Aerobic stability of tifton 85 silage with and without pre-drying in the sun

The objective of this study was to evaluate pH, ammoniacal nitrogen, and aerobic stability of silage of Tifton 85 grass silage with two dry matter contents at different silos opening times. The experimental design was completely randomized, in a subdivided plots scheme, in which the silages constituted the plots and aerobic exposure times the subplots, with four replications. To verify the aerobic stability of the silages, the temperature and pH were analyzed at seven hours after the silos were opened (1, 24, 48, 72, 96, 120, and 144 hours). The pH reached adequate levels for conservation only after 90 days of fermentation for the silages with and without pre-drying in the sun. Ammoniacal nitrogen remained below the recommended limits in both silages. As for the silage temperature, no loss of aerobic stability was observed. However, the observed pH revealed a break instability after 72 hours when the silos were opened at 28 days, with no changes for the remaining silage periods. It is possible to obtain suitable silages from Tifton 85 with or without pre-warming in the sun, however, a minimum fermentation period of 90 days should be adopted. The studied silages presented high aerobic stability, but when kept silage for only 28 days, they should be consumed by the animals within 48 hours after the supply.

Analysis of the verification results of the laboratory ability to detect ammonia nitrogen in drinking water in the CDC in Hubei Province / 公共卫生与预防医学

Objective To understand the ability of the CDC to detect ammonia nitrogen in drinking water in Hubei Province. Methods The blind samples of two concentration levels were tested in the laboratories of the disease control institutions in the province, and the test results were evaluated by double-sample Z score. Results The satisfaction rate was 76.29% (74/97), the problem rate was 15.46% (15/97), and the dissatisfaction rate was 8.25% (8/97). Conclusion The detection ability of ammonia nitrogen in drinking water in laboratories of disease control institutions in Hubei Province is generally high，however，some laboratories need to be further improved.

Ciclagem do nitrogênio pela parte aérea do milho submetido a doses de dejeto líquido de suínos / Recovery of nitrogen by maize shoots subjected to doses of pig slurry

A aplicação de dejeto líquido de suínos como alternativa de adubação é cada vez mais frequente na agricultura brasileira, entretanto a falta de sincronismo entre a disponibilidade e demanda de nutrientes pelas culturas geram acúmulos de elementos químicos no solo propensos a causar riscos ao ambiente. Desta forma, o presente trabalho teve por objetivo avaliar a recuperação aparente do nitrogênio pelas diferentes frações da parte aérea do milho cultivado com doses de dejeto líquido de suínos, em solo submetido a diferentes manejos na implantação da cultura de inverno. O delineamento experimental foi em blocos ao acaso, com quatro repetições, em esquema fatorial sendo que os tratamentos constaram da interação de doses de dejeto (0, 20, 40 e 80 m3 ha-1) mais um tratamento com adubação mineral seguindo as recomendações técnicas para a cultura, e ainda três manejos de solo (plantio direto, escarificado e cultivo mínimo) realizados na implantação da cultura da aveia branca, que antecedeu o milho. Os manejos de solo não afetaram o aproveitamento de nitrogênio aplicado via dejeto líquido de suínos. A aplicação de dejeto líquido de suínos promoveu incrementos lineares ao acúmulo de nitrogênio pela parte aérea do milho, no entanto, com o aumento das doses reduziu-se o aproveitamento do nitrogênio pela cultura, o que pode potencializar sua perda do sistema e contaminação ambiental. Aproximadamente 70% do nitrogênio do dejeto líquido de suínos adicionado ao solo não são recuperados pela parte aérea da cultura do milho.

The application of swine slurry as an alternative of fertilization is increasingly common in Brazilian agriculture, however the lack of synchrony between availability and demand of nutrients by crops generate accumulation of chemical elements in the soil likely to pose risks to the environment. Thus, this work had as objective to evaluate the apparent recovery of nitrogen by different fractions of the maize shoot grown with doses of swine slurry in soil under different managements in the implementation of the winter crop. The experimental design was a randomized block design with four replications in a factorial and the treatments consisted of the interaction of manure doses (0, 20, 40 and 80 m3 ha-1) more a mineral fertilizer treatment following the technical recommendations for the crop, and three soil management (tillage, chisel plow and minimum tillage) performed before the deployment of the cover crop soil. The soil managements do not affect the utilization of nitrogen applied through swine slurry. The application of swine slurry promotes linear increase in accumulation of nitrogen by maize shoots, however, with the increase of doses there is a reduction the utilization of nitrogen by the crop, which can increase the loss of the system and environmental contamination. Approximately 70% of nitrogen from swine slurry added to soil is not recovered by maize shoots.

