Table 3.

Results from univariable analyses of candidate variables with respect to their association with type of herd (high calf mortality > 5% and low calf mortality ≤ 5%) in 50 German dairy herds, visited between September 2012 and October 2014.

Variable	category	Low calf mortality	High calf mortality	p-value
ADG from birth to weaning in g/day b,c	Median	739	663	0.096
Serum total protein concentration in the first week of life in g/l b	Median	53.9	52.8	0.110
Percentage of calves with FPT a,c	≤ 25% > 25%	7 16	2 23	0.068
Serum albumin concentration around weaning in g/l b	Median	34.8	34.2	0.141
Disinfection of the maternity pen b,c	no yes, but not against cryptosporidia yes, against cryptosporidia	13 9 3	8 8 9	0.111
Separation of maternity pen and box for sick cows b,c	no next to each other yes	5 11 9	8 4 13	0.090
Time per day without staff at the farm a	≤ 2 hours > 2 hours	10 15	5 19	0.146
Maximal time interval between calving and harvesting first colostrum of the dam b	≤ 2 hours > 2 - 8 hours > 8 hours	8 10 7	5 6 14	0.130
Latest feeding of first colostrum to newborn calves (hours post natum) b	≤ 2 hours > 2 - 4 hours > 4 hours	12 2 11	8 7 9	0.140
First colostrum offered at second meal b	no partly yes	7 10 8	14 6 5	0.130
Age at first offer of water to calves (all-season) a,c	≤ 7 days > 7 days	14 11	8 17	0.087
Age at first offer of hay to calves b,c	≤ 7 days > 7 days not before weaning	11 10 4	3 17 5	0.033
Amount of concentrates consumed around weaning in kg b	Normally distributed	1.5	1.0	0.072
Change between stalls with warm climate and outdoor climate housing before weaning a	change no change	18 7	13 12	0.145
Use of halofuginone lactate a,c	no yes	19 6	8 17	0.002
Interruption of milk feeding for calves with NCD a	maximum one meal more than one meal	18 7	13 12	0.145

a – chi-square-test; b – logistic regression; c – candidate variables for multivariable model.