Carcass, meat quality traits, and economic analysis of Nellore bulls fed with finishing feedlot diets containing mechanically processed corn silage.

Effects of mechanical processing (MP) of corn silage and its inclusion in feedlot diets on carcass and meat quality traits of Nellore (Bos indicus) were analyzed. Seventy-two bulls aged approximately 18 months and with an initial average body weight of 392.8 ± 22.3 kg were used. The experimental design was a 2 × 2 factorial arrangement, considering the concentrate-roughage (C:R) ratio (40:60 or 20:80), MP of silage and their interactions. After slaughter, hot carcass weight (HCW), pH, temperature, backfat thickness (BFT), and ribeye area (REA), yields of meat cuts (tenderloin, striploin, ribeye steak, neck steak, and sirloin cap), meat quality traits and economic analysis were evaluated. A lower final pH was found in the carcasses of animals consuming diets containing MP versus unprocessed silage (pH = 5.81 versus 5.93). Carcass variables (HCW, BFT, and REA) and meat cut yields were not affected by treatments. The C:R 20:80 increased the intramuscular fat (IMF) content by approximately 1%, without affecting moisture, ash, and protein contents. Meat/fat color (L*, a* and b*) and Warner-Bratzler shear force (WBSF) were similar among treatments. The results indicated that the MP of corn silage in finishing diets can provide better carcass pH results in Nellore bulls, without negatively influencing carcass weight, fatness, and meat tenderness (WBSF). The IMF content of meat was slightly improved using a C:R 20:80 and lower total costs per arroba produced (3.5%), daily costs per animal/day (4.2%), and cost per ton of feeds (5.15%) were found with MP silage.

Valor nutritivo do capim-xaraés em três intensidades luminosas / Nutritive value of xaraés palisade grass in three light intensities

Este trabalho teve como objetivo avaliar o valor nutritivo e a força de cisalhamento da cultivar de Urochloa brizantha (syn Brachiaria brizantha) cv Xaraés submetida a três intensidades luminosas e quatro cortes. O experimento foi conduzido na FMVZ - Unesp de Botucatu, com delineamento experimental em blocos ao acaso, sendo os tratamentos: luminosidade natural, redução de 30% e 60% de luz, com quatro cortes e três repetições. As análises realizadas foram: composição bromatológica, digestibilidade e a força de cisalhamento. Não houve diferença na digestibilidade entre os tratamentos em nenhum dos cortes, mas a qualidade forrageira foi influenciada pelos níveis de intensidade de luz, tendo o tratamento com 60% de redução de luminosidade apresentado maiores concentrações de proteína bruta e cinzas, menores teores de fibra em detergente neutro, hemicelulose, celulose e força de cisalhamento. Em relação aos cortes estudados, o primeiro teve o menor intervalo de corte e produziu forragem com qualidade superior em comparação ao último, pois obteve menor teor de fibra em detergente ácido, lignina, hemicelulose, celulose e consequente menor força de cisalhamento. Portanto, a redução de 60% de luminosidade é benéfica à qualidade e à força de cisalhamento da cultivar Xaraés.(AU)

This study aimed to evaluate the nutritive value and shear strength of the Xaraés grass (Urochloa brizantha) under the three intensities of light and four cuts. The experiment was conducted at FMVZ - UNESP, Botucatu, with a randomized block design, with the following treatments: natural luminosity, 30% and 60% light reduction, with four cuts and three replications. The analyzes were bromatological composition, digestibility, and shearing strength. There was no difference in digestibility between the treatments in any of the cuts, forage quality was influenced by the light intensity levels, and the treatment with 60% of light reduction produced higher concentrations of crude protein and ash, lower levels of neutral detergent fiber, hemicellulose, cellulose and shear strength. According to the studied cuts, the first one had the lowest cut interval and produced superior forage compared with the last one, as it obtained lower fiber content in acid detergent, lignin, hemicellulose, cellulose and consequent lower shear force. Therefore, the reduction of 60% of luminosity is beneficial to the quality and shear force of the Xaraés palisade grass.(AU)

Valor nutritivo do capim-xaraés em três intensidades luminosas / Nutritive value of xaraés palisade grass in three light intensities

