ABSTRACT. This study aimed to evaluate whether different fertilization strategies influence the morphogenic, structural, and production characteristics of Megathyrsus maximus cv. Mombaça. The experimental design adopted was a randomized block design with a 4 × 3 factorial scheme having five replications. The treatments were as per the following fertilization recommendations: 5th Approach Guide (5AP), Pará Guide (PG), Nutrient Replacement (RP), and the Michaelis and Menten adapted model (MM), applied for three days after application of the nitrogen (N) source following defoliation (days 0, 3, and 6). The interaction between factors affected the following variables: leaf appearance rate (LAR), leaf elongation rate (LER), and leaf senescence rate (LSR). The highest stem elongation rate (SER) was observed for the 5AP recommendation treatment with N application on day 0 (0.113 cm). The highest leaf area index (LAI; 5.33) and tiller population density (TPD; 421.5 tillers m-2) were observed for the 5AP recommendation. The 5AP recommendation with N application on day 0 and on the sixth day after defoliation, and the MM recommendation with fertilization on day 0 showed the best LAR and LER, as well as a greater number of cycles and greater absolute values of leaf blade dry mass.

ABSTRACT. This study evaluated an alternative heating-stirring system in the determination of in vitro ruminal digestibility of dry matter (IVRDMD) of forages using the Tilley and Terry (TT) method. For this purpose, the IVRDMD of three forage species (Marandu, Tifton 85, and Mombasa) was determined by incubating 500 mg of each dried and ground (1 mm) forage in 50-mL rumen inoculum during 48h, followed by quantification of the incubation residue. Two heating-stirring systems were used: i) heating in a water bath at 39°C with manual stirring every two hours (i.e., traditional system); and ii) heating in an oven with controlled temperature at 39°C and automatic agitation (44 rpm; alternative system); there was no effect of the interaction between the heating-stirring system and the type of forage (p = 0.829) on the IVRDMD of forages. The type of heating-stirring system (p = 0.422) did not affect the IVRDMD of forages. Nevertheless, the IVRDMD values of Marandu grass (system i = 598.7 g kg-1 vs system ii = 599.4 g kg-1) were greater (p < 0.001) than Tifton 85 (system i = 392.1 vs g kg-1 vs system ii = 370.7 g kg-1) and Mombasa (system i = 397.4 g kg-1; system ii = 369.7 g kg-1) grasses. In conclusion, the obtained data indicate that the alternative heating-stirring system produces similar results to those obtained using the traditionally heating-stirring system during the determination of the IVRDMD of forages.

Abstract In the Amazonian Forest, diverse plants have bioactive compounds, which can potentially be used as modulators of ruminal fermentation. Despite the importance, few studies have been developed to evaluate the use of extracts from Amazonian plants as natural feed additives in ruminant nutrition. Thus, the objective of this study is to present a brief overview of the scientific data in the literature regarding the effects of the use of extracts of açaí, copaíba, sage-do-marajó, peach palm, and bacuri on the ruminal fermentation and their potential for use in the diet of ruminants. Açaí (Euterpe oleracea Mart.) has 16.08 mg/g of dry matter of flavonoids, compounds with potent antimicrobial activity. Studies with açaí oil supplementation have shown modulatory effects on rumen fermentation and milk production in sheep and cows. Additionally, the copaiba oleoresin (Copaifera spp.) and the bacuri (Platonia insignis Mart.) seed butter have 88% and 41% of terpenes, respectively; the phytochemical composition of marajó sage oil (Hyptis crenata Pohl ex Benth) is not completely resolved, but this source is mostly composed of the terpenes, camphor (33.62%), 1,8-cineole (19.76%) and α-pinene (15.24%), which have in vitro antimicrobial effects against different bacterial strains. The findings of this review demonstrate the potential of Amazonian extracts in maximizing animal production, due to the possible effects on the modulation of ruminal fermentation, being encouraged to carry out additional studies aiming at a greater exploration of them. Although, there are no current studies associated with the effects of açaí, sage, peach palm, and bacuri on rumen fermentation, it is inferred that, due to their phytochemical composition, they may have a similar effect to ionophores on ruminant production.

