To reduce calf mortality rates, the Netherlands Food and Consumer Product Safety Authority (NVWA) developed various letters for distribution amongst three subgroups of dairy farmers. The impact measurement shows that calf mortality decreased in the overall target group, although the letters did not produce any measurable outcomes.

Why this experiment was conducted: calf rearing necessitates a significant amount of care
Failure to ensure appropriate care for animals in dairy farming operations can have adverse consequences for animal welfare and animal health, and may even result in calf fatalities. In the years leading up to this project, many farms had high calf mortality rates, in excess of 15% amongst calves aged 0 to 14 days old. The Netherlands Food and Consumer Product Safety Authority (NVWA) conducted a target group study to examine the causes of these high mortality rates. Calf care is seemingly not a subject of discussion, workloads are high and with many dairy farmers suffering from business blindness, habits become ingrained. Added to this, farmers are unaware of the scale of the problem on their farms and across the industry as a whole.

Type of intervention: individualised letters
The NVWA created individualised letters for three subgroups of dairy farmers incorporating the most promising launch points from the target group analysis: rewards and risk awareness.
• Letter 1 was sent to dairy farmers with calf mortality rates at or below the national average of 3%. Each received positive feedback on the mortality rate at their farm. Green colours were used for the purpose of a visual comparison with the national average, accompanied by the text: 'Dit is positief' (This is positive) and 'Met uw inzet weet u de kalversterfe op uw bedrijf laag te houden. Hiermee draagt u positief bij aan het dierenwelzijn in Nederland' (Thanks to your actions, calf mortality is low on your farm. In this way, you are making a positive contribution to animal welfare in the Netherlands)
• Letter 2 was sent to dairy farmers with improved calf mortality, which was nonetheless too high. They each received positive feedback about the improved situation on their farms, including the message 'Dat is positief, maar u bent er nog niet' (That is positive, but you still have improvements to make) and a text urging them to continue this positive trend. The farm was compared to the sector average by means of red and yellow colouring.
• Letter 3 was sent to dairy farmers with high calf mortality rates (15% or more). The letter included a comparison with the national average in predominantly shades of red, mentioned the possibility of an inspection and sought to lessen opposition (resistance) with the text 'De NVWA begrijpt dat u ook geen hoge kalversterfe wilt op uw bedrijf en mogelijk al maatregelen heef getrofen om uw kalver- sterfecijfer terug te dringen' (The NVWA understands that you also don't want calf mortality to be high on your farm and may have already taken measures to reduce your calf mortality rate).

Method used: experiment
In each subgroup, a selection of dairy farmers received the letter (intervention group) while others received no letter (control group), in April 2021. For these groups, calf mortality rates were compared one year before and one year after the letter was sent.

Result obtained: the mortality rate decreased, although this is not attributable to the letters
Across all the dairy farms, average calf mortality in the 0-14 day age group decreased by 1.06% between 2018 and 2021. This is likely due to increased attention for the issue of calf mortality and various sector initiatives. The proportion of farms with high calf mortality decreased from 2.8% to 1.1% during this period.
• Letter 1: the calf mortality rate in the intervention group with low calf mortality increased slightly. The rate in the control group seems to have increased more sharply, although calf mortality remains low in both groups. The letter is unlikely to have contributed to this result.
• Letter 2: calf mortality increased slightly in both the control and intervention groups of dairy farmers with improved calf mortality, which was nonetheless too high.
• Letter 3: calf mortality decreased in the group of dairy farmers with high calf mortality. This is a positive development, although no difference was measured between the control and intervention groups.

Impact: improved animal welfare
The NVWA monitors the welfare of farmed animals, including in the dairy farming sector. Farms must, for example, ensure that animals are provided with appropriate nutrition and sufficient water, and medical care if needed. Investigating what motivates dairy farmers to comply with these welfare rules enables the NVWA to deploy the mix of enforcement tools more effectively.

Source: https://www.binnl.nl/home+-+en/knowledge/publications/bin+nl+publications/HandlerDownloadFiles.ashx?idnv=2719979