BayesDA (version 2012.04-1)

cow: Data from an Experiment with Treatment Assignment Based on Covariates

Description

An experiment was conducted on 50 cows to estimate the effect of a feed additive (methionine hydroxy analog) on six outcomes related to the amount of milk fat produced by each cow. Four diets (treatments) were considered, corresponding to different levels of the additive, and three variables were recorded before treatment assignment: lactation number ( seasons of lactation), age, and initial weight of cow. Multiple randomizations were calculated, and choosen that one with `best balane', however that was defined.

Usage

data(cow)

Format

A data frame with 50 observations on the following 10 variables.

level

diet, treatment

lactation

lactation number, pretreatment

age

age of cow, pretreatment variable

initial.weight

initial weight, pretreatment

dry

response

milk

response

fat

response

solids

response

final.weight

response

protein

response

Examples

data(cow)
summary(cow)
names(cow)
# Investigating balance on pretreatment variables:
with(cow, tapply(lactation, level, mean))
with(cow, tapply(age, level, mean))