Influence of irrigation and supplementation on performance and ingestive behavior of beef cattle on mixed grass pastures

The purpose of this study was to evaluate the performance of beef cattle with two levels of energy-protein supplementation of low-consumption on African Bermudagrass pasture, overseeded in winter with oat and ryegrass, with or without irrigation. Twenty-four castrated Angus steers (11 months old and had an initial average of 220 kg body weight (BW)) were used in experimental area of 3.6 ha. The experiment was completely randomized in a 2×2 factorial design, with three replicates. The evaluation period was 249 days (July/2019 to March/2020). The treatments were: irrigated pasture with supplementation of 1 g/kg BW or 2.7 g/kg BW and non-irrigated pasture with 1 g/kg BW of supplement or 2.7 g/kg BW. The grazing method was continuous with a variable stocking rate. Irrigation provided pastures with better chemical composition in winter and spring. Irrigation increased the daily accumulation rate in winter (84.6 vs. 45.9 kg DM/ha/day), providing a greater stocking rate (1,702 vs. 1,385 kg/ha) and, consequently, body weight gain per hectare. Supplementation of 2.7 g/kg BW provided a greater stocking rate in winter (1,652 vs. 1,435 kg/ha) and spring (3,096 vs. 2,811 kg/ha), not changing in summer. The association of irrigation and supplementation of 2.7 vs. 1.0 g/kg BW improves the intake pattern by the animal in summer without changing productivity parameters. Irrigation increases productivity and the nutritional value of pasture with higher livestock production per area in periods of water deficit. The supply of 2.7 vs. 1.0 g/kg BW provides a greater stocking rate and body weight gain per hectare.(AU)

Weaning and concentrate supplementation on the characteristics of carcass cuts and longissimus muscle of Suffolk lambs finished on pasture

The aim of this study was to evaluate the influence of weaning and concentrate supplementation on the characteristics of carcass cuts and longissimus muscle of Suffolk lambs finished on a Tifton 85 (Cynodon spp.) pasture. Weaning and concentrate supplementation strategies were evaluated in four finishing systems: i) non-weaned and non-supplemented lambs; ii) non-weaned lambs supplemented with concentrate in creep feeding; iii) weaned and non-supplemented lambs; and iv) weaned lambs supplemented with concentrate. In the systems with weaning, lambs were weaned at 46 ± 6 days of age. In the systems with supplementation, the concentrate was offered daily at 2% of lambs' body weight. Weaning led to a decrease, whereas supplementation led to an increase in carcass cut weights. Supplemented lambs had lower yields of neck and uncovered ribs, and higher yields of breast + flank and loin. The characteristics of loin eye and fat thickness over the longissimus muscle presented lower values in weaned lambs and higher values in supplemented lambs. Keeping lambs with their dams and offering concentrate supplementation until slaughter are strategies recommended to obtain heavier cuts with increased muscularity and fat content.(AU)

Protein and carbohydrate fractionation of Jiggs Bermudagrass in different seasons and under intermittent grazing by Holstein cows

Jiggs bermudagrass has presented competitive production potential over other forages. However, there is a lack of information about the nutritional value of this forage with important relevance in ruminant nutrition. This study aimed to evaluate the protein and carbohydrate fractionation of Jiggs bermudagrass in different seasons of the year under intermittent grazing by Holstein cows. The experiment was conducted during one year in a completely randomized design with nine replications and treatments consisted of the effect of four seasons: fall, winter, spring and summer. The results showed that there were seasonal variations in the fractions of proteins and carbohydrate, with the exception of the protein fraction B3. The better climatic conditions in spring and summer contributed to an increase in the protein fraction A and carbohydrate A+B1. The winter had a greater fraction C of protein and carbohydrate, reflecting the nutritive value of the forage. The use of irrigation during fall and winter had a positive effect on nitrogen fractions B1 and B2 and on non-fiber carbohydrates.

Protein and carbohydrate fractionation of Jiggs Bermudagrass in different seasons and under intermittent grazing by Holstein cows

Jiggs bermudagrass has presented competitive production potential over other forages. However, there is a lack of information about the nutritional value of this forage with important relevance in ruminant nutrition. This study aimed to evaluate the protein and carbohydrate fractionation of Jiggs bermudagrass in different seasons of the year under intermittent grazing by Holstein cows. The experiment was conducted during one year in a completely randomized design with nine replications and treatments consisted of the effect of four seasons: fall, winter, spring and summer. The results showed that there were seasonal variations in the fractions of proteins and carbohydrate, with the exception of the protein fraction B3. The better climatic conditions in spring and summer contributed to an increase in the protein fraction A and carbohydrate A+B1. The winter had a greater fraction C of protein and carbohydrate, reflecting the nutritive value of the forage. The use of irrigation during fall and winter had a positive effect on nitrogen fractions B1 and B2 and on non-fiber carbohydrates.(AU)

Replacement of Tifton hay by spineless cactus in Girolando post-weaned heifers´ diets.

