Table 8.

Results from linear models investigating the association of O. ostertagi, F. hepatica and D. viviparus BTM ELISA results and average milk fat content (%) in three regions of Germany. Full models were significantly different from null models containing only an intercept term (North: Df = 14, F = 6.1, p < 0.001; East: Df = 13, F = 7.4, p = < 0.001; South: Df = 16, F = 2.7, p < 0.001). Significant p-values are printed in bold. Seropositivity categories are defined as follows: O. ostertagi: +: ODR ≥ 0.5, ++: ODR ≥ 0.8; F. hepatica: +: 30% < S/P ≤ 80%, ++: 80% < S/P < 150%, +++: S/P ≥ 150%; D. viviparus: +: ODR ≥ 0.41.

	North (N = 192)				East (N = 195) a				South (N = 208)
Variable	Est.	SE	t	P	Est.	SE	t	p	Est.	SE	t	p
Intercept	5.36	0.31	17.07	<0.001	5.26	0.45	11.67	<0.001	4.60	0.43	10.67	<0.001
O. ostertagi +	−0.03	0.03	−1.00	0.320	0.01	0.03	0.40	0.686	−0.04	0.04	−1.22	0.223
O. ostertagi ++	−0.04	0.05	−0.88	0.378	0.03	0.06	0.61	0.545	−0.13	0.06	−2.01	0.046
F. hepatica +	−0.02	0.06	−0.40	0.686	−0.08	0.19	−0.43	0.667	0.01	0.06	0.20	0.844
F. hepatica ++	0.11	0.07	1.60	0.111	-	-	-	-	−0.09	0.06	−1.68	0.094
F. hepatica +++	0.05	0.06	0.85	0.394	−0.11	0.14	−0.83	0.406	−0.12	0.06	−1.84	0.067
D. viviparus +	−0.01	0.07	−0.11	0.915	0.11	0.09	1.19	0.235	-	-	-	-
Breed type (DP vs. HD)	−0.12	0.13	−0.88	0.378	0.17	0.14	1.25	0.214	−0.49	0.29	−1.68	0.095
Breed type (Mix vs. HD)	−0.15	0.13	−1.16	0.249	0.01	0.06	0.15	0.885	−0.83	0.35	−2.35	0.020
Lactation no.	−0.34	0.21	−1.62	0.106	−0.35	0.33	−1.05	0.294	0.20	0.19	1.04	0.301
Lactation no. (squared)	0.06	0.04	1.77	0.079	0.07	0.06	1.19	0.236	−0.04	0.03	−1.29	0.200
SCC (×1000/mL)	−2.12 × 10−4	1.71 × 10−4	−1.24	0.216	−2.29 × 10−4	1.59 × 10−4	−1.45	0.150	2.36 × 10−4	1.68 × 10−4	1.41	0.161
Herd size	−4.87 × 10−4	2.67 × 10−4	−1.83	0.069	1.21 × 10−5	4.14 × 10−5	0.29	0.770	−3.88 × 10−4	3.28 × 10−4	−1.18	0.238
farm type (ORG vs. CON)	−0.16	0.08	−1.89	0.061	−0.09	0.07	−1.34	0.183	−0.06	0.06	−1.07	0.287
farm type (TRA vs. CON)					-	-	-	-	−0.06	0.08	−0.72	0.472
Milk yield (kg)	−7.70 × 10−5	1.15 × 10−5	−6.69	<0.001	−8.12 × 10−5	1.27 × 10−5	−6.42	<0.001	−7.58 × 10−5	3.37 × 10−5	−2.25	0.025
Breed type (DP)/Milk yield	-	-	-	-	-	-	-	-	5.16 × 10−5	3.51 × 10−5	1.47	0.143
Breed type (Mix)/Milk yield	-	-	-	-	-	-	-	-	1.04 × 10−4	4.50 × 10−5	2.31	0.022

^a One outlier was excluded. Abbreviations: CON, conventional; Est., estimate; DP, dual-purpose; HD, high-performance dairy; ORG, organic; SCC, somatic cell count; SE, standard error; TRA, in transition from conventional to organic.