Qualidade de carne de bovinos submetidos a diferentes estratégias durante a recria e terminação
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Data
2020-05-05
Autores
Torrecilhas, Juliana Akamine
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Universidade Estadual Paulista (Unesp)
Resumo
Nosso objetivo foi avaliar o efeito da estratégia de suplementação durante a fase de recria na qualidade da carne de bovinos terminados em pasto mais concentrado ou confinamento. Cento e vinte machos não castrados [10 ± 2 meses de idade e 256,54 ± 28,92 kg de peso vivo (PC) inicial] foram blocados por peso e aleatoriamente designados para os tratamentos em design fatorial 2 × 2, dois suplementos durante a fase de recria: mineral (ad libitum – MIN) ou proteína + energia (0,3% PC/ animal/ dia – PRE) e dois sistema de terminação: pasto mais suplementação com concentrado (2% PC/ animal/ dia - PAST); e confinamento (25:75 %; silagem de milho: concentrado - FLOT). Depois de 285 dias os bovinos (503,89 ± 56,61 kg) foram abatidos em frigorifico comercial, a carcaça foi dividida medialmente do esterno e da coluna, resultando em duas metades semelhantes. Amostras (10g) do Longíssius thoracis (LT) foram removidas imediatamente depois do abate, entre a 12ª e 13ª costela de cada animal e congeladas (nitrogênio líquido) para: atividade de enzima lipogênica e relativa abundancia de RNAm associado com metabolismo de lipídeos, analisados por qRT-PCR os genes alvos incluíram PPARγ, SREBP1c, SCD1, ACCα LPL, FBP4, CPT2, ACOX e PPARα. Após 24 horas de resfriamento de carcaça, o pH foi mesurado entre a 12ª e 13ª costela do LT. A gordura subcutânea e cinco bifes de 2,54 cm do LT (entre a 9ª a 13ª costela) foram coletados para análises: perfil de ácido graxo, composição química, força de cisalhamento, comprimento de sarcômero, índice de fragmentação miofibrilar, perda de descongelamento, perda de cocção, capacidade retenção de água, cor de gordura, mioglobina, oxidação lipídica e parâmetros de cor que foram avaliados nos dia 1, 4, 7, 10, 14 de exposição ao oxigênio a 0 ± 4°C. O sistema FLOT aumentou (P < 0,050) a espessura de gordura subcutânea (7,01 vs. 3,07 mm), o comprimento de sarcômero (1,59 vs. 1,42 µm) e diminuiu (P < 0,050) a força de cisalhamento da carne (36,29 vs. 43,20 N), enquanto o grupo do PAST mostrou maior (P < 0,050) capacidade retenção de água (68,16 vs. 64,32%), gordura amarela (16,66 vs. 14,30), concentração de mioglobina (4,56 vs. 3,95 mg/g de carne). A carne dos bovinos alimentados com MIN durante a fase de crescimento seguidos pela terminação FLOT mostraram aumento (P < 0,050) da oxidação lipídica comparado aos bovinos do MIN seguidos do sistema PAST (0.35 vs. 0.27 mg/kg de carne). Durante o tempo de armazenamento, a carne dos bovinos alimentados com MIN seguido pelo sistema PAST mostraram menores (P < 0,050) valores de L* comparados com os outros tratamentos. Nos dias, 4 e 7 de display, o grupo FLOT tiveram aumento (P < 0,050) de a* e C* na carne comparado ao PAST. Os animais do sistema PAST mostraram menores (P < 0,050) valores de b* comparado ao FLOT (12,17 vs. 13,40, respectivamente). O sistema FLOT aumentou (P < 0,050) o conteúdo de lipídeo na carne do que o PAST (2,72 vs. 1,49%, respectivamente). Os animais alimentados com MIN seguidos da terminação FLOT mostraram um aumento (P < 0,050) dos ácidos C12:0, C14:0, e C16:0, o que levou a um aumento da concentração do total de ácido graxo saturado. Os bovinos terminados no sistema FLOT tiveram maior (P < 0,050) concentração do total de ácido graxo monoinsaturado coincidindo com o aumento (P < 0,050) da expressão do gene SCD1 no musculo em comparação ao sistema PAST. A carne dos bovinos do sistema FLOT mostrou diminuição (P < 0,050) de C18:2n6, C20:3n6, C20:4n6, C20:5n3, razão n6/n3, e isocitrato desidrogenase em comparação ao sistema PAST. Além disso, os bovinos alimentados com PRE seguidos pela terminação FLOT tiveram maior (P < 0,050) expressão de CPT2 no musculo, enquanto que a suplementação MIN seguido pelo sistema PAST mostraram diminuição (P < 0,050) de SREBP1c, aumento (P < 0,050) da expressão de CPT2 e PPARα no musculo. Em geral, esses resultados sugerirem que os atributos relacionados com a maciez da carne não foram afetados pela fase de crescimento. O sistema PAST diminuiu a maciez e luminosidade da carne, mas esses atributos ainda mostraram dentro dos padrões aceitos na indústria de carne. Além disso, o sistema FLOT aumentou o lipídio intramuscular em comparação com o sistema PAST, mas os animais alimentados com MIN durante a fase de crescimento acompanhado do sistema PAST apresentaram maior expressão de genes relacionados à degradação lipídica e menores genes relacionados à síntese de lipídios.
