Table 4.

Factor associated with the percentage of dead on arrival (DOA) from 13,581 truckloads of broilers raised by one of Thailand's largest broiler producers without an antibiotic program and slaughtered in 2021.

Variable	Estimates1	SE	Statistic	P-value	95% confidence interval
Season
Winter	0.149	0.019	7.942	<0.001	0.1120	0.1860
Summer	−0.154	0.019	−8.037	<0.001	−0.1160	−0.1910
Rainy	Ref
Time of transport2
Night	−0.178	0.013	−14.102	<0.001	−0.2030	−0.1530
Morning	−0.235	0.024	−9.940	<0.001	−0.2810	−0.1880
Day	Ref
Sex
Male	0.199	0.020	9.814	<0.001	0.1590	0.2380
Female	−0.119	0.020	−5.976	<0.001	−0.1580	−0.0799
Mixed sex	Ref
Age
40–43 d	−0.181	0.030	−6.115	<0.001	−0.2390	−0.1230
44–47 d	−0.152	0.029	−5.280	<0.001	−0.2090	−0.0959
48–51 d	0.085	0.056	1.514	0.130	−0.0252	0.1960
52–55 d	−0.066	0.106	−0.627	0.531	−0.2740	0.1410
56–71 d	Ref
Mortality and culling (%)	0.0512	0.0033	15.566	<0.001	0.0448	0.0577
Weight per crate (kg)	0.0515	0.0033	14.446	<0.001	0.0445	0.0585
Transport duration (min)	0.0011	0.0002	5.304	<0.001	0.0007	0.0011
Lairage time (min)	0.0009	0.0001	7.693	<0.001	0.0006	0.0009
Feed withdrawal time (min)	0.0008	0.0001	10.011	<0.001	0.0006	0.0014

Intraclass correlation coefficient (ICC) = 0.08.

¹Estimates (β) indicate how likely an outcome is to occur in one context relative to another or one unit increase or decrease in the predictor to a β value increase or decrease in the outcome.

²Time of transport (night = 18:00–04:00, morning = 04:00–08:00, day = 8:00–8:00).