# Help with table interpretation

I am an agricultural genomics student and I need help understanding this table of statistics from a study of 1340 cows. can you please explain to me what it means when the mean value is 0? and how to interpret its standard deviation in this case?

• You need to tell us what these traits are, what they represent. Jun 21, 2022 at 12:53
• Residual energy intake (REI) is an often-suggested trait for direct selection of dairy cows for feed efficiency. in this study two phenotypes of this trait were selected(REI1 and REI2) for further investigations, Milk yield is the trait for milk production, BW is Body Weight, BCS is Body Condition Score, Energy balance is the the amount of energy a cow needs to both maintain metabolism and pregnancy. Jun 21, 2022 at 13:08
• also, production data were analyzed from weekly averaged DIM(Days in milk) 1 to 305. Observations of FEI(Feed Energy Intake), milk yield, milk ingredients, EB(Energy Balance), BW, and BW changes exceeding the range of ± 4 standard deviations of the mean value were eliminated. Jun 21, 2022 at 13:10
• Please add new information as an edit to the post, and not only in comments. Comments are easily overlooked and can be deleted! Jun 22, 2022 at 18:29

## 1 Answer

A mean of 0 means that on average the effect of your variable REI1 and REI2 is 0. But the standard deviation comes from the fact that for each sample this effect may differ from zero. See the image below for an illustration.