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Aimed with this study was evaluate the increasing levels of crambe crushed, on in vitro digestibility of dry matter (IVDDM), organic matter (IVDOM) and crude protein (IVDCP), parameters of fermentation and kinetics of the cumulative gas production. The crushed crambe were included in the diets at 0; 50; 100; 150 g/kg of DM. There was a quadratic effect of the proportions of crambe crushed in the concentrated supplements on IVDDM and IVDOM (maximum point at 0.25 and 0.91 g Kg-1 DM, respectively). Total gas production (A + D) was influenced by the presence of crambe crushed with quadratic effect on minimal point on 0.02 g Kg-1 DM. There was a quadratic effect for pH in the collection times in all diets, the lowest pH values were observed between 4.8 to 8.7 hours. There was a quadratic effect for ammoniacal nitrogen in the collection times in all diets with peaks of NH3-N production occurred between 4.8 and 6.3 hours after the beginning of the incubation. Concluded that the inclusion of crambe crushed up to 150 g kg-1 DM in diets for ruminants does not impair the ruminal degradation kinetics.(AU)

O objetivo deste estudo foi avaliar a inclusão de níveis crescentes de torta de crambe, sobre a digestibilidade in vitro da matéria seca (DIVMS), matéria orgânica (DIVMO) e proteína bruta, cinética da produção cumulativa de gás e parâmetros de fermentação. Foram avaliadas as inclusões de 0; 50; 100; 150 g / kg de MS em dietas. Houve efeito quadrático das proporções de torta de crambe nos suplementos concentrados para DIVMS e DIVMO (ponto máximo em 0,25 e 0,91 g Kg-1 DM, respectivamente). A produção total de gás (A + D) foi influenciada por a presença de torta de crambe com efeito quadrático tendo como ponto mínimo em 0,02 g kg-1 DM. Houve um efeito quadrático do pH e NH3-N nos tempos de coleta em todas as dietas, os menores valores de pH foram observados entre 4,8 a 8,7 e os picos de produção de NH3-N entre 4,8 e 6,3 horas após o início da incubação. Conclui-se que a substituição do farelo de soja por crambe triturado até 150 g kg-1 em suplementos concentrados para ruminantes não prejudica a cinética de degradação ruminal.(AU)

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The objective of this study was to evaluate the fermentation profile and nutritional value of Marandu grass silage (Urochloa brizantha(Hoschst.Ex. A. Rich) R. D. Webster cv. Marandu Syn. Brachiaria brizantha(Hochst. Ex A. Rich) Stapf cv. Marandu} with different levels of inclusion of dehydrated banana peel. The experiment was conducted in a completely randomized design with marandu grass with five levels of dehydrated banana peel (0, 10, 20, 30 and 40% of natural matter) with eight replicates. The data collected were submitted to analysis of variance and, when the "F" test was significant, the inclusion levels of the pre-dried banana peel were analyzed utilizing orthogonal polynomials and linear and quadratic regression models. The mean values of N-NH3 were adjusted to the linear regression model (p<0.01), while the pH values had the lowest value of 4.3 with the inclusion of 15% of banana peel. The mean values of the gas loss (PG, P = 0.01) and the dry matter recovery (RMS; P = 0.01) were adjusted to the quadratic regression model, with a minimum point of 16.15% for losses and 21% as the maximum point for dry matter recovery. The rate of degradation potential degradability of the dry matter (SD; P = 0.74) did not vary with the inclusion of the banana peel. The potential degradability standardized at 2, 5 and 8% was adjusted to the regressive linear regression model (p<0.01), and for each percentage point of inclusion of the banana peel, there was a reduction of 0.23, 0.14 and 0.10%, respectively. The inclusion of 10 to 20% dehydrated banana peel in the marandu grass silage improves the fermentation profile and the nutritional value of the silage.(AU)

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The effect of different feed substrates incubated in filter bags [no bag (NB); Ankom® F57, 25 µm pore size (25AN); polyester, 45 µm pore size (45PB); polyester, 67 µm pore size (67PB) ] or dispersed in the medium on gas production, digestion and rumen fermentation was evaluated using an in vitro gas production system. Filter bags reduced (P < 0.01) gas production but increased (P < 0.01) the in vitro dry matter digestibility (45PB and 67PB). Additionally, the use of filter bags with smaller pore size, reduced total volatile fatty acid (P < 0.01), but had minimal effects on acetate, propionate, and butyrate concentration. Our research suggested that using filter bags with a pore size of 67 µ would reduce some negative effects of incubating feed substrate dispersed in the medium or in filter bags with smaller pore size. However, the use of bags with a larger pore size might allow the wash out of small feed particles with consequent overestimation of digestibility.

O efeito de diferentes substratos alimentares incubados em sacos de filtro [sem saco (NB); Ankom® F57, tamanho de poro de 25 µm (25AN); poliéster, tamanho de poro de 45 µm (45PB); poliéster, tamanho de poro de 67 µm (67PB) ] ou disperso no meio na produção de gás, digestão e fermentação ruminal foi avaliada usando um sistema de produção de gás in vitro. As bolsas de filtro reduziram (P < 0,01) a produção de gases, mas aumentaram (P < 0,01) a digestibilidade da matéria seca in vitro (45PB e 67PB). Adicionalmente, o uso de bolsas de filtro com tamanho de poro menor reduziu o ácido graxo volátil total (P < 0,01), mas teve efeitos mínimos na concentração de acetato, propionato e butirato. Nosso trabalho sugere que usar sacos de filtro com tamanho de poro de 67 µ reduziria alguns efeitos negativos da incubação de substrato de alimentação disperso no meio ou em sacos de filtro com tamanho de poro menor. No entanto, o uso de sacolas com poros maiores pode permitir a eliminação de pequenas partículas de ração com consequente superestimação da digestibilidade.

