RESUMO

Microencapsulation is an alternative to increase the survival capacity of microorganisms, including Yarrowia lipolytica, a widely studied yeast that produces high-value metabolites, such as lipids, aromatic compounds, biomass, lipases, and organic acids. Thus, the present study sought to investigate the effectiveness of different wall materials and the influence of the addition of salts on the microencapsulation of Y. lipolytica, evaluating yield, relationship with cell stability, ability to survive during storage, and in vitro application of ruminant diets. The spray drying process was performed via atomization, testing 11 different compositions using maltodextrin (MD), modified starch (MS) and whey protein concentrate (WPC), Y. lipolytica (Y. lipo) cells, tripolyphosphate (TPP), and sodium erythorbate (SE). The data show a reduction in the water activity value in all treatments. The highest encapsulation yield was found in treatments using MD + TPP + Y. lipo (84.0%) and WPC + TPP + Y. lipo (81.6%). Microencapsulated particles showed a survival rate ranging from 71.61 to 99.83% after 24 h. The treatments WPC + Y. lipo, WPC + SE + Y. lipo, WPC + TPP + Y. lipo, and MD + SE + Y. lipo remained stable for up to 105 days under storage conditions. The treatment WPC + SE + Y. lipo (microencapsulated yeast) was applied in the diet of ruminants due to the greater stability of cell survival. The comparison between the WPC + SE + Y. lipo treatment, wall materials, and the non-microencapsulated yeast showed that the microencapsulated yeast obtained a higher soluble fraction, degradability potential, and release of nutrients.

Assuntos

RESUMO

The objective of this study was to evaluate whether there is an interaction between pepper extract (PE) supplementation and evaporative cooling regimens on the performance, thermal comfort, and metabolism of lactating cows. The experiment was designed as a double 4 × 4 Latin square using eight multiparous Holstein cows (days in milk 147 ± 43.8 days). Treatments were a 2 × 2 factorial arrangement; two evaporative cooling regimens [sprinkler cycles of 30 s on and 4.5 min off (R5) and 30 s on and 9.5 min off (R10)] were combined with no inclusion of pepper extract (CT) or 800 mg/cow daily of PE. The inclusion of PE allowed a greater reduction in the surface temperature of the coat, and the cows remained for longer periods in the feeding area. There was an interaction between the use of PE and the climate regimen for surface temperature, which was lower for PER5. Cows experiencing greater intermittency in the spraying cycles (R10) spent 35% more time at the feeding area. A significant interaction was observed for milk production, with greater production for CTR5 compared to the other treatments. The feed efficiency for R5 was higher than that for R10. The R5 treatment combined with PE reduced water intake. There was no significant difference in serum parameters other than gamma-glutamyl transferase, with an interaction between treatments and greater activity for PER10, and total protein and albumin, which had cooling effects that were higher for R10. The two factors tested interfered in different and dissociated ways. The evaporative cooling strategies were effective, and the R5 treatment resulted in higher feed efficiency and milk production. The inclusion of PE enhanced heat reduction in cows when they were subjected to a cooling regime.

RESUMO

Dry ground corn kernels are widely used as sources of energy readily available for microbial synthesis in the rumen. The objective of the present study was to measure the effect of particle size on the storage length of rehydrated and ensiled corn grain. Commercial corn was milled in 2-, 4-, 6-, 8-, and 10-mm sieves, rehydrated until reaching 65% DM, and ensiled for 14, 28, and 56 days, in a completely randomized design with a 5 x 3 factorial arrangement, with six replications per treatment. PVC mini-silos were used, with dimensions of 25 cm height x 10 cm of diameter. The variables DM, MM, CP, NDF, ADF, pH, molds and yeasts count, fermentative losses, in vitro degradability and aerobic stability were subjected to analysis of variance. The Tukey test was used to compare means. LAB counts was subjected to Wilcoxon's nonparametric test, considering significance at p < 0.05. Rehydrated corn silages with smaller particles (2 and 4 mm) showed higher LAB and mold counts, higher levels of CP and EE and higher density at opening silos than that of coarser particles. However, they showed lower percentages of DM, and were susceptible to microbial attack and faster temperature increases than were coarse particles during the chosen storage times. Silage subjected to 56 days of fermentation showed lower contents of NDF, ADF and CP, lower gas losses and lower pH values in aerobiosis, and increased levels of soluble protein (A + B1 fractions), losses by effluents, number of hours to reach maximum temperature, and time to break aerobic stability. Coarse-grind silages subjected to 56 days of storage showed better chemical composition, lower LAB and mold counts, and less susceptibility to microbial degradation when exposed to air.(AU)

O milho moído seco é um dos ingredientes mais utilizados como fonte de energia rapidamente disponível para a síntese microbiana no rúmen. Objetivou-se avaliar o efeito do tamanho de partícula associada ao tempo de armazenamento sobre o milho moído reidratado e ensilado. Foi realizada a moagem de milho comercial em peneiras de 2, 4, 6, 8 e 10 mm, reidratado até atingir 65 % de MS e ensilado por 14, 28 e 56 dias, num delineamento inteiramente casualizado em arranjo fatorial 5x3, com seis repetições por tratamento. Foram utilizados mini-silos de PVC, de dimensões 25 cm altura x 10 cm diâmetro. Os dados referentes às variáveis MS, MM, PB, FDN, FDA, pH, contagem de bolores e leveduras, perdas fermentativas, degradabilidade in vitro e estabilidade aeróbia foram submetidas à análise de variância e o teste Tukey para comparação de médias, e a contagem de BAL foi submetida ao teste não-paramétrico de Wilcoxon, ambos considerando significância 5%. Silagens de grãos milho reidratados com partículas menores (2 e 4 mm) apresentaram maiores contagens de BAL e bolores, teores mais elevados de PB, EE e maior massa específica na abertura dos silos em relação às partículas mais grossas. Porém, demonstraram menores percentuais de MS, e foram passíveis de ataque microbiano e elevação de temperatura mais rapidamente do que partículas grossas durante os tempos de armazenamento avaliados. Silagens armazenadas por 56 dias apresentaram menores teores de FDN, FDA e PB, menores perdas por gases e menores valores de pH em aerobiose, e aumentaram a proteína solúvel (frações A + B1), as perdas por efluentes e o tempo para quebra da estabilidade aeróbia das silagens. Silagens com moagem grossa e submetidas a 56 dias de armazenamento apresentaram melhor composição bromatológica, menores contagens de BAL e bolores, e menor susceptibilidade à degradação microbiana quando expostas ao ar.(AU)

Assuntos

RESUMO

The objective of this study was to evaluated fermentation losses and silage quality with the addition of different by-products in TMR. A completely randomized design was used with four treatments: Control (CTL, with hay, corn silage, cracked corn, soybean meal, wheat bran and minerals); CTL plus the addition of fresh orange pulp (FOP); CTL plus soybean hulls (SBH) or CTL plus wet brewery wastes (WBW), with six replicates. The ingredients were mixed and ensiled in 24 PVC experimental silos. After 56 days of ensiling, fermentation losses (effluents, dry matter and gases), and the TMR silage pH and chemical composition were analyzed; aerobic stability was evaluated over seven days after the silos were opened. Lower dry matter (P ≤ 0.0001) was observed in TMR ensiled with wet (WBW and FOP) compared to dry (SBH) by-products. Greater ADF (P = 0.031) was observed in SBH when compared to others by-products. WBW and FOP increased dry matter (P ≤ 0.0001) and effluent losses (P ≤ 0.0001) when compared to CTL and SBH. SBH treatment remained stable after 176-hour, which differ (P=0.0015) compared with the other treatments (range from 94.5 to 99 hours of exposure to air). The density (kg DM/m3) changed (P ≤ 0.0001) among treatments. The inclusion of SBH in TMR silages had the greatest density, followed by CTL, WBW and FOP. The density was negatively correlated with DM losses ( r= - 0,81; P ≤ 0.0001). The pH differ (P = 0.003) among treatments. Highest pH of TMR silage was observed for SBH (3,67) and the lowest (3,56) for FOP. Soybean hulls successful improved aerobic stability and density, whereas aerobic stability and density were decreased and fermentation losses increased when fresh orange pulp and wet brewery were used. Little effects on chemical composition were observed, thereby agro-industrial by-products can be used in TMR silages as long as there is adequate product availability and pricing.(AU)

