Questions to be addressed

• In response to these questions we shall first summarise milk offtake by location and use graphical methods to explore the overall variation in milk offtake and to find out how average milk offtake differs between the two locations.

• By treating milk offtake as the response variable and the age of calf (synonymous with stage of lactation) as the explanatory variable, we shall use regression analysis to investigate the nature of the relationship between the two variables and the extent to which it differed between the two locations. We shall achieve this by including an additional parameter to describe location. We shall firstly use analysis of variance to fit parallel regression lines for the locations, and then fit two regression lines with separate slopes.

• These results will then be used together with questionnaire information on average milk consumption by members of the household to estimate surplus levels of milk production available for marketing.