Simulating rewetting events in intermittent rivers and ephemeral streams: a global analysis of leached nutrients and organic matter

Climate change and human pressures are changing the global distribution and extent of intermittent rivers and ephemeral streams (IRES), which comprise half of the global river network area. IRES are characterized by periods of flow cessation, during which channel substrates accumulate and undergo physico‐chemical changes (preconditioning), and periods of flow resumption, when these substrates are rewetted and release pulses of dissolved nutrients and organic matter (OM). However, there are no estimates of the amounts and quality of leached substances, nor is there information on the underlying environmental constraints operating at the global scale. We experimentally simulated, under standard laboratory conditions, rewetting of leaves, riverbed sediments, and epilithic biofilms collected during the dry phase across 205 IRES from five major climate zones. We determined the amounts and qualitative characteristics of the leached nutrients and OM, and estimated their areal fluxes from riverbeds. In addition, we evaluated the variance in leachate characteristics in relation to selected environmental variables and substrate characteristics. We found that sediments, due to their large quantities within riverbeds, contribute most to the overall flux of dissolved substances during rewetting events (56‐98%), and that flux rates distinctly differ among climate zones. Dissolved organic carbon, phenolics, and nitrate contributed most to the areal fluxes. The largest amounts of leached substances were found in the continental climate zone, coinciding with the lowest potential bioavailability of the leached organic matter. The opposite pattern was found in the arid zone. Environmental variables expected to be modified under climate change (i.e. potential evapotranspiration, aridity, dry period duration, land use) were correlated with the amount of leached substances, with the strongest relationship found for sediments. These results show that the role of IRES should be accounted for in global biogeochemical cycles, especially because prevalence of IRES will increase due to increasing severity of drying events

Simulating rewetting events in intermittent rivers and ephemeral streams: A global analysis of leached nutrients and organic matter

Climate change and human pressures are changing the global distribution and the ex‐ tent of intermittent rivers and ephemeral streams (IRES), which comprise half of the global river network area. IRES are characterized by periods of flow cessation, during which channel substrates accumulate and undergo physico‐chemical changes (precon‐ ditioning), and periods of flow resumption, when these substrates are rewetted and release pulses of dissolved nutrients and organic matter (OM). However, there are no estimates of the amounts and quality of leached substances, nor is there information on the underlying environmental constraints operating at the global scale. We experi‐ mentally simulated, under standard laboratory conditions, rewetting of leaves, river‐ bed sediments, and epilithic biofilms collected during the dry phase across 205 IRES from five major climate zones. We determined the amounts and qualitative character‐ istics of the leached nutrients and OM, and estimated their areal fluxes from riverbeds. In addition, we evaluated the variance in leachate characteristics in relation to selected environmental variables and substrate characteristics. We found that sediments, due to their large quantities within riverbeds, contribute most to the overall flux of dis‐ solved substances during rewetting events (56%–98%), and that flux rates distinctly differ among climate zones. Dissolved organic carbon, phenolics, and nitrate contrib‐ uted most to the areal fluxes. The largest amounts of leached substances were found in the continental climate zone, coinciding with the lowest potential bioavailability of the leached OM. The opposite pattern was found in the arid zone. Environmental vari‐ ables expected to be modified under climate change (i.e. potential evapotranspiration, aridity, dry period duration, land use) were correlated with the amount of leached sub‐ stances, with the strongest relationship found for sediments. These results show that the role of IRES should be accounted for in global biogeochemical cycles, especially because prevalence of IRES will increase due to increasing severity of drying event

Comprehensive analysis of ethanol production from coffee mucilage under sustainability indicators

This article shows the results obtained by analyzing an emerging technology to produce bioethanol from coffee mucilage under sustainable development constraints. The investigation showed that the addition of an antibiotic is important to avoid contamination of the mucilage related to the presence of bacteria since these microorganisms can eat the sugars present in the biomass for their metabolism. On the other hand, for the conversion of cellulose and hemicellulose into simple reducing sugars present in coffee mucilage, the addition of the enzyme pectinase was necessary. The ANOVA analysis showed that the cellulase dose is the most significant factor in the hydrolysis process. The adequate doses of enzymes for the enzymatic hydrolysis process of coffee mucilage were obtained by the response surface method, finding an optimal value of 0,352 mL and 0,134 mL of cellulase and hemicellulase, respectively, per 100 mL of mucilage. From the logistics approach, the supply of coffee mucilage to a second-generation ethanol pilot plant with an installed capacity of 15.000 liters of mucilage per week was considered. Ideally, the pulping process must be carried out mechanically without water, ensuring a mucilage Brix content between 16 and 21, which would favor an ethanol yield close to 8% (v/v) in the must. A potential production of 4,137 liters of ethanol could be achieved with a total logistics cost of USD 305 if the available mucilage is collected. A potential reduction of 7,650 kg of carbon dioxide is possible if the ethanol produced is used to replace the same amount of gasoline in the trans portation industr

Effect of dietary phytic acid and inorganic iron on the quality of chilled pork.

