Dry matter food intake (DMFI) and digestibility (DIG) of the forage are two important nutritional aspects contributing to lambs growth and subsequent meat production. However, there is a lack of literature describing their inheritance and their phenotypic correlations with production traits, e.g. ultrasonic muscle and fat depth and growth rate, in the grazing lamb. This study aimed to investigate and quantify these parameters for grazing lambs.

This study involved 90 male Texel-Oxford lambs in 1995 and 82 in 1996. The sires in 1996 were lambs in 1995, providing genetic links between these two generations. The lambs were split equally between two lines previously selected for increased or decreased carcass lean content. The lambs were born in a five week period in March-April each year, and they were reared on, and grazed, improved mixed- species pasture, typical of a Scottish upland farm.