Effects of dietary phytase with or without multi-carbohydrase supplementation on growth performance, nutrient digestibility, and bone traits in nursery pigs

The aim was to determine the effects of supplementing increasing doses of phytase alone or in combination with a multi-carbohydrase blend to a phosphorus (P)-deficient diet for nursery pigs on growth performance, nutrient digestibility, and metacarpal bone characteristics. A total of 192 weaned pigs (7.7 ± 0.05 kg) were allotted to one of eight dietary treatments each with eight replicates in a randomized complete block design based on initial body weight. Fecal samples (days 18, 19, and 20) and metacarpal bones (day 21) were collected to determine apparent total tract digestibility (ATTD) of energy and nutrients and bone mineralization, respectively. During week 3 and overall period, increasing doses of phytase quadratically increased ( P < 0.05) average daily gain. The ATTD of ash and P quadratically increased ( P < 0.05) when doses of phytase increased. Phytase had quadratic ( P < 0.05) effects by increasing fat-free dry weight, ash content, and P in metacarpal bone. In conclusion, increasing levels of phytase quadratically improved growth performance in week 2, nutrient digestibility, and bone traits of pigs fed a P-deficient diet. In general, however, there was no effect of multi-carbohydrase supplementation on growth performance and metacarpal characteristics in nursery pigs.