The objective of this study was to evaluate the effect of supplementing inorganic iron and phytic acid to the diet for finishing pigs on meat quality after 24 hours and 7 days of refrigeration. Forty castrated male finishing pigs of a commercial genotype, with an initial mean weight of 64.34 ± 6.64 kg and age of 108 days, were used. The animals were weighed and housed individually in brick pens with an area of three m2 and compact floor, receiving water and ration ad libitum for 30 days. A randomized block design in a 2 x 2 factorial scheme was used, corresponding to diets supplemented or not with inorganic iron and with two levels of phytic acid, high (4.85%) and low (2.98%). The animals were slaughtered when they had reached a mean weight of 100.76 ± 6.54 kg and longissimus dorsi muscle samples were collected for the analysis of meat quality. The following parameters were analyzed in the samples: pH, color, marbling, water loss through pressure, shear force, iron composition, and lipid oxidation. No differences in the variables analyzed were observed between factors, except for muscle iron concentration, which was higher for the diet with inclusion of inorganic iron. Lipid oxidation was not influenced by the presence or absence of phytic acid and inorganic iron. The results show that diets with elevated phytic acid levels supplemented or not with inorganic iron can be used for finishing pigs without compromising meat quality during the refrigeration phase.</span

Supplementation of diets for weaned piglets withL-Valine and L-Glutamine+ L-Glutamic acid

The objective of this study was to evaluate the effects of supplementation of diets for weaned piglets with L-valine and L-glutamine + L-glutamic acid on performance, frequency of diarrhea, organ weight, digesta pH, intestinal morphology, and economic viability. Seventy-two piglets with a live weight of 7.53 ± 0.84 kg and 24 days of age were used. The animals were submitted to the following four treatments from 24 to 46 days of age: diet not supplemented with amino acids (control diet, CD); diet supplemented with glutamine + glutamic acid (GD); diet supplemented with glutamine + glutamic acid + valine (GVD), and diet supplemented with valine (VD). Two sequential phases (pre-initial I and pre-initial II) with a duration of 12 and 11 days, respectively, were established. A completely randomized design, consisting of six repetitions and three pigs per experimental unit, was used. Nine days after weaning, at 32 days of age, a piglet per pen was slaughtered for the evaluation of organ weight, digesta pH and intestinal morphology. All animals received a single diet from days 47 to 65. No effects on performance were observed during the pre-initial phases I and II; however, when the whole study period was considered (24 to 65 days of age), piglets fed GVD consumed less feed and exhibited better feed conversion than animals of the VD group. With respect to morphometric parameters, GD provided a greater ileal crypt depth than CD and VD. There was an economic advantage of diets supplemented with L-valine and L-glutamine + L-glutamic acid, validating their use in diets for weaned piglets until 46 days of age.</span

Efeitos da condição de alojamento e do nível de glutamina sobre odesempenho de leitões desmamados

