Effects of feed processing on the apparent ileal digestibility of amino acids in pig diets containing wheat bran or wheat middlings

The effects of feed processing on the apparent ileal digestibility of amino acid and the utilisation of nitrogen (N) in diets containing wheat by-products were studied in five castrated male pigs (live weight 40-109 kg). A T-cannula was surgically fitted into the caecum of the pigs at a live weight of 27 kg using the steered ileo-caecal valve technique. The experiment was conducted with a 6 x 5 cyclic change-over design in which six diets were arranged 2x3 factorially. The corresponding factors were type of wheat by-product in the diets: wheat bran (152 g/kg) or wheat middlings (328 g/kg), and method of feed processing: steam pelleting, expanding or extrusion. The other dietary feed ingredients were barley and soya bean meal. The feed-processing method or dietary wheat by-product had no effect on the apparent ileal digestibility of amino acids and crude protein. The pigs on diets containing wheat middlings tended to retain more N per intake (