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Seaweed plays a significant role in reducing green-house gasses (GHG) emitted by ruminant animals, in particular methane gas (CH4) generated during rumen fermentation of the feed. Euchaema cottonii is one of potential cultivated seaweed in tropical country. A preservation procedure is necessary for further application in CH4 reduction program. The study looked at how three drying methods (sun drying, oven drying, and freeze drying) affected the E.cottonii ability in reducing CH4 methane as measured by an in vitro technique. The addition of dried E. cottonii up to 4% dry matter (DM) was tested using rice straw diets mixed with concentrate in the ratio of 70%:30% in DM base. Measurements was conducted on gas production, degradability and end product of rumen fermentation during 48-hour incubation using a gas production system and ANKOM Daisy II techniques. Overall, the three dried products of E. cottonii found to considerably lower production of CH4, increased DM and OM degradability as well as total VFA production (P<0.05). The three treatments have no effect on NH3 concentration and the bacterial population, but decreased protozoa population (P<0.01). The lowering of CH4 gas production in the rumen is impacted by all three drying methods in the same way. It is concluded that dried E.cottonii addition up to 4% DM effective in depressing enteric CH4 production, without causing negative effect on DM and OM degradability as well as did not depress total VFA formation and bacterial activities. The three different drying-methods have similar effect on reducing CH4 production, with the most affective is freeze-drying method.

As algas desempenham um papel significativo na redução dos gases de efeito estufa (GEE) emitidos pelos ruminantes, em particular o gás metano (CH4) gerado durante a fermentação ruminal do alimento. Euchaema cottonii é uma espécie de alga potencialmente cultivada em países tropicais. Um procedimento de conservação é necessário para uma aplicação futura no programa de redução de CH4. O estudo analisou como três métodos de secagem (secagem solar, secagem em forno e secagem por congelamento) afetaram a capacidade de E.cottonii em reduzir o metano CH4, medida por uma técnica in vitro. A adição de E. cottonii seco até 4% de matéria seca (MS) foi testada usando dietas de palha de arroz misturadas com concentrado na proporção de 70%:30% na base de MS. Foram realizadas medições da produção de gás, degradabilidade e o produto final da fermentação ruminal durante 48 horas de incubação usando um sistema de produção de gás e técnicas da ANKOM Daisy II. No geral, os três produtos secos de E. cottonii foram encontrados para reduzir consideravelmente a produção de CH4, aumentar a degradabilidade de MS e MO, bem como a produção total de VFA (P<0.05). Os três tratamentos não tiveram efeito na concentração de NH3 e na população bacteriana, mas diminuíram a população de protozoários (P<0.01). A redução da projeção de gás CH4 no rúmen foi afetada por todos os três métodos de secagem da mesma forma. Conclui-se que a adição de E.cottonii até 4% de MS é eficaz na redução da produção de CH4 entérico, sem causar efeito negativo na degradabilidade de MS e MO, bem como não reduziu a formação total de VFA e atividades bacterianas. Os três diferentes métodos de secagem têm efeito semelhante na redução da produção de CH4, sendo o método de secagem por congelamento o mais eficaz.

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The objective of this study was to evaluate the in vitro fermentation products, digestibility, gas production (GP) kinetics, and enteric greenhouse emissions (CH4 and CO2) of substrates with different forage:concentrate ratios (100F, grass hay only; 100C, concentrate mixture only, and mixture, an equal proportion of them) within non-woven fabric (NWT; 100 g/m2) or F57 (Ankom®) filter bags compared to directly dispersed in the medium (DIS), arranged in a 3 × 3 factorial arrangement. Substrates (0.5 g) were incubated using an AnkomRF GP System. Gas samples were collected during 24 and 48 h of incubation. We observed substrate × dispersion method interactions on GP at 48 h (GP48) and on in vitro organic matter digestibility (IVOMD). The GP48 and IVOMD of the 100C substrate were greatest in DIS, intermediate in NWT, and least in F57. With mixture substrate, there were no differences in GP48 and IVOMD between DIS and NWT, but they were greater than in F57. The GP48 and IVOMD were greater in NWT than in DIS and F57 when 100F was incubated. There were no dispersion method × substrate interactions on molar proportions and total volatile fatty acids. With the increase in forage:concentrate ratio incubated, there was a linear decrease in CH4 and CO2 emission relative to organic matter digested. Overall, CH4 and CO2 emissions and digestibility were lower when substrates were incubated within filter bags. The noteworthy interaction between the incubation method and substrates indicates that the ranking of these variables for substrates with differing fermentabilities changes with the dispersion method employed.(AU)

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This study was carried out to evaluate the effects of corn dried distillers' grains (DDG) levels in non-forage diets by in vitro, in situ (0 to 50%), and in vivo (0 to 40%) trials on kinetic parameters of gas production (GP) on rumen-degradable protein (RDP) and rumen-undegradable protein (RUP) as well as on nitrogen (N) metabolism in Nellore cattle. For in vitro and in situ studies, three rumen cannulated Nellore males with body weight of 340.48 ± 22.22 kg were used. For the in vivo study, five non-castrated male Nellore cattle with an initial body weight of 355.20 ± 35.28 kg and 24 ± 3 months old were used to evaluate the effect of increasing DDG levels in non-forage diets on N metabolism by a 5 × 5 Latin square design. Experimental diets were based on ground corn, cottonseed cake, urea, mineral supplement, and increasing levels of DDG replacing ground corn. The DDG levels caused a linear decrease in GP and in vitro dry matter digestibility. The DDG presented a lower dry matter digestibility (DMD) and RDP and higher RUP than corn grain and cottonseed cake, making DDG diets present lower DMD and RDP than control. The DDG levels linearly increased the intake of crude protein, neutral detergent fiber, and ether extract, whereas non-fiber carbohydrates intake decreased and tended to decrease the DMD and organic matter digestibility. The DDG levels caused a linear increase in N intake and in total, fecal, and urinary N excretion, which was the major N excretion route, causing a quadratic drop in retained N and caused a quadratic effect on alanine aminotransferase. In contrast, triglycerides were cubically affected, and total blood protein increased. Thus, DDG levels negatively affect in vitro and in situ digestibility, increasing N intake but increasing urinary N excretion.(AU)

