Skip to main content

Table 5 Results of multivariable random-effect Weibull model for risk factors for culling due to slaughter and death in 232,445 lactations of 140,934 dairy cows (herds n = 410)

From: Culling reasons and risk factors in Estonian dairy cows

Variable

Category

Na,b

Hazard Rate Ratio

95% Confidence Intervals

Animal-level variables

Days in milk at first test-milking (centered)

  

1.008

1.007; 1.009

Square term of days in milk at first test-milking (centered)

  

0.9997

0.9995; 0.9997

Milk yield at first test-milking (centered) (kg)

  

0.96

0.956; 0.958

Square term of milk yield at first test-milking (centered)

  

1.001

1.0011; 1.0013

Milk fat/protein ratio at first test-milkingb

< 1.5

181,507

1

 

≥1.5

50,938

1.23

1.20; 1.26

Milk somatic cell count at first test-milking (*1000/mL)b

< 200

174,387

1

 

≥200

58,058

1.31

1.28; 1.34

Milking method at first test-milkingb

Milking twice a day

163,033

1

 

Milking three times a day

41,773

0.79

0.74; 0.84

Robot milking

27,639

0.57

0.53; 0.61

Breeda

Estonian Holstein

113,284

1

 

Estonian Red and Estonian Native

27,650

0.79

0.76; 0.82

Parityb

First

77,456

1

 

Second

60,689

2.09

2.03; 2.16

Third

41,267

2.89

2.79; 2.99

Fourth

25,810

3.65

3.52; 3.78

Fifth

14,398

4.35

4.18; 4.53

Sixth

7334

4.96

4.72; 5.21

≥Seventh

5491

6.12

5.80; 6.45

Calving yearb

2013

77,968

1

 

2014

81,011

0.996

0.97; 1.02

2015

73,466

0.95

0.92; 0.97

Herd-level variables

    

Herd average number of cows (one unit change is 50 cows)

  

1.01

1.001; 1.03

Herd average milk yield (one unit change is 500 kg)

  

1.15

1.13; 1.17

Regiona,d

Northeast

117

1

 

Southeast

98

0.87

0.76; 0.9993

Southwest

121

0.90

0.90; 1.003

Northwest

74

0.90

0.80; 1.02

Change of herd size from 2013 to 2015c

No change (±5%)

135

1

 

Decrease > 5 to 15%

71

1.03

0.86; 1.23

Decrease > 15%

68

1.48

1.24; 1.77

Increase > 5 to 15%

74

0.89

0.74; 1.06

Increase > 15%

62

0.86

0.71; 1.03

  1. Shape parameter p = 1.09
  2. anumber of cows in each category
  3. bnumber of observations in each category
  4. cnumber of herds in each category
  5. dNortheast Estonia: Ida-Viru, Lääne-Viru, Jõgeva, Järva county; Southeast Estonia: Tartu, Valga, Võru, Põlva county; Southwest Estonia: Pärnu, Viljandi, Saare county; Northwest Estonia: Harju, Rapla, Lääne, Hiiu county