Estimation of important genetic and phenotypic parameters of some productive traits in the New Zealand Romney Marsh sheep : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science at Massey University

Early in the 1920's, Fisher, Wright and Haldane provided the theoretical basis for studies in quantitative inheritance which was later extensively applied to animal breeding problems by Lush (1937), Dickerson and Hazel (1944) and others. The pioneering work of these authors led to the basic concept of modern animal breeding in which the objective is to change the mean value of a 'population' instead of putting emphasis on obtaining an ideal 'individual' as was common in the Mendelian era. With tne occurrence of this shift of emphasis from individuals to populations, the measurements suitable for non-discrete variation had to be designed so that the production figures could be averaged and subjected to various statistical analysis. The importance of measurement in animal breeding has been discussed by McBride (1954) and Turner (1964