Table 2.
Model estimates (with standard error in brackets) from the poisson or negative binomial (NB) model estimates in 620 free-stalls and 192 tie-stalls cows using Proc Genmod in SAS.
| Disease event | Intercept | Tie-stall | Herd size | Interaction tie-stall herd size | Dispersion (If NB fit) |
|---|---|---|---|---|---|
| Severe/moderate mastitis | -1.8233 (0.0918)xxx | 0.0160 (0.0695) | -0.0060 (0.0031)0.005 | 0.4254 (0.0379) | |
| All cases of mastitis | -1.2239 (0.0922)xxx | -0.3144 (0.2075) | -0.0124 (0.0032)xxx | 0.0121 (0.0072)0.09 | 0.4188 (0.0325) |
| Teat injuries | -3.7139 (0.2233)xxx | 0.6633 (0.1487)xxx | -0.0285 (0.0077)xxx | 1.0733 (0.2602) | |
| Ketosis | -3.7847 (0.2240)xxx | 0.9649 (0.1520)xxx | -0.0189 (0.0076)x | 1.8793 (0.2907) | |
| Milk fever | -2.9452 (0.0391)xxx | 0.0702 (0.0782) | 0.2071 (0.0476) | ||
| Indigestions | -4.1680 (0.3249)xxx | -0.2089 (0.5558) | -0.0303 (0.0115)xx | 0.0391 (0.0189)x | 1.2651 (03637) |
| Retained placenta | -3.3586 (0.0539)xxx | -0.0812 (0.1126) | 0.6680 (0.1071) | ||
| Abortions | -6.0659 (0.1622)xxx | -0.5325 (0.4113) | Poisson | ||
| Anoestrus | -4.4459 (0.1232)xxx | 0.7085 (0.2334)xx | 5.8928 (0.8265) | ||
| Metritis | -4.4742 (0.0859)xxx | -0.4554 (0.2016)x | 1.1197 (0.3160) | ||
| Cystic ovaries | -4.8557 (0.1151)xxx | -0.4537 (0.2151)x | 3.1334 (0.6429) | ||
| All diseases | -0.4513 (0.0812)xxx | -0.0461 (0.0620) | -0.0062 (0.0028)x | 0.4869 (0.0282) |
x = p < 0.05, xx = p < 0.01, xxx = 0.001
(Effect of free-stall = 0 in the models).