Pesticide Usage in Scotland: Rodenticides on Grassland & Fodder Farms 2017

Supplementary data

In addition to the collection of rodenticide usage data, farmers were also asked a series of supplementary questions relating to aspects of their farm operation, their use of non-chemical rodent control, rodenticide stewardship and their compliance with best practice in rodenticide use.

In contrast to the rodenticide usage data presented in the previous sections of this report, this information is not raised to provide national estimates of use, but is presented as responses from the sample surveyed.

Non-chemical rodent control

For the first time in this survey series, data were collected about non-chemical methods of rodent control employed on grass and fodder farms. Farmers used a range of non-chemical rodent control measures, with some farmers employing more than one method (Figure 10).

Figure 10 Non-chemical control on grassland and fodder farms (percentage of total methods used) - 2017

On holdings on which rodenticides were not used (n=252), 56 per cent of the farmers reported using one or more non-chemical control approaches. The most commonly encountered methods were use of cats and traps (61 and 23 per cent of all methods reported respectively). Shooting, dogs and ferrets were also used to control rodents. In addition, two per cent of farmers who didn't use rodenticides (n=5) reported that rodent populations were controlled by natural predators (wild cats, stoats, weasels and owls were cited).

On holdings using rodenticides (n=383), 45 per cent reported that they used additional non-chemical methods of rodent control. Again, the most common methods used were cats and traps (57 and 26 per cent of all methods reported respectively) with lower use of shooting and dogs.

Non-chemical control data were not collected in the 2013 grass and fodder farm survey as this data point was added to the rodenticide survey series in 2014. In the arable farm surveys there was a greater difference in non-chemical control uptake between farms using and not using chemical rodenticides. In 2016, 61 per cent of arable farmers who didn't use rodenticides used non-chemical methods, compared to 26 per cent of farmers who did use rodenticides. The control methods reported in this survey were very similar to those reported in the 2016 arable surveys, with cats and traps being the most commonly used approach.

Compliance with rodenticide best practice

All farmers and PCPs who were responsible for rodenticide baiting on the surveyed farms were asked about their training history and their compliance with the principles of best practice of rodenticide use ^{[ 4]} (Table 3).

These data are expressed as percentage of respondents giving a positive answer to each question. Not all of those surveyed provided this data, responses were provided by 208 farmers, representing 97 per cent of those farmers who conducted their own rodenticide baiting. Where statistically significant differences in the response between farmers and PCPs were found these are noted.

All PCPs and 12 per cent of farmers had attended a training course on rodenticide use. The uptake of training was significantly different between farmers and PCPs (P<0.001).

All PCPs and 90 per cent of farmers stated that they recorded the quantity and location of baits, and all PCPs and farmers stated that these baits were protected from non-target animals. Bait was reported to be regularly inspected by all PCPs and 99 per cent of farmers.

Sixty eight per cent of PCPs and 57 per cent of farmers removed bait after targeted baiting periods.

Ninety six per cent of PCPs and 63 per cent of farmers stated that they searched for and removed rodent carcasses. Compliance with this element of best practice was significantly different between farmers and PCPs (P<0.001). Most respondents stated that they rarely saw carcasses. However, those farmers who did encounter carcasses employed a range of disposal methods; primarily incineration and burying, but also landfill and disposal in dung heaps, slurry pits and with fallen stock. PCPs disposed of carcasses by incineration, burial and landfill (refer to Table 3 for details).

The pattern of responses to these questions, both by farmers and PCPs, are very similar to those provided in the 2013 grass and fodder crop survey. In 2013 the only significant differences in farmer and PCP responses were also in relation to uptake of training and searching for rodent carcasses.

During this survey, 32 per cent of the PCPs who provided information volunteered that they used monitor bait to assess rodent populations to inform their control strategies. Use of placebo baits (without any active substance) confirms rodent activity levels before baiting regimes are implemented and is good practice when using rodenticides. Use of monitor baits was not a formal data collection point in this study, but will be added to the future rodenticide surveys.

Farm operation data

Farmers were asked a series of questions relating to aspects of farm operation which might affect rodenticide use pattern (Table 4). Not all of those surveyed provided this data, responses were provided by 578 farmers, representing 91 per cent of the farms sampled overall.