Rendimento, valor nutritivo e características fermentativas de silagens de cereais de inverno / Yield, nutritive value and fermentative parameters of winter cereals silages

O experimento foi conduzido para avaliar o rendimento de forragem, valor nutritivo e a qualidade fermentativa de silagens de cereais de inverno. Foram avaliados doze genótipos de gramíneas anuais de inverno: aveias brancas: URS 21, URS Guapa e Barbarasul; trigos: BRS Tarumã e BRS Umbu; triticales: Embrapa 53 e BRS Minotauro; centeio: BRS Serrano; cevada: BRS Cauê; e aveias pretas: BRS 139-Neblina, IAPAR 61-Ibiporã e Ucrânia. A ensilagem foi realizada no estádio de grão pastoso a massa firme, com 30 a 35% de matéria seca, e armazenada em silos experimentais de PVC, por 90 dias, para avaliação. O delineamento foi em blocos casualizados, com três repetições. Todos os genótipos avaliados apresentaram características satisfatórias para ensilagem. O centeio BRS Serrano apresentou maior produção de biomassa ensilável, enquanto a cevada BRS Cauê, o trigo BRS Umbu e as aveias brancas UFRGS 19, URS Fapa-Slava e UPF 16 apresentaram os maiores teores de proteína bruta.

The study was carried out to evaluate the forage yield for ensilage, nutritive value and fermentative parameters for winter cereals silages. It was evaluated twelve winter annual grasses genotypes: white oat URS 21, URS Guapa and Barbarasul, wheat BRS Tarumã and BRS Umbu, triticale Embrapa 53 and BRS Minotauro, rye BRS Serrano, barley BRS Cauê and black oat BRS 139-Neblina, IAPAR 61-Ibiporã and Ucrânia. The genotypes were ensiled at dough grain to firm mass stages, with 30 at 35% dry matter, and packaged, for ninety days, in PVC experimental silos. The design was a randomized complete block, with three replications. All genotypes evaluated present satisfactory characteristics for ensilage. The BRS Serrano rye presented greater biomass yield. The BRS Cauê barley, BRS Umbu wheat and UFRGS 19, URS Fapa-Slava and UPF 16 white oats present higher crude protein concentrations.

Accuracy of the estimates of ammonia concentration in rumen fluid using different analytical methods / Exatidão das estimativas de concentração de amônia em fluido ruminal utilizando diferentes métodos analíticos

The accuracy of two different methods in measuring the ammonia nitrogen (N-NH3) concentration in rumen fluid were evaluated: a catalyzed indophenol colorimetric reaction (CICR) and the Kjeldahl distillation (KD). Five buffered standard solutions containing volatile fatty acids, true protein, and known ammonia concentrations (0, 3, 6, 12, and 24 N-NH3 mg/dL) were used to simulate rumen fluid. Different ratios (10:1, 7.5:1, 5:1, 2.5:1, 1:1, 1:2.5, 1:5, 1:7.5, and 1:10) of a potassium hydroxide solution (KOH, 2 mol/L) to standard solutions were evaluated by the KD method. The accuracy of each method was evaluated by adjusting a simple linear regression model of the estimated N-NH3 concentrations on the N-NH3 concentrations in the standard solutions. When the KD method was used, N-NH3 was observed to be released from the deamination of true protein (P<0.05), and an incomplete recovery of N-NH3 was observed (P<0.05), except for 7.5:1 and 5:1 ratios of KOH solution to standard solutions (P>0.05). The estimates of the N-NH3 concentration obtained by the CICR method were found to be accurate (P>0.05). After the accuracy evaluation, ninety-three samples of rumen fluid were evaluated by the CICR and KD methods (using the 5:1 ratio of KOH solution to rumen fluid sample), assuming that the CICR estimates would be accurate. The N-NH3 concentrations obtained by the two methods were observed to be different (P<0.05) but strongly correlated (r = 0.9701). Thus, it was concluded that the estimates obtained by the Kjeldahl distillation using a 5:1 ratio of KOH solution to rumen fluid sample can be adjusted to avoid biases. Furthermore, a model to adjust the N-NH3 concentration is suggested.

