Dietary Netutral Detergent Fibre level on performance traits and meat quality in Nero Siciliano pigs

The use of forages produced locally could significantly increase, in most cases, the sustainability and profitability of the farming system. The aim of this study was to evaluate the effect of two fibre levels on some performance traits and meat quality in Nero Siciliano fattening pigs. The study was carried out on 40 Nero Siciliano fattening pigs, 20 castrated males and 20 females, divided into two homogeneous groups for number, sex, age and live weight, called “Moderate Fibre” (MF) and “High Fibre” (HF). Two diets were formulated to contain two different levels of Neutral Detergent Fibre (NDF): 183 g/kg NDF (MF) and 418 g/kg NDF (HF). The different level of dietary fibre was obtained by administration of meadow hay to the animals of HF group. The quantities of daily NDF intake were for the MF group of 275 g/head/d and for the HF group 1,025 g/head/d, while the quantities of daily Crude Protein intake were of 250 g/head/d for each group. The trial lasted 106 days. Every thirty-six days, the productive performance of the pigs were recorded. At slaughter, Carcass traits were measured and the Compactness Index was calculated. At 24 hours post mortem from the left half-carcass of each animal, one sample of Longissimus lumborum muscle was taken and the physical, chemical and acidic composition were determined. The HF group showed significant lower values for Final Body Weight (MF 110.25 kg vs. HF 99.56 kg; P = 0014) and Average Daily Gain (MF 0.264 kg/head/d vs. HF 0.162 kg/head/d; P = 0038) and significant higher values for Feed Conversion Ratio (MF 6.17 kg/kg vs. HF 14.76 kg/kg; P = 00005). The MF group showed, as expected, a better Compactness Index than that of the HF group (MF 1.12 kg/cm vs. HF 0.95 kg/cm; P = 0003). The technical and nutritional characteristics of the meat were not influenced by the dietary treatment (P >005) and appeared within the ranges reported by the literature. Further studies devoted to the relationship between NDF fibre content and its functionalities are necessary in order to identify an appropriate fibre level that reduce ammonia emission, promote intestinal health and still allow fair pig performance.