Metrichecking – Why Bother?
Metrichecking has been around for some time now – a quick, cost-effective way of checking if cows are dirty or not.
In the first few years, farmers checked cows at 10 – 21 days post mating, having several visits over the calving period. As this was such a hassle, slowly the trend changed to checking only once or twice, often late in the calving period or just before mating. Not only was it simpler, but substantially fewer cows were found to be dirty.
Simple – YES
Cost effective? – NO!
A recent NZ study by Dr Mick Clews, of Vetora, Reparoa, presented at recent the World Buiatrics (Reproduction) Conference in Dublin, looked at this issue, with some rather sobering results.
15,500 cows from 29 seasonal calving farms in the central North Island were included in the study.
A vet visited every 21 days for 3 visits, at approximately 69, 48 and 27 days before the planned start of mating (PSM). All cows calved between 7 and 21 days at each visit were metrichecked.
Cows checked between 8 -18 days post calving had about 18% dirty, but this number dropped between days 19 – 28 post-calving to around 6% dirty from day 42 post-calving – ie by day 42 about 2/3rds of the dirty cows appeared clean on metrichecking.
Great, you say – let’s wait until day 42 and just treat those 6% – BAD CALL!
In this study, half the cows found dirty at the first examination (the control group) were left untreated until the 3rd check, and treated at that stage, with 6% appearing dirty at day 42.
Reproductive performance of this group was compared against those cows treated when first found to be dirty at day 8-21 days post-calving.
The control group, when compared with cows treated between 8 – 18 days post- calving:
- Conceived 3 days later
- Had a 3% lower 84 day (12 week)pregnancy rate
- Had a 7.3% lower 6 week in calf rate
The supposed “self-cure” group do not do so in the short term – ie in time for mating start.
The study also looked at the effect over the WHOLE herd.
Overall, early examination and treatment resulted in:
- Early treatment herds getting in calf on average 2 days earlier than late / non-treated herds (for a 400 cow herd that’s an 800 extra cow days in milk. If doing 1.5 kg at $6/kg = $7,200)
- 2.4% higher 6 week in calf rate. (Using InCalf Gap calculator, based on $5 / kg MS this = $3,840)
- 1.65% higher 12 week in calf rate, ie 1.65% less empty if 12 week mating = $6600 using the Incalf Gap calculator for empty rate (at a $5 payout).
Conclusion: EARLY metrichecking and treatment is worth a good $10k or more for a 400 cow herd.