Objetivou-se avaliar as perdas fermentativas e qualidade química da ração total misturada (TMR) ensilada com a adição de diferentes subprodutos da indústria. Um delineamento inteiramente casualizado com quatro tratamentos foi utilizado: CTL (Feno, silagem de milho, milho quirera, farelo de soja, farelo de trigo e mistura mineral), FOP (CTL com adição de bagaço de laranja in-natura), ou SBH (CTL com adição de casca de soja) e WBW (CTL com adição de resíduo úmido de cervejaria), utilizando-se seis repetições por tratamento. Os ingredientes foram misturados e armazenados em 24 silos experimentais de PVC. Após 56 dias de armazenamento, as perdas fermentativas (efluentes, perda de matéria seca e produção de gases), e o pH, composição bromatológica e estabilidade aeróbica durante 7 dias das silagens de TMR foram mensuradas. Menor teor de MS (P ≤ 0,0001) foi observado para TMR ensiladas com resíduos úmidos (WBW e FOP) comparado com SBH. O uso de SBH apresentou maior teor de FDA (P = 0,031) comparado aos demais tratamentos. Adição de WBW e FOP aumentou as perdas de matéria seca (P ≤ 0,0001) e efluentes (P ≤ 0,0001) em relação a CTL e SBH. O tratamento SBH não apresentou quebra de estabilidade (176 horas), diferindo (P = 0,0015) em relação aos outros tratamentos (variação de 94,5 a 99 horas de exposição ao ar). A densidade (kg MS/m³) foi diferente (P ≤ 0.0001) entre os tratamentos. A inclusão de SBH na silagem de TMR apresentou as maiores densidades, seguido pelo tratamento CTL, WBW e FOP. A densidade teve correlação negative com as perdas de MS ( r= -0,81; P ≤ 0.0001). O pH diferiu entre tratamento (P = 0,003), sendo maior para CSC (3,67) e menor para BLI (3,56). O tratamento casca de soja apresentou a melhor estabilidade aeróbia e densidade, enquanto a estabilidade e densidade diminuíram e as perdas fermentativas aumentaram quando bagaço de laranja in-natura e resíduo úmido de cervejaria foram utilizados. Apesar das diferenças na composição das [...].(AU)

Assuntos

RESUMO

The objective of this study was to evaluated fermentation losses and silage quality with the addition of different by-products in TMR. A completely randomized design was used with four treatments: Control (CTL, with hay, corn silage, cracked corn, soybean meal, wheat bran and minerals); CTL plus the addition of fresh orange pulp (FOP); CTL plus soybean hulls (SBH) or CTL plus wet brewery wastes (WBW), with six replicates. The ingredients were mixed and ensiled in 24 PVC experimental silos. After 56 days of ensiling, fermentation losses (effluents, dry matter and gases), and the TMR silage pH and chemical composition were analyzed; aerobic stability was evaluated over seven days after the silos were opened. Lower dry matter (P ≤ 0.0001) was observed in TMR ensiled with wet (WBW and FOP) compared to dry (SBH) by-products. Greater ADF (P = 0.031) was observed in SBH when compared to others by-products. WBW and FOP increased dry matter (P ≤ 0.0001) and effluent losses (P ≤ 0.0001) when compared to CTL and SBH. SBH treatment remained stable after 176-hour, which differ (P=0.0015) compared with the other treatments (range from 94.5 to 99 hours of exposure to air). The density (kg DM/m3) changed (P ≤ 0.0001) among treatments. The inclusion of SBH in TMR silages had the greatest density, followed by CTL, WBW and FOP. The density was negatively correlated with DM losses ( r= - 0,81; P ≤ 0.0001). The pH differ (P = 0.003) among treatments. Highest pH of TMR silage was observed for SBH (3,67) and the lowest (3,56) for FOP. Soybean hulls successful improved aerobic stability and density, whereas aerobic stability and density were decreased and fermentation losses increased when fresh orange pulp and wet brewery were used. Little effects on chemical composition were observed, thereby agro-industrial by-products can be used in TMR silages as long as there is adequate product availability and pricing.

Objetivou-se avaliar as perdas fermentativas e qualidade química da ração total misturada (TMR) ensilada com a adição de diferentes subprodutos da indústria. Um delineamento inteiramente casualizado com quatro tratamentos foi utilizado: CTL (Feno, silagem de milho, milho quirera, farelo de soja, farelo de trigo e mistura mineral), FOP (CTL com adição de bagaço de laranja in-natura), ou SBH (CTL com adição de casca de soja) e WBW (CTL com adição de resíduo úmido de cervejaria), utilizando-se seis repetições por tratamento. Os ingredientes foram misturados e armazenados em 24 silos experimentais de PVC. Após 56 dias de armazenamento, as perdas fermentativas (efluentes, perda de matéria seca e produção de gases), e o pH, composição bromatológica e estabilidade aeróbica durante 7 dias das silagens de TMR foram mensuradas. Menor teor de MS (P ≤ 0,0001) foi observado para TMR ensiladas com resíduos úmidos (WBW e FOP) comparado com SBH. O uso de SBH apresentou maior teor de FDA (P = 0,031) comparado aos demais tratamentos. Adição de WBW e FOP aumentou as perdas de matéria seca (P ≤ 0,0001) e efluentes (P ≤ 0,0001) em relação a CTL e SBH. O tratamento SBH não apresentou quebra de estabilidade (176 horas), diferindo (P = 0,0015) em relação aos outros tratamentos (variação de 94,5 a 99 horas de exposição ao ar). A densidade (kg MS/m³) foi diferente (P ≤ 0.0001) entre os tratamentos. A inclusão de SBH na silagem de TMR apresentou as maiores densidades, seguido pelo tratamento CTL, WBW e FOP. A densidade teve correlação negative com as perdas de MS ( r= -0,81; P ≤ 0.0001). O pH diferiu entre tratamento (P = 0,003), sendo maior para CSC (3,67) e menor para BLI (3,56). O tratamento casca de soja apresentou a melhor estabilidade aeróbia e densidade, enquanto a estabilidade e densidade diminuíram e as perdas fermentativas aumentaram quando bagaço de laranja in-natura e resíduo úmido de cervejaria foram utilizados. Apesar das diferenças na composição das [...].

Assuntos

RESUMO

Corn ensiling is a feed preservation practice used for ruminant production. During the process of making and opening the silos, the quality of the silage may change due to the entrance of air, which can cause damage and decrease the voluntary intake of the animals. The objective of this work was to evaluate the chemical composition of corn silages during their use in commercial bunker silos, as well as to correlate this with qualitative and quantitative characteristics related to the silage making process. Technical data on silage making and samples were collected from 14 bunker silos, with five samples collected along each silo (at 10, 30, 50, 70 and 90% of their lengths); additionally, two sampling methodologies were compared (“W” vs. layer collections in silo panels: top, middle and bottom). The values for the pH and titratable acidity (TA) were significant (p < 0.05) in relation to the sampling method, where the pH of the top was higher (3.8±0.5) than that of the middle and the bottom layers (3.6±0.3 and 3.5±0.3); therefore, the TA was lower in the top of the silos. The dry matter, ashes, crude protein, neutral detergent fiber, acid detergent fiber, pH, TA, as well as the silo sampling method during the unloading of commercial bunker silos did not differ for any of the variables (p < 0.05). Also, the particle size did not differ during the unloading of the commercial bunker silos (p > 0.05). According to the collected technical data, 78.57% of the bunker silos were built directly on the ground, the harvesting equipment was mostly borrowed from municipalities or farmers associations (for 35.7 and 28.5% of the farms, respectively), and in only 64.2% of the farms, the harvester was sharpened before silage cutting. Good practices were applied during the corn silage process and throughout the use of the silos, homogeneous quality was detected in the western region of Santa Catarina. Either “W” or layer collections can be used to sample corn silage.(AU)