This study aims to evaluate the effect of the Tifton 85 hay (Cynodon dactylon L. Pers) replacement by Orelha de Elefante Mexicana spineless cactus (Opuntia stricta [Haw.] Haw) on the nutrient intake and digestibility, growth performance, microbial protein synthesis, and efficiency of dietary nitrogen compound utilization in the diets of Girolando heifers. Twenty-four (3.5 months and 100 kg ± 3.5 kg) Girolando heifers (5/8 Holstein x Gyr) were used and arranged in a completely randomized design. Dry matter, organic matter, crude protein, and neutral detergent fiber decreased linearly as a function of the levels of Tifton hay (TH) replacement by Orelha de Elefante Mexicana spineless cactus (OEM). The non-fiber carbohydrate intake and coefficient of dry matter digestibility increased, while the neutral detergent fiber (NDF) digestibility decreased linearly with the OEM inclusion. After evaluating the growth performance by observing weight gain and morphometric measurements, there were no significant alterations. The urinary volume, nitrogen balance as well as the efficiency of nitrogen retention had increased, while the urinary and plasma urea concentrations had decreased linearly with the OEM inclusion. The results obtained in this study show that Orelha de Elefante Mexicana spineless cactus should replace Tifton hay in post-weaned heifer diets.

Hay Tifton 85 grass under nitrogen doses in different days of regrowth / Feno do capim-tifton 85 sob doses de nitrogênio em diferentes dias de rebrota

The objective of this study was to evaluate the yield, nutritional value and potential ruminaldegradation of Tifton 85 hay (Cynodon spp.) harvested at four regrowth ages (28, 35, 42 and 49 days) andfertilized with two nitrogen doses (N; 100 and 300 kg N ha-1). The experimental design was a randomizedblock design, arranged in a 4 x 2 factorial scheme, with six replications each. Nitrogen fertilizationincreased (p < 0.05) dry matter yield and digestible dry matter production of hay and also lignin and crudeprotein contents. Nitrogen fertilization increased (p < 0.01) the dry matter yield and the digestible drymatter production of hay, as well as lignin (p = 0.01) and crude protein (p = 0.01). The neutral detergentfiber corrected for ash and protein (p = 0.01), acid detergent fiber (p = 0.01) and cellulose (p = 0.02)adjusted to the quadratic function regression model of the regrowth ages. For potential rumendegradability hay, it was observed quadratic effect (p = 0.01) with maximum value of 73.1% at 37 days ofregrowth. Tifton 85 hay fertilized with 300 kg ha -1 of N and harvested up to 37 days of regrowth results inhigher hay dry matter yield, higher crude protein content, and better dry matter rumen degradability.

Objetivou-se avaliar a produção, o valor nutritivo e a degradação ruminal potencial do feno decapim-Tifton 85 (Cynodon spp.) colhido em quatro idades de rebrota (28, 35, 42 e 49 dias) e adubado comduas doses de nitrogênio (N; 100 e 300 kg N ha-1). O delineamento foi o em blocos ao acaso, arranjado emesquema fatorial 4 x 2, com seis repetições. A área experimental foi o critério de blocagem. A adubaçãonitrogenada incrementou (p < 0,01) a produção de matéria seca e a produção de matéria seca digestível dofeno e também os teores de lignina (p = 0,01) e proteína bruta (p = 0,01). Os teores de fibra em detergenteneutro corrigida para cinzas e proteína (p = 0,01), fibra em detergente ácido (p = 0,01) e celulose (p =0,02) ajustaram-se ao modelo quadrático de regressão em função das idades de rebrota. Paradegradabilidade ruminal potencial do feno foi observado efeito quadrático (p = 0,01), com valor máximode 73,1% aos 37 dias de rebrota. O feno de capim-Tifton 85 adubado com 300 kg ha-1 de N e colhido até os37 dias de rebrota resulta em maior produção de matéria seca de feno, maiores teores de proteína bruta,melhor degradabilidade ruminal potencial da matéria seca.

Valor nutritivo de gramíneas do gênero Cynodon consorciadas com amendoim forrageiro / Nutritive value of grasses of genus Cynodon mixed with forage peanut

O objetivo do presente estudo foi avaliar o valor nutritivo do consórcio forrageiro entre gramíneas do gênero Cynodon (cv. tifton 85 ou coastcross) com Arachis pintoi (amendoim forrageiro). O experimento foi conduzido na Universidade Tecnológica Federal do Paraná, Câmpus Dois Vizinhos, em área de aproximadamente 3000m2. O delineamento experimental foi de blocos ao acaso, com quatro tratamentos e três repetições. Os tratamentos foram: tifton 85 e coastcross em cultivo estreme, tifton 85 + AF e coastcross + AF. Foram avaliados os teores de PB, FDN, FDA, DIVMS, MM e MS das lâminas foliares, colmo+bainha, amendoim forrageiro e da MF disponível da simulação de pastejo. Foi observado que a coastcross tem menor teor de fibra, independentemente do tratamento. O avanço das estações do ano proporcionou menores valores de PB e DIVMS em todos os tratamentos. A simulação de pastejo demonstrou que a tifton 85 tem maiores teores de MS, assim como valores inferiores são encontrados para os consórcios. Quando consorciado com as gramíneas, o amendoim forrageiro reduziu os compostos fibrosos na pastagem, acrescentando maiores teores de PB em pastagem de gramíneas no final do ciclo produtivo.(AU)

