The experimental design included a total of 43 cows. Each cow in the

experimental group was injected with BST and had completed at least one
 
lactation while on the drug. A somatic cell count was used to detect mastitis

in the animals.
  
	Data collection involved the measuring the SCC for all animals at 30-day

intervals for their entire lactation.  It was impossible to be present for the entire

lactation, however for a period of two months during the summer, data was collected

by the researchers.  This meant that for the rest of the year, data was collected by

others for the researchers.
  	
	SCC can be affected by many things.  Cows with a high body score (larger, fatter

cows) seem to be more inclined to have high somatic cell counts, and as cows age,

they seem to have increasing somatic cell counts.  Accordingly, an analysis technique

was devised that controls for the differences between individual cows.  This enabled

investigation of the effects of BST on the somatic cell count of the Jersey cows.