination.
Instead to put a necklace and collar on all open cows after DIM 40, a goal for number of cows to inseminate per months was set. Goal for number of pregnant cows was set to 10 +/- 2 per months, and number of inseminations per months to about 20. Cows were directly after calving selected to be culled or not. Goal for recruitment was set to 40 %. When counting the number of pregnancies, a surplus of 10 heifers per year was predicted. This is equivalent to 20 pregnancies with beef semen. Those cows were also selected strategically and equals 16 % of pregnancies that will not contribute to next generation of dairy cows. This will lead to an overall increased genetic improvement in the herd.
It is of course too early to predict the long term effect of the installation of Heatime®, but the results from the first year give very positive signals.