Our objective was to evaluate the supplementation strategy during the growing phase on the meat quality of bulls finished in pasture plus concentrate or feedlot. One hundred and twenty young bulls uncastrated males [10 ± 2 month old and 256.54 ± 28.92 kg of body weight (BW)] were blocked by weight and randomly assigned to treatments in 2 × 2 factorial design, two supplements during the growing phase: mineral (ad libitum - MIN) or Protein + Energy (0.3% BW/ animal/ day - PE) and two finishing system: pasture plus concentrate (2% BW/ animal/ day - PAST) or feedlot (25:75; corn silage: concentrate - FLOT). After 285 days the bulls (503.89 ± 56.61 kg) were slaughtered, the carcasses were divided medially from the sternum and the spine, resulting in two similar halves. The Longissimus thoracis (LT) sample (10 g) was removed immediately after slaughtered between 12th and 13th ribs from each animal and frozen (liquid nitrogen) for: lipogenic enzyme activity and relative abundance of mRNA associated with lipid metabolism measured by qRT-PCR, target genes include PPARγ, SREBP1c, SCD1, ACCα, LPL, FBP4, CPT2, ACOX, and PPARα. After 24 h carcass chilling, the pH was measured between the 12th and 13th ribs of the LT. The fat thickness and five steaks of 2.54 cm from LT (between the 9th and 13th ribs) were collected for fatty acid profile, chemical composition, shear force, sarcomere length, myofibrillar fragmentation index, thawing loss, cooking loss, water holding capacity, fat color, myoglobin, lipid oxidation and meat color which was measured on days, 1, 4, 7, 10 and 14 storage time exposed to oxygen at 0 ± 4°C. The FLOT system increased (P < 0.050) the fat thickness (7.01 vs. 3.07 mm), sarcomere length (1.59 vs. 1.42 µm), and decreased the meat shear force (36.29 vs. 43.20 N), while the PAST group showed higher (P < 0.050) water holding capacity (68.16 vs. 64.32%), yellowness fat (16.66 vs. 14.30), myoglobin concentration (4.56 vs. 3.95 mg/g of meat). The meat of bulls fed with MIN during the growing phase following by FLOT finishing showed increased (P < 0.050) of lipid oxidation compared to bulls from MIN following by PAST system (0.35 vs. 0.27 mg/kg of meat). During the storage time, the meat of bulls fed with MIN following by PAST system showed lower (P < 0.050) L* value compared to the other treatments. On days, 4 and 7 of the display, the FLOT group had increased (P < 0.050) of a* and C* in meat compared to PAST. The bulls from PAST system showed lower (P < 0.050) b* value compared to FLOT (12.17 vs. 13.40, respectively). The FLOT group had (P < 0.050) higher lipid content than PAST (2.72 vs 1.49%, respectively). The bulls fed with MIN following by FLOT system showed an increase (P < 0.050) of C12:0, C14:0, and C16:0 which led to greater saturation fatty acid total concentration. The bulls finished in FLOT system had higher (P < 0.050) monounsaturated fatty acid total concentration coinciding with the up-regulated (P < 0.050) of gene expression of SCD1 compared to PAST system. The meat of bulls from FLOT system showed a decrease (P < 0.050) of C18:2n6, C20:3n6, C20:4n6, C20:5n3, n6/n3 ratio and isocitrate dehydrogenase compared to PAST system. In addition, the animals fed with PRE following by FLOT finishing had higher (P < 0.050) CPT2 expression, while the MIN supplementation following by PAST system showed decreased (P < 0.050) of SREBP1c, increased (P < 0.050) CPT2 and PPARα expression. Globally, these results suggested which the attributes relationship with tenderness meat was not affected by the growing phase. The PAST system decreased the tenderness and lightness of meat, but these attributes still showed within the acceptable standards of the meat industry. In addition, the FLOT system increased the intramuscular lipid compared to PAST system, but the animals fed with MIN during the growing phase following by PAST showed greater genes expression related to lipid degradation and lower gene expression related with synthesis of lipids.