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The objective of this study was to evaluate the effects of an essential oil blend (EO), based on cinnamaldehyde and diallyl disulfide, associated or not with antibiotics on intake and nutrient digestibility, ingestive behavior, rumen fermentation, ruminal microbial synthesis, and blood metabolites of feedlot cattle fed a no-forage diet. The study was carried out as a Latin Square with five treatments consisting of a blend of essential oil (EO), monensin (MON) and virginiamycin (VM), both separately and combined as follows: CON (monensin at 30 mg kg­1 DM), VM (virginiamycin at 25 mg kg­1 DM and monensin at 30 mg kg­1 DM), MEO25 (monensin at 30 mg kg­1 DM and EO at 25 mg kg­1 DM), MEO35 (monensin at 30 mg kg­1 DM and EO at 35 mg kg­1 DM) and EO35 (blend of EO at 35 mg kg­1 DM). There were no effects from additives and their combinations on the intake and apparent digestibility of nutrients or ingestive behavior. Furthermore, treatments did not modify the ruminal pH, nor the concentration of short-chain fatty acids and ammonia, nor the microbial protein synthesis. Blood glucose concentration was higher 4 h after morning feeding for all treatments. There was a significant contrast between the VM and EO for the blood concentration of D-Lactate and L-Lactate. There was no difference between the additives in the concentration of cortisol metabolites in the feces. The blend of essential oil studied, containing cinnamaldehyde and diallyl disulfide, associated or not with antibiotics, does not change the nutritional parameters nor the metabolism of feedlot cattle fed a no-forage diet.

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This study evaluated the effects of tannin extract of Acacia mearnsii De Wild. or monensin on intake, digestibility, nitrogen balance, and ruminal variables of lambs. Five rumen cannulated lambs (40.3 ± 2.8 kg) were used in a 5 × 5 Latin square design, with periods of 21 days each. The treatments were: control, without additive; Tan-0.60, Tan-1.20, and Tan-1.80 for the doses of 0.60, 1.20, and 1.80 g kg−1 body weight (BW) of tannin extract, respectively; and ionophore (monensin) at 0.75 mg kg−1 of BW. Tannins reduced the digestibility of dry matter (DM) and the greatest effects were observed for Tan-1.80. Tannins also increased or tended to increase the fecal excretion of DM, and the greatest effects were observed for Tan-1.20 and Tan-1.80. Tannins increased the fecal excretion of N, decreased the amount of N in urine, but did not affect N retained. Furthermore, tannins reduced the concentration of valerate and the acetate:propionate ratio and increased propionate without affecting the amount of total volatile fatty acids, and the greatest effects were observed for Tan-1.80. The use of ionophore only increased the elimination of N in the urine. Thus, monensin does not affect nitrogen retention, and tannin impairs digestibility, but increases propionate production.(AU)

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Diets composed of whole flint corn grain (WCG) without any roughage source are often used in South American countries. The primary source of protein in theses diets is soybean meal. We hypothesized that the combination of different protein sources improves ruminal fermentation and nutrient digestibility. This study was carried out to assess the impacts of replacing 50% of the soybean meal by other protein sources on voluntary dry matter intake (DMI), digestibility, efficiency of N utilization, efficiency of grain use, metabolic characteristics, and ingestive behavior of Nellore cattle fed WCG diets. Five rumen-cannulated Nellore Bulls (average BW = 651.6 ± 31.83 kg) were used in a 5 x 5 Latin square design, randomly assigned to five diets consisting of 85% of WCG and 15% of pellet supplement with combination of different protein sources: SM - pellet supplement with soybean meal only; CM - soybean meal and cottonseed meal; SFM - soybean meal and sunflower meal; DDG - soybean meal and DDG; DDGS - soybean meal and DDGS. The replacement of 50% of soybean meal by DDG increased (P<0.05) DMI and organic matter intake (OMI), both DMI and OMI were lower with CM. Digestibility, ruminal pH (mean = 5.7), efficiency of N utilization, and diurnal ingestive behavior were not affected (P>0.05) by protein sources. Protein sources also did not affect the grain-use efficiency (P>0.05), with an average value of 96.6% and only 3.4% of the corn grains recovered in the feces. The concentration of GGT enzyme was greatest (P<0.05) for CM and DDGS. The inclusion of DDG increased the DMI but did not improve the nutrients' digestibility or N metabolism. The results suggest that 50% of the soybean meal can be replaced by sunflower meal, DDG, and DDGS without affecting the nutritional and metabolic parameters of Nellore cattle fed whole flint corn grain diets, providing opportunities for reducing costs in feedlot systems.(AU)

Dietas com milho grãos inteiros (MGI) e sem volumoso são frequentemente usadas em países da América do Sul. A principal fonte de proteína nessas dietas é o farelo de soja. Nossa hipótese é que a combinação de diferentes fontes de proteína melhora o padrão de fermentação ruminal e a digestibilidade dos nutrientes. Este estudo foi realizado para avaliar os impactos da substituição de 50% do farelo de soja por outras fontes proteicas sobre o consumo voluntário, digestibilidade, eficiência de utilização do N, eficiência de utilização de grãos, características metabólicas e comportamento de bovinos Nelores alimentados com dietas de MGI. Cinco bovinos Nelores, machos não-castrados e com cânula ruminal (Peso corporal médio = 651,6 ± 31,83 kg) foram utilizados em delineamento quadrado latino 5 x 5, distribuídos aleatoriamente em cinco dietas com 85% de MGI e 15% de um suplemento peletizado com combinação de diferentes fontes proteicas, a saber: FS - núcleo somente com farelo de soja; FA - núcleo com farelo de soja e farelo de algodão; FG - núcleo com farelo de soja e farelo de girassol; DDG - núcleo com farelo de soja e DDG; DDGS - núcleo com farelo de soja e DDGS. A substituição de 50% do farelo de soja por DDG aumentou (P<0,05) o consumo de matéria seca (CMS) e o consumo de matéria orgânica (CMO). Tanto o CMS quanto o CMO foram menores com FA. A digestibilidade dos nutrientes, pH ruminal (média = 5,7), eficiência de utilização do N e comportamento não foram afetados (P>0,05) pelas fontes proteicas. A eficiência de utilização dos grãos também não modificou (P>0,05) com a combinação das fontes proteicas, com valor médio de 96,6% e cerca de apenas 3,4% dos grãos de milho recuperados nas fezes. A concentração da enzima gama aminotransferase foi maior para CM e DDGS (P>0,05). A inclusão de DDG aumentou o CMS, mas não melhorou a digestibilidade dos nutrientes da dieta ou o metabolismo do N. Os resultados sugerem que 50% do farelo de soja pode ser substituído por farelo de girassol, DDG ou DDGS sem afetar os parâmetros nutricionais e metabólicos de bovinos Nelore alimentados com dietas de milho grão inteiro, fornecendo uma oportunidade para reduzir os custos.(AU)