The goal of this study was to evaluate the fodder performance and production of Cynodon (Cv. Tifton 85 or Coastcross) mixed with Arachis pintoi (Forage peanut). The experiment was conducted at the Universidade Tecnológica Federal do Paraná, Câmpus Dois Vizinhos, at an area of approximately 3000m2. A completely randomized block design was applied, with four treatments and three replicates. The treatments were: Tifton 85 and Coastcross in pure crop, Tifton 85 + AF and Coastcross + AF with rotated and successive implantation of one line to the grass and three consecutive lines to the legume. The content of CP, NDF, ADF, IVDMD ashe and DM of the leaf blades, stem of grasses forage peanut and total forage mass available of grazing simulation was evaluated. Coastcross has lower fibrous contents, regardless of treatment. The changing of the seasons during the year provided lower values of CP and IVDMD for all treatments. The evaluation of the grazing simulation showed that Tifton 85 has higher DM values just as the lower ones are found for consortia. When mixed with grasses, forage peanuts reduce the fibrous compounds on pasture, increasing the CP levels in grass pasture at the end of productive cycle.(AU)

Hay Tifton 85 grass under nitrogen doses in different days of regrowth / Feno do capim-tifton 85 sob doses de nitrogênio em diferentes dias de rebrota

The objective of this study was to evaluate the yield, nutritional value and potential ruminaldegradation of Tifton 85 hay (Cynodon spp.) harvested at four regrowth ages (28, 35, 42 and 49 days) andfertilized with two nitrogen doses (N; 100 and 300 kg N ha-1). The experimental design was a randomizedblock design, arranged in a 4 x 2 factorial scheme, with six replications each. Nitrogen fertilizationincreased (p < 0.05) dry matter yield and digestible dry matter production of hay and also lignin and crudeprotein contents. Nitrogen fertilization increased (p < 0.01) the dry matter yield and the digestible drymatter production of hay, as well as lignin (p = 0.01) and crude protein (p = 0.01). The neutral detergentfiber corrected for ash and protein (p = 0.01), acid detergent fiber (p = 0.01) and cellulose (p = 0.02)adjusted to the quadratic function regression model of the regrowth ages. For potential rumendegradability hay, it was observed quadratic effect (p = 0.01) with maximum value of 73.1% at 37 days ofregrowth. Tifton 85 hay fertilized with 300 kg ha -1 of N and harvested up to 37 days of regrowth results inhigher hay dry matter yield, higher crude protein content, and better dry matter rumen degradability.(AU)

Objetivou-se avaliar a produção, o valor nutritivo e a degradação ruminal potencial do feno decapim-Tifton 85 (Cynodon spp.) colhido em quatro idades de rebrota (28, 35, 42 e 49 dias) e adubado comduas doses de nitrogênio (N; 100 e 300 kg N ha-1). O delineamento foi o em blocos ao acaso, arranjado emesquema fatorial 4 x 2, com seis repetições. A área experimental foi o critério de blocagem. A adubaçãonitrogenada incrementou (p < 0,01) a produção de matéria seca e a produção de matéria seca digestível dofeno e também os teores de lignina (p = 0,01) e proteína bruta (p = 0,01). Os teores de fibra em detergenteneutro corrigida para cinzas e proteína (p = 0,01), fibra em detergente ácido (p = 0,01) e celulose (p =0,02) ajustaram-se ao modelo quadrático de regressão em função das idades de rebrota. Paradegradabilidade ruminal potencial do feno foi observado efeito quadrático (p = 0,01), com valor máximode 73,1% aos 37 dias de rebrota. O feno de capim-Tifton 85 adubado com 300 kg ha-1 de N e colhido até os37 dias de rebrota resulta em maior produção de matéria seca de feno, maiores teores de proteína bruta,melhor degradabilidade ruminal potencial da matéria seca.(AU)

Valor nutritivo de gramíneas do gênero Cynodon consorciadas com amendoim forrageiro / Nutritive value of grasses of genus Cynodon mixed with forage peanut

O objetivo do presente estudo foi avaliar o valor nutritivo do consórcio forrageiro entre gramíneas do gênero Cynodon (cv. tifton 85 ou coastcross) com Arachis pintoi (amendoim forrageiro). O experimento foi conduzido na Universidade Tecnológica Federal do Paraná, Câmpus Dois Vizinhos, em área de aproximadamente 3000m2. O delineamento experimental foi de blocos ao acaso, com quatro tratamentos e três repetições. Os tratamentos foram: tifton 85 e coastcross em cultivo estreme, tifton 85 + AF e coastcross + AF. Foram avaliados os teores de PB, FDN, FDA, DIVMS, MM e MS das lâminas foliares, colmo+bainha, amendoim forrageiro e da MF disponível da simulação de pastejo. Foi observado que a coastcross tem menor teor de fibra, independentemente do tratamento. O avanço das estações do ano proporcionou menores valores de PB e DIVMS em todos os tratamentos. A simulação de pastejo demonstrou que a tifton 85 tem maiores teores de MS, assim como valores inferiores são encontrados para os consórcios. Quando consorciado com as gramíneas, o amendoim forrageiro reduziu os compostos fibrosos na pastagem, acrescentando maiores teores de PB em pastagem de gramíneas no final do ciclo produtivo.(AU)

