Influence of the feeding system on in vitam and post mortem performances of Nero Siciliano pigs

Abstract

The effect of two feeding system, experimental vs. traditional, on in vitam and post mortem performances of 30 Nero Siciliano pigs was studied. The animals, 16 castrated males and 14 females, were divided into two groups of 15 each one, homogeneous for live weight (32.47±1.74 kg), sex (8 males and 7 females) and age (2 months), called “Traditional” (TRA) and “Experimental” (EXPE). The pigs of the “Traditional” group were fed barleycorn (2 kg/head/day) and citrus pulp (1 kg/head/day) whereas, those of the “Experimental” group received 1.3 kg/head/day of a pellet complete feed (Dry Matter: 87.5%, on a DM basis: 18.29% Crude Protein, 3.43% Ether Extract, 6.06% Crude Fiber, 7.43% Ash) appropriately formulated to be isoenergetic and isonitrogenous with the traditional diet. The trial lasted 93 days, preceded by 15-day adaptation period. Monthly, the individual weight of the pigs (electronic scale – Laumas Elettronica®) was recorded and the average daily weight gain (ADG) as well as the feed conversion race (FCR) calculated. Pigs were slaughtered after fasting for 18 hours. Yield and lean percentages of the carcasses were determined, the latter by Introscope; the thickness of the back-fat at the first (1T), at the last (UT) thoracic vertebra and at the top of the medium gluteus muscle (GM) was measured using a calibre and the pH1 (45’) value of the Longissimus lumborum muscle determined. After 24 hours of refrigeration at 4°C from the right halfcarcass of each animal, one sample of Longissimus lumborum muscle (L2-L5) was taken and the pHu, colour (CIEL*a*b* system; Spectral Scanner DV s.r.l.), Chroma and Hue, cooking loss and Warner-Bratzler shear force (INSTRON 5542) were determined. Data were subjected to the statistical analysis of variance by GLM procedure of SAS. The in vitam performances were influenced by the diet. The EXPE group showed higher final live weight (TRA 61.69 kg vs. EXPE 67.4kg; P=0.20), ADG (TRA 327.7 g/d vs. EXPE 359.7 g/d; P=0.19) and a significant (P=0.0001) difference for FCR (TRA 6.65 kg/kg vs. EXPE 3.71 kg/kg).As regards slaughtering traits, the EXPE group showed a significant difference for the yield (TRA 72.9% vs. 79.9%; P=0.008), whereas, no significant difference was observed for the lean meat percentage (TRA 48.7% vs. EXPE 49.9%; P=0.25), the back-fat at the 1T (TRA 3.4cm vs. EXPE 3.5cm; P=0.27), at the UT (TRA 1.7cm vs. EXPE 2.3cm; P=0.08) and at the GM (TRA 2.1cm vs. EXPE 2.5cm; P=0.12).The pH1 (TRA 6.37 vs. EXPE 6.34; P=0.43) and pHu (TRA 5.65 vs. EXPE 5.56; P=0.24) values indicate a good progress of meat acidification. No significant differences were observed for the Luminosity (TRA 61.35 vs. EXPE 61.14; P=0.90), Hue (TRA 0.81 vs. EXPE 0.80; P=0.96), Chroma (TRA 20.72 vs. EXPE 21.27; P=0.31), Cooking loss (TRA 22.41% vs. EXPE 25.24%; P=0.22) and WBS (TRA 3.21 kg f/cm2 vs. EXPE 2.97 kg f/cm2; P=0.28).Therefore, also in the productive reality of the Nero Siciliano pig, the feeding with pellet complete feed represents a valid alternative to obtain good performances and farming profit.