Our objective was to evaluate the supplementation strategy during the growing phase on the meat quality of bulls finished in pasture plus concentrate or feedlot. One hundred and twenty young bulls uncastrated males [10 ± 2 month old and 256.54 ± 28.92 kg of body weight (BW)] were blocked by weight and randomly assigned to treatments in 2 × 2 factorial design, two supplements during the growing phase: mineral (ad libitum - MIN) or Protein + Energy (0.3% BW/ animal/ day - PE) and two finishing system: pasture plus concentrate (2% BW/ animal/ day - PAST) or feedlot (25:75; corn silage: concentrate - FLOT). After 285 days the bulls (503.89 ± 56.61 kg) were slaughtered, the carcasses were divided medially from the sternum and the spine, resulting in two similar halves. The Longissimus thoracis (LT) sample (10 g) was removed immediately after slaughtered between 12th and 13th ribs from each animal and frozen (liquid nitrogen) for: lipogenic enzyme activity and relative abundance of mRNA associated with lipid metabolism measured by qRT-PCR, target genes include PPARγ, SREBP1c, SCD1, ACCα, LPL, FBP4, CPT2, ACOX, and PPARα. After 24 h carcass chilling, the pH was measured between the 12th and 13th ribs of the LT. The fat thickness and five steaks of 2.54 cm from LT (between the 9th and 13th ribs) were collected for fatty acid profile, chemical composition, shear force, sarcomere length, myofibrillar fragmentation index, thawing loss, cooking loss, water holding capacity, fat color, myoglobin, lipid oxidation and meat color which was measured on days, 1, 4, 7, 10 and 14 storage time exposed to oxygen at 0 ± 4°C. The FLOT system increased (P < 0.050) the fat thickness (7.01 vs. 3.07 mm), sarcomere length (1.59 vs. 1.42 µm), and decreased the meat shear force (36.29 vs. 43.20 N), while the PAST group showed higher (P < 0.050) water holding capacity (68.16 vs. 64.32%), yellowness fat (16.66 vs. 14.30), myoglobin concentration (4.56 vs. 3.95 mg/g of meat). The meat of bulls fed with MIN during the growing phase following by FLOT finishing showed increased (P < 0.050) of lipid oxidation compared to bulls from MIN following by PAST system (0.35 vs. 0.27 mg/kg of meat). During the storage time, the meat of bulls fed with MIN following by PAST system showed lower (P < 0.050) L* value compared to the other treatments. On days, 4 and 7 of the display, the FLOT group had increased (P < 0.050) of a* and C* in meat compared to PAST. The bulls from PAST system showed lower (P < 0.050) b* value compared to FLOT (12.17 vs. 13.40, respectively). The FLOT group had (P < 0.050) higher lipid content than PAST (2.72 vs 1.49%, respectively). The bulls fed with MIN following by FLOT system showed an increase (P < 0.050) of C12:0, C14:0, and C16:0 which led to greater saturation fatty acid total concentration. The bulls finished in FLOT system had higher (P < 0.050) monounsaturated fatty acid total concentration coinciding with the up-regulated (P < 0.050) of gene expression of SCD1 compared to PAST system. The meat of bulls from FLOT system showed a decrease (P < 0.050) of C18:2n6, C20:3n6, C20:4n6, C20:5n3, n6/n3 ratio and isocitrate dehydrogenase compared to PAST system. In addition, the animals fed with PRE following by FLOT finishing had higher (P < 0.050) CPT2 expression, while the MIN supplementation following by PAST system showed decreased (P < 0.050) of SREBP1c, increased (P < 0.050) CPT2 and PPARα expression. Globally, these results suggested which the attributes relationship with tenderness meat was not affected by the growing phase. The PAST system decreased the tenderness and lightness of meat, but these attributes still showed within the acceptable standards of the meat industry. In addition, the FLOT system increased the intramuscular lipid compared to PAST system, but the animals fed with MIN during the growing phase following by PAST showed greater genes expression related to lipid degradation and lower gene expression related with synthesis of lipids.
Descrição
Palavras-chave
Coloração, Expressão de genes, Marmoreio, Suplementação intensiva