Fatty acid profile and beef quality of Nellore and Angus bulls fed whole shelled corn

ABSTRACT: This study aimed to evaluate the quality traits and fatty acid profile of beef from Nellore and Angus bulls fed whole shelled corn (WSC) and ground corn plus maize silage (GC) diets. Eighteen Nellore and 18 Angus young bulls [381 ± 12 kg initial body weight (BW) and an average age of 20 ± 1.9 months] were used in a completely randomized design using a 2 × 2 factorial arrangement and were slaughtered at a final BW of 451.5 kg and 545.5 kg, respectively. Twentyfour hours after slaughter, samples of longissimus thoracis muscle were collected for the analysis of lipid oxidation, color, fatty acid profile, shear force, and cooking loss. There was no effect of diet × breed interaction on meat color, lipid oxidation, shear force, and cooking loss. Angus beef had lower shear force (p 0.05) than Nellore beef and had a greater concentration of linoleic acid and polyunsaturated fatty acids (PUFA) (p 0.01). Beef of bulls fed WSC tended to have greater concentration of CLA C18:2c9t11 (p = 0.09), greater concentration of CLA C18:2t10c12 (p = 0.01), and PUFA (p = 0.05), and consequently, higher oxidation levels. Angus bulls produced beef with greater tenderness and PUFA concentration. The results of fatty acid show a possible change in biohydrogenation when animals are fed the WSC diet, reducing lipogenesis, as this diet increases the C18:2t10c12 content.

Fatty acid profile and beef quality of Nellore and Angus bulls fed whole shelled corn

This study aimed to evaluate the quality traits and fatty acid profile of beef from Nellore and Angus bulls fed whole shelled corn (WSC) and ground corn plus maize silage (GC) diets. Eighteen Nellore and 18 Angus young bulls [381 ± 12 kg initial body weight (BW) and an average age of 20 ± 1.9 months] were used in a completely randomized design using a 2 × 2 factorial arrangement and were slaughtered at a final BW of 451.5 kg and 545.5 kg, respectively. Twenty­four hours after slaughter, samples of longissimus thoracis muscle were collected for the analysis of lipid oxidation, color, fatty acid profile, shear force, and cooking loss. There was no effect of diet × breed interaction on meat color, lipid oxidation, shear force, and cooking loss. Angus beef had lower shear force (p < 0.05) than Nellore beef and had a greater concentration of linoleic acid and polyunsaturated fatty acids (PUFA) (p < 0.01). Beef of bulls fed WSC tended to have greater concentration of CLA C18:2c9t11 (p = 0.09), greater concentration of CLA C18:2t10c12 (p = 0.01), and PUFA (p = 0.05), and consequently, higher oxidation levels. Angus bulls produced beef with greater tenderness and PUFA concentration. The results of fatty acid show a possible change in biohydrogenation when animals are fed the WSC diet, reducing lipogenesis, as this diet increases the C18:2t10c12 content.

Fatty acid profile and beef quality of Nellore and Angus bulls fed whole shelled corn

This study aimed to evaluate the quality traits and fatty acid profile of beef from Nellore and Angus bulls fed whole shelled corn (WSC) and ground corn plus maize silage (GC) diets. Eighteen Nellore and 18 Angus young bulls [381 ± 12 kg initial body weight (BW) and an average age of 20 ± 1.9 months] were used in a completely randomized design using a 2 × 2 factorial arrangement and were slaughtered at a final BW of 451.5 kg and 545.5 kg, respectively. Twenty–four hours after slaughter, samples of longissimus thoracis muscle were collected for the analysis of lipid oxidation, color, fatty acid profile, shear force, and cooking loss. There was no effect of diet × breed interaction on meat color, lipid oxidation, shear force, and cooking loss. Angus beef had lower shear force (p < 0.05) than Nellore beef and had a greater concentration of linoleic acid and polyunsaturated fatty acids (PUFA) (p < 0.01). Beef of bulls fed WSC tended to have greater concentration of CLA C18:2c9t11 (p = 0.09), greater concentration of CLA C18:2t10c12 (p = 0.01), and PUFA (p = 0.05), and consequently, higher oxidation levels. Angus bulls produced beef with greater tenderness and PUFA concentration. The results of fatty acid show a possible change in biohydrogenation when animals are fed the WSC diet, reducing lipogenesis, as this diet increases the C18:2t10c12 content.

