Table 1 Mean values (±standard deviation) of the productive and reproductive performance indicators of dairy cattle herds of Treviso province, North-East Italy. Data were collected monthly at the herd level (n = 127 herds), from January 2009 to June 2012

1

Average daily milk production per cow (L/day/cow)

29.08 (±5.46)

27.44 (±4.54)

29.23 (±4.52)

27.05 (±4.57)

29.16 (±4.69)

27.33 (±4.60)

29.32 (±4.69)

2

Average milk protein content (%)

3.43 (±0.19)

3.43 (±0.16)

3.39 (±0.14)

3.4 (±0.28)

3.36 (±0.14)

3.43 (±0.18)

3.42 (±0.15)

3

Average milk fat content (%)

3.65 (±0.33)

3.73 (±0.32)

3.67 (±0.31)

3.71 (±0.43)

3.61 (±0.32)

3.68 (±0.32)

3.72 (±0.30)

4

Average number of lactations per cow (no.)

2.37 (±0.30)

2.36 (±0.30)

2.34 (±0.28)

2.34 (±0.27)

2.33 (±0.27)

2.33 (±0.28)

2.33 (±0.28)

5

Average lactation length (days)

200.75 (±34.37)

203.41 (±37.20)

203.42 (±38.30)

203.83 (±38.73)

198.8 (±33.28)

195.03 (±32.89)

198.89 (±31.81)

6

Average calving-to-conception interval (days)

163.65 (±34.65)

167.28 (±38.08)

164.03 (±38.36)

166.25 (±38.95)

159.34 (±34.71)

158.44 (±34.60)

157.5 (±34.46)

7

Average number of inseminations per pregnancy (no.)

2.38 (±0.63)

2.36 (±0.66)

2.43 (±0.74)

2.47 (±0.76)

2.39 (±0.78)

2.34 (±0.71)

2.36 (±0.69)

8

Average number of inseminations per pregnancy in primiparous cows (no.)

2.36 (±0.83)

2.36 (±0.89)

2.44 (±0.88)

2.48 (±0.98)

2.42 (±0.95)

2.32 (±0.87)

2.39 (±0.84)

9

Average number of inseminations per pregnancy in multiparous cows (no.)

2.39 (±0.71)

2.35 (±0.67)

2.42 (±0.81)

2.48 (±0.84)

2.37 (±0.86)

2.35 (±0.77)

2.33 (±0.77)

10

Average number of inseminations per pregnancy leading to a registered newborn (no.)^a

0.66 (±0.58)

0.81 (±0.73)

0.67 (±0.64)

0.79 (±0.75)

0.67 (±0.63)

0.76 (±0.74)

0.65 (±0.61)

11

Total number of registered newborns (no.)^b

5.04 (±4.18)

4.47 (±3.69)

5.34(±4.37)

4.74 (±3.80)

5.34 (±4.38)

4.71 (±4.22)

4.98 (±3.69)

12

Number of cows per farm (no.)

70.27 (±45.49)

70.54 (±48.23)

70.67 (±48.17)

71.52 (±50.00)

72.72 (±49.51)

73.73 (±52.68)

64.65 (±22.36)

13

Cows’ average age (months)

46.19 (±5.98)

46.66 (±6.67)

46.61 (±6.38)

46.73 (±5.98)

46.69 (±5.16)

46.77 (±5.18)

46.85 (±5.85)

14

Average length of dry period (days)

76.78 (±59.67)

76.03 (±66.95)

74.16 (±41.76)

74.15 (±38.01)

70.1 (±20.19)

67.96 (±13.57)

67.09 (±14.23)

15

Proportion of pregnant primiparous cows (%)

44.63 (±14.18)

45.74 (±15.34)

43.79 (±15.59)

45.96 (±15.99)

46.53 (±15.82)

46.48 (±16.22)

44.84 (±16.07)

16

Proportion of pregnant multiparous cows (%)

41.66 (±13.53)

42.21 (±14.07)

40.4 (±14.93)

43.13 (±14.41)

42.62 (±13.76)

42.42 (±14.75)

40.72 (±14.92)

17

Proportion of artificial inseminations (%)

91.67 (±20.39)

91.48 (±21.35)

91.61 (±22.42)

89.95 (±25.04)

89.02 (±26.32)

89.62 (±25.56)

89.65 (±25.39)

18

Proportion of culled cows (%)

2.54 (±3.09)

3.04 (±3.18)

2.27 (±2.29)

2.83 (±2.55)

2.37 (±2.40)

2.85 (±2.74)

2.31 (±2.35)

19

Cows’ average age at first delivery (months)

27.15 (±4.04)

27.87 (±6.67)

28.17 (±6.71)

31.32 (±39.57)

21.07 (±12.97)

20.9 (±12.00)

19.25 (±12.88)