Farm-level risk factors and treatment protocols for lameness in New Zealand dairy cattle

Figures & data

Table 1. Characteristics of farms (n = 119) enrolled into a lameness prevalence and risk factors study, from the North (n = 60) and South (n = 59) Islands of New Zealand.

Characteristic	Overall (n = 119)	North (n = 60)	South (n = 59)	P-value^a
Herd size; n (%)				<0.001
110–359	40 (34)	30 (50)	10 (17)
360–560	39 (33)	19 (32)	20 (34)
561–1,850	39 (33)	11 (18)	28 (48)
Missing	1	0	1
Milk solids (kg/cow/year); n (%)				0.023
240–399	39 (34)	26 (44)	13 (23)
400–460	39 (34)	20 (34)	19 (34)
461–600	37 (32)	13 (22)	24 (43)
Missing	4	1	3
Number of full-time staff; n (%)				0.006
<2.5	66 (56)	41 (68)	25 (43)
≥2.5	52 (44)	19 (32)	33 (57)
Missing	1	0	1
Milking frequency; n (%)				0.17
Less than twice-a-day	33 (28)	20 (33)	13 (22)
Twice-a-day all year	86 (72)	40 (67)	46 (78)
Yard size (m^2); n (%)				<0.001
<300	21 (36)	16 (53)	5 (17)
300–600	18 (31)	11 (37)	7 (24)
>600	20 (34)	3 (10)	17 (59)
Missing	60	30	30
Predominant breed; n (%)				0.016
Holstein-Friesian	47 (39)	27 (45)	20 (34)
Jersey	18 (15)	13 (22)	5 (8.5)
Holstein/Jersey cross	54 (45)	20 (33)	34 (58)
Milking parlour; n (%)				0.008
Herringbone	59 (50)	37 (62)	22 (37)
Rotary	60 (50)	23 (38)	37 (63)
Calving system; n (%)				<0.001
100% spring calving	108 (91)	49 (82)	59 (100)
Split calving	11 (9.2)	11 (18)	0 (0)
Yard shape; n (%)				0.052
Circular	81 (70)	46 (78)	35 (61)
Rectangular	35 (30)	13 (22)	22 (39)
Missing	3	1	2
Farmer-reported % lame: n (%)				0.12
<7%	40 (40)	21 (38)	19 (42)
7–15%	35 (35)	16 (29)	19 (42)
>15%	25 (25)	18 (33)	7 (16)
Missing	19	5	14
Peak lameness; n (%)				<0.001
No peak	4 (3.4)	3 (5.1)	1 (1.8)
January–March	15 (13)	0 (0)	15 (26)
April–June	11 (9.5)	2 (3.4)	9 (16)
July–September	32 (28)	22 (37)	10 (18)
October–December	54 (47)	32 (54)	22 (39)
Missing	3	1	2

^a Pearson's χ² test of proportions comparing responses from farms from the two islands.

Table 2. Descriptive statistics of lameness treatment and recovery management as reported by 119 farmers enrolled into a lameness prevalence and risk factors study, from the North (n = 60) and South (n = 59) Islands of New Zealand.

Characteristic	Overall (n = 119)	North (n = 60)	South (n = 59)	P-value^c
Identify lame cows; n (%)				0.010
Dedicated lameness scoring or technology	27 (23)	8 (13)	19 (33)
Informal, non-dedicated task	90 (77)	52 (87)	38 (67)
Missing	2	0	2
Primary lameness; n (%)				0.047
Footrot	18 (15)	13 (22)	5 (8.6)
Multiple lesions	18 (15)	4 (6.7)	14 (24)
Other	6 (5.1)	3 (5.0)	3 (5.2)
Sole lesions	25 (21)	14 (23)	11 (19)
White line	51 (43)	26 (43)	25 (43)
Missing	1	0	1
Lift hoof; n (%)				0.70
Always	75 (91)	40 (93)	35 (90)
Never or sometimes	7 (8.5)	3 (7.0)	4 (10)
Missing	37	17^a	20^b
% Treated with hoofblock; n (%)				0.68
≤22	49 (50)	26 (48)	23 (52)
>22	49 (50)	28 (52)	21 (48)
Missing	21	6	15^b
Where lame cows are treated; n (%)				0.001
Lame cow crush	59 (52)	20 (36)	39 (67)
Other	54 (48)	35 (64)	19 (33)
Missing	6	5	1
External trimmer; n (%)				0.11
No	75 (65)	34 (58)	41 (72)
Yes	41 (35)	25 (42)	16 (28)
Missing	3	1	2
Formal trimming training; n (%)				0.56
No	69 (62)	36 (64)	33 (59)
Yes	43 (38)	20 (36)	23 (41)
Missing	7	4	3
% treated with NSAID; n (%)				>0.99
≤30	55 (53)	27 (53)	28 (53)
>30	49 (47)	24 (47)	25 (47)
Missing	15	9	6
Lame milked once-a-day; n (%)				0.051
No	12 (12)	9 (21)	3 (5.4)
Sometimes	15 (15)	7 (16)	8 (14)
Yes	72 (73)	27 (63)	45 (80)
Missing	20	17	3
Cull based on lameness; n (%)				0.050
Maybe	13 (12)	5 (8.9)	8 (15)
No	25 (23)	18 (32)	7 (13)
Yes	72 (65)	33 (59)	39 (72)
Missing	9	4	5
Prioritise culling based on lameness; n (%)				0.062
Maybe	34 (30)	12 (21)	22 (39)
No	31 (27)	20 (36)	11 (19)
Yes	48 (42)	24 (43)	24 (42)
Missing	6	4	2
Management when lame; n (%)				0.031
Always in separate herd near shed	85 (83)	33 (73)	52 (90)
Other	18 (17)	12 (27)	6 (10)
Missing	16	15^a	1