The majority of respondents (86 per cent) were a member of a quality assurance scheme, greater than the 68 per cent recorded in 2013. A range of assurance schemes were encountered; the most common were Quality Meat Scotland ( QMS) and Scottish Quality Crops ( SQC). Both of these schemes specify that effective rodent control measures must be in place, although the use of anticoagulant rodenticides is not mandatory. Membership of both QMS and SQC also permits purchase and use of rodenticide products authorised under stewardship conditions. More farms that practised rodenticide baiting were members of a quality assurance scheme (93 per cent) than farms that did not use rodenticides (73 per cent) and this difference was significant (P<0.001).

Ninety six per cent of those surveyed kept livestock on their holdings, compared to 91 per cent in 2013. Only one per cent of farms had a pig unit and two per cent had a poultry unit. These intensive livestock production sectors tend to be greater users of rodenticides due to storage of large volumes of feed and concern about feed spoilage and rodent related disease introduction.

Lastly, 19 per cent of holdings surveyed had an on-farm grain store, and a significantly greater number of farms using rodenticides had a grain store (25 per cent) than farms that did not use rodenticides (6 per cent) (P<0.001).

In 2013, as in 2017, statistically significant differences between those farmers using and not using rodenticides were only found in relation to quality assurance membership uptake and presence of a grain store.

Rodenticide approval and stewardship

EU and UK Regulatory risk assessments have concluded that the use of First and Second Generation Anticoagulant Rodenticides outdoors present a higher level of risk to non-target animals (such as predatory birds and mammals) than would normally be considered acceptable. As a result, outdoor use of these rodenticides would not usually be approved. However the UK Government recognises that, despite these risks, outdoor use of anticoagulant rodenticides is necessary for rodent control.

In order to be able to re-authorise these rodenticides for use outdoors, Government must be assured that the risks will be properly managed to minimise unacceptable effects to non-target species. This has been addressed by an industry led stewardship scheme, managed by the Campaign for Responsible Rodenticide Use ( CRRU) ^{[ 5]}, which was launched in 2015.

With the launch of the stewardship scheme providing environmental risk mitigation measures for rodenticide use, HSE has, during 2016 and 2017, re-approved rodenticide product authorisations. As part of this re-authorisation the approval conditions for some products have been amended, notably in relation to the outdoor use of active substances that were previously restricted to use inside buildings (brodifacoum, flocoumafen and difethialone).

Some additional questions were included in the 2017 survey to investigate knowledge and participation in the rodenticide stewardship scheme (Table 5). Not all of those surveyed provided this data, responses were provided by 208 farmers, representing 97 per cent of those farmers who conducted their own rodenticide baiting.

Sixty one per cent of farmers were aware of the rodenticide stewardship scheme's existence. Seven per cent of the farmers surveyed had attended a stewardship compliant training scheme which provided certification acceptable for point of sale purchase of professional rodenticide products. In addition, 32 per cent of farmers stated they intended to complete this training in future.

Farmers were also asked if they had purchased rodenticides after April 2016, when the product authorisations under stewardship had been implemented. Seventy six per cent of farmers had purchased rodenticides; the majority (53 per cent of purchases) were made by demonstrating membership of a compliant quality assurance scheme. Followed by purchase of amateur products (15 per cent of purchases), production of a stewardship compliant training certificate (7 per cent) and purchasing non-stewardship products available until September 2016 (6 per cent).

This is the first time that the grassland and fodder crop survey has been conducted since the introduction of rodenticide stewardship. The same questions were asked in the 2016 arable survey. In 2016, 68 per cent of farmers were aware of the scheme, 9 per cent had completed stewardship compliant rodenticide use training and 51 per cent intended to complete training in future. This difference in intention to complete stewardship training may be associated with traits displayed by growers in different crop sectors. However, as professional rodenticide products can now be purchased by membership of a compliant QA scheme, an arrangement which was an interim measure at the time of the 2016 survey, the motivation to complete training may have decreased over time. Data relating to rodenticide best practice compliance and stewardship will continue to be collected in future surveys.