Avaliou-se a exatidão de dois métodos para mensuração da concentração de nitrogênio amoniacal (N-NH3) em fluido ruminal: reação colorimétrica catalisada por indofenol (RCCI) e destilação de Kjeldahl (DK). Cinco soluções-tampão contendo ácidos graxos voláteis, proteína verdadeira e concentrações conhecidas de amônia (0, 3, 6, 12 e 24 N-NH3mg/dL) foram utilizadas para simular o fluido ruminal. Diferentes relações (10:1; 7,5:1; 5:1; 2,5:1; 1:1; 1:2,5; 1:5; 1:7,5 e 1:10) entre a solução de hidróxido de potássio (KOH, 2 mol/L) e as soluções-padrão foram avaliadas no método DK. A exatidão de cada método foi avaliada por intermédio do ajustamento de um modelo de regressão linear simples das concentrações estimadas de N-NH3sobre as concentrações reais de N-NH3nas soluções-padrão. Com a utilização da DK observou-se que N-NH3foi liberada a partir da deaminação de proteína verdadeira (P<0,05). Adicionalmente, a utilização da DK promoveu recuperação incompleta da N-NH3(P<0,05), com exceção das razões entre a solução de KOH e as soluções-padrão de de 7,5:1 e de 5:1 (P>0,05). As estimativas de concentração de amônia obtidas por intermédio do método de RCCI foram exatas (P>0,05). Após a avaliação da exatidão, noventa e três amostras de fluido ruminal foram avaliadas por intermédio dos métodos de RCCI e de DK (neste caso usando a razão entre solução de KOH e fluido ruminal de 5:1). Nesta avaliação assumiu-se que as estimativas obtidas com a RCCI seriam exatas. Observou-se que as concentrações de N-NH3obtidas pelos dois métodos foram diferentes (P<0,05), mas fortemente correlacionadas (r = 0,9701). Concluiu-se que as estimativas obtidas com a DK utilizando-se razão entre a solução de KOH e a amostra de fluido ruminal de 5:1 poderiam ser ajustadas para correções de vieses Um modelo para realização desse ajustamento foi sugerido.

Efecto de la liberación controlada de nitrógeno sobre la fermentación y la degradabilidad in situ de Cynodon dactylon / Effect of controlled-release of nitrogen on fermentation and in situ digestibility of Cynodon dactylon

Objetivo. Evaluar el efecto de una fuente no proteica de liberación controlada de nitrógeno (NnpLC) sobre algunos parámetros de la fermentación ruminal y degradabilidad in situ de Cynodon dactylon. Materiales y métodos. 4 vacas fistuladas al rumen alimentadas con una dieta base de heno de Cynodon dactylon (4.8% proteína cruda y 78.4% fibra detergente neutra), 1 kg de melaza de caña y 55 g de mezcla mineral (tratamiento Control), y tratamientos experimentales con adición a la dieta base de 150 g urea (Urea), sustitución de Urea por NnpLC a razón de 50% del aporte de nitrógeno (Urea/ NnpLC) y 183 g NnpLC (NnpLC). En un Cuadrado Latino 4x4 y períodos de 17 días, se registró consumo del día 7 al 14. El día 15 fueron tomadas muestras seriadas de contenido ruminal para evaluar pH, nitrógeno amoniacal (N-NH3) y ácidos grasos volátiles. La degradabilidad de la materia orgánica (DMO48) y fibra detergente neutro (DFND48) a las 48 h fueron medidas con bolsas de nylon. Resultados. No hubo diferencias (p>0.05) en consumo de materia seca (8.2±0.35 kgMS/animal/día), pH (6.1±0.21), DMO48 (52.2±6.2%) y DFND48 (30.1±2.8%); aunque hubo diferencias (p<0.01) en valores medios de N-NH3 (19.1, 166.7, 181.6 y 281.8 mg/L; respectivamente). NnpLC incrementó (p<0.05) el ácido propiónico (27.3%), redujo el T1/2 (13.2%) y optimizó la relación P:E (22.0± 0.76). Conclusiones. El uso de una fuente NnpLC generó un perfil de ácidos grasos volátiles con patrón gluconeogénico, optimizó la concentración de N-NH3 y mejoró la relación P:E, por lo que debe considerarse una alternativa para manipular el medio ambiente ruminal de vacunos alimentados con recursos fibrosos.

