Hello, I am analysing the interaction of lunar phases on feed intake(DMINT), water intake(WI), milk yield(MY) and body weight (Live_wgt) on cattle. I have data from 2012-2016. There are +-200 cows. The cows are divided into two genetic groups (C and S), then they are subdivided into 2 feeding type groups (XB and XH). I am trying to see if there is a significant interaction between LunarPhase and the 4 variables or could this interaction be an effect of the variables on each other. My data is unbalanced, so proc mixed was seen as a more useful procedure. There are fixed effects: Eartag (animal ID), Date, Parity(LactNo) Days in milk (DIM) Season, Year, system (Genetic group*feeding type), and Weight (live_wgt). With focusing on feed intake (DMINT) as an example, I have been using the code; proc mixed data=MYdata PLOTS (maxpoints=9000); class EARTAG Date LunarPhase Season DIM Year Lactno System Live_weight; model DMINT=LunarPhase DIM Season*Year Lactno System Live_weight/ s; random EARTAG*Lactno; run; Now my question is that when I am trying to look at the relationship and add MY to my model it says that there is an error issue. How do I make this code work, what am I doing wrong, what procedure could I use to fix this?
... View more