This study aimed to determine the effects of housing conditions and glutamine (GLN) levels on growth performance and incidence of diarrhea in weaned piglets. Forty-eight piglets were randomly assigned (4x2 factorial design) to one of the eight experimental diets represented by four levels of dietary GLN (0.0, 1.0, 1.5 or 2.0 %) and two housing conditions (AD = adequate and INAD = inadequate). From 22 to 28 days of age all animals were challenged daily with Escherichia coli polysaccharides. No effect of GLN level was found on daily gain (ADG), daily feed intake (ADFI) or body weight at 28 days postweaning (BW28). For housing conditions, ADG at 21 days after weaning was greater for animals of treatment AD than INAD, and AD had lower body weight variation than INAD pigs at 21 days after weaning. Considering the whole period, AD had a higher ADG, ADFI and BW28 than INAD. However, an interaction effect was observed for feed:gain rate, in which values decreased linearly (Y = 2.1727 - 0.4017x; R2=0.92) just for AD pigs as GLN levels increased. No GLN level effects were observed for diarrhea incidence; however, AD had a higher number of animals without diarrhea and with lower incidence of severe diarrhea than INAD pigs. In conclusion, supplementing GLN doesn’t affect ADG, ADFI or BW28 but it improves feed efficiency when housing conditions are adequate.Este estudo visou determinar o efeito das condições de alojamento e dos níveis de glutamina (GLN) sobre o desempenho e a incidência de diarréia em leitões desmamados. Quarenta e oito leitões foram divididos aleatoriamente (modelo fatorial 4x2) e submetidos a oito dietas experimentais representadas por quatro níveis de GLN dietética (0.0, 1.0, 1.5 ou 2.0 %) e duas condições de alojamento (AD = adequada e INAD = inadequada). A partir do 22º dia de idade até os 28 dias de experimentação, todos os leitões foram desafiados com lipopolissacarídeo de Escherichia coli. Nenhum efeito do nível de GLN foi observado sobre o ganho de peso diário (GDP) consumo diário de ração (CDR), conversão alimentar (CA), e peso dos animais no dia 28 pós-desmame (BW28). Para a condição de alojamento, o valor de GDP no dia 21 pós-desmame foi maior para os animais AD que os INAD e os animais AD apresentaram menor heterogeneidade de peso que INAD. Considerando todo o período experimental, os animais de AD obtiveram maiores GDP, CDR e BW28 que animais INAD. No entanto, houve efeito de interação para CA, com valores decrescendo linearmente (Y = 2,1727 0,4017x; R2 = 0.92) para leitões AD conforme aumentou a suplementação de GLN. Nenhum efeito de nível de GLN foi observado para a incidência de diarreia, no entanto, o tratamento AD apresentou maior número de animais sem diarreia e menor número de diarreias severas. Em conclusão, a suplementação com GLN não afeta GDP, CDR e BW28, mas melhora a eficiência alimentar quando as condições de alojamento são favoráveis

Effect of growth promoters for pigs on live performance, quality intestinal and the efficiency of biodigestion of wastes

Objetivou-se avaliar em suínos em fase de crescimento e terminação os efeitos de promotores de crescimento sobre o desempenho, características de carcaça, perfil histológico intestinal, peso dos órgãos do trato digestório, e os reflexos desses tratamentos sobre os efluentes submetidos ao processo de biodigestão. Utilizaram-se 80 suínos, com peso médio inicial de 40,00 ± 1,90 kg, submetidos a quatro tratamentos, durante 61 dias, até atingirem 100,00 ± 4,50kg, correspondendo às dietas: Controle, Simbiótico; Colistina (10ppm); e Tilosina (40ppm). Constatou-se diferença na fase de crescimento, com maior consumo diário de ração para o tratamento Tilosina em relação ao tratamento Colistina. Não houve diferença para as características de carcaça, para o peso dos órgãos e para os parâmetros avaliados no processo de biodigestão dos dejetos (pH, sólidos totais, demanda química de oxigênio e demanda bioquímica de oxigênio). Quanto à morfometria intestinal, os animais do tratamento Tilosina apresentaram maior profundidade de cripta (P?0,05) no duodeno em relação aos animais dos tratamentos Controle e Simbiótico, assim como maior profundidade de cripta no jejuno (P?0,05). Houve diferença para a taxa vilosidade/cripta, com o tratamento Controle apresentando maior valor em relação aos demais tratamentos. Para o íleo, houve diferença para a profundidade de cripta dos animais do tratamento Controle em relação ao tratamento Tilosina. Apesar das diferenças observadas para as características de morfometria intestinal, não houve vantagem na utilização dos aditivos para os parâmetros de interesse zootécnico. Quanto aos efeitos sobre a fermentação dos efluentes provenientes dos animais submetidos aos tratamentos, os resultados não indicaram vantagens para nenhum aditivo.This study aimed to evaluate the effects of growth promoters in growing and finishing pigs on performance and carcass characteristics, intestinal histological profile, organs weight of the digestive tract, and the consequences of these treatments on the effluent through the process of biodigestion. We used 80 pigs with an average initial weight of 40.00 ± 1.90 kg, submitted to four treatments, during 61 days, until to reach 100.00 ± 4.50 kg of livewight, corresponding to diets with the following additives: Control (diet without growth promoters); Symbiotic; Colistin (10ppm) and Tylosin (40ppm). Difference was observed to the daily feed intake during the growing phase with a greater consumption for the treatment Tylosin regarding treatment Colistin. There was no difference for carcass traits, for the weight of the organs and to the parameters evaluated in the process of digestion of manure (pH, total solids, chemical oxygen demand and biochemical oxygen demand). Regarding the intestinal morphology, animals treated with Tylosin had higher crypt depth (P ? 0.05) in the duodenum compared to animals fed with Control and Symbiotic diets, as well as larger crypt depth in the jejunum (P ? 0.05). There were differences in the rate villi / crypt with the Control treatment showing higher value compared to other treatments. For the ileum, there was a difference to crypt depth treatment of the animals compared to Control and Tylosin treatments. Despite observed differences in the characteristics of intestinal morphology, there was no advantage in the use of additives for the parameters of zootechnical interest. The effects on the fermentation process did not indicate any advantages for the additives evaluated