The goal of this study was to evaluate the fodder performance and production of Cynodon (Cv. Tifton 85 or Coastcross) mixed with Arachis pintoi (Forage peanut). The experiment was conducted at the Universidade Tecnológica Federal do Paraná, Câmpus Dois Vizinhos, at an area of approximately 3000m2. A completely randomized block design was applied, with four treatments and three replicates. The treatments were: Tifton 85 and Coastcross in pure crop, Tifton 85 + AF and Coastcross + AF with rotated and successive implantation of one line to the grass and three consecutive lines to the legume. The content of CP, NDF, ADF, IVDMD ashe and DM of the leaf blades, stem of grasses forage peanut and total forage mass available of grazing simulation was evaluated. Coastcross has lower fibrous contents, regardless of treatment. The changing of the seasons during the year provided lower values of CP and IVDMD for all treatments. The evaluation of the grazing simulation showed that Tifton 85 has higher DM values just as the lower ones are found for consortia. When mixed with grasses, forage peanuts reduce the fibrous compounds on pasture, increasing the CP levels in grass pasture at the end of productive cycle.(AU)

Nutritional value of tifton 85 bermudagrass at two cutting heights and different times of storage / Valor nutricional do feno de capim tifton 85 sob duas alturas de corte e tempos de armazenamento

The goal of this study was to assess the dehydration curve and nutritional value of Tifton 85 bermudagrass at two cutting heights from ground level (4 and 8 cm) during 120 days of storage in a closed shed. The dehydration curve was determined using samples from the entire plant at eight different times. The experimental design consisted of randomized blocks with plots subdivided per times and five replicates. The second step consisted of assessing the nutritional value of the stored Tifton 85 bermudagrass in randomized blocks with plots subdivided per times and two treatments per plot: cutting height of four and eight centimeters from the ground, and five different times for the subplots, with five replicates. Dehydration of Tifton 85 bermudagrass at the two heights occurred in 48 hours, considered an ideal time for hay drying. The dry matter content responded quadratically to the time of storage of the two heights, only differing during baling and after 120 days of storage. Crude protein content had a quadratic behavior in the two cutting heights, with the smallest value after 30 days of storage (107.0 g kg-1) and the largest after 90 days (147.8 g kg-1) in the cutting height of eight centimeters. The ether extract exhibited a quadratic behavior in the two cutting heights, only differing after 90 days of storage. The neutral detergent fiber content had linear positive response according to the time of storage, with nodifference between the cutting heights. For the neutral detergent fiber content in the two cutting heights,the quadratic regression model was the best fit to the data, differing between the heights after 30 and 60days of storage. In vitro dry matter digestibility and in vitro cell wall digestibility values of the stored haywere lower than the values obtained at the time of cutting. Cutting performed at four centimeters fromthe ground was the most suitable for hay production due to higher dry matter production and nutritionalvalue without...(AU)

O estudo objetivou avaliar a curva de desidratação e valor nutricional do feno de capim Tifton 85 sob duas alturas de corte em relação ao nível do solo (4 e 8 cm), durante 120 dias de armazenamento em galpão fechado. A curva de desidratação foi determinada utilizando amostras da planta inteira em oito tempos. O delineamento experimental foi em blocos casualizados com parcelas subdivididas no tempo, com cinco repetições. Na segunda etapa avaliou-se o valor nutricional do feno de Tifton 85 armazenado, para isto adotou-se o delineamento em blocos casualizados, em esquema de parcelas subdivididas no tempo, com 2 tratamentos alocados nas parcelas: altura de corte de 4 e 8 cm do solo e cinco tempos nas subparcelas, com cinco repetições. A desidratação do capim Tifton 85 ocorreu em 48 horas para as duas alturas de corte, sendo considerado um tempo ideal para secagem de feno. O teor de matéria seca respondeu de forma quadrática ao tempo de armazenamento do feno, nas duas alturas de corte, diferindo entre as alturas apenas no enfardamento e após 120 dias de armazenamento. O teor de proteína bruta apresentou comportamento quadrático, tanto para o corte a 4 cm, como para o corte à 8 cm do solo, apresentando aos 30 dias de armazenamento o menor valor (107,0 g kg-1) e o maior valor aos 90 dias de armazenamento (147,8 g kg-1), para corte à 8 cm do solo. O extrato etéreo apresentou comportamento quadrático, tanto para o corte à 4 cm, como para o corte à 8 cm do solo, diferindo entreas alturas apenas aos 90 dias de armazenamento. O teor de FDN apresentou resposta linear positiva emfunção do tempo de armazenamento, não diferindo entre as alturas de corte. Para o teor de FDA, emambas as alturas de corte do capim Tifton 85, o modelo de regressão quadrático foi o que melhor seajustou aos dados, diferindo entre as alturas aos 30 e 60 dias de armazenamento. Os valores de DIVMSe DIVPC do feno armazenado foram inferiores aos valores obtidos no momento do corte...(AU)

Nutritional value of tifton 85 bermudagrass at two cutting heights and different times of storage / Valor nutricional do feno de capim tifton 85 sob duas alturas de corte e tempos de armazenamento

