Effect of dietary particle size and nutrient supply on energy digestibility and nitrogen excretion in ileal cannulated grower pigs

Abstract

Diets with two particle sizes (600 and 900 µm) and two nutrient supply levels [digestible energy (DE)-limiting and amino acid (AA)-limiting; 2.8 and 1.8 g digestible lysine Mcal-1 DE, 3.15 and 3.40 Mcal DE kg-1, respectively] were used. Eight ileal cannulated pigs (25 ± 2 kg) had restricted access to feed (3 × maintenance DE) for three periods (N = 6 per diet). Reducing particle size from 900 to 600 µm did not alter urinary or total N excretion (P > 0.10), reduced faecal N excretion 11%, increased total-tract digestibility of N and energy 3%, and increased ileal digestibility of N 9% and energy 11% (P < 0.05). Reducing particle size increased energy digestibility but did not reduce total N excretion. Key words: Particle size, pig, nitrogen, excretion, energy, digestibility