ACKNOWLEDGEMENTS â Research supported by the Italian Ministry for University. REFERENCES â ASPA, 1991. ISMEA, Roma, Italy. Beattie, V.E., O'Connell, ...
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Effects of rearing system and genotype on intramuscular collagen properties of pigs G. Maiorano, F. Filetti, M. Gambacorta, A. Ciarlariello, C. Cavone Dipartimento di Scienze Animali, Vegetali e dell’Ambiente – Università del Molise, Italy.
RIASSUNTO – Effetti del sistema di allevamento e del genotipo sulle proprietà del collagene intramuscolare del suino – Questo studio ha inteso valutare gli effetti di genotipo (Cinta Senese, CS, e derivato Large White, dLW), sistema di allevamento (SA; intensivo e semibrado) e muscolo (M; longissimus lumborum, LL, e semimembranosus, SM) sul collagene intramuscolare (CIM) di 24 suini maschi castrati. Il CS ha mostrato, rispetto al dLW, quantità più elevate di CIM e del legame crociato idrossilisilpiridinolina (HLP), oltre ad un maggiore rapporto HLP/CIM. Il LL, rispetto al SM, ha avuto meno CIM, mentre l’allevamento semibrado, rispetto a quello intensivo, ha determinato una maggiore sintesi di HLP. L’attività fisica connessa al SA ha determinato una risposta metabolica del CIM diversa in relazione al tipo di M. KEY WORDS: pig, rearing system, genotype, intramuscular collagen. INTRODUCTION – In the past few years there has been an increasing interest in animal products originating from rearing systems that could be considered ‘natural’ or ‘traditional’, and niche market opportunities are available for pork produced with socially-acceptable assurances. Nevertheless, research comparing the effects of housing systems (outdoors vs indoors) on pork tenderness has yielded conflicting results, perhaps due to geographical location, climate and genotypes evaluated (Beattie et al., 2000; Gentry et al., 2001; Guy and Edwards, 2001). Therefore, this study aimed to evaluate the effects of rearing system (RS) and genotype (G) on intramuscular collagen (IMC) properties, which are mostly conditioned by live-animal factors and valuable predictors of meat toughness (Bosselmann et al., 1995; McCormick, 1999). MATERIAL AND METHODS – Longissimus lumborum (LL) and semimembranosus (SM) muscle (M) samples were collected from chilled carcasses (24 h at 2-4°C) of twenty-four barrows (12 Cinta Senese, CS and 12 of a Large White, LW-derived line – born and raised in the same farm where the trial has been conducted, in the Basilicata region, and thus named Locale, L). Starting from 110 d of age, pigs were allotted within weight to a complete randomized design with a 2x2 factorial arrangement of G and RS. Indoor pigs were placed in multiple pens (3 pigs/pen, 4 m2/pig) on part-solid and part-slatted floor, while the outdoor pigs were housed in paddocks (700 m2/pig) on woodland pasture. All pigs were given access to a grower/finisher diet that met nutrient requirements (15% CP and 3403 kcal DE/kg DM) and were conventionally slaughtered (A.S.P.A., 1991) after approximately 40 wk from the start of the trial. Samples were trimmed of fat and epimysium, lyophilized, and then hydrolyzed in 6N HCl to determine hydroxyproline (Woessner, 1961) and hydroxylysylpyridinoline (HLP) crosslink concentrations. IMC amount was calculated assuming that collagen weighed 7.25 times the measured hydroxyproline weight (Eastoe and Leach, 1958). HLP crosslinks were evaluated using a modification (Maiorano et al., 1999) of the HPLC procedure developed by Eyre et al. (1984). ANOVA was performed with GLM of SPSS (2000), including the animal effect, using a factorial model where G, RS, and M were the main factors (only significant interactions are reported).
ITAL.J.ANIM.SCI.
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2 (SUPPL. 1), 385-387, 2003
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PROC. 15th CONGR. A.S.P.A., PARMA, ITALY
RESULTS AND CONCLUSIONS – As showed in Table 1, G clearly influenced IMC properties. CS pigs had muscles with higher (P