The goal of this study was to assess the dehydration curve and nutritional value of Tifton 85 bermudagrass at two cutting heights from ground level (4 and 8 cm) during 120 days of storage in a closed shed. The dehydration curve was determined using samples from the entire plant at eight different times. The experimental design consisted of randomized blocks with plots subdivided per times and five replicates. The second step consisted of assessing the nutritional value of the stored Tifton 85 bermudagrass in randomized blocks with plots subdivided per times and two treatments per plot: cutting height of four and eight centimeters from the ground, and five different times for the subplots, with five replicates. Dehydration of Tifton 85 bermudagrass at the two heights occurred in 48 hours, considered an ideal time for hay drying. The dry matter content responded quadratically to the time of storage of the two heights, only differing during baling and after 120 days of storage. Crude protein content had a quadratic behavior in the two cutting heights, with the smallest value after 30 days of storage (107.0 g kg-1) and the largest after 90 days (147.8 g kg-1) in the cutting height of eight centimeters. The ether extract exhibited a quadratic behavior in the two cutting heights, only differing after 90 days of storage. The neutral detergent fiber content had linear positive response according to the time of storage, with nodifference between the cutting heights. For the neutral detergent fiber content in the two cutting heights,the quadratic regression model was the best fit to the data, differing between the heights after 30 and 60days of storage. In vitro dry matter digestibility and in vitro cell wall digestibility values of the stored haywere lower than the values obtained at the time of cutting. Cutting performed at four centimeters fromthe ground was the most suitable for hay production due to higher dry matter production and nutritionalvalue without...

O estudo objetivou avaliar a curva de desidratação e valor nutricional do feno de capim Tifton 85 sob duas alturas de corte em relação ao nível do solo (4 e 8 cm), durante 120 dias de armazenamento em galpão fechado. A curva de desidratação foi determinada utilizando amostras da planta inteira em oito tempos. O delineamento experimental foi em blocos casualizados com parcelas subdivididas no tempo, com cinco repetições. Na segunda etapa avaliou-se o valor nutricional do feno de Tifton 85 armazenado, para isto adotou-se o delineamento em blocos casualizados, em esquema de parcelas subdivididas no tempo, com 2 tratamentos alocados nas parcelas: altura de corte de 4 e 8 cm do solo e cinco tempos nas subparcelas, com cinco repetições. A desidratação do capim Tifton 85 ocorreu em 48 horas para as duas alturas de corte, sendo considerado um tempo ideal para secagem de feno. O teor de matéria seca respondeu de forma quadrática ao tempo de armazenamento do feno, nas duas alturas de corte, diferindo entre as alturas apenas no enfardamento e após 120 dias de armazenamento. O teor de proteína bruta apresentou comportamento quadrático, tanto para o corte a 4 cm, como para o corte à 8 cm do solo, apresentando aos 30 dias de armazenamento o menor valor (107,0 g kg-1) e o maior valor aos 90 dias de armazenamento (147,8 g kg-1), para corte à 8 cm do solo. O extrato etéreo apresentou comportamento quadrático, tanto para o corte à 4 cm, como para o corte à 8 cm do solo, diferindo entreas alturas apenas aos 90 dias de armazenamento. O teor de FDN apresentou resposta linear positiva emfunção do tempo de armazenamento, não diferindo entre as alturas de corte. Para o teor de FDA, emambas as alturas de corte do capim Tifton 85, o modelo de regressão quadrático foi o que melhor seajustou aos dados, diferindo entre as alturas aos 30 e 60 dias de armazenamento. Os valores de DIVMSe DIVPC do feno armazenado foram inferiores aos valores obtidos no momento do corte...

Mass and nutritional quality of upper and lower strata of tropical forages / Acúmulo e qualidade de forragem dos estratos superior e inferior de forrageiras tropicais

The goal of this work was to evaluate the growth dynamics and chemical characteristics of the upper and lower strata of summer perennial grasses under a four cuts system. The experiment was conducted in a randomized block design, composed of 28 treatments in a factorial arrangement of 7x4, with four repetitions. The cultivars evaluated were Star Grass, Coast-cross, Tifton 68, Tifton 85, Jiggs, Roxinha and Quicuio. Each cultivar was cut when it reached 95% light interception. The cultivars Jiggs and Tifton 68 had the highest (P 0.05) accumulation of dry biomass ha-1 during the four cuts, with productions of 21,348 and 21,016 kg ha-1, respectively. The ash content varied (P 0.05) among species and times of cutting for both strata. Cellulose contents were significantly different in the upper stratum, with the highest concentrations found in cvs. Quicuio and Tifton 68 (39.12% and 38.07%, respectively). We found the highest levels of lignin (P 0.05), for both strata, in cv. Quicuio. Cultivars Jiggs and Tifton 68 were the most appropriate for a management system of four cuts, displaying good chemical composition and high productivity.