Este trabalho teve como objetivo avaliar o valor nutritivo e a força de cisalhamento da cultivar de Urochloa brizantha (syn Brachiaria brizantha) cv Xaraés submetida a três intensidades luminosas e quatro cortes. O experimento foi conduzido na FMVZ - Unesp de Botucatu, com delineamento experimental em blocos ao acaso, sendo os tratamentos: luminosidade natural, redução de 30% e 60% de luz, com quatro cortes e três repetições. As análises realizadas foram: composição bromatológica, digestibilidade e a força de cisalhamento. Não houve diferença na digestibilidade entre os tratamentos em nenhum dos cortes, mas a qualidade forrageira foi influenciada pelos níveis de intensidade de luz, tendo o tratamento com 60% de redução de luminosidade apresentado maiores concentrações de proteína bruta e cinzas, menores teores de fibra em detergente neutro, hemicelulose, celulose e força de cisalhamento. Em relação aos cortes estudados, o primeiro teve o menor intervalo de corte e produziu forragem com qualidade superior em comparação ao último, pois obteve menor teor de fibra em detergente ácido, lignina, hemicelulose, celulose e consequente menor força de cisalhamento. Portanto, a redução de 60% de luminosidade é benéfica à qualidade e à força de cisalhamento da cultivar Xaraés.(AU)

This study aimed to evaluate the nutritive value and shear strength of the Xaraés grass (Urochloa brizantha) under the three intensities of light and four cuts. The experiment was conducted at FMVZ - UNESP, Botucatu, with a randomized block design, with the following treatments: natural luminosity, 30% and 60% light reduction, with four cuts and three replications. The analyzes were bromatological composition, digestibility, and shearing strength. There was no difference in digestibility between the treatments in any of the cuts, forage quality was influenced by the light intensity levels, and the treatment with 60% of light reduction produced higher concentrations of crude protein and ash, lower levels of neutral detergent fiber, hemicellulose, cellulose and shear strength. According to the studied cuts, the first one had the lowest cut interval and produced superior forage compared with the last one, as it obtained lower fiber content in acid detergent, lignin, hemicellulose, cellulose and consequent lower shear force. Therefore, the reduction of 60% of luminosity is beneficial to the quality and shear force of the Xaraés palisade grass.(AU)

In vivo ultrasound and biometric measurements predict the empty body chemical composition in Nellore cattle.

Evaluation of the body chemical composition of beef cattle can only be measured postmortem and those data cannot be used in real production scenarios to adjust nutritional plans. The objective of this study was to develop multiple linear regression equations from in vivo measurements, such as ultrasound parameters [backfat thickness (uBFT, mm), rump fat thickness (uRF, mm), and ribeye area (uLMA, cm2)], shrunk body weight (SBW, kg), age (AG, d), hip height (HH, m), as well as from postmortem measurements (composition of the 9th to 11th rib section) to predict the empty body and carcass chemical composition for Nellore cattle. Thirty-three young bulls were used (339 ± 36.15 kg and 448 ± 17.78 d for initial weight and age, respectively). Empty body chemical composition (protein, fat, water, and ash in kg) was obtained by combining noncarcass and carcass components. Data were analyzed using the PROC REG procedure of SAS software. Mallows' Cp values were close to the ideal value of number of independent variables in the prediction equations plus one. Equations to predict chemical components of both empty body and carcass using in vivo measurements presented higher R2 values than those determined by postmortem measurements. Chemical composition of the empty body using in vivo measurements was predicted with R2 > 0.73. Equations to predict chemical composition of the carcass from in vivo measurements showed R2 lower (R2< 0.68) than observed for empty body, except for the water (R2 = 0.84). The independent variables SBW, uRF, and AG were sufficient to predict the fat, water, energy components of the empty body, whereas for estimation of protein content the uRF, HH, and SBW were satisfactory. For the calculation of the ash, the SBW variable in the equation was sufficient. Chemical compounds from components of the empty body of Nellore cattle can be calculated by the following equations: protein (kg) = 47.92 + 0.18 × SBW - 1.46 × uRF - 30.72 × HH (R2 = 0.94, RMSPE = 1.79); fat (kg) = 11.33 + 0.16 × SBW + 2.09 × uRF - 0.06 × AG (R2 = 0.74, RMSPE = 4.18); water (kg) = - 34.00 + 0.55 × SBW + 0.10 × AG - 2.34 × uRF (R2 = 0.96, RMSPE = 5.47). In conclusion, the coefficients of determination (for determining the chemical composition of the empty body) of the equations derived from in vivo measures were higher than those of the equations obtained from rib section measurements taken postmortem, and better than coefficients of determination of the equations to predict the chemical composition of the carcass.

