Table 2.

Description of symbols used in model diagram

Symbol	Parameter	Symbol	Parameter	Symbol	Parameter
AGS	Average group size purchased	FC	Fencing cost (consumables and labour)	QBC	Bedding cost in quarantine
BD	Cost of keeping bedding dry	FCC	Fencing construction cost	QT	Extra labour in quarantine
BDI	Time for keeping bedding dry – intervention	FPL	Farm perimeter length	RR	Herd self-replacement rate
BDB	Time for keeping bedding dry – baseline	FQU	Frequency of quarantine use	SAC	Cost of maintaining land for set aside
BFM	Number of youngstock born in a 15-month period	FS	Farm size	SD	Proportion of cows served to dairy semen
BS	Cost of barley straw	GK	Cost of grass keep	SDC	Proportion of heifers aged >18 months that calve
CBC	Combined main herd bedding cost	HSC	Proportion of heifers born that survive and conceive	SDG	Pasture stocking density
CF	Calving frequency	L	Labour cost	SDM	Amount of sawdust used on mattresses
CH	Cost of maintaining a closed herd using quarantine	LDF	Length of double fencing	SDU	Sawdust cost
COST	Combined cost of interventions	MTM	Mortality rate (age 24 h to 3 months)	SN	Sand cost
CP	Proportion of cows calving per year	N	Number of dairy cows in herd	SSY	Amount of straw used in straw yards
CR	Culling rate	PDF	Proportion of perimeter double-fenced	SUC	Amount of straw used on cubicles
DC	Cost of preventing direct contact between cattle	PM	Perinatal mortality (birth to 24 h)	YM	Mortality rate (age 3–18 months)
DSC	Amount of sand used in deep sand cubicles	QB	Bedding use in quarantine	YS	Average number of youngstock (age 3–18 months)