O objetivo deste trabalho foi avaliar a dinâmica de crescimento e as características químicas dos estratos superior e inferior de gramíneas perenes estivais sob sistema de quatro cortes. O experimento foi conduzido em delineamento de blocos casualizados, composto por 28 tratamentos em esquema fatorial 7x4, com 4 repetições. Foram avaliadas as cultivares Estrela roxa, Coast-cross, Tifton 68, Tifton 85, Jiggs, Hemartrhia roxinha e Quicuio, e o corte de cada cultivar foi estabelecido no momento em que as mesmas alcançaram 95% de interceptação luminosa. As cvs. Jiggs e Tifton 68 foram responsáveis pelo maior (P 0,05) acúmulo de massa de forragem seca ha-1 durante os quatro cortes, com produções de 21.348 e 21.016 kg ha-1, respectivamente. O teor de matéria mineral apontou variações (P 0,05) entre as espécies avaliadas e as épocas em que os cortes foram realizados, tanto no estrato superior como no estrato inferior. Houve diferença significativa entre os teores de celulose do estrato superior, onde, as cvs. Quicuio e Tifton 68 foram responsáveis pelas maiores concentrações dessa fração (39,12% e 38,07%, respectivamente), e em ambos estratos a cv. Quicuio teve o maior (P 0,05) nível de lignina. Em manejo de quatro cortes, as cvs. Jiggs e Tifton 68 se mostraram as mais adequadas, pois apresentaram boa composição química e alta produtividade.

Mass and nutritional quality of upper and lower strata of tropical forages / Acúmulo e qualidade de forragem dos estratos superior e inferior de forrageiras tropicais

The goal of this work was to evaluate the growth dynamics and chemical characteristics of the upper and lower strata of summer perennial grasses under a four cuts system. The experiment was conducted in a randomized block design, composed of 28 treatments in a factorial arrangement of 7x4, with four repetitions. The cultivars evaluated were Star Grass, Coast-cross, Tifton 68, Tifton 85, Jiggs, Roxinha and Quicuio. Each cultivar was cut when it reached 95% light interception. The cultivars Jiggs and Tifton 68 had the highest (P 0.05) accumulation of dry biomass ha-1 during the four cuts, with productions of 21,348 and 21,016 kg ha-1, respectively. The ash content varied (P 0.05) among species and times of cutting for both strata. Cellulose contents were significantly different in the upper stratum, with the highest concentrations found in cvs. Quicuio and Tifton 68 (39.12% and 38.07%, respectively). We found the highest levels of lignin (P 0.05), for both strata, in cv. Quicuio. Cultivars Jiggs and Tifton 68 were the most appropriate for a management system of four cuts, displaying good chemical composition and high productivity.(AU)

O objetivo deste trabalho foi avaliar a dinâmica de crescimento e as características químicas dos estratos superior e inferior de gramíneas perenes estivais sob sistema de quatro cortes. O experimento foi conduzido em delineamento de blocos casualizados, composto por 28 tratamentos em esquema fatorial 7x4, com 4 repetições. Foram avaliadas as cultivares Estrela roxa, Coast-cross, Tifton 68, Tifton 85, Jiggs, Hemartrhia roxinha e Quicuio, e o corte de cada cultivar foi estabelecido no momento em que as mesmas alcançaram 95% de interceptação luminosa. As cvs. Jiggs e Tifton 68 foram responsáveis pelo maior (P 0,05) acúmulo de massa de forragem seca ha-1 durante os quatro cortes, com produções de 21.348 e 21.016 kg ha-1, respectivamente. O teor de matéria mineral apontou variações (P 0,05) entre as espécies avaliadas e as épocas em que os cortes foram realizados, tanto no estrato superior como no estrato inferior. Houve diferença significativa entre os teores de celulose do estrato superior, onde, as cvs. Quicuio e Tifton 68 foram responsáveis pelas maiores concentrações dessa fração (39,12% e 38,07%, respectivamente), e em ambos estratos a cv. Quicuio teve o maior (P 0,05) nível de lignina. Em manejo de quatro cortes, as cvs. Jiggs e Tifton 68 se mostraram as mais adequadas, pois apresentaram boa composição química e alta produtividade.(AU)

Fermentation kinetics and in vitro degradation rates of grasses of the genus Cynodon / Cinética da fermentação e taxa de degradação in vitro de gramíneas do gênero Cynodon

The present study aimed to evaluate the fermentation kinetics and degradation rates of Cynodon grasses estimated by semi-automated technique of in vitro gas production. The forages were: Coastcross, Tifton 85 and Tifton 68. Pressure readings were taken at 0, 2, 4, 6, 8, 10, 12, 15, 19, 24, 30, 36, 48, 72 and 96 hours. Dry matter degradability (DMD) was obtained by the percentage of dry matter (DM) remaining after 0, 6, 12, 24, 48 and 96 hours of fermentation. Tifton 85 showed a higher total gas production (p 0.05). Higher fermentation rates were found at the beginning of fermentation followed by subsequent reduction (p 0.05) over time. Tifton 85 and Tifton 68 showed higher values (p 0.05) for soluble fraction, potentially degradable insoluble fraction, insoluble fraction, potential and effective degradability of dry matter in relation to Coastcross grass. Higher gas production during in vitro incubation of dry matter was observed for Tifton 85 g.

Objetivou-se avaliar a cinética da fermentação e taxas de degradação de gramíneas do gênero Cynodon estimadas pela técnica semi automática de produção de gases in vitro. As forrageiras utilizadas foram: Coastcross, Tifton 85 e Tifton 68. As leituras de pressão foram realizadas nos tempos: 0, 2, 4, 6, 8, 10, 12, 15, 19, 24, 30, 36, 48, 72 e 96h. A degradabilidade da matéria seca (DMS) foi obtida pela porcentagem de matéria seca (MS) remanescente após 0, 6, 12, 24, 48 e 96h de fermentação. A gramínea Tifton 85 apresentou uma produção total de gases superior (p 0,05). Maiores taxas de fermentação ocorreram no tempo inicial de fermentação decrescendo (p 0,05) com o avançar do tempo. As gramíneas Tifton 85 e Tifton 68 apresentaram valores superiores (p 0,05) de fração solúvel, insolúvel potencialmente degradável, insolúvel, degradabilidade potencial e efetiva da matéria seca em relação à gramínea Coastcross. Maior produção de gases durante a incubação in vitro da matéria seca foi observada para o capim Tifton 85.