Inclusion of crushed corn grains and citrus pulp improves the quality of soybean silage / Inclusão de grãos de milho moído e polpa cítrica melhora a qualidade da silagem de soja

Objetivamos avaliar o efeito da inclusão de milho e polpa cítrica como aditivo em silagem de soja em tubos plásticos de PVC. O delineamento experimental foi inteiramente casualizado, com arranjo fatorial 2x4, dois grupos aditivos (milho e polpa cítrica) e quatro níveis de inclusão (sem inclusão, 7, 14 e 21%). O experimento foi conduzido no Setor Forrageiro da Fazenda Experimental Lageado da Faculdade de Medicina Veterinária e Zootecnia da UNESP de Botucatu - SP e nas análises de composição química realizadas no laboratório de Bromatologia. A variedade de soja utilizada foi a BMX Potência RR e a colheita mecânica ocorreu no estádio fenológico R7, na altura de 15 cm, utilizando-se um Harvester equipado com plataforma de duas fileiras, com o material cortado em partículas médias entre 3 e 6 mm. Após 45 dias, as silagens foram analisadas quanto à matéria seca (MS), proteína bruta (PB), nutrientes digestíveis totais (NDT), pH, extrato etéreo (EE), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), lignina (LIG), perda total de matéria seca (PMS) e carboidratos totais (CHOS). A inclusão de milho (21%) e polpa cítrica (14 e 21%) reduziu os valores de PB (P <0,05). A silagem sem inclusão apresentou menor quantidade de carboidratos totais (P <0,05). A inclusão de fubá é melhor que a polpa cítrica para melhorar os valores da silagem de soja.

We aimed to evaluate the effect of the inclusion of corn and citrus pulp as additives in soybean silage made in plastic (PVC) tubes. The experimental design was completely randomized, with a 2x4 factorial arrangement consisting of two additive groups (corn and citrus pulp) and four inclusion levels (no inclusion, 7, 14 and 21%). The experiment was conducted at the Forage Sector of the Lageado Experimental Farm, Faculty of Veterinary Medicine and Animal Science, UNESP, Botucatu, SP, and chemical composition analysis was carried out at the Laboratory of Bromatology. The soybean variety used was BMX Potência RR. Mechanical harvest occurred at the R7 phenological stage, at a height of 15 cm, using a harvester equipped with a two-row platform. The material was chopped into medium particles of 3 to 6 mm. After 45 days, the silages were analyzed for dry matter, crude protein (CP), total digestible nutrients, pH, ethereal extract, neutral detergent fiber, acid detergent fiber, lignin, total dry matter loss, and total carbohydrates (CHOS). The inclusion of corn (21%) and citrus pulp (14 and 21%) reduced CP values (P<0.05). Control silage contained less CHOS (P<0.05). The inclusion of corn meal is better than citrus pulp to improve the values of soybean silage.

Inclusion of crushed corn grains and citrus pulp improves the quality of soybean silage / Inclusão de grãos de milho moído e polpa cítrica melhora a qualidade da silagem de soja

Objetivamos avaliar o efeito da inclusão de milho e polpa cítrica como aditivo em silagem de soja em tubos plásticos de PVC. O delineamento experimental foi inteiramente casualizado, com arranjo fatorial 2x4, dois grupos aditivos (milho e polpa cítrica) e quatro níveis de inclusão (sem inclusão, 7, 14 e 21%). O experimento foi conduzido no Setor Forrageiro da Fazenda Experimental Lageado da Faculdade de Medicina Veterinária e Zootecnia da UNESP de Botucatu - SP e nas análises de composição química realizadas no laboratório de Bromatologia. A variedade de soja utilizada foi a BMX Potência RR e a colheita mecânica ocorreu no estádio fenológico R7, na altura de 15 cm, utilizando-se um Harvester equipado com plataforma de duas fileiras, com o material cortado em partículas médias entre 3 e 6 mm. Após 45 dias, as silagens foram analisadas quanto à matéria seca (MS), proteína bruta (PB), nutrientes digestíveis totais (NDT), pH, extrato etéreo (EE), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), lignina (LIG), perda total de matéria seca (PMS) e carboidratos totais (CHOS). A inclusão de milho (21%) e polpa cítrica (14 e 21%) reduziu os valores de PB (P <0,05). A silagem sem inclusão apresentou menor quantidade de carboidratos totais (P <0,05). A inclusão de fubá é melhor que a polpa cítrica para melhorar os valores da silagem de soja.(AU)

