Effect of low- and high-forage diets on meat quality and fatty acid composition of Alentejana and Barrosã beef breeds

Abstract

This study investigated the effects of genotype and diet on meat fat composition and palatability obtained from Alentejana (AL) and Barrosã (BA) breeds. Herein, 20 males from each breed allocated at 11 months of age were fed ad libitum a low-forage diet or a high-forage diet and slaughtered at 18 months of age. Trained sensory panel analysis found that the longissimus lumborum (Ll) muscle from BA had higher tenderness, juiciness and overall acceptability scores than the AL breed. The highest scores for those attributes were observed in the BA breed fed the high-forage diet. Regarding the semitendinosus (St) muscle, breed was a source of variation of tenderness scores. In contrast to the Ll muscle, the highest tenderness scores for the St muscle were observed in the AL breed. The intramuscular fat (IMF) content was positively correlated with tenderness, juiciness and overall acceptability in Ll muscle and negatively correlated with flavour in the St muscle. The levels of 14:0 and 16:0, 16:1c9, 18:1c9 and 18:1c11 were positively correlated to juiciness, tenderness and overall acceptability in the Ll muscle. These correlations were not observed in the St muscle, which may be related to its low IMF content. Nonetheless, negative correlations were observed for the St muscle between flavour and 14:0, 16:0 and 18:0 FA contents.The IMF varied widely in the Ll but not in the St muscle. The latter had higher levels of 16:1c9 and trans fatty acids ( P TFA) in the BA than in the AL breed. Regarding the Ll muscle, the BA had higher amounts of 14:0, 16:0, 16:1c9, 18:0, 18:1c9, 18:1c11, saturated fatty acids ( P SFA), cis monounsaturated fatty acids ( P cis MUFA), P TFA and n-3 polyunsaturated fatty acids ( P n-3 PUFA) than the AL breed. The diet exerted an influence on the IMF content and on the levels of 14:0, 16:0, 16:1c9, 18:0, 18:1c9, 18:1c11, P SFA, P cis MUFA and P TFA in both Ll and St muscles. Moreover, the levels of P n-3 PUFA in the Ll muscle and 18:2n-6, 20:4n-6, P n-6 PUFA and P PUFA in the St muscle were influenced by diet. The results obtained in this study, with two Portuguese breeds, confirm that genetic background plays a major role in the determination of meat eating quality.Keywords: meat quality, fatty acids, trained sensory panel, forage diet, young bulls Implications This is the first work on the effects of genotype and feeding strategy (low-forage or high-forage diet) on Alentejana and Barrosã meat sensory attributes. The results obtained are new and can be used in further decisions including how meat from these breeds should be produced and marketed.

Beef palatability and its relationship with protein degradation and muscle fibre type profile in longissimus thoracis in Alentejana breed from divergent growth pathways

“…However, identifying the specific relationships between meat quality and myofibre characteristics, including fibre types and CSA, remains a difficult task (Lee et al, 2010;Lefaucheur, 2010). As expected, increasing tenderness and juiciness were associated with higher global acceptability which is in accordance with a previous study from our research team (Costa et al, 2012). No significant correlations were observed between IMF, MFI 7d and WBSF and sensory panel scores in both groups, CG and DG.…”

“…The tenderness, global acceptance, juiciness, flavour, WBSF, MFI 7d , IIX and IIA fibres formed a distinguishable group, suggesting a relationship among these variables in DG bulls. The close association between tenderness and global acceptability, also observed in CG bulls, was expected (Costa et al, 2012) and confirms the decisive role of tenderness in beef acceptability.…”

“…In general, the correlation between tenderness and WBSF is significant across muscles. However, this is not always observed and sometimes the tenderness perceived by a sensory panel and the instrumental WBSF are not in accordance (Costa et al, 2012).…”

Carcass fat partitioning and meat quality of Alentejana and Barrosã young bulls fed high or low maize silage diets

“…Nonetheless, further studies are needed for the full understanding of the factors and mechanisms underlying lipid metabolism and, thus, carcass composition and meat quality. Significance: ns, P >0.1; ‡, P b 0.1; *, P b 0.05; **, P b 0.01; ***, P b 0.001. a Published in Costa et al (2012). b WBSF, Warner-Bratzler shear force.…”

Repercussions of growth path on carcass characteristics, meat colour and shear force in Alentejana bulls

“…Meat tenderness strongly influences the consumer's re-purchase and choices for a particular meat cut and/or brand (Schönfeldt and Strydom, 2011;Costa et al, 2012). The two major factors determining meat tenderness are the ageing time and the quantity and characteristics of the intramuscular collagen (Takahashi, 1996;Chriki et al, 2012).…”