Table 1.

Description of variables collected at sampling visits for initial inclusion in statistical analyses

Variables	Species	Type	Description and coding of variable
Farm identity	Cattle/sheep	Categorical
Purchase policy	Cattle	Categorical	0 = No purchased stock (closed herd)
			1 = Occasional purchase of cows
			2 = Frequent purchase
Group size	Cattle/sheep	Continuous	Number of animals in sampled group (transformed into quintiles)
Where sampled	Cattle/sheep	Categorical	Inside = 1; outside = 0
Zone	Cattle/sheep	Categorical	1 = Southern Fylde
			2 = North Lancashire
			3 = South East Lancashire
Date of sampling	Cattle/sheep	Dd/mm/yy
Average daily milk yield	Cattle	Continuous	Average daily milk yield (litres) on sampling day (transformed into quintiles)
Feeding system	Cattle	Categorical	Feeding system used as follows:
			1 = TMR – total mixed ration
			2 = Hybrid TMR – TMR and parlour feed
			3 = Grazing and buffer feed and parlour feed
			4 = Grazing and parlour feed
			5 = Silage and parlour feed
Number of fresh cows	Cattle	Continuous	Number of cows calved within last month (transformed into quintiles)
Faecal score	Cattle	Categorical Binary	Score of 1–5 depending on consistency with score 1 being very firm and score 5 being liquid [17]; firm = score 2 or 3, loose = score 4 or 5
Sieve score	Cattle	Binary	Score being a composite score for presence of grains and long fibres with 0 = no (or a few) grains or long fibres; 1 = large amounts of grains and presence of many long fibres [18]
Stocking density	Sheep	Continuous	Number of sheep per hectare (transformed into quartiles)
Pasture quality	Sheep	Categorical	Quality of pasture, scored 0 or 1 (0 = poor; 1 = mediocre to lush)
Lambing season	Sheep	Categorical	Were the flock lambing at the time of sampling?
			1 = sampled in lambing season
			0 = sampled out of lambing season