Weight gain for different methionine sources

Data consist of average body weight gain of chickens being treated with one of the two methionine sources DLM and HMTBA.

data(methionine)

Format

A data frame with 9 observations on the following 3 variables:

product

a factor with levels control, DLM and MHA denoting the treatments

dose

a numeric vector of methionine dose

gain

a numeric vector of average body weight gain

Details

The dataset contains a common control measurement for the two treatments.

Source

Kratzer. D. D. and Littell, R. C. (2006) Appropriate Statistical Methods to Compare Dose Responses of Methionine Sources, Poultry Science, 85, 947--954.

Examples

# NOT RUN {
library(drc)

## Fitting model with constraint on one parameter 
met.ar.m1 <- drm(gain~dose, product, data = methionine,
fct = AR.3(), pmodels = list(~1, ~factor(product), ~factor(product)),
upperl = c(Inf, Inf, 1700, Inf, Inf))

plot(met.ar.m1, xlim=c(0,0.3), ylim=c(1450, 1800))
abline(h=1700, lty=1)

summary(met.ar.m1)
# }