Enzymatic complex in feed containing defatted corn germ meal for pigs during growth and finish phases

O objetivo deste experimento foi avaliar a uso do farelo de gérmen de milho desengordurado (FGMD) em associação a um complexo enzimático (CE) nas rações de suínos em fase de crescimento e terminação sobre o desempenho, digestibilidade, características de carcaça, qualidade da carne e sobre parâmetros de eficiência econômica. Foram utilizados 50 suínos (Agroceres PIC), 25 machos castrados e 25 fêmeas, com peso médio inicial de 41,14 ± 2,95 kg. Os animais foram submetidos a cinco tratamentos experimentais: T1- ração controle (milho + farelo de soja); T2- ração com milho + farelo de soja + 20% FGMD (isonutriente e isoenergética em relação a T1) ; T3- ração com milho + farelo de soja + 20% FGMD e CE (isonutriente e isoenergética em relação a T1); T4- ração com milho + farelo de soja + 20% FGMD sem CE (formulada igual a T3, descontada a matriz nutricional do CE, com menores níveis nutricionais e energéticos que T1); T5- ração com milho + farelo de soja + 20% FGMD e CE (formulada igual a T2, com o CE adicionado na forma on top, apresentando valores nutricionais e energéticos superiores a T1). O delineamento experimental foi em blocos casualizados, com 5 tratamentos e 5 repetições, sendo cada baia com dois animais de diferentes sexos a unidade experimental. Foi verificada diferença significativa (p<0,05) para o ganho médio de peso, com melhores resultados para T5 e piores para T4. Para a conversão alimentar o pior resultado observado foi para T4 (P<0,05). Os maiores valores de pH final da carne foram observados para T1, mas influencias deste parâmetro sobre a qualidade da carne não foram verificadas para nenhum dos tratamentos. Na avaliação econômica os melhores resultados foram observados para T3. A adição do complexo enzimático em dietas de suínos em crescimento e terminação contendo a inclusão de 20% de FGMD melhorou o desempenho zootécnico sem comprometer as características de carcaça e de qualidade da carne, demonstrando vantagens econômicas.The aim of this experiment was to evaluate the use of defatted corn germ meal (DCGM) with an enzymatic complex (EC) in feed for pigs in growing and finishing phases on the performance, digestibility, carcass, meat quality and economic efficiency characteristics. A total of 50 pigs (Agroceres PIC), 25 castrated male and 25 female, with initial average weight of 41.14 ± 2.95 kg, were used The animals were submitted to 5 treatments: T1- control feed (corn + soya meal), T2- ration with corn + soybean meal + 20% DCGM (isonutrient and isoenergetic compared to T1), T3- ration with corn + soybean meal + 20% DCGM and CE (isonutrient and isoenergetic compared to T1), T4 - ration with corn + soybean meal + 20% DCGM without EC (formulated equal T3, without considering the nutritional matrix of CE, with lower nutritional and energetic levels than T1), T5-ration with corn + soybean meal + 20% DCGM and EC (formulated equal T2, with EC added in on top form, presenting higher nutritional and energetic levels than T1). The experimental design was in random blocks, with 5 treatments and 5 repetitions per treatment, being each pen with two animals of different genders considered an experimental unit. Significant difference was verified for average weight gain when was considered the entire experimental period, with advantages for T5 and worst results for T4. For feed conversion, the worst result was verified in T4 (P<0.05). The highest final pH values for meat were observed for T1, but influences from this parameter could not be verified (in any of the treatments) on the quality of the meat. Economic evaluations have shown best results for T3. Adding the enzymatic complex to diets in growing and finishing pigs with 20% DCGM has improved the zoo-technical performance without compromising carcass characteristic neither meat quality, with an increase in economic feasibility