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. 2025 Sep 24;21:541. doi: 10.1186/s12917-025-04948-w

Table 2.

Univariable logistic analysis results for antibiotic use in 129 semi-intensive broiler farms in Kenya

Variable Levels Antibiotic use Coefficient OR(95% CI) P-value
Yes (N = 93) n (%) or median (IQR) No (N = 36) n (%) or median (IQR)
Internal biosecurity
Disease management
Day old chicks vaccinated No 19(20) 4(11) 1.56 Ref
Yes 74(80) 32(89) -0.72 0.5 (0.2,1.6) 0.22*
Vaccination during the production cycle No 48 (52) 18 (50) 0.98 Ref 0.87
Yes 45 (48) 18 (50) -0.39 0.9 (0.4.2.0)
Farms have separate area for sick chicken No 59 (63) 24 (67) 0.89 Ref
Yes 34 (37) 12 (33) 0.14 1.2(0.5,2.6) 0.73
Flock size Median (IQR) 400 (300, 600) 350 (300, 425) 0.001 1(1,1) 0.22*
Average number of chicken per flock Median (IQR) 400 (300, 500) 400 (300, 550) 0.001 1(1,1) 0.92
Cleaning and disinfection
Farms have footbath per chicken room No 74 (80) 28 (78) 0.97 Ref
Yes 19 (20) 8 (22) -0.11 0.9(0.4,2.3) 0.82
Farms have drinkers cleaning protocol No 20(22) 12(33) 0.51 Ref
Yes 73(78) 24(67) 0.6 1.8(0.8,4.3) 0.17*
Farms have feeders cleaning protocol No 27 (29) 12 (33) 0.81 Ref
Yes 66 (71) 24 (67) 0.2 1.2(0.5,2.8) 0.63
Resting period between batches < 7 days 32 (34) 8 (22) 1.39 Ref
8–14 days 46 (49) 20 (56) -0.76 0.5(0.2,1.5) 0.20*
15–30 days 15 (16) 8 (22) -0.55 0.6(0.2,1.5) 0.25*
Farmers check disinfection outcome Never 47 (51) 17 (47) 1.02 Ref
Sometimes 13 (14) 2 (5.6) 0.85 2.4(0.5,11.5 0.39
Always 33 (35) 17 (47) -0.35 0.7(0.3,1.6) 0.29
Chicken feed store cleaning procedure None 19 (20) 6 (17) 1.15 Ref
Sweep 40 (43) 12 (33) 0.05 1.1(0.3,3.2) 0.93
Clean and disinfect 22 (24) 14 (39) -0.7 0.5(0.2,1.6) 0.23*
Sweep & clean with water 12 (13) 4 (11) -0.05 1.0(0.2,4.1) 0.94
Farm divided(clean-restricted area/dirty area) No 72 (77) 25 (69) 1.06 Ref
Yes 21 (23) 11 (31) -0.41 0.7(0.3,1.6) 0.35
Materials and measures between compartments
No. of locks per farm Median(IQR) 2 (1, 2) 2(1, 3) -0.06 0.9(0.6,1.4) 0.75
External biosecurity
Feed and water
Farms have chicken automated drinkers No 82 (88) 29 (81) 1.04 Ref
Yes 11 (12) 7 (19) -0.59 0.6(0.2,1.6) 0.27
Farms’ water source Dam 4 (4.3) 3 (8.3) 0.29 Ref
Borehole 45 (48) 21 (58) 0.47 1.6(0.3,7.8) 0.56
Municipal 39 (42) 10 (28) 1.07 2.9(0.6,15.2) 0.20*
Rainwater 5 (5.4) 2 (5.6) 0.63 1.9(0.2,17.3) 0.58
Location of chicken feed store Within the chicken house 49 (53) 20 (56) 0.89 Ref
Separate house 44 (47) 16 (44) 0.12 1.1(0.5,2.4) 0.77
Storage of chicken feed On the floor 31 (34) 16 (44) 0.66 Ref
Elevated 61 (66) 20 (56) 0.45 1.6(0.7,3.5) 0.26
Chicken store sealed No 46 (50) 22 (61) 0.74 Ref
Yes 46 (50) 14 (39) 0.45 1.6(0.7,3.4) 0.26
Infrastructure and biological factors
Farm fenced No 23 (25) 10 (28) 0.83 Ref
Yes 70 (75) 26 (72) 0.16 1.2(0.5,2.8) 0.72
Wild animal entry into the farms Yes 32 (34) 13 (36) 0.9 Ref
No 61 (66) 23 (64) 0.07 1.1(0.5,2.4) 0.86
Frequency of vermin problem Often 42 (45) 18 (50) 0.85 Ref
Sometimes 37 (40) 11 (31) 0.37 1.4(0.6,3.4) 0.41
Never 14 (15) 7 (19) -0.15 0.9(0.3,2.5) 0.78
Farms keep backyard chicken Yes 48 (52) 15 (42) 1.16 Ref
No 45 (48) 21 (58) -0.4 0.7(0.3,1.5) 0.31
Farms keep pets None 22 (24) 6 (17) 1.3 Ref
Cats 19 (20) 10 (28) -0.66 0.5(0.2,1.7) 0.28
Dogs 8 (8.6) 5 (14) -0.83 0.4(0.1,1.8) 0.26
Dogs & cats 44 (47) 15 (42) -0.22 0.8 (0.3,2.4) 0.68
Visitors and farmworkers
Farms allow visitor entry Yes 68 (73) 27 (75) 0.92 Ref
No 25 (27) 9 (25) 0.1 1.1(0.5,2.7) 0.83
Farms have visitor entry protocol No 19 (20) 7 (19) 0.99 Ref
Yes 74 (80) 29 (81) -0.06 0.9(0.4,2.5) 0.9
Location of the farm
Distance to neighbouring farms Less than 500 40 (43) 21 (58) 0.64 Ref
Between 500–1 km 34 (37) 7 (19) 0.94 2.6(1.0,6.7) 0.05*
More than 1 km 19 (20) 8 (22) 0.22 1.3(0.5,3.3) 0.66
Demographic factors
Age Median (IQR) 52 (43, 59) 47 (43, 56) 0.03 1.0(0.9,1.1) 0.09*
Farmers’ level of education Primary 19 (20) 9 (25) 0.75 Ref
Secondary 48 (52) 17 (47) 0.29 1.3(0.5,3.5) 0.56
Tertiary 26 (28) 10 (28) 0.21 1.2(0.4,3.6) 0.7
Farmers broiler farming experience Median (IQR) 6 (3, 10) 5.5 (3, 10) 0.002 1(1.0,1–1) 0.93
County Machakos 4 (4) 1 (3) 1.39 Ref
Kajiado 12 (13) 7 (19) -0.85 0.4 (0,4.6) 0.49
Kiambu 77 (83) 28 (78) -0.37 0.7 (0.1,6.4) 0.74

Summary of farms with internal and external biosecurity measures and demographic factors, in relation to antibiotic use. The associations between biosecurity measures and antibiotic use are presented, displaying the model coefficients, odds ratio (OR), 95% confidence interval (CI), and p-values. Values marked with an asterisk (*) had P < 0.25 and were included in multivariable model