Objective. To evaluate the effect of a controlled-release non protein nitrogen source (CRNpn) on some parameters of rumen fermentation and in situ digestibility of Cynodon dactylon. Materials and methods. Four rumen fistulated cows fed a basal diet with Cynodon dactylon hay (4.8% crude protein and 78.4% neutral detergent fiber), 1 kg sugar cane molasses and 55 g mineral mix (Control), and experimental treatment plus 150 g urea (Urea), replaced Urea with CRNpn by 50% of the nitrogen contribution (Urea/CRNpn) and 183 g CRNpn (CRNpn), in a 4x4 Latin Square with periods of 17 days. Intake was measured between days 7 and 14, serial rumen content samples were taken to measure pH, ammonia nitrogen (N-NH3) and volatile fatty acids on day 15. Organic matter (OMD48) and neutral detergent fiber (NDF48) digestibility were measured with nylon bags at 48 h. Results. No differences (p>0.05) on dry matter intake (8.2±0.35 kgDM/animal/day), ruminal pH (6.1±0.21), OMD48 (52.2±6.2%) and NDF48 (30.1±2.8%) were observed. However, there were differences (p<0.01) in N-NH3 daily averages (19.1, 166.7, 181.6 and 281.8 mg/L; respectively). CRNpn increased (p<0.05) the propionic acid (27.3%), reduced T1/2 (13.2%) and optimized the P:E relation (22.0±0.76). Conclusions. The use of a CRNpn source generated a volatile fatty acid profile with gluconeogenic pattern, optimized the N-NH3 concentration and improved the P:E relation, and therefore may be considered as an alternative to manipulate the ruminal environment of cattle fed with fibrous resources.

Analysis of water quality factors influencing the speciation of inorganic nitrogen using GRA.

Based on the water quality data from 2006 to 2008, grey relational analysis (GRA) is used to analyze factors that may have influence on the speciation of inorganic nitrogen in the Chengdu section of middle Min river. The results show that water temperature, changing from 20.2±2.7, 13.4±5.7 and 16.8±5.6oC, is the first restrictive factor for the speciation of inorganic nitrogen; it is negatively correlated with the ratio of total ammonia nitrogen to total inorganic nitrogen contents [m(AN)/m(TIN)] in three different periods of wet season, dry season and year-round. The average pH values for years, in wet and dry periods are 7.6±0.4, 7.3±0.3 and 7.8±0.2, respectively, and have different influences in different seasons. It is the second restrictive factor and positive correlation between pH and m(AN)/m(TIN) in wet season and through the year yet it is the fourth factor in dry seasons. The values of dissolved oxygen (DO), which are 4.6±1.4, 4.6±2.4, 4.6±2.0 respectively, is the third factor and negatively correlates with m(AN)/m(TIN) in third different periods. The chemical oxygen demand (COD) indirectly inhibits the nitrifying bacteria because the DO is depleted in the decomposition of organic matter by heterotrophic bacteria, showing the positive correlation. As the alkalinity can meet the requirement of nitrification in wet season and through the year, it is not restrictive factor. However, it is the second restrictive factor in dry season because of low content of alkalinity inhibiting the growth of nitrifying bacteria.

Potencial de silagens de ramas de batata-doce para alimentação animal / Potential of silages of sweet-potato foliages for animal feeding

Objetivou-se avaliar o potencial de silagens de ramas de diferentes clones de batata-doce para alimentação animal. O trabalho foi realizado na Fazenda Forquilha localizada no Distrito de Batatal, município de Diamantina MG, no período de 23/12/2007 a 23/06/2008. O experimento foi conduzido no esquema de parcelas subdivididas em delineamento de blocos completos casualizados. Foram avaliadas a produtividade de matéria verde e matéria seca das ramas e a composição químico-bromatológica, além do perfil fermentativo de suas silagens, em três idades de colheita (120, 150 e 180 dias), em oito clones de batata doce. A produtividade de matéria seca não variou com a época de colheita das ramas, obtendo-se média de 6,01t ha-1. Os teores de matéria seca nas ramas aumentaram com o ciclo da cultura, verificando-se teores médios de 11,94; 12,16 e 19,62 por cento, aos 120, 150 e 180 dias após o corte, respectivamente. As silagens das ramas de batata-doce apresentaram altos teores protéicos e energéticos e adequado perfil fermentativo, portanto, apresentam potencial para utilização na alimentação animal, independentemente dos clones.

