Digestibility, passage rate, growth, and digesta properties in Windsnyer pigs fed increasing potato hash silage

Abstract

The study was conducted to determine the apparent total tract digestibility, the rate of digesta passage, growth performance, and physicochemical properties of the digesta of Windsnyer pigs fed on increasing levels of potato hash silage. Diets were formulated to contain 0, 80, 160, 240, 320, and 400 g potato hash silage/kg of diet. Pigs were randomly assigned to six diets according to a completely randomised design. Six pigs were allocated to each dietary treatment. All diets were blended with chromic oxide (Cr2O3) to calculate apparent total tract digestibility and rate of passage. Pigs were fed diets containing different levels of potato hash silage for 5 d, following 7 d of adaptation. Thereafter, pigs were subjected to a 35-day growth performance experiment. Thirty-six pigs were slaughtered and eviscerated to determine digesta characteristics and gut compartment weights. There was a positive correlation (p < 0.05) between mean retention time and each of digestibility of dry matter, organic matter, and crude protein. There was a quadratic increase (p < 0.05) in digestibility of organic matter, crude protein, fibre and feed intake as dietary levels of potato hash silage increased. Average daily gain and gain-to-feed ratio decreased linearly (p < 0.05) in pigs as levels of potato hash silage increased. The swelling capacity (SWC) of the digesta from ileum decreased linearly (p < 0.05) as dietary levels of potato hash silage increased. The SWC of the digesta from the caecum increased linearly (p < 0.05) as dietary levels of potato hash silage increased. The water holding capacity (WHC) of the stomach digesta decreased linearly (p < 0.05) as dietary levels of potato hash silage increased. The WHC of the digesta from the ileum and caecum displayed negative quadratic responses (p < 0.05) as dietary levels of potato hash silage increased. The WHC of digesta from the proximal colon showed a linear decline (p < 0.05) as dietary levels of potato hash silage increased. The WHC of digesta from the distal colon increased linearly (p < 0.05) as dietary levels of potato hash silage increased. The results indicated that Windsnyer pigs can effectively utilise potato hash silage in diets until the 240 g/kg inclusion level beyond which total tract digestibility and feed intake are compromised.