Resumen En la selva amazónica, innumerables plantas poseen compuestos bioactivos, que potencialmente pueden ser utilizados como moduladores de la fermentación ruminal. A pesar de la importancia, han sido desarrollados pocos estudios evaluando el uso de extractos de plantas amazónicas como aditivos alimentarios naturales en la nutrición de rumiantes. Así, el objetivo de este estudio es presentar un breve panorama de los datos científicos en la literatura sobre los efectos del uso de extractos de açaí, copaíba, salvia-do-marajó, chontaduro y bacuri en la fermentación ruminal y su potencial de uso en la dieta de los rumiantes. Açaí (Euterpe oleracea Mart.) tiene 16,08 mg/g de materia seca de flavonoides, compuestos con potente acción antimicrobiana. Los estudios con suplementos de aceite de açaí han demostrado efectos moduladores sobre la fermentación ruminal y la producción de leche en ovejas y vacas. Adicionalmente, la oleorresina de copaiba (Copaifera spp.) y la mantequilla de semilla de bacuri (Platonia insignis Mart.) poseen 88% y 41% de terpenos, respectivamente; la composición fitoquímica del aceite de salvia de marajó (Hyptis crenata Pohl ex Benth) no está completamente resuelta, sin embargo esta fuente está mayoritariamente compuesta de los terpenos alcanfor (33,62%), 1,8-cineol (19,76%) y α-pineno (15,24%), los cuales poseen efecto antimicrobiano in vitro frente a diferentes cepas bacterianas. Los hallazgos de esta revisión demuestran el potencial de los extractos amazónicos en la maximización de la producción animal, debido a sus posibles efectos sobre la modulación de la fermentación ruminal, siendo incentivados a realizar estudios adicionales con el objetivo de una mayor exploración de estos. Aunque actualmente no existen estudios asociados a los efectos del açaí, la salvia, el chontaduro y el bacuri en la fermentación ruminal, se supone que, por su composición fitoquímica, podrían tener un efecto similar a los ionóforos en la producción de rumiantes.

Resumo Na flora amazônica, incontáveis plantas possuem compostos bioativos, que potencialmente podem ser utilizados como moduladores da fermentação ruminal. Apesar da importância, poucos estudos têm sido desenvolvidos para avaliar a utilização de plantas amazônicas como aditivos alimentares naturais na nutrição de ruminantes. Assim, objetiva-se apresentar um panorama dos dados científicos da literatura sobre os efeitos do uso dos extratos de açaí, copaíba, salva-do-marajó, pupunha e bacuri na fermentação ruminal e os seus potenciais de utilização na dieta de ruminantes. O açaí (Euterpe oleracea Mart.), possui 16,08 mg/g de matéria seca de flavonoides, compostos com potente ação antimicrobiana. Estudos com suplementação do óleo de açaí tem mostrado efeitos modulatórios na fermentação ruminal e na produção de leite de ovelhas e vacas. Adicionalmente, a oleoresina de copaíba (Copaifera spp.) e a manteiga das sementes de bacuri (Platonia insignis Mart.), possuem, respectivamente, 88% e 41% de terpenos; a composição fitoquímica do óleo de salva-do-marajó (Hyptis crenata Pohl ex Benth) ainda não está completamente caracterizada, mas esta fonte está majoritariamente composta por terpenos cânfora (33,62%), 1,8-cineol (19,76%) e α-pineno (15,24%), que apresentam atividade in vitro antimicrobiana, capaz de reduzir a produção total de gás em ambiente ruminal in vitro. A pupunha, fruto da pupunheira (Bactris gasipaes Kunth.), possui 355,95 mg/kg de carotenoides, com efeito antimicrobiano in vitro contra algumas cepas bacterianas. Os achados desta revisão demonstram as potencialidades dos extratos amazônicos na maximização da produção animal, em razão dos possíveis efeitos na modulação da fermentação ruminal, sendo encorajada a realização de estudos adicionais visando uma maior exploração deles. Embora, atualmente, não existam estudos associados aos efeitos do açaí, salva-do-marajó, pupunha e bacuri na fermentação ruminal, pressupõe-se que pela sua composição fitoquímica, poderiam ter um efeito semelhante aos ionóforos na produção de ruminantes.

Abstract The characteristics of milk are controlled by several genes, with emphasis on the four genes from casein, CSN1S1; CSN1S2; CSN2 and CSN3, which are responsible encoding of fractions the milk protein. The study of genetic variants in these genes, seek to investigate alleles, insertions or deletions, that can directly reflect on productive characteristics, indicating differences in milk quality, composition and yield. The CSN1S1 and CSN3 genes were analyzed in lactating Murrah buffaloes using nucleotide sequencing. An SNP was found in the amplified fragment of the CSN1S1 gene, located in nucleotide number 2,123 of the promoter region in position nt-258 (A/G). As for the CSN3 gene, two SNPs of exon number 4 were identified in codons 33 (ACC/ATC) and 34 (ACC/ACT) of the analyzed fragment. This study contributes to important associations between genetic variants and the desired characteristics of milk and its derivatives in future studies, because the variants found may be associated with the quality of milk, enabling genetic selection to be assisted by molecular markers, indicating a major advance that makes it possible to select animals early.

Resumen Antecedentes: El pH, espesor de la grasa subcutánea (SFT) y color, son variables importantes que definen las características organolépticas de la carne de rumiantes. Sin embargo, su relación multivariada en carne bovina permanece inexplorada hasta ahora. Objetivo: Investigar la relación multivariada entre el pH, SFT y parámetros de color en carne bovina mediante el análisis de correlación canónica. Métodos: Se construyó una base de datos con 173 registros individuales de pH, SFT y parámetros de color (a*: intensidad de color rojo, b*: intensidad de color amarillo y L*: luminosidad) de cinco tipos de cortes de carne bovina brasileña (Raza: Nellore; cortes: acém, contrafilé, fraldinha, patinho y picanha). La relación multivariada entre las variables de color (a*, b* y L*) y las variables químicas (pH y SFT) se exploró usando el procedimiento CANCORR de SAS. Resultados: Dos correlaciones canónicas entre las variables U (compuesta por a*, b* y L*; variables de color) y V (compuesta por pH y SFT; variables químicas) fueron significativas (p<0,01). La primera y la segunda correlación canónica fueron 0,463 y 0,282, respectivamente. Los pesos canónicos para las variables canónicas fueron para U1: a* = 0,707, b* = 0,406 y L* = -0,039; U2: a* = 0,364, b* = -0,898 y L* = 1,234; V1: pH = -0,376 y SFT = 0,935; V2: pH = 0,927 y SFT = 0,356. Conclusión: El espesor de grasa subcutánea afectó significativamente la intensidad de los colores rojo y amarillo, mientras que el pH afectó significativamente la luminosidad. Los resultados de este estudio pueden ser útiles para comprender el papel del metabolismo muscular y sus implicaciones en las características organolépticas de la carne bovina.

Resumo Antecedentes: O pH, a espessura da gordura subcutânea (SFT) e a cor, são variáveis importantes que definem as características organolépticas da carne de ruminantes. No entanto, sua relação multivariada em carne bovina até o momento permanece inexplorada. Objetivo: Investigar a relação multivariada entre o pH, SFT e os parâmetros de cor em carne bovina, utilizando a análise de correlação canônica. Métodos: Foi construído um banco de dados contendo 173 registros individuais de pH, SFT e parâmetros de cor (a*: intensidade de cor vermelha, b*: intensidade de cor amarela y L*: luminosidade) de cinco tipos de cortes de carne bovina brasileira (Raça: Nellore; cortes: acém, contrafilé, fraldinha, patinho e picanha). A relação multivariada entre variáveis de cor (a *, b * e L*) e variáveis químicas (pH e SFT) foi explorada usando o procedimento CANCORR do SAS. Resultados: Duas correlações canônicas entre as variáveis U (composta de a *, b * e L *, variáveis de cor) e V (composta de pH e SFT, variáveis químicas) foram significativas (p<0,01). A primeira e segunda correlação canônica foram 0,463 e 0,282, respectivamente. Os pesos canônicos para as variáveis canônicas foram para U1: a* = 0,707, b* = 0,406 e L* = -0,039; U2: a* = 0,364, b* = -0,898 e L* = 1,234; V1: pH = -0,376 e SFT = 0,935; V2: pH = 0,927 e SFT = 0,356. Conclusão: A espessura de gordura subcutânea afetou significativamente a intensidade das cores vermelha e amarela, enquanto o pH afetou significativamente a luminosidade, em carne bovina. Os resultados deste estudo podem ser úteis para entender melhor o papel do metabolismo muscular e suas implicações nas características organolépticas da carne bovina.

Abstract Background: pH, subcutaneous fat thickness (SFT), and color are fundamental variables to define the organoleptic characteristics of meat. However, multivariate relationships of those traits remain unexplored in bovine meat. Objective: To investigate the multivariate relationships among pH, subcutaneous fat thickness, and color parameters in bovine meat using canonical correlation analysis. Methods: A dataset containing 173 individual records of pH, SFT, and color parameters (a*: intensity of red color, b*: intensity of yellow color, and L*: lightness) from five Brazilian beef cut types (Breed: Nellore; cuts: acém, contrafilé, fraldinha, patinho and picanha) was constructed. Multivariate relationships between color variables (a*, b*, and L*) and chemical variables (pH and SFT) were explored using the CANCORR procedure of SAS. Results: Two canonical correlations between U (a*, b*, and L*; color variables) and V (pH and SFT; chemical variables) variates were significant (p<0.01). First and second canonical correlations were 0.463 and 0.282, respectively. Canonical weights for variates were for U1: a* = 0.707, b* = 0.406, and L* = -0.039; U2: a* = 0.364, b* = -0.898, and L* = 1.234; V1: pH = -0.376 and SFT = 0.935; V2: pH = 0.927 and STF = 0.356. Conclusion: Subcutaneous fat thickness significantly affected intensity of red and yellow colors, whereas pH significantly affected lightness. The results of this study may be useful for a better understanding of the role of muscle metabolism and its implications on the organoleptic characteristics of bovine meat.