The objective was to evaluate the potential of silage derived from different clones of sweet potato for animal feed. The study was conducted at Forquilha Farm located in Batatal district, MG Diamantina in the period from 23/12/2007 to 23/06/2008. The experiment was conducted in split plot design in a randomized complete block. It was evaluated the green and dry matter yield, the chemical composition and the fermentative profile of silage harvested on three dates (days 120, 150 and 180), of eight clones of sweet potato. The dry matter yield did not vary according to the harvest time of the branches, resulting in an average of 6.01t ha-1. The dry matter content in the stems increased with the growth cycle, and there are average levels of 11.94, 12.16 and 19.62 percent on days 120, 150 and 180 after cutting, respectively. The raw potato silage showed high protein content and adequate energy fermentation and therefore, potential for use in animal feed, regardless of clones.

Effect of free ammonia nitrogen on the methanogenic activity of swine wastewater

Swine wastewater is characterized by high organic matter content, solids, nitrogen (expressed as total ammonia and protein) and heavy metals. This work determines the methanogenic toxicity effect of free ammonia contained in swine wastewater comparing raw swine wastewater (RW) and the liquid fraction of swine wastewater (TW). The values of IC50 (50 percent of inhibition) obtained for methanogenic bacteria ranged between 56 and 84 percent for RW, meanwhile IC50 for TW was ranged between 84 and 94 percent. Such inhibitory effects can be related to the free ammonia nitrogen concentration (> 40 mg NH3-N/L) contained in swine wastewater.

Perdas na ensilagem de capim-elefante aditivado com farelo de cacau e cana-de-açúcar / Losses in ensiling of elephantgrass added with cocoa meal and sugarcane

Foram estudados os efeitos da adição de farelo de cacau e de cana-de-açúcar sobre as perdas de silagem de capim-elefante. Utilizou-se um esquema fatorial 2 x 4, sendo 0 e 15 por cento de farelo de cacau e 0, 15, 30 e 45 por cento de cana-de-açúcar, com quatro repetições, no delineamento inteiramente ao acaso. O capim-elefante apresentava 29,2 por cento de matéria seca, e as silagens foram produzidas em silos experimentais de PVC, utilizando-se compactação de 600 kg de silagem/m³. A abertura dos silos ocorreu aos 60 dias após a ensilagem, quando foram determinados o teor de nitrogênio amoniacal e o pH das silagens. O farelo de cacau foi eficaz na redução da umidade e da concentração de nitrogênio amoniacal. Recomenda-se a inclusão de até 22,4 por cento da cana-de-açúcar, cv-IAC86-2480, na ensilagem de capim-elefante com 29 por cento de matéria seca, podendo-se aumentar para 45 por cento, desde que se utilizem 15 por cento de farelo de cacau.

The effects of the addition of cocoa meal and sugarcane in the elephant-grass silage losses were studied. A 2 x 4 factorial scheme was used, being 0 and 15 percent of cocoa meal and 0, 15, 30, and 45 percent of sugarcane, with four repetitions, in a completely randomized design. The elephant-grass showed 29.2 percent of dry matter and the silages were produced in PVC experimental silos, using 600 kg/m³ silage compaction. The silos were opened 60 days after ensilage, when ammonia nitrogen content and pH of the silages were determined. Cocoa meal was effective in the reduction of moisture and ammonia nitrogen concentrations. It is recommended the inclusion of up to 22.4 percent of the sugar-cane, cv-IAC86-2480, in the elephant-grass ensiling with 29 percent of dry matter, which can be increased to 45 percent, since 15 percent of cocoa meal be used.

Frações nitrogenadas de silagens de milho "safrinha" sob diferentes tempos de exposição ao ar antes da ensilagem / Nitrogenous fractions of silages from a maize crop planted late in season, under different periods of air exposure previous to ensiling

Objetivou-se avaliar o efeito da maturidade dos grãos de milho e do tempo de exposição ao ar antes da ensilagem sobre o pH e os componentes nitrogenados de silagens de milho "safrinha". O experimento foi conduzido em delineamento completamente casualizado com arranjo fatorial 2 x 4, no qual foram testados dois estádios de maturidade (MA) ao corte (grão completamente leitoso (GL) ou grão ½ leitoso ½ farináceo (GF)) e quatro tempos de exposição ao ar (EX), sem compