Table 4.

Odds ratio, confidence intervals and P-values

	Tail undocked				Substrates				Objects
	Odds	95% CI		P values	Odds	95% CI		P values	Odds	95% CI		P values
Year
2013	Intercept				Intercept				Intercept
2014	1.481	1.316	1.667	<0.001	1.811	1.723	1.902	<0.001	2.440	2.314	2.573	<0.001
2015	1.066	0.946	1.202	0.29	2.483	2.359	2.614	<0.001	2.139	2.027	2.257	<0.001
2016	1.318	1.120	1.551	<0.001	3.151	2.924	3.394	<0.001	2.749	2.546	2.968	<0.001

Absence of tail docking, and the presence of enrichment at pen level were the dependent variables and the year was the independent variable in a model that considered the effect of farm.