Factors affecting the microbiological quality and contamination of farm bulk milk by Staphylococcus aureus in dairy farms in Asella, Ethiopia

Table 2 Univariable regression analysis of sociodemographic factors associated with TBC, CC, CPS and the occurrence of S. aureus in bulk farm milk

Variable	Category	No. of farms (%)	p-value
Variable	Category	No. of farms (%)	log₁₀ TBC	log₁₀ CC	log₁₀ CPS	Occurrence of S. aureus
Age of farm owner (yr)	Continuous		0.036	–	–	0.032
Production system	Urban	36 (72)	–	0.011	0.139	–
	Peri-urban	14 (28)
Dairying primary income	Yes	29 (58)	–	0.147	–	–
	No	21 (42)
Sex of milker	Male	23 (46)	–	0.044	0.053	0.058
	Female	27 (54)
Age of milker	Continuous		0.043	–	–	–
Cow shade roof type	Iron sheet	37 (74)	0.245	0.019	0.094
	Plastic	5 (10)
	Open	8 (16)
Herd size	< 10	46 (92)	–	0.048	–	0.197
	> 10	4 (8)
Season	Dry	30 (60)	0.000	0.022	0.200	0.079
	Wet	20 (40)

TB Total bacterial count, CC Coliform count, CPS Coagulase-positive staphylococci count. Note: Linear regression was used when the outcome/dependent variable was continuous (bacterial count data), while logistic regression was used for categorical variables (S. aureus presence/absence). P ≤ 0.25 in the univariable regression analysis are shown in the table

ISSN: 1471-2180