^a Farmers from Northland did not answer this question.

^b Farmers from West Coast did not answer this question.

^c Pearson's χ² test of proportions comparing responses from farms from the two islands.

NSAID = non-steroidal anti-inflammatory drug.

Table 3. Descriptive data of management strategies for lameness as reported by 119 farmers enrolled into a lameness prevalence and risk factors study, from the North (n = 60) and South (n = 59) Islands of New Zealand.

Characteristic	Overall (n = 119)	North (n = 60)	South (n = 59)	P-value^a
Top gate; n (%)				<0.001
No	63 (55)	44 (77)	19 (33)
Yes	52 (45)	13 (23)	39 (67)
Unknown	4	3	1
Electrified backing/top gate; n (%)				0.12
No	89 (77)	48 (83)	41 (71)
Yes	27 (23)	10 (17)	17 (29)
Unknown	3	2	1
Backing gate alarm/hose; n (%)				<0.001
No	34 (29)	26 (45)	8 (14)
Yes	82 (71)	32 (55)	50 (86)
Unknown	3	2	1
Use dogs to move cows; n (%)				0.010
No	98 (84)	44 (76)	54 (93)
Yes	18 (16)	14 (24)	4 (6.9)
Unknown	3	2	1
Concrete stand-off pad; n (%)				<0.001
No	79 (68)	30 (52)	49 (84)
Yes	37 (32)	28 (48)	9 (16)
Unknown	3	2	1
In-shed feeding; n (%)				<0.001
No	41 (40)	34 (59)	7 (16)
Yes	62 (60)	24 (41)	38 (84)
Unknown	16	2	14
Permanent footbath; n (%)				0.49
No	106 (92)	54 (95)	52 (90)
Yes	9 (7.8)	3 (5.3)	6 (10)
Unknown	4	3	1
Farm policy for managing lameness; n (%)				<0.001
No	25 (22)	21 (36)	4 (7.1)
Yes	89 (78)	37 (64)	52 (93)
Unknown	5	2	3
Maximum one-way distance; n (%)				0.26
≤1.5 km	68 (60)	32 (55)	36 (65)
>1.5 km	45 (40)	26 (45)	19 (35)
Unknown	6	2	4
Track maintenance over past 12 months; n (%)				<0.001
≤20%	75 (65)	48 (83)	27 (47)
>20%	40 (35)	10 (17)	30 (53)
Unknown	4	2	2
Average distance walked per day; n (%)				0.77
≤2 km	55 (50)	28 (49)	27 (52)
>2 km	54 (50)	29 (51)	25 (48)
Unknown	10	3	7

^a Pearson’s χ² test of proportions comparing responses from farms from the two islands.

Table 4. Final Bayesian multivariable logistic mixed regression model for the association between farm-level risk factors and the odds of lameness with output as OR and 95% equal-tailed credible intervals (ETI). Data from cows across 119 farms, using multiple imputed chained equation (n = 10) for missing data.

Characteristic	Estimate	Std. error	OR (95% ETI)^a
Peak lameness incidence
July – December	Reference
January – June^b	−0.44	0.14	0.64 (0.47–0.88)
Concrete stand-off pad
No	Reference
Yes	0.37	0.16	1.45 (1.07–1.88)

^a OR and 95% highest density uncertainty interval.

^b January–June also includes four farms that stated all months of the year had equal incidence of lameness.