A ensilagem de milho é uma prática de conservação de alimento utilizada na produção de ruminantes. Durante o processo de confecção e abertura do silo, a silagem pode ter alterações em sua qualidade em função da entrada de ar, que pode causar prejuízos e diminuir o consumo dos animais. Objetivou-se avaliar a composição bromatológica das silagens de milho ao longo da utilização, de silos comerciais do tipo trincheira, bem como correlaciona-las com as características qualitativas e quantitativas, relacionadas ao processo de confecção das silagens. Os dados técnicos sobre a confecção da silagem, bem como amostras foram coletas à campo em 14 propriedades, em que foram coletadas cinco amostras ao longo de cada silo (relativos à 10, 30, 50, 70 e 90% do seu comprimento), e adicionalmente duas metodologias de amostragem foram comparadas (coletas em “W” vs. coletas em estratos do painel do silo: topo, meio e base). Os valores de pH e AT (p < 0,05), foram significativos em relação ao método de amostragem, em que o pH do topo foi maior (3,8±0,5) que o do meio e o da base (3,6±0,3 e 3,5±0,3); portanto, a AT foi menor no topo dos silos. Os resultados encontrados para MS, MM, PB, FDN e FDA, pH e AT, assim como comparado ao método de amostragem do silo não diferiram entre si para nenhuma das variáveis (p < 0,05). Além disso, o tamanho das partículas não diferiu ao longo da utilização dos silos comerciais tipo trincheira (p > 0.05). O levantamento técnico mostrou que 78,57% dos silos trincheira avaliados foram construídos diretamente no solo, que os equipamentos de colheita utilizados foram emprestados de prefeituras ou associações de agricultores (para 35,7% e 28,5% das fazendas), ou que em somente 64,2% das fazendas o equipamento de colheita foi afiado antes da colheita. Foram observadas boas práticas de ensilagem de milho e homogênea qualidade ao longo do silo. Ambos métodos de coleta, em “W” como em estratos do painel podem ser usados durante amostragem de silagem de milho.(AU)

Assuntos

RESUMO

Corn ensiling is a feed preservation practice used for ruminant production. During the process of making and opening the silos, the quality of the silage may change due to the entrance of air, which can cause damage and decrease the voluntary intake of the animals. The objective of this work was to evaluate the chemical composition of corn silages during their use in commercial bunker silos, as well as to correlate this with qualitative and quantitative characteristics related to the silage making process. Technical data on silage making and samples were collected from 14 bunker silos, with five samples collected along each silo (at 10, 30, 50, 70 and 90% of their lengths); additionally, two sampling methodologies were compared (“W” vs. layer collections in silo panels: top, middle and bottom). The values for the pH and titratable acidity (TA) were significant (p 0.05). According to the collected technical data, 78.57% of the bunker silos were built directly on the ground, the harvesting equipment was mostly borrowed from municipalities or farmers’ associations (for 35.7 and 28.5% of the farms, respectively), and in only 64.2% of the farms, the harvester was sharpened before silage cutting. Good practices were applied during the corn silage process and throughout the use of the silos, homogeneous quality was detected in the western region of Santa Catarina. Either “W” or layer collections can be used to sample corn silage.

A ensilagem de milho é uma prática de conservação de alimento utilizada na produção de ruminantes. Durante o processo de confecção e abertura do silo, a silagem pode ter alterações em sua qualidade em função da entrada de ar, que pode causar prejuízos e diminuir o consumo dos animais. Objetivou-se avaliar a composição bromatológica das silagens de milho ao longo da utilização, de silos comerciais do tipo trincheira, bem como correlaciona-las com as características qualitativas e quantitativas, relacionadas ao processo de confecção das silagens. Os dados técnicos sobre a confecção da silagem, bem como amostras foram coletas à campo em 14 propriedades, em que foram coletadas cinco amostras ao longo de cada silo (relativos à 10, 30, 50, 70 e 90% do seu comprimento), e adicionalmente duas metodologias de amostragem foram comparadas (coletas em “W” vs. coletas em estratos do painel do silo: topo, meio e base). Os valores de pH e AT (p 0.05). O levantamento técnico mostrou que 78,57% dos silos trincheira avaliados foram construídos diretamente no solo, que os equipamentos de colheita utilizados foram emprestados de prefeituras ou associações de agricultores (para 35,7% e 28,5% das fazendas), ou que em somente 64,2% das fazendas o equipamento de colheita foi afiado antes da colheita. Foram observadas boas práticas de ensilagem de milho e homogênea qualidade ao longo do silo. Ambos métodos de coleta, em “W” como em estratos do painel podem ser usados durante amostragem de silagem de milho.

