Table 4.
Best fit model for fixed effects on birth body weight (BBW) in kilograms by a generalized linear model procedure using a gamma distribution with a log link function.
| Variable | Level | EMM | p | Log Likelihood Ratio Tests | ||
|---|---|---|---|---|---|---|
| X² | DF | p | ||||
| Intercept | Intercept | <0.001 | ||||
| Treatment (TREAT) | NM | 38.2 | 0.003 | 8.92 | 1 | 0.003 |
| Calf sex (SEX) | Male | 39.1 | <0.001 | 34.22 | 1 | <0.001 |
| Season at birth (SEASON) | Rainy | 38.9 | <0.001 | 18.45 | 1 | <0.001 |
| Year of treatment (YEAR) | 2014 | 39.4 | 0.186 | 172.67 | 5 | <0.001 |
| 2015 | 39.1 | 0.531 | ||||
| 2016 | 39.6 | 0.084 | ||||
| 2017 | 38.2 | 0.091 | ||||
| 2018 | 36.1 | <0.001 | ||||
| Cow’s age (AGE) | 4–5 | 38.5 | 0.005 | 34.33 | 4 | <0.001 |
| 6–7 | 38.8 | <0.001 | ||||
| 8–9 | 39.4 | <0.001 | ||||
| ≥10 | 38.3 | 0.094 | ||||
Model info: R-squared = 0.180; AIC = 5757.398; Deviance = 7.867; Residual DF = 1095; Chi-squared/DF = 0.0064. Reference level [EMM]: TREAT (ET [38.9]); SEX (female [38.0]); SEASON (dry [39.0]); AGE (2–3 [38.3]), YEAR (2013 [38.9]). Estimated marginal means (EMM), degrees of freedom (DF), natural mating (NM), embryo transfer (ET).