Milk Fever ROI Calculator

Cost Sources: DairyNZ research establishes costs at $800 per clinical case and $150 per sub-clinical case at current NZ milk solids payout ($9.30/kg MS). These figures are automatically adjusted if you change the milk price input. Clinical cases include treatment, vet costs, and production loss from 14% reduction over early lactation. Sub-clinical cases include approximately 4.5% production loss in early lactation. View DairyNZ guidance

Risk Data: Age-specific sub-clinical rates from Roberts & McDougall 2018 (NZ Vet J. 67:1-20). Clinical rates are scaled to match your farm's overall rate.

Clinical Milk Fever Efficacy: Single dose calcium bolus efficacy based on Leno et al. 2018 (J. Dairy Sci. 101:3285-3302), showing 43% reduction in calcium retreatment for multiparous cows with low calcium (Table 8, RR=0.57). Double bolus (multiple dose) efficacy based on Thilsing-Hansen et al. 2002 meta-analysis (Acta Vet. Scand. 43:1-19), showing 50-60% mean efficacy for milk fever prevention. Cow Start Complete efficacy based on Lawlor et al. 2024 (Anim. Vet. Sci. 12(6):154-160), demonstrating 0% clinical milk fever incidence in supplemented cows vs 13.3% in controls.

Sub-clinical Hypocalcemia Efficacy: Blood calcium status is the primary measure of sub-clinical efficacy, with normocalcemia defined as Ca >2.0 mmol/L. Standard single calcium boluses show minimal blood calcium elevation (Leno et al. 2018), while traditional double bolus protocols achieve average blood Ca of ~2.04 mmol/L but with variable sustained effect. Cow Start Complete demonstrates sustained blood calcium elevation of 2.14 mmol/L (vs 1.98 mmol/L control, P<0.0001) over 96 hours, maintaining cows above the 2.0 mmol/L threshold throughout the critical 48-hour post-partum period (Lawlor et al. 2024). This sustained normocalcemic status translates to the estimated 70% reduction in sub-clinical exposure, as cows spend significantly less time in the sub-clinical range (<2.0 mmol/L) compared to untreated controls or standard calcium supplementation.

Understanding the Results: Milk fever and sub-clinical milk fever are always present in dairy herds despite best management practices. This is a natural physiological challenge that occurs at calving when calcium demand suddenly increases for colostrum and milk production. While some level of milk fever cannot be completely eliminated, the economic losses can be significantly reduced through strategic calcium supplementation.

Reading the Chart: The leftmost bar (No Treatment) shows your baseline costs from milk fever cases that would occur without intervention. Each treatment strategy bar shows: remaining disease costs in red shades (cases that still occur despite treatment), treatment costs in orange (cost of the intervention), and net savings in blue (money saved compared to no treatment). The goal is to maximize the blue section while keeping orange costs reasonable - this is your return on investment.