Hello StatDave_sas, can I use GENMOD to analyze my data? Or GLIMMIX? I always used glm or mixed to analyze milk data, but I tested the distribution and my milk residual have better fitting with Gamma distribution (because it have a lot of zeros in one side - see the image attached, please, I think is that the reason that gamma is better, right?) My classes are: treatment (treated and control), day of lactation (1,3,7,15,30,45 and 60th), parturition order (multiparous and primiparous) and the cow. My effects are: treatment, day of lactation, parturition order, day/month/year of data observation/measurement (same year), age and interaction treatment*day of lactation, treatment*parturition order. I collected one data for each day of lactation (1,3,7,15,30,45 and 60th), totalizing seven information per cow. I have 20 different cows in each treatment, totalizing 40 cows in the experiment. Thank you always. Best, Aska.
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