Prevalence of bovine mastitis and its associated risk factors under different production system in Borena district of South Wollo Zone, Amhara, Ethiopia

Figures & data

Table 1. Prevalence of mastitis in function of production system

Variables	Number of animals examined	Positive, n (%)		Prevalence (%)	OR (P)
		Clinical	Sub-clinical
Production system
Mixed farming	175	28 (16.0)	92 (52.6)	68.6	6.38 (0.000)
Peri-urban	54	12 (22.2)	35 (64.8)	87.0
Total	229	40 (17.5)	127 (55.5)	73.0

n = number of animals, OR: Odds ratio.

Table 2. Clinical, blind, and California mastitis test scores of each quarter of a lactating cow

	Quarters Examined, N	Mastitis positive, n (%)	Severity of the diseases				Prevalence (%)	Blind teats, n
			T	1	2	3
Left front	225	84 (37.3)	7	36	22	19	9.9	4
Left rear	224	125 (55.8)	16	58	28	23	6.5	5
Right front	227	91 (40.1)	23	38	26	21	9.7	2
Right rear	226	115 (50.8)	13	30	34	27	5.75	3
Total	902	415 (46,0)	59 (6.5%)	162 (18%)	110 (12.2%)	90 (10%)	46.01	14 (1.5%)

N = number of quarters, T = trace (T),

1 = weak positive (1), 2 = distinct positive (2), 3 = strong positive (3).

Table 3. Previous history and visual observation of mastitis prevalence

Variables	Animals examined	No of Positive animals	Prevalence (%)	OR (p-value)
Previous mastitis history
Yes	17	13	76.5
No	212	154	72.6	3.5 (0.547)
Teat lesion
Present	31	28	91.3
Absent	198	138	69.7	2.5 (0.328)
Gross milk quality
Watery	28	24	85.7
Blood tinged	19	19	100	3.1 (0.426)
Clot	7	7	100	0.7 (0.000)
Normal	175	117	66.9	0.58 (0.000)

OR: Odds ratio.

Table 4. Host (cow) related risk factor

Variables	Category levels	number of animals examined	Clinical mastitis positive	Subclinical mastitis positive	Overall prevalence (%)	OR(P-value)
Breed	Local breed	132	21 (15.9%)	67 (50.8%)	66.7
	Cross breed	84	17 (20.2%)	51 (60.7%)	80.9	2.9 (0.018)
	Exotic breed	13	2 (15.4%)	9 (69.2%)	84.6	1.3 (0.013)
Calving date
	1–60 days	64	13 (20.3%)	38 (59.4%)	79.7
	61–120 days	48	14 (19.2%)	18 (37.5%)	58.3	1.5 (0.459)
	>120 days	117	13 (11.1%)	71 (60.7%)	71.8	1.7 (0.017)
Parity
	1 calves	40	4 (10%)	10 (25.0%)	35.0
	2 calves	73	10 (13.7%)	39 (53.4%)	67.1	34.3 (.000)
	3 calves	54	13 (24.1%)	34 (63%)	87.0	8.1 (0.11)
	4 calves	23	5 (21.7%)	15 (65.2%)	89.9	3.5 (0.031)
	>4 calves	39	8 (20.5%)	29 (74.4%)	94.9	2.9 (0.210)

OR: Odds ratio.

Table 5. Housing-related risk factors (HHRRF) for mastitis prevalence

HHRRF	Number of households (%)	No Examined animals	Positive n	Overall Percent (%)	OR (P-value
Floor-type
Concrete	14(7.8)	38	28(73.7)	12.3
Stone	166(92.2)	191	139(72.7)	60.7	2.9(0.333)
Manure removal
Once a day	174(96.7)	204	143(70.1)	62.5
More than a week	6(3.3)	25	24(96)	10.5	0.9(0.825)
Manure removal in the milking house (barn)
Yes	71(39.4)	108	62(57.4)	27.1

OR: Odds ratio.

Table 6. Milking practice-related risk factors (MPRRF)

MPRRF	Number of households (%)	No animals examined	No Positive animals	Overall prevalence (%)	OR (P-value)
Udder washing
Yes	34(18.9)	60	45(75)	19.7
No	146 (81.1)	169	122(72.2)	53.3	2.5(0.320)
Calve suckling
Suckle after and before milking	112(62.2)	125	88(70)	38.4
Suckle before milking	68(37.8)	104	79(75)	34.5	2.1(0.545)
Hand washing
Yes	180(100)	229	167(73.2)	73
No	0	0	0	0	-

OR: Odds ratio.