Energy and nutrient digestibility and effect of increasing the dietary inclusion of hull-less oats replacing wheat grain on growth performance of weanling pigs

To compare energy and nutrient digestibility, 3 diets including 95 % AC Gehl hull-less oats, CDC Utmost VB wheat or nitrogen-free were fed to 8 ileal cannulated pigs (30.2 ± 2.2 kg) over 3 periods (Exp. 1). To evaluate effects on growth performance, 160 weaned pigs (7.7 ± 0.4 kg) were fed 4 nursery diets over 28 days (Exp. 2). AC Gehl hull-less oats replaced CDC Utmost VB wheat at 0/3, 1/3, 2/3, and 3/3. Hull-less oats contained less fibre, more fat, Lys, Arg, Leu, Val but less Glu and Pro than wheat. In Exp. 1, feeding hull-less oats resulted in greater (P < 0.05) coefficient of apparent ileal digestibility (CAID) and coefficient of apparent total tract digestibility of dry matter, digestible energy and predicted net energy value than wheat. Although CAID and coefficient of standardised ileal digestibility (CSID) of crude protein and most amino acids (AA) were lower (P < 0.05) for pigs fed hull-less oats, CAID of Lys and most SID AA content were greater than wheat (P < 0.05). In Exp. 2, feeding hull-less oats replacing wheat did not affect weekly pen average daily feed disappearance, average daily weight gain or body weight; however, overall gain-to-feed ratio decreased (P = 0.001) linearly (0.01 g/g per each 1/3 replacement). In conclusion, feeding AC Gehl hull-less oats resulted in lower CAID (except Lys) and CSID of AA, but greater SID AA content thus can fully replace CDC Utmost VB wheat grain in weanling pig diets without affecting most production parameters.