Assuntos

RESUMO

The objective of this study was to evaluate performance, hematological parameters, leukocyte counts, and respiratory microbiota of broilers under heat stress receiving eucalyptus oil supplementation. Cobb broilers (n = 1200) were randomly distributed on the first day of life in a factorial arrangement with additional treatment (2 × 2 + 1) with two periods of oil administration via drinking water (daily, from 18 to 35 days of life) and two periods of oil administration via spray (daily, from 18 to 35 days of age) plus a control treatment, consisting of twelve replications, with 20 animals each. The birds were kept in a controlled environment with constant temperature at 32 °C to induce heat stress by infrared heaters. Eucalyptus oil was supplied by drinking water (1 L of oil to 4000 L of water) or by spray applications with a pump (1 L of oil to 200 L of water). Bird weight was recorded at 42 days of age, along with remaining feed, to determine weight gain, feed intake, and feed conversion. In addition, one blood sample from each bird repetition was collected for hematological and leucocytic evaluation. To assess respiratory microbiota, a tracheal flushing was performed for bacteria counts. There was no difference in performance, hematological parameters, and leukocyte counts, except hematocrit, which was lower in birds that received eucalyptus oil after 18 days of age. No significant differences were observed in the respiratory microbiota comparing oil-treated and -untreated groups. Although it was not possible to verify statistical difference, the birds that received eucalyptus oil via spray plus spray from 18 days old showed lower bacterial counts and absence of isolation of Gram negatives, while the control group was the one with the highest number of Gram negatives. Therefore, eucalyptus oil can be used for heat-stressed broilers without impairing their development.(AU)

Assuntos

RESUMO

This study was carried out to evaluate the effect of a blend of additives (choline, methionine, selenium, and organic zinc) on performance, feed efficiency, rumen parameters, and carcass traits of Nellore heifers finished with roughage-free diet. Nellore heifers (n = 36; average BW = 244±24.1 kg; average 24 months of age) were maintained in a feedlot system for 86 d. Heifers were separated into two groups: control and additive. Heifers in control group were fed a based diet composed of 850 g kg−1 corn grain and 150 g kg−1 of a mineral-vitamin-protein pellet. The additive group was fed a diet supplemented with a blend of choline, methionine, selenium, and organic zinc at 1,667, 4,000, 1, and 24.37 mg kg−1 of the diet dry matter, respectively. The animals were allotted to 18 pens (two heifers/pen), with nine pens per treatment. Heifers were weighed, blood samples were collected, ultrasonography examinations were performed periodically, and hot carcass and papillae samples were taken at slaughter. Data were analyzed as a completely randomized design. The model included the fixed effect of treatments (control and additive). Additive supplementation did not change dry matter intake, performance, or feed efficiency. There was no effect of additives on muscle or fat tissue deposition. Consequently, no changes in hot carcass weight and dressing were found. Overall, additive inclusion did not alter blood parameters, blood electrolyte balance, and rumen traits. Nellore heifers finished with roughage-free diets have no improvement on production traits nor in their rumen health by supplementation with a blend of choline, methionine, selenium, and organic zinc.(AU)

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RESUMO

ABSTRACT: Additives are used in high concentrate diets to prevent metabolic disorders in cattle. This study was designed to evaluate the effect of calcium sources and monensin on the control of ruminal acidosis in Nellore cattle that were abruptly shifted to a high (92.3%) concentrate diet. Eight cannulated steers were randomly assigned to two contemporary 4x4 Latin square. Treatments involved the addition of a calcium source, either limestone (LI) or a product derived from calcareous algae (CA), to the basic diet with or without the presence of monensin. Calcareous alga (Lithothamnium calcareum) is a natural and renewable product and a source of calcium carbonate. The quantity of added limestone, calcareous algae and monensin was 7.1g kg-1, 7.4g kg-1 and 30mg kg-1 DM, respectively. There was no effect of calcium source (P=0.607) or monensin (P=0.294) on feed intake or on the concentration of short chain fatty acids. Treatments with calcareous algae resulted in a higher mean ruminal pH (P=0.039), a shorter amount of time with the ruminal pH under 5.2 (P<0.001) and a better control of blood pH (P=0.006). Treatments with monensin also resulted in a shorter amount of time with the ruminal pH below 5.2 (P=0.023). Calcareous algae were shown to be effective in controlling adverse changes in the rumen and in blood variables for Nellore cattle that were subjected to an abrupt change to a high concentrate diet.