Intake, physiological parameters and behavior of Angus and Nellore bulls subjected to heat stress / Consumo, parâmetros fisiológicos e comportamento de tourinhos Angus e Nelore submetidos a estresse por calor

Genetics differences between breeds may determine the tolerance to high temperature, effect dry matter intake and consequently cattle performance. The effect of temperature and humidity index (THI) on diurnal, nocturnal and daily intake, water intake, physiologic parameters and behavior of Nellore (B. indicus) and Angus (B. taurus) bulls were evaluated. Eight Angus and eight Nellore young bulls (337±7.4 kg and 16 months of age) were allocated in two climate-controlled rooms for 32 days. In the period 1, all bulls were housed in thermoneutral conditions (TN, THI = 72.6) for 10 days. In period 2 (10 days), four Angus and four Nellore bulls were subjected to low heat stress (LHS, THI = 76.4) in daytime, and four Angus and four Nellore bulls were subjected to high heat stress (HHS, THI = 81.5) in daytime. The diurnal and daily dry matter intake (DMI) of Nellore were not affected (P>0.05) by heat stress. However, Angus bulls decreased diurnal DMI by 24% and daily DMI decreased (P 0.05) by 15% on HHS. In TN Angus bulls had higher (P 0.05) daily DMI (36.2 g/kg of BW) than Nellore (29.1 g/kg of BW), but in HHS they had similar (P>0.05) daily DMI (31.6 and 30.2 g/kg of BW, respectively). We observed an increase (P 0.05) in respiratory frequency, but water intake was not affected (P>0.05) by heat stress. The heart rate decreased (P 0.05) with heat stress. No differences were found (P>0.05) in feeding behavior. Therefore, THI stress threshold should distinct for Angus and Nellore bulls. The use of feed intake information may improve the prediction of thermic discomfort on specific climate condition.(AU)

Diferenças genéticas entre raças podem determinar a tolerância a temperaturas elevadas, afetar o consumo de alimentos e consequentemente o desempenho de bovinos. Avaliou-se o efeito do índice de temperatura e umidade (ITU) sobre o consumo diurno, noturno e diário de matéria seca (MS), ingestão diária de água, parâmetros fisiológicos e comportamento de tourinhos da raça Nelore (Bos indicus) e da raça Angus (Bos taurus). Foram utilizados oito tourinhos da raça Nelore e da raça oito Angus (337 ± 7,4 kg e 16 meses de idade) alocados em duas salas climatizadas por 32 dias. No primeiro período, todos os tourinhos foram alojados em condições de termoneutralidade (TN, ITU = 72,6) por 10 dias. No segundo período (10 dias) quatro tourinhos da raça Angus e quatro da raça Nelore foram submetidos a baixo estresse por calor (BEC, ITU = 76,4) durante o dia e quatro tourinhos Angus e quatro Nelore foram submetidos a alto estresse por calor (AEC, ITU = 81,5) durante o dia. O consumo diurno e diário de matéria seca (MS) dos animais da raça Nelore não foi afetado (P> 0,05) pelo estresse calórico. No entanto, os tourinhos da raça Angus reduziram o CMS diurno em 24% e a CMS diário reduziu (P 0,05) em 15% sob AEC. No TN, os animais da raça Angus apresentaram maior (P 0,05) CMS diário (36,2 g / kg de PC) que os da raça Nelore (29,1 g / kg do PC), mas em AEC eles tiveram (P> 0,05) CMS semelhantes (31,6 e 30,2 g / kg do PC, respectivamente). Observou-se aumento (P <0,05) na frequência respiratória, mas a ingestão de água não foi afetada (P> 0,05) pelo estresse calórico. A Frequência cardíaca diminuiu (P <0,05) com o estresse calórico. Não foi observado efeito do ITU (P> 0,05) sobre o comportamento alimentar. Portanto,recomenda-se o uso de intervalos distintos de ITU para indicar segurança térmica em tourinhos das raças Angus e Nelore.(AU)