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It is important to evaluate nutritional value of new grass species, which can be better characterized through rumen fermentation and degradation techniques. The aim was to evaluate the effects of Nitrogen (N) fertilization on the kinetics of fermentation and ruminal degradation of the Mulato II grass. Two distinct sources of N (common and protected urea) were used during two periods of the year (summer - I and autumn - II). A completely randomized experimental design was used, in a 2x4 factorial arrangement with three replicates. Fraction A changed based on N dosage. The passage rate (K) and effective degradability (ED) were influenced by sources and doses of N, while Fraction B and Lag Time were not influenced during period I. Fractions A and B and EDs were all influenced by N sources and doses during period II. Lag time and potential degradability were influenced by N sources only. Among the kinetics parameters of dry matter ruminal fermentation obtained during period I, only K1 was influenced by the interaction between N doses x sources, while the remaining parameters were only influenced by the N doses applied. As for period II, with the exception of K2, all remaining parameters were influenced by the interaction of N doses and sources. Protected urea improved fermentation parameters during period I. The dose equivalent to applying 150kg/ha positively influenced ruminal fermentation parameters of the Mulato II grass mainly in the summer. The use of protected urea as a Nitrogen source improved fermentation parameters in the summer.

É importante avaliar o valor nutricional de novas espécies forrageiras, parâmetro que pode ser melhor caracterizado por meio de técnicas de fermentação e degradação ruminal. Objetivou-se avaliar os efeitos da adubação nitrogenada (N) sobre a cinética de fermentação e degradação ruminal do capim Mulato II. Duas fontes de N (ureia comum e protegida) foram utilizadas em dois períodos do ano (verão - I e outono - II). O delineamento experimental utilizado foi inteiramente casualizado, em esquema fatorial 2x4 com três repetições. A fração A mudou com base na dosagem de N. A taxa de passagem (K) e a degradabilidade efetiva (DE) foram influenciadas pelas fontes e doses de N, enquanto a Fração B e Lag Time não foram influenciadas durante o período I. As frações A e B e DE foram influenciadas pelas fontes e doses de N durante o período II. Lag time e a degradabilidade potencial foram influenciadas apenas pelas fontes de N. Dentre os parâmetros cinéticos da fermentação ruminal da matéria seca obtidos no período I, apenas K1 foi influenciado pela interação entre doses de N x fontes, enquanto os demais parâmetros foram influenciados apenas pelas doses de N aplicadas. Já para o período II, com exceção do K2, todos os demais parâmetros foram influenciados pela interação das doses e fontes de N. A ureia protegida trouxe melhorias para os parâmetros fermentativos no período I. A dose equivalente à aplicação de 150kg/ha influenciou positivamente os parâmetros fermentativos ruminais do capim Mulato II, principalmente no verão. O uso de ureia protegida como fonte de nitrogênio melhorou os parâmetros de fermentação no verão.

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The aim of this study was to evaluate the effect of exogenous amylase on gas production, in vitro dry matter digestibility (IVDMD), and in vitro digestion kinetics of sorghum (Sorghum vulgaris) and two corn hybrids of different grain textures. Ruminal fluid was collected from two rumen-fistulated cows receiving or not exogenous amylase (0.7g kg-1 of dry matter (DM basis)), provided to achieve 396 kilo Novo units kg-1 for amylase activity (DM basis). Gas production was measured after 1, 3, 6, 9, 12, 15, 18, 21, 24, 30, 36, 42 e 48 hours of incubation. Amylase increased gas production (mL) by 5.4%. Corn hybrids have higher in vitro dry matter digestibility than sorghum. Exogenous amylase increased the potential of gas production (A) (P=0.01). There was an effect of hybrid for IVDMD (P<0.01). The addition of exogenous amylase increases the in vitro gas production, improves fermentation kinetics, and increases the production of the ammonia nitrogen of corn and sorghum grains, but does not affect in vitro and dry matter digestibility or the short-chain fatty acids production.

O objetivo deste estudo foi avaliar o efeito da amilase exógena na produção de gases, a digestibilidade in vitro da matéria seca (DIVMS) e a cinética de digestão in vitro de sorgo (Sorghum vulgaris) e de dois híbridos de milho de diferentes texturas de grãos. O líquido ruminal foi coletado de duas vacas fistuladas no rúmen recebendo ou não amilase exógena (0,7g kg-1 de matéria seca (MS)), fornecida para atingir 396 kg Novo unidades kg-1 para atividade de amilase (base na MS). A produção de gás foi medida após uma, três, seis, nove, 12, 15, 18, 21, 24, 30, 36, 42 e 48 horas de incubação. A amilase aumentou a produção de gás (mL) em 5,4%. Híbridos de milho apresentam maior DIVMS que o sorgo. A amilase exógena aumentou o potencial de produção de gás (A) (P=0,01). Houve efeito de híbrido para DIVMS (P<0,01). Amilase exógena aumenta a produção de gás in vitro, melhora a cinética da fermentação e aumenta a produção de nitrogênio amoniacal de grãos de milho e sorgo, mas não afeta a digestibilidade in vitro da matéria seca ou a produção de ácidos graxos de cadeia curta.