RESUMO: Os aditivos são amplamente utilizados em dietas com elevada proporção de concentrado a fim de prevenir distúrbios metabólicos em bovinos. Este estudo foi desenvolvido para avaliar o efeito das diferentes fontes de cálcio, com ou sem monensina sódica na dieta, no controle da acidose ruminal de bovinos Nelore, recebendo, de forma abrupta, uma dieta com elevada proporção (92,3%) de concentrado. Oito bovinos portadores de cânulas ruminais foram distribuídos em um delineamento quadrado latino (4x4) duplo contemporâneo. Os tratamentos foram a adição de diferentes fontes de cálcio, calcário calcítico (LI) ou produto a base de alga calcária (CA), com (WIMO) ou sem (WOMO) a presença de monensina, à dieta base. A alga calcária, Lithothamnium calcareum, é um produto natural, renovável e fonte de carbonato de cálcio, podendo ser uma alternativa no controle desses distúrbios. A inclusão de LI, CA e monensina foi de 7,1g kg-1, 7,4g kg-1 e 30mg kg-1 MS, respectivamente. Não houve efeito das fontes de cálcio e da monensina sobre o consumo alimentar e concentração total dos ácidos graxos de cadeia curta. Os tratamentos com AC resultaram em maior pH ruminal médio (P=0,039), menor tempo com pH ruminal abaixo de 5,2 (P<0,001) e um maior pH sanguíneo (P=0,006). Os tratamentos com monensina apresentaram menor tempo com pH ruminal abaixo de 5,2 (P=0,023). O produto a base de alga calcária foi eficiente no controle das mudanças adversas das variáveis ruminais e sanguíneas em bovinos Nelore submetidos a mudanças abruptas para dietas com elevada proporção de concentrado.

RESUMO

Additives are used in high concentrate diets to prevent metabolic disorders in cattle. This study was designed to evaluate the effect of calcium sources and monensin on the control of ruminal acidosis in Nellore cattle that were abruptly shifted to a high (92.3%) concentrate diet. Eight cannulated steers were randomly assigned to two contemporary 4x4 Latin square. Treatments involved the addition of a calcium source, either limestone (LI) or a product derived from calcareous algae (CA), to the basic diet with or without the presence of monensin. Calcareous alga (Lithothamnium calcareum) is a natural and renewable product and a source of calcium carbonate. The quantity of added limestone, calcareous algae and monensin was 7.1g kg-1, 7.4g kg-1 and 30mg kg-1 DM, respectively. There was no effect of calcium source (P=0.607) or monensin (P=0.294) on feed intake or on the concentration of short chain fatty acids. Treatments with calcareous algae resulted in a higher mean ruminal pH (P=0.039), a shorter amount of time with the ruminal pH under 5.2 (P 0.001) and a better control of blood pH (P=0.006). Treatments with monensin also resulted in a shorter amount of time with the ruminal pH below 5.2 (P=0.023). Calcareous algae were shown to be effective in controlling adverse changes in the rumen and in blood variables for Nellore cattle that were subjected to an abrupt change to a high concentrate diet.(AU)

Os aditivos são amplamente utilizados em dietas com elevada proporção de concentrado a fim de prevenir distúrbios metabólicos em bovinos. Este estudo foi desenvolvido para avaliar o efeito das diferentes fontes de cálcio, com ou sem monensina sódica na dieta, no controle da acidose ruminal de bovinos Nelore, recebendo, de forma abrupta, uma dieta com elevada proporção (92,3%) de concentrado. Oito bovinos portadores de cânulas ruminais foram distribuídos em um delineamento quadrado latino (4x4) duplo contemporâneo. Os tratamentos foram a adição de diferentes fontes de cálcio, calcário calcítico (LI) ou produto a base de alga calcária (CA), com (WIMO) ou sem (WOMO) a presença de monensina, à dieta base. A alga calcária, Lithothamnium calcareum, é um produto natural, renovável e fonte de carbonato de cálcio, podendo ser uma alternativa no controle desses distúrbios. A inclusão de LI, CA e monensina foi de 7,1g kg-1, 7,4g kg-1 e 30mg kg-1 MS, respectivamente. Não houve efeito das fontes de cálcio e da monensina sobre o consumo alimentar e concentração total dos ácidos graxos de cadeia curta. Os tratamentos com AC resultaram em maior pH ruminal médio (P=0,039), menor tempo com pH ruminal abaixo de 5,2 (P 0,001) e um maior pH sanguíneo (P=0,006). Os tratamentos com monensina apresentaram menor tempo com pH ruminal abaixo de 5,2 (P=0,023). O produto a base de alga calcária foi eficiente no controle das mudanças adversas das variáveis ruminais e sanguíneas em bovinos Nelore submetidos a mudanças abruptas para dietas com elevada proporção de concentrado.(AU)

Assuntos