Oriental theileriosis in dairy cows causes a significant milk production loss

Parasites & Vectors

Table 6 A comparison of milk protein (kg) among different categories of dairy cows

Variable		Milk protein at 100 days of lactation				Milk protein at 305 days of lactation
	Group ( n)^a	Mean difference^b(Standard error)	95% Confidence interval^b	P-value^b	Group ( n)^a	Mean difference^b(Standard error)	95% Confidence interval^b	P-value^b
Clinical and molecular test results	1 (16)	-12.6 (2.9)	-18.2, -7.0	<0.001	1 (15)	-26.0 (7.0)	-39.7, -12.3	<0.001
	2 (14)	-8.6 (3.0)	-14.5, -2.7	0.005	2 (14)	-11.1 (6.7)	-24.3, 2.1	0.099
	3 (244)	0.30 (1.0)	-1.6, 2.2	0.76	3 (219)	2.9 (2.2)	-1.5, 7.3	0.20
	4 (309)	Reference group			4 (289)	Reference group
Age (years)	≥ 6 (184)	20.7 (1.4)	18.0, 23.5	<0.001	≥ 6 (158)	39.6 (3.3)	33.2, 46.0	<0.001
	3-5 (302)	17.2 (1.3)	14.6, 19.8	<0.001	3-5 (283)	31.6 (2.9)	25.8, 37.4	<0.001
	≤ 2 (97)	Reference group			≤ 2 (96)	Reference group

Intercepts for milk protein produced at 100 and 305 days of lactation were 61.5 kg and 160.0 kg, respectively.
^aNumbers of cows differed, because some cows “dried off” or were sold.
^bMean difference was adjusted for three age categories (i.e., two years or less, three to five years, and six years or more).
Group 1, with cardinal clinical signs of oriental theileriosis & molecular test-positive for T. orientalis; group 2, with mild or suspected signs of theileriosis & test-positive for T. orientalis; group 3, with no clinical signs & test-positive for T. orientalis; and group 4, with no clinical signs & test-negative for T. orientalis.
P-values were obtained by comparing each category with the reference group.

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