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Climate change is a very relevant and worrying topic today and is present in the agendas of different spheres of society. High concentrations of greenhouse gases (GHGs) are released into the atmosphere, causing global temperatures to rise. In agricultural production, methane (CH4) is considered one of the highest GHG emissions, causing a negative impact on natural resources and accelerating climate change. In the coming years, with the increase in the world population, food production should be implemented in self-sufficient, quality, and sustainable production systems to meet the need for high consumption. The reduction in CH4 production is related to the better efficiency of energy use of the feed by the animals; therefore, the knowledge of the ruminal fermentation parameters, identification of the ruminal microbiota, and selection of more efficient animals, with lower consumption and greater weight gain, in addition to producing less GHGs like CH4, have a less negative impact on the environment and are economically viable. This review presents some aspects of selection for feed efficiency in sheep as a strategy to mitigate GHG emission and some techniques for measuring these gases.

As alterações climáticas são tema muito relevante e preocupante na atualidade e está presente nas pautas de diferentes esferas da sociedade. Altas concentrações de gases de efeito estufa são lançados na atmosfera, fazendo com que a tem-peratura global se eleve. Na produção agrícola, o metano (CH4) é considerado uma das maiores emissões de GEE, causando impacto negativo nos recursos naturais e acelerando as mudanças climáticas. Nos próximos anos, com o aumento da população mundial, a produção de alimentos deverá estar implementada em sistemas produtivos autossuficientes, de qualidade e sustentáveis para suprir a necessidade do elevado consumo. A redução na produção de CH4 está relacionada com a melhor eficiência do uso de energia da ração pelos animais; portanto, o conhecimento dos parâmetros da fermentação ruminal, identificação da microbiota ruminal e seleção de animais mais eficientes, com menor consumo e maior ganho de peso, além de produzirem menos GEEs como o CH4, impactam menos o meio ambiente e são economicamente viável. Esta revisão apresenta alguns aspectos da seleção para eficiência alimentar em ovinos como estratégia para mitigar a emissão de GEE e algumas técnicas para mensuração desses gases

Resumo

The objective of this study was to evaluate the dietary inclusion of crude glycerin (CG) derived from biodiesel production from residual frying oils, replacing corn, on intake, fermentation parameters, and rumen degradability of dry matter (DM) and crude protein (CP). Four rumen-cannulated sheep were fed diets containing 0, 25, 50, and 75 g CG kg-1 of the total diet DM. A 4×4 Latin square design was adopted. To determine degradability, concentrate samples were incubated in the rumen at 0, 3, 6, 12, 18, 24, 48, and 72 h. Orthogonal contrasts were tested for linear and quadratic effects, which were considered significant when P < 0.05 and a trend when P < 0.10. The inclusion of CG did not influence the intakes of DM (average = 991.5 g day-1) or CP (average = 114.65 g day-1); however, ether extract (EE) intake increased linearly (P < 0.05), ranging from 20.8 to 36.7 g day-1, respectively, for the CG levels of 0 and 75 g kg-1 diet DM. There was no interaction effect (P > 0.05) between collection time and CG level on rumen pH or N-NH3. The lowest pH values were observed at 2 h (5.83) and 4 h (5.87) after feeding. Ammoniacal nitrogen (N-NH3) showed a quadratic decrease (P = 0.02), with a minimum value of 8 mg dL-1 at the CG level of 41.5 g kg-1 DM. The "A" fraction of the concentrate DM decreased quadratically (P = 0.05), with the lowest value (19.7%) occurring at the CG level of 74.1 g kg-1 DM; the "B" fraction and effective degradability (ED; 8% h-1) decreased linearly (P < 0.05); and potential degradability (PD) tended to decrease (P < 0.10) with increasing CG levels. Crude glycerin did not affect the "c" fraction, lag time, or the ED (2% h-1) of concentrate DM. As regards CP, there was also no effect on fractions "A" (average = 41.5%), "B" (average = 51.0%), or PD (average = 92.4%); on the other hand, fraction "c" and ED increased linearly (P < 0.05), whereas lag time decreased linearly (P < 0.05) with increasing CG. In conclusion, the CG used in this study can be added up to the level of 75 g kg-1 of the total DM of the sheep diet.(AU)

Objetivou-se avaliar a inclusão da glicerina bruta (GB) oriunda da produção de biodiesel, a partir de óleos residuais de frituras, em substituição ao milho, sobre o consumo, parâmetros de fermentação e da degradabilidade ruminal da matéria seca (MS) e da proteína bruta (PB). Utilizou-se quatro ovinos canulados no rúmen, recebendo dietas contendo 0, 25, 50 e 75 g GB kg-1 da MS total da dieta. O delineamento utilizado foi o quadrado latino 4×4. Para determinação da degradabilidade, amostras do concentrado foram incubadas no rúmen nos tempos 0h, 3h00, 6h00, 12h00, 18h00, 24h00, 48h00 e 72h00. Contrastes ortogonais foram testados para efeitos linear e quadrático, considerando estes significativos quando o P < 0,05 e tendência quando P < 0,10. A inclusão da GB não influenciou os consumos de MS (média = 991,5 g dia-1) e de PB (média = 114,65 g dia-1), no entanto, o consumo de extrato etéreo (EE) aumentou linearmente (P < 0,05), o qual variou de 20,8 a 36,7 g dia-1, respectivamente, para os níveis de 0 e 75 g GB kg-1 MS da dieta. Não houve efeito da interação (P > 0,05) entre o tempo de coleta e o nível de GB para o pH e o N-NH3 ruminal. Os menores valores de pH foram observados 2 h (5,83) e 4 h (5,87) após a alimentação. O N-NH3 sofreu redução quadrática (P = 0,02), com valor mínimo de 8 mg dL-1 ao nível de 41,5 g GB kg-1 MS. A fração "A" da MS do concentrado reduziu de forma quadrática (P = 0,05), com menor valor (19,7%) ao nível de 74,1 g GB kg-1 MS, a fração "B" e a degradabilidade efetiva (DE; 8%h-1) reduziram linearmente (P < 0,05) e a degradabilidade potencial (DP) tendeu a reduzir (P < 0,10) com o aumento do nível de GB. Não foi observado efeito da inclusão da GB sobre a fração "c", o lag time e a DE (2% h-1) da MS do concentrado. Para a PB, não foi observado efeito paras as frações "A" (média = 41,5%), "B" (média = 51,0%) e "DP" (média =92,4%), por outro lado, a fração "c" e a DE aumentaram linearmente (P < 0,05), ao passo que o lag time diminuiu linearmente (P < 0,05) com o aumento do nível de GB. Conclui-se que a GB usada nesta pesquisa pode ser adicionada até 75 g kg-1 da MS total da dieta de ovinos.(AU)

