The effect of sub-clinical infection with Mycobacterium avium subsp. paratuberculosis on milk production in a New Zealand dairy herd

Table 4 Results of a linear mixed model predicting daily kgMS production

Input variable	Coefficient	SE	p-value
Intercept	1.77	0.03	< 0.001
Parity
Primiparous	Ref
Multiparous	0.73	0.03	< 0.001
Days in Milk	−0.002	0.0001	< 0.001
Wilmink’s correction^a
exp(− 0.1 × DIM)	−0.13	0.22	0.546
Cow breed
> 75% Friesian	Ref
50–75% Friesian,	−0.09	0.02	< 0.001
< 50% Friesian	−0.07	0.02	< 0.001
DIM × parity
DIM × Primiparous	Ref
DIM × Multiparous	−0.002	0.0002	< 0.001
Wilmink’s correction × parity
exp(−0.1 × DIM × primiparous)	Ref
exp(−0.1 × DIM × multiparous)	−0.21	0.24	0.379
Season
2013–14	Ref
2014–15	0.22	0.01	< 0.001
MAP status^b
Undetected	Ref
Moderate latent	−0.03	0.02	0.136
High latent	−0.07	0.03	0.004
Moderate shedding	−0.07	0.04	0.036
High shedding	−0.20	0.04	< 0.001

Ref = the reference category for each categorical variable
^aOverall significance of Wilmink’s correction and its interaction in the model < 0.001
^bOverall significance of MAP status in the model < 0.001

ISSN: 1746-6148