Intake, physiological parameters and behavior of Angus and Nellore bulls subjected to heat stress / Consumo, parâmetros fisiológicos e comportamento de tourinhos Angus e Nelore submetidos a estresse por calor

Genetics differences between breeds may determine the tolerance to high temperature, effect dry matter intake and consequently cattle performance. The effect of temperature and humidity index (THI) on diurnal, nocturnal and daily intake, water intake, physiologic parameters and behavior of Nellore (B. indicus) and Angus (B. taurus) bulls were evaluated. Eight Angus and eight Nellore young bulls (337±7.4 kg and 16 months of age) were allocated in two climate-controlled rooms for 32 days. In the period 1, all bulls were housed in thermoneutral conditions (TN, THI = 72.6) for 10 days. In period 2 (10 days), four Angus and four Nellore bulls were subjected to low heat stress (LHS, THI = 76.4) in daytime, and four Angus and four Nellore bulls were subjected to high heat stress (HHS, THI = 81.5) in daytime. The diurnal and daily dry matter intake (DMI) of Nellore were not affected (P>0.05) by heat stress. However, Angus bulls decreased diurnal DMI by 24% and daily DMI decreased (P 0.05) by 15% on HHS. In TN Angus bulls had higher (P 0.05) daily DMI (36.2 g/kg of BW) than Nellore (29.1 g/kg of BW), but in HHS they had similar (P>0.05) daily DMI (31.6 and 30.2 g/kg of BW, respectively). We observed an increase (P 0.05) in respiratory frequency, but water intake was not affected (P>0.05) by heat stress. The heart rate decreased (P 0.05) with heat stress. No differences were found (P>0.05) in feeding behavior. Therefore, THI stress threshold should distinct for Angus and Nellore bulls. The use of feed intake information may improve the prediction of thermic discomfort on specific climate condition.

Diferenças genéticas entre raças podem determinar a tolerância a temperaturas elevadas, afetar o consumo de alimentos e consequentemente o desempenho de bovinos. Avaliou-se o efeito do índice de temperatura e umidade (ITU) sobre o consumo diurno, noturno e diário de matéria seca (MS), ingestão diária de água, parâmetros fisiológicos e comportamento de tourinhos da raça Nelore (Bos indicus) e da raça Angus (Bos taurus). Foram utilizados oito tourinhos da raça Nelore e da raça oito Angus (337 ± 7,4 kg e 16 meses de idade) alocados em duas salas climatizadas por 32 dias. No primeiro período, todos os tourinhos foram alojados em condições de termoneutralidade (TN, ITU = 72,6) por 10 dias. No segundo período (10 dias) quatro tourinhos da raça Angus e quatro da raça Nelore foram submetidos a baixo estresse por calor (BEC, ITU = 76,4) durante o dia e quatro tourinhos Angus e quatro Nelore foram submetidos a alto estresse por calor (AEC, ITU = 81,5) durante o dia. O consumo diurno e diário de matéria seca (MS) dos animais da raça Nelore não foi afetado (P> 0,05) pelo estresse calórico. No entanto, os tourinhos da raça Angus reduziram o CMS diurno em 24% e a CMS diário reduziu (P 0,05) em 15% sob AEC. No TN, os animais da raça Angus apresentaram maior (P 0,05) CMS diário (36,2 g / kg de PC) que os da raça Nelore (29,1 g / kg do PC), mas em AEC eles tiveram (P> 0,05) CMS semelhantes (31,6 e 30,2 g / kg do PC, respectivamente). Observou-se aumento (P 0,05) pelo estresse calórico. A Frequência cardíaca diminuiu (P 0,05) sobre o comportamento alimentar. Portanto,recomenda-se o uso de intervalos distintos de ITU para indicar segurança térmica em tourinhos das raças Angus e Nelore.