Resumo

The objectives were to evaluate the effects of monensin and virginiamycin, alone or combined, on supplemented Nellore cattle grazing tropical grass during the rainy season. Two experiments were conducted simultaneously to evaluate intake, digestibility, CH4 emissions, blood parameters, performance, and carcass characteristics (Exp. 1), and ruminal fermentation and relative abundance of ruminal microorganisms (Exp. 2). Animals (n = 92 Exp. 1 and n = 12 Exp. 2) were distributed in a completely randomized design and allocated in twelve paddocks composed of Urochloa brizantha (A. Rich.) Stapf. cv. Xaraés. A protein-energetic supplementation of 3 g/kg of BW per day was provided to all animals. Supplements were: without additives (WA), monensin alone at 80 mg/kg of product (MN), virginiamycin alone at 150 mg/kg of product (VM), and monensin (80 mg/kg of product) combined with virginiamycin (150 mg/kg of product; MNVM). Treatments did not affect intakes of total dry matter (DM), supplement DM, and nutrients. However, the intakes of forage DM and crude protein decreased in cattle fed MNVM compared with animals fed WA, MN, and VM. Total volatile fatty acids increased in animals fed VM. Ruminal NH3-N decreased, and pH increased in animals fed MN, VM, and MNVM. Relative abundance of total F. succinogenes and S. ruminantium decreased and R. flavefaciens increased in animals fed MN and VM at d 118. Treatments had no effect on enteric CH4 emissions. The average daily gain (ADG) and total gain were greater in cattle fed MNVM than in cattle fed MN. Combination of monensin and virginiamycin altered the rumen microbial populations but did not decrease enteric CH4 emissions. However, it decreased forage dry matter intake without altering the ADG and total weight gain, leading to an increase in feed efficiency. Results from this study indicate an advantage in including feed additives combined in the diet of supplemented Nellore cattle grazing tropical grass during the rainy season.

Resumo

The purpose of this study was to propose a bicompartmental nonlinear model and to identify the best-performing model between the proposed model and the bicompartmental logistic (BL) mode regarding the quality of fit to the curve of cumulative gas production (CGP) using corn silage, sunflower, and their mixtures. Gas production was measured 2, 3, 4, 6, 8, 9, 10, 12, 15, 19, 24, 30, 36, 48, 72, and 96 h after beginning the in vitro fermentation process. The generated data were used to generate the parameters of each model tested using the stats package of the R computational tool version 4.0.4. The mathematical models were subjected to the following selection criteria: the adjusted coefficient of determination (Raj.), residual mean square (RMS), mean absolute deviation (MAD), and Akaike information criterion (AIC). It was demonstrated that the proposed model had better performance with a high Raj., and lower values of RMS, AIC, and MAD than the bicompartmental logistic model for the prediction of the parameters of cumulative gas production (CGP), per to present a superior fit in the set of criteria according to the methodology and conditions in which the present study was developed.(AU)

No presente trabalho, com silagem de milho, girassol e suas misturas, objetivou-se propor um modelo não linear bicompartimental e identificar entre o modelo proposto e Logístico Bicompartimental (LB), aquele que apresenta maior qualidade de ajuste à curva de cinética de produção cumulativa de gases (PCG). A leitura da produção de gás foi realizada nos tempos 2, 3, 4, 6, 8, 9, 10, 12, 15, 19, 24, 30, 36, 48, 72 e 96 horas, após o início do processo de fermentação in vitro. Os dados gerados foram utilizados para geração dos parâmetros de cada modelo testado com auxílio do pacote stats da ferramenta computacional R versão 4.0.4. Os modelos matemáticos foram submetidos aos seguintes critérios de seleção o coeficiente de determinação ajustado (Raj.), quadrado médio do resíduo (QMR), desvio médio absoluto (DMA) e o critério de informação de Akaike (AIC). Foi demonstrado que o modelo proposto teve melhor desempenho com altos Raj., e menores valores de QMR, AIC e DMA, por apresentar um ajustamento superior no conjunto dos critérios em comparação com o modelo logístico bicompartimental para a predição dos parâmetros de produção cumulativa de gases (PCG) de acordo com a metodologia e condições em que foi desenvolvido o presente estudo.(AU)