RESUMO. Este trabalho foi realizado para avaliar os tipos de taninos sob diferentes níveis de inclusão em alimentos protéicos com adição de água, sobre a quantidade de proteína não degradável no rúmen (PNDR) e PNDR digestível (PNDRd). Foram analisados 60 tratamentos, arranjados da seguinte forma: adição de três misturas de tanino (com diferentes concentrações de taninos hidrolisáveis e condensados) que foram adicionados em quatro diferentes quantidades (0; 1; 2,5 e 5%) sob três alimentos protéicos (farelo de soja, farelo de soja integral e farelo de amendoim) que passaram ou não por processo de umedecimento. As amostras foram incubadas em bovinos, via cânula ruminal, em triplicata, para a quantificação da proteína degradada no rúmen, PNDR e PNDRd. A divergência do valor nutricional proteico, baseada em variáveis discriminatórias entre os grupos, foi estimada por meio de análise de agrupamento. Para aumentar o teor de PNDR digestível da dieta recomenda-se a utilização de farelo de soja tratado, em meio aquoso, com 2,5% de tanino com 85% de tanino condensado e 15% de tanino hidrolisável. Recomenda-se testar a inclusão desse ingrediente em avaliações in vivo para determinar o aumento de produtividade e o nível de inclusão a ser adotado.

ABSTRACT. Several tannins at different inclusion levels of protein-rich food and water addition on the amount of rumen undegradable protein (RUP) and digestible RUP (RUPd) in the rumen were evaluated. Sixty treatments were analyzed, namely: three mixtures of tannin (with different concentrations of hydrolysable and condensed tannins) were added at four different amounts (0, 1, 2.5 and 5%) in three protein foods (soybean meal, whole soybean meal and peanut meal) with and without moisture. Samples were incubated in cattle, via rumen cannula, in triplicate, to quantify rumen degraded protein (RDP), rumen undegradable protein (RUP) and digestible RUP (RUPd). Divergence in protein nutritional rate, based on discriminating variables among the groups, was estimated by cluster analysis. Increase in RUPd of treatments required soybean meal with 2.5% tannin, with 85% of condensed tannins and 15% hydrolysable tannins, in an aqueous medium. The inclusion of tannin is recommended to test in in vivo evaluations for productivity increase and inclusion level used.

The objective of this study was to evaluate the contents of fibrous compounds in tropical grasses and legumes according to utilization of sodium sulfite in the neutral detergent solution or using a procedure for contaminant protein correction. Samples of ten grasses and ten legumes were used. The contents of neutral detergent fiber were decreased when sodium sulfite was used; however, more prominent reductions were verified in legumes. Sodium sulfite decreased the acid detergent fiber content in both forage groups. The contents of neutral and acid detergent insoluble protein and lignin were reduced by sodium sulfite in legumes, but no effect was observed in grasses with regard to these variables. The decrease in fiber contents in legumes could be explained by the solubilization of lignin and decrease in insoluble nitrogen. However, the decreases in fiber in grasses could not be solely explained by the decrease in contaminant protein and solubilization of lignin, and loss of other fibrous compounds probably occurred. The utilization of sodium sulfite compromises the accuracy of the estimates of fibrous compounds contents in tropical forages. The precision of the estimates were not relevantly increased by sodium sulfite. The correction of insoluble fibrous compounds for protein is suggested instead of using sodium sulfite because there are no modifications on neutral detergent solution or undesirable solubilization of fibrous compounds.

Sixty 18-month-old steers (20 Nellore, 20 F1 Simmental × Nellore and 20 F1 Angus × Nellore with average body weight of 265.6±6.4 kg; 325.3±4.7 kg and 324.6±6.0 kg, respectively) were used. The effects of feeding regime and genetic group on physical carcass composition, empty body composition, composition of the gain, as well as the pattern of tissue deposition were evaluated in this trial. The interaction between genetic group and feeding regime was not significant for any variable evaluated. Animals fed at the maintenance level produced carcass with larger proportions of bones and muscle than the animals fed ad libitum and Nellore animals had larger muscle portion and smaller adipose tissue portion on the carcass than the crossbred animals. Nellore animals and those fed at maintenance had smaller amount of total fat in the carcass than the crossbred animals and those fed ad libitum, respectively. Fat was deposited more pronouncedly in the intermuscular depot, followed by the visceral depot. The rate of deposition of the carcass tissues was smaller in the Nellore animals and in the animals fed the diet with concentrate allowance equivalent to 1% body weight (except for subcutaneous fat tissue), when compared with the crossbred animals and those fed the diet with 2% BW on concentrate, respectively. The rate of fat deposition on the visceral depot was larger in the F1 Angus × Nellore animals and on those fed the 2% of BW of concentrate diet when compared with F1 Simmental × Nellore animals and those fed the diet with the lowest concentrate allowance (1% BW).