We aimed to evaluate the effect of the inclusion of corn and citrus pulp as additives in soybean silage made in plastic (PVC) tubes. The experimental design was completely randomized, with a 2x4 factorial arrangement consisting of two additive groups (corn and citrus pulp) and four inclusion levels (no inclusion, 7, 14 and 21%). The experiment was conducted at the Forage Sector of the Lageado Experimental Farm, Faculty of Veterinary Medicine and Animal Science, UNESP, Botucatu, SP, and chemical composition analysis was carried out at the Laboratory of Bromatology. The soybean variety used was BMX Potência RR. Mechanical harvest occurred at the R7 phenological stage, at a height of 15 cm, using a harvester equipped with a two-row platform. The material was chopped into medium particles of 3 to 6 mm. After 45 days, the silages were analyzed for dry matter, crude protein (CP), total digestible nutrients, pH, ethereal extract, neutral detergent fiber, acid detergent fiber, lignin, total dry matter loss, and total carbohydrates (CHOS). The inclusion of corn (21%) and citrus pulp (14 and 21%) reduced CP values (P<0.05). Control silage contained less CHOS (P<0.05). The inclusion of corn meal is better than citrus pulp to improve the values of soybean silage.(AU)

Concentração de lactato, peso corporal e qualidade da carne em bovinos Nelore terminados em confinamento / Lactate concentration, body weight and meat quality in nelore cattle feedlot finished

Este estudo foi realizado com o objetivo de determinar a concentração de lactato sanguíneo durante o período de confinamento e após o abate, e verificar sua influência em peso corporal e características de qualidade da carne de bovinos Nelore terminados em confinamento. Foram utilizados 90 animais machos não castrados da raça Nelore, com peso médio inicial de 390 ± 37 kg e idade próxima de 24 meses. A concentração de lactato no sangue foi medida por espectrofotometria nos dias 1 (Lac01), 14 (Lac14), 27 (Lac27) e 69 (Lac69) do período de confinamento e imediatamente após o abate (Lac96). Foram coletadas amostras de carne in natura do músculo Longissimus thoracis para determinação de luminosidade, intensidade de coloração vermelha (a*) e amarela (b*), força de cisalhamento e pH da carne sem maturação e com maturação de sete dias. As concentrações de lactato foram analisadas pelo PROC MIXED do programa SAS, considerando no modelo os efeitos de baia e dia da coleta da amostra de sangue. Correlações simples entre as variáveis estudadas foram estimadas utilizando-se o procedimento CORR do programa SAS. O lactato se manteve estável durante o período do confinamento, com médias iguais a 4,83 ± 0,30 mMol/L; 5,68 ± 0,29 mMol/L; 5,03 ± 0,29 mMol/L e 4,15 ± 0,31 mMol/L para Lac01, Lac14, Lac27 e Lac69, respectivamente. A maior média da concentração de lactato foi obtida no dia do abate (Lac96: 10,77 ± 0,27 mMol/L). Foi detectada associação significativa entre os parâmetros de cor a* e b* da carne não maturada e a concentração de lactato no dia do abate (Lac96). Não há associação entre a concentração sanguínea de lactato no dia do abate e o peso corporal de animais Nelore terminados em confinamento..(AU)

The objective of this study was to determine blood lactate concentration during the finishing period and after slaughter and to verify its influence on body weight and meat quality traits of Nellore bulls feedlot finished. Ninety Nellore males were used, with a mean initial body weight of 390 ± 37 kg and age of 24 months. Lactate concentration in the blood was measured by spectrophotometry on days 1 (Lac01), 14 (Lac14), 27 (Lac27) and 69 (Lac69) of the feedlot period and immediately after slaughter (Lac96). Fresh meat samples were collected from the Longissimus thoracis muscle for determination of luminosity, red (a *) and yellow (b *) intensity, shear force and pH of unaged meat and aged for seven days. Lactate concentrations were analyzed by the PROC MIXED of the SAS program, considering in the model the effects of pen and day of blood samples collection. Simple correlations between the studied variables were estimated using the procedure CORR of the program SAS. The lactate was stable during the confinement period, with mean values equal to 4.83 ± 0.30 mMol/L; 5.68 ± 0.29 mMol/L; 5.03 ± 0.29 mMol/L and 4.15 ± 0.31 mMol/L for Lac01, Lac14, Lac27 and Lac69, respectively. The highest mean lactate concentration was obtained on the day of slaughter (Lac96: 10.77 ± 0.27 mMol/L). Significant association was detected between a * and b * color parameters of the unaged meat and the lactate concentration at the day of slaughter (Lac96). There is no association between blood lactate concentration at the day of slaughter and body weight of Nellore animals feedlot finished. Blood lactate concentration on the day of slaughter is associated with the coloring of the meat and is independent of other measures of meat quality in Nellore animals feedlot finished...(AU)