Fermentation kinetics and in vitro degradation rates of grasses of the genus Cynodon / Cinética da fermentação e taxa de degradação in vitro de gramíneas do gênero Cynodon

The present study aimed to evaluate the fermentation kinetics and degradation rates of Cynodon grasses estimated by semi-automated technique of in vitro gas production. The forages were: Coastcross, Tifton 85 and Tifton 68. Pressure readings were taken at 0, 2, 4, 6, 8, 10, 12, 15, 19, 24, 30, 36, 48, 72 and 96 hours. Dry matter degradability (DMD) was obtained by the percentage of dry matter (DM) remaining after 0, 6, 12, 24, 48 and 96 hours of fermentation. Tifton 85 showed a higher total gas production (p 0.05). Higher fermentation rates were found at the beginning of fermentation followed by subsequent reduction (p 0.05) over time. Tifton 85 and Tifton 68 showed higher values (p 0.05) for soluble fraction, potentially degradable insoluble fraction, insoluble fraction, potential and effective degradability of dry matter in relation to Coastcross grass. Higher gas production during in vitro incubation of dry matter was observed for Tifton 85 g.(AU)

Objetivou-se avaliar a cinética da fermentação e taxas de degradação de gramíneas do gênero Cynodon estimadas pela técnica semi automática de produção de gases in vitro. As forrageiras utilizadas foram: Coastcross, Tifton 85 e Tifton 68. As leituras de pressão foram realizadas nos tempos: 0, 2, 4, 6, 8, 10, 12, 15, 19, 24, 30, 36, 48, 72 e 96h. A degradabilidade da matéria seca (DMS) foi obtida pela porcentagem de matéria seca (MS) remanescente após 0, 6, 12, 24, 48 e 96h de fermentação. A gramínea Tifton 85 apresentou uma produção total de gases superior (p 0,05). Maiores taxas de fermentação ocorreram no tempo inicial de fermentação decrescendo (p 0,05) com o avançar do tempo. As gramíneas Tifton 85 e Tifton 68 apresentaram valores superiores (p 0,05) de fração solúvel, insolúvel potencialmente degradável, insolúvel, degradabilidade potencial e efetiva da matéria seca em relação à gramínea Coastcross. Maior produção de gases durante a incubação in vitro da matéria seca foi observada para o capim Tifton 85.(AU)

Ruminal degradability of neutral detergent fiber of Cynodon spp. grasses at four regrowth ages / Degradabilidade ruminal da fibra em detergente neutro de gramíneas Cynodon spp. em quatro idades de rebrota

The aim of this work was to determine ruminal degradation of neutral detergent fiber of grasses of the genus Cynodon, harvested at four cutting ages. It was used a randomized block design, with five treatments arranged in a split plot, the five evaluated genotypes: Tifton 85, Jiggs, Russel, Tifton 68 and Vaquero; were the plots and ages of cutting were the subplots: 28, 48, 63 and 79 days. By adding one day in the cutting age, there was a linear reduction in the effective degradability of neutral detergent fiber of blade and stem of 0.16 and 0.18%, respectively. The increase in the cutting age had a linear and positive influence on the undegradable neutral detergent fiber with daily increments for leaf and stem of 0.12 and 0.18%, respectively. At the 28 regrowth day, all genotypes showed higher content of potentially degradable insoluble fraction, effective degradability and lower undegradable fraction of the neutral detergent fiber of blade and stem in relation to other ages, in this way this interval is recommended for cutting management.

Objetivou-se por meio deste trabalho determinar a degradação ruminal da fibra em detergente neutro de gramíneas do gênero Cynodon, colhidas em quatro idades de corte. Foi utilizado o delineamento em blocos ao acaso, com cinco tratamentos arranjados em um esquema de parcelas subdivididas, sendo os cinco genótipos: Tifton 85, Jiggs, Russel, Tifton 68 e Vaqueiro; estudadas as parcelas e as quatro idades de corte as subparcelas: 28, 48, 63 e 79 dias. À medida que aumentou um dia na idade de corte, houve redução linear da degradabilidade efetiva da fibra em detergente neutro da lâmina e do colmo em 0,16 e 0,18%,respectivamente. O avanço na idade de corte influenciou linearmente e positivamente a fração indegradável da fibra em detergente neutro com incrementos diários para a lâmina foliar e para o colmo de 0,12 e 0,18%,respectivamente. Na idade de 28 dias de rebrota, todos os genótipos apresentaram maiores teores de fração insolúvel potencialmente degradável, degradabilidade efetiva e menor fração indegradável da fibra em detergente neutro da lâmina e do colmo em relação às demais idades, sendo desta forma recomendado esse intervalo para manejo de corte.

Ruminal degradability of neutral detergent fiber of Cynodon spp. grasses at four regrowth ages / Degradabilidade ruminal da fibra em detergente neutro de gramíneas Cynodon spp. em quatro idades de rebrota

The aim of this work was to determine ruminal degradation of neutral detergent fiber of grasses of the genus Cynodon, harvested at four cutting ages. It was used a randomized block design, with five treatments arranged in a split plot, the five evaluated genotypes: Tifton 85, Jiggs, Russel, Tifton 68 and Vaquero; were the plots and ages of cutting were the subplots: 28, 48, 63 and 79 days. By adding one day in the cutting age, there was a linear reduction in the effective degradability of neutral detergent fiber of blade and stem of 0.16 and 0.18%, respectively. The increase in the cutting age had a linear and positive influence on the undegradable neutral detergent fiber with daily increments for leaf and stem of 0.12 and 0.18%, respectively. At the 28 regrowth day, all genotypes showed higher content of potentially degradable insoluble fraction, effective degradability and lower undegradable fraction of the neutral detergent fiber of blade and stem in relation to other ages, in this way this interval is recommended for cutting management.(AU)

Objetivou-se por meio deste trabalho determinar a degradação ruminal da fibra em detergente neutro de gramíneas do gênero Cynodon, colhidas em quatro idades de corte. Foi utilizado o delineamento em blocos ao acaso, com cinco tratamentos arranjados em um esquema de parcelas subdivididas, sendo os cinco genótipos: Tifton 85, Jiggs, Russel, Tifton 68 e Vaqueiro; estudadas as parcelas e as quatro idades de corte as subparcelas: 28, 48, 63 e 79 dias. À medida que aumentou um dia na idade de corte, houve redução linear da degradabilidade efetiva da fibra em detergente neutro da lâmina e do colmo em 0,16 e 0,18%,respectivamente. O avanço na idade de corte influenciou linearmente e positivamente a fração indegradável da fibra em detergente neutro com incrementos diários para a lâmina foliar e para o colmo de 0,12 e 0,18%,respectivamente. Na idade de 28 dias de rebrota, todos os genótipos apresentaram maiores teores de fração insolúvel potencialmente degradável, degradabilidade efetiva e menor fração indegradável da fibra em detergente neutro da lâmina e do colmo em relação às demais idades, sendo desta forma recomendado esse intervalo para manejo de corte.(AU)

Optimization of fibrolytic enzyme production by Aspergillus japonicus C03 with potential application in ruminant feed and their effects on tropical forages hydrolysis.

Fibrolytic enzyme production by Aspergillus japonicus C03 was optimized in a medium containing agro-industrial wastes, supplemented with peptone and yeast extract. A 2(3) full factorial composite and response surface methodology were used to design the experiments and analysis of results. Tropical forages were hydrolyzed by A. japonicus C03 enzymatic extract in different levels, and they were also tested as enzymatic substrate. Optimal production to xylanase was obtained with soybean bran added to crushed corncob (1:3), 0.01% peptone, and 0.2% yeast extract, initial pH 5.0, at 30 °C under static conditions for 5 days of incubation. Optimal endoglucanase production was obtained with wheat bran added to sugarcane bagasse (3:1), 0.01% peptone, and 0.2% yeast extract, initial pH 4.0, at 30 °C, for 6 days, under static conditions. Addition of nitrogen sources as ammonium salts either inhibited or did not influence xylanase production. This enzymatic extract had a good result on tropical forage hydrolyzes and showed better performance in the Brachiaria genera, due to their low cell wall lignin quantity. These results represent a step forward toward the use of low-cost agricultural residues for the production of valuable enzymes with potential application in animal feed, using fermentation conditions.

European and Mexican vs US diagnostic extracts of Bermuda grass and cat in skin testing.

BACKGROUND: Laboratory testing of various diagnostic extracts has shown lower potencies for several European and Mexican extracts relative to the US Food and Drug Administration (FDA) reference (10,000 BAU/mL). Quantitative skin prick testing (QSPT) with Dermatophagoides pteronyssinus extracts have previously shown a similar picture. OBJECTIVE: To compare European and Mexican Bermuda grass (BG) and cat diagnostic extracts against an FDA-validated extract using QSPT. METHODS: Six diagnostic BG and cat extracts (1 reference FDA extract, 3 European extracts, 1 imported nonstandardized extract from the United States, and 1 Mexican extract) were tested with quadruplicate QSPT, as a concentrate and as 2 serial 2-fold dilutions, in cat and BG allergic individuals. RESULTS: BG showed good dose response in wheal size for the concentrate (1:2-1:4 dilutions; steep part of the curve). Cat showed poorer dose response. The Wilcoxon test for linked random samples was used to investigate whether the distribution of the reference differed from each of the test extracts to a statistically significant degree (2-sided asymptotic significance, α = .05). All BG and 2 cat extracts were statistically less potent than the 10,000 BAU/mL US reference. European BG extracts were 7,700, 4,100, and 1,600 BAU/mL, and cat extracts were 12,500, 4,400, and 5,100 BAU/mL. CONCLUSIONS: The potency of some diagnostic extracts of BG and cat used in Europe, Mexico, and the United States differs, with the US extracts being generally more potent. On the basis of provocation tests, optimal diagnostic concentrations should be determined. Similar comparisons using other manufacturers and therapeutic extracts might be interesting.