Table 3 Associations of the control variables included in the ‘semester-based’ mixed-effects linear models for the average lactation length and average calving-to-conception interval of 127 dairy cattle herds of Treviso province, Italy, with first order autoregressive variance structure fitted to monthly measurements (January 2009 to June 2012)
Control variable | Average lactation length (days)a | Average calving-to-conception interval (days)a | ||||
|---|---|---|---|---|---|---|
Coefficient | F-value | p-value | Coefficient | F-value | p-value | |
Herd size | −4.69 | 1.63 | 0.2047 | −1.32 | 0.07 | 0.7858 |
Cows’ average age (months) | −0.09 | 0.51 | 0.4737 | −0.19 | 2.21 | 0.1369 |
Average calving-to-conception interval (days) | 0.15 | 85.63 | <0.0001 | - | - | - |
Average monthly temperature | 0.82 | 167.86 | <0.0001 | −0.05 | 1.25 | 0.2643 |
Proportion of pregnant primiparous cows (%) | 0.33 | 213.63 | <0.0001 | −0.01 | 0.47 | 0.4928 |
Proportion of pregnant multiparous cows (%) | 0.46 | 275.41 | <0.0001 | −0.07 | 9.21 | 0.0024 |
Average length of dry period (days) | −0.03 | 4.16 | 0.0414 | −0.07 | 21.11 | <0.0001 |
Proportion of artificial inseminations (%) | 0.11 | 7.27 | 0.0071 | 0.43 | 120.17 | <0.0001 |
Proportion of culled cows (%) | −0.45 | 61.78 | <0.0001 | −0.28 | 32.04 | <0.0001 |