Concentração de lactato, peso corporal e qualidade da carne em bovinos Nelore terminados em confinamento / Lactate concentration, body weight and meat quality in nelore cattle feedlot finished

Este estudo foi realizado com o objetivo de determinar a concentração de lactato sanguíneo durante o período de confinamento e após o abate, e verificar sua influência em peso corporal e características de qualidade da carne de bovinos Nelore terminados em confinamento. Foram utilizados 90 animais machos não castrados da raça Nelore, com peso médio inicial de 390 ± 37 kg e idade próxima de 24 meses. A concentração de lactato no sangue foi medida por espectrofotometria nos dias 1 (Lac01), 14 (Lac14), 27 (Lac27) e 69 (Lac69) do período de confinamento e imediatamente após o abate (Lac96). Foram coletadas amostras de carne in natura do músculo Longissimus thoracis para determinação de luminosidade, intensidade de coloração vermelha (a*) e amarela (b*), força de cisalhamento e pH da carne sem maturação e com maturação de sete dias. As concentrações de lactato foram analisadas pelo PROC MIXED do programa SAS, considerando no modelo os efeitos de baia e dia da coleta da amostra de sangue. Correlações simples entre as variáveis estudadas foram estimadas utilizando-se o procedimento CORR do programa SAS. O lactato se manteve estável durante o período do confinamento, com médias iguais a 4,83 ± 0,30 mMol/L; 5,68 ± 0,29 mMol/L; 5,03 ± 0,29 mMol/L e 4,15 ± 0,31 mMol/L para Lac01, Lac14, Lac27 e Lac69, respectivamente. A maior média da concentração de lactato foi obtida no dia do abate (Lac96: 10,77 ± 0,27 mMol/L). Foi detectada associação significativa entre os parâmetros de cor a* e b* da carne não maturada e a concentração de lactato no dia do abate (Lac96). Não há associação entre a concentração sanguínea de lactato no dia do abate e o peso corporal de animais Nelore terminados em confinamento..

The objective of this study was to determine blood lactate concentration during the finishing period and after slaughter and to verify its influence on body weight and meat quality traits of Nellore bulls feedlot finished. Ninety Nellore males were used, with a mean initial body weight of 390 ± 37 kg and age of 24 months. Lactate concentration in the blood was measured by spectrophotometry on days 1 (Lac01), 14 (Lac14), 27 (Lac27) and 69 (Lac69) of the feedlot period and immediately after slaughter (Lac96). Fresh meat samples were collected from the Longissimus thoracis muscle for determination of luminosity, red (a *) and yellow (b *) intensity, shear force and pH of unaged meat and aged for seven days. Lactate concentrations were analyzed by the PROC MIXED of the SAS program, considering in the model the effects of pen and day of blood samples collection. Simple correlations between the studied variables were estimated using the procedure CORR of the program SAS. The lactate was stable during the confinement period, with mean values equal to 4.83 ± 0.30 mMol/L; 5.68 ± 0.29 mMol/L; 5.03 ± 0.29 mMol/L and 4.15 ± 0.31 mMol/L for Lac01, Lac14, Lac27 and Lac69, respectively. The highest mean lactate concentration was obtained on the day of slaughter (Lac96: 10.77 ± 0.27 mMol/L). Significant association was detected between a * and b * color parameters of the unaged meat and the lactate concentration at the day of slaughter (Lac96). There is no association between blood lactate concentration at the day of slaughter and body weight of Nellore animals feedlot finished. Blood lactate concentration on the day of slaughter is associated with the coloring of the meat and is independent of other measures of meat quality in Nellore animals feedlot finished...