| Abstract: | New Zealand White rabbits, aged between 5 and 8 weeks, were offered diets based on oatmeal together with up to 500 g kg?1 of ground oat husk, or 500 g kg?1 of ground barley straw or 400 g of a purified cellulose. The rabbits gained about 40 g liveweight per day when fed a well-balanced control diet (in which oatmeal, grassmeal, corn oil and fishmeal were the main constituents) and, apart from one occasion, there was no significant reduction in this rate of gain even when the diets offered contained up to 500 g kg?1 of these fibre sources. Food consumption increased from 80 g day?1 to 115 g day?1 as the acid detergent fibre concentration in the diet increased from 39 to 270 g kg?1. Digestible and metabolisable energy contents of the diets fell as the fibre concentration rose but the rabbits were able to adjust their intakes and maintain their daily metabolisable energy intakes constant at about 1100 kJ. The proportion of fat in the body dry matter fell as the fibre concentration in the diet was raised. A minimum dietary fibre content of 100 g kg?1 as measured by the acid detergent fibre or crude fibre techniques is suggested for optimum healthy growth. |
