Table 3.

Descriptive statistics for parity, days in milk (DIM), milk yield (kg/cow/day), milk protein content (%) and milk fat content (%) for D. viviparus positive and negative cows where test-day data was available [two records per cow if faecal examination and test-day data were available in summer and autumn (n = 1532); note that some cows changed infection status]

	D. viviparus-positive cows			D. viviparus-negative cows
	Mean	SD	Range	Mean	SD	Range
Parity	1.3	0.7	1.0–4.0	2.9	1.8	1.0–11.0
DIM	116.1	55.4	19.0–254.0	191.8	119.5	1.0–741.0
Milk yield	19.9	5.5	9.4–34.4	21.4	7.1	2.4–47.6
Milk protein content	3.4	0.3	2.7–4.0	3.5	0.4	2.4–6.3
Milk fat content	4.1	0.5	3.3–5.6	4.2	0.7	2.0–7.2

Abbreviation: SD standard deviation