Resumo

The objective was to evaluate the inclusion of chitosan (CHI) and technical cashew nut shell liquid (CNSLt) as natural feed additives in cattle diets on nutrient digestibility, ruminal fermentation, and in vitro gas production kinetics. We conducted a completely randomized design with 5×4 factorial arrangement, with 20, 35, 50, 65, and 100% Tifton 85 hay and four additives, monensin (200 mg/kg DM), CNSLt (500 mg/kg DM), CHI (500 mg/kg DM), and CNSLt+CHI (500 mg/kg DM/each). Dry matter (DM) and organic matter (OM) digestibility showed a linear reduction according to forage levels. The highest DM digestibility was observed with CHI on cattle diets. Inclusion of CHI increased DM digestibility. The highest in vitro organic matter and crude protein (CP) digestibilities were observed for CNSLt+CHI. The in vitro dry matter digestibility increased linearly with concentrate in the diet. There was interaction of forage:concentrate ratio and the additives for neutral detergent fiber, acid detergent fiber and hemicellulose digestibility. Chitosan, CNSLt, and CNSLt+CHI promoted the lowest acetate:propionate ratio compared with monensin. Total gas production showed interaction of the forage:concentrate ratio and additives. Lag time was lowest with CNSLt+CHI. Chitosan and CNSLt can be considered alternative fermentation modulators to ionophores by improving nutrient digestibility and increasing ruminal propionate concentrations.(AU)

Resumo

This study aimed to evaluate the effects of combining functional oils (FO) [ricinoleic acid (RA) and cashew nutshell liquid (CNSL)] on nutrient intake and total-tract apparent digestibility, ruminal fermentation, nitrogen utilization, and predicted rumen microbial protein (Pmic) in heifers. Twelve Jersey heifers (14±0.6 months and 264±18.7 kg BW) were assigned to a 4 × 4 Latin square experiment with the following treatments: Control (CON), diet without feed additives; Ricinoleic acid, dietary inclusion of RA at 2 g kg-1 dry matter (DM); Cashew nutshell liquid, dietary inclusion of CNSL at 2 g kg-1 DM; and a mixture of 1 g kg-1 DM of RA and 1 g kg1 DM of CNSL (RA+CNSL). Heifers were allowed 14 d for treatment adaptation followed by 5 days of sampling. Total feces collection was performed to determine digestibility. Rumen fluid was collected to determine short-chain fatty acids (SCFA) concentration. Urine samples were collected for nitrogen and purine derivatives analyses. Feeding RA decreased intake of DM, but increased crude protein (CP) digestibility and ruminal acetate concentration. Feeding CSNL increased NDF digestibility and lowered Pmic. The association of RA+CNSL increased neutral detergent fiber (NDF) digestibility and ruminal concentration of total SCFA without affecting DM intake. Feeding RA treatment decreased N intake and N excreted in feces and urine. CNSL group had the highest values of N balance. Heifers fed RA had lower Pmic than CNSL and RA+CNSL. The association of RA+CNSL improved digestibility of fiber and increased ruminal concentration of SCFA without altering N balance and Pmic.(AU)

O objetivo deste estudo foi avaliar os efeitos da combinação de óleos funcionais (OF) [ácido ricinoleico (AR) e líquido da castanha de caju (LCC)] no consumo e digestibilidade de nutrientes, fermentação ruminal, utilização de nitrogênio e estimativa de proteína microbiana de novilhas leiteiras. Doze novilhas da raça Jersey (14±0,6 meses e 264±18,7 kg PV) foram alocadas em um experimento de quadrado latino 4×4 contendo os tratamentos a seguir: controle (CON), uma dieta sem aditivos; Ácido ricinoleico, inclusão de 2g kg-1 de matéria seca (MS) de AR na dieta; Líquido da castanha de caju (LCC), inclusão de 2 g kg-1 MS de LCC na dieta; e uma mistura de 1 g kg-1 MS de AR e 1 g kg-1 MS de LCC na dieta (AR+LCC). Cada período experimental tinha 14 dias para adaptação aos tratamentos e 5 dias de coleta. O consumo de alimentos foi mensurado diariamente, e uma coleta total de fezes foi realizada durante 3 dias consecutivos de cada período experimental para determinar a digestibilidade de nutrientes. Amostras de fluído ruminal foram coletadas no último dia de cada período para determinação da concentração de ácidos graxos de cadeia curta. Amostras de urina foram coletadas no dia 18 de cada período para análises de nitrogênio e derivados de purina. O fornecimento de AR diminuiu o consumo de MS e proteína bruta (PB), mas aumentou a digestibilidade de proteína bruta e concentração ruminal de acetato. O fornecimento de LCC não afetou o consumo, mas aumentou a digestibilidade da fibra em detergente neutro (FDN). A associação de AR+LCC aumentou a digestibilidade da PB e FDN como também a concentração total de ácidos graxos de cadeia curta no rúmen, sem alterar o consumo de MS. O tratamento AR diminuiu a ingestão de N como também a excreção de N pelas fezes e urina. As novilhas do grupo LCC tiveram os maiores valores de N absorvido e retido enquanto as novilhas do grupo AR tiveram os menores valores. As novilhas do grupo RA tiveram menor estimativa de proteína microbiana em comparação com aquelas no grupo LCC e AR+LCC mas não diferiram do CON. Em conclusão, a associação de AR+LCC melhorou a digestibilidade da fibra e aumentou a concentração do total de ácidos graxos de cadeia curta no rúmen sem alterar o balanço de N e estimativa da proteína microbiana no rúmen.(AU)

Resumo

Para satisfacer la demanda de los consumidores, cada vez más preocupados por la salud y el bienestar, se han adoptado estrategias como la modificación del perfil de ácidos grasos de productos de rumiantes (carne y leche) para obtener una menor proporción de ácidos grasos saturados (AGS) que son generalmente asociado con el riesgo de desarrollar enfermedad cardiovascular. La inclusión de fuentes lipídicas, como los aceites vegetales, ricos en ácidos grasos insaturados en la dieta de los rumiantes, ha tenido como objetivo mejorar la eficiencia del uso energético, ya que tiene un menor aumento calórico en comparación con los carbohidratos, así como mejorar la calidad cualitativa. aspectos de la carne, principalmente en lo que respecta al perfil de ácidos grasos, y al aumento de los compuestos funcionales de la carne. Sin embargo, debido a que la naturaleza alimentaria de los rumiantes está asociada al consumo de forrajes, los cuales son pobres en este nutriente, existe una limitación en su uso, ya que son tóxicos para los microorganismos ruminales. Así, se han realizado investigaciones que evalúan la inclusión de fuentes lipídicas en la dieta de los rumiantes como alternativa alimentaria para mejorar la calidad de la carne, minimizando los efectos sobre la fermentación ruminal.

To meet the demand of consumers, increasingly concerned about health and well-being, strategies such as modifying the fatty acid profile of products from ruminants (meat and milk) have been adopted to obtain a lower proportion of saturated fatty acids (SFA) which are generally associated with the risk of developing cardiovascular disease. The inclusion of lipid sources, such as vegetable oils, rich in unsaturated fatty acids in the diet of ruminants, has been aimed at improving the efficiency of energy use, as it has a lower caloric increase compared to carbohydrates, as well as improving the qualitative aspects of the meat, mainly with regard to the fatty acid profile, and the increase in the functional compounds of the meat. However, because the food nature of ruminants is associated with the consumption of forages, which are poor in this nutrient, there is a limitation in their use, since they are toxic to ruminal microorganisms. Thus, researches evaluating the inclusion of lipid sources in the diet of ruminant animals have been carried out as a food alternative to improve meat quality, minimizing the effects on ruminal fermentation.

Para atender a demanda dos consumidores, cada vez mais preocupados com a saúde e bem estar, estratégias como a modificação do perfil de ácidos graxos dos produtos oriundos de ruminantes (carne e leite) têm sido adotadas, para obter uma menor proporção de ácidos graxos saturados (AGS) os quais geralmente estão associados ao risco de desenvolvimento de doenças cardiovasculares. A inclusão de fontes lipídicas, como por exemplo os óleos vegetais, ricos em ácidos graxos insaturados na dieta de ruminantes, têm tido como objetivo melhorar a eficiência de utilização de energia, uma vez que apresenta menor incremento calórico em comparação aos carboidratos, bem como melhorar os aspectos qualitativos da carne, principalmente no que se refere ao perfil de ácidos graxos, e aumento dos compostos funcionais da carne. Entretanto, devido à natureza alimentar dos ruminantes ser associada ao consumo de forragens, pobres nesse nutriente, há uma limitação em sua utilização, uma vez que são tóxicos aos microrganismos ruminais. Assim, pesquisas avaliando a inclusão de fontes lipídicas na dieta de animais ruminantes, têm sido realizadas como alternativa alimentar para melhorar a qualidade da carne, minimizando os efeitos sobre a fermentação ruminal.

Resumo

This study aimed to evaluate the fermentation profile and nutritional value of millet grain silages rehydrated with whey and/or molasses. The experiment was conducted in a completely randomized design with four treatments and six replications, with a control treatment (water rehydration), whey rehydration, water rehydration plus molasses (2.5%), and whey plus molasses (2.5%). Lower values of dry matter content (DM = 66.37; 1.55%) were found for the control silage, but within the recommended range. The contents of crude protein, neutral detergent fiber, acid detergent fiber, lignin and hemicellulose were not influenced by the use of additives. There was no difference (p>0.05) for aerobic stability and ammonia-N (6.04%) between treatments. For pH, lower values were observed for silages with molasses. There was a higher concentration (p <0.05) of lactic acid in silages with whey, and a higher concentration of butyric acid in silages added exclusively with molasses. The use of whey improved dry matter recovery compared to control silages.

Objetivou-se avaliar o perfil fermentativo e o valor nutricional de silagens de grãos de milheto reidratados com soro de leite e/ou melaço. O experimento foi conduzido em delineamento inteiramente casualizado com quatro tratamentos e seis repetições, sendo tratamento controle (reidratação com água), reidratação com soro de leite, reidratação com água mais melaço (2.5%), e soro de leite mais melaço (2.5%). Observou-se menor teor de matéria seca (MS = 66.37; 1.55%) na silagem controle em relação aos demais tratamentos, contudo este se encontra dentro do limite desejável. Os teores de proteína bruta, fibra em detergente neutro, fibra em detergente ácido, lignina e hemicelulose não foram influenciados pelo uso dos aditivos. Não houve diferença (p >0.05) para estabilidade aeróbica e N-amoniacal (6.04% NT) entre os tratamentos. Para valores de pH observou-se menores valores para as silagens com melaço em relação as demais. Houve maior concentração (p <0.05) de ácido lático nas silagens com soro de leite e maior concentração de ácido butírico nas silagens aditivadas exclusivamente com melaço. A utilização do soro de leite melhorou a recuperação da matéria seca em relação às silagens controle. Observou-se maior degradabilidade da matéria seca com 8% de taxa de passagem nas silagens aditivadas com melaço e/ou soro em relação ao controle.

Resumo

A diverse group of rangeland-medicinal plants are being used by ruminant whilst some of them have not been assessed for their nutritional value. This study was aimed to evaluate the chemical and mineral composition, buffering capacity, and in vitro fermentation of some rangeland-medicinal plants including Thymus kotschyanus, Ziziphora persica, Lallemantia royleana, and Scutellaria litwinowii in the family Lamiaceae, and Hypericum scabrum, in the family Hypericaceae. The results indicated that crude protein (CP) content ranged from 8.66% (S. litwinowii) to 12.17% of DM (H. scabrum). It was found that Z. persica had the highest potential gas production, metabolism energy (ME), relative feed value (RFV), and dry matter digestibility (DMD) values of 53.44 (mL 200-1 mg DM), 5.84 (MJ kg-1 DM), 170.66 and 70.88%, respectively. Mineral content differed among plants; Ca ranged from 5.79 to 41.96 g kg-1 DM. The concentrations of Ca, K, Mg, Fe, Zn, and Co were highest for L. royleana. Total volatile fatty acids (TVFA) and propionate concentrations were highest in the culture medium cultured with Z. persica, however, acetate, and butyrate were highest in H. scabrum. Acid-base buffering capacity was lower in T. kotschyanus and H. scabrum compared to other plants, while it was higher in S. litwinowii. Overall, it can be concluded that among plants evaluated in this study, Z. persica had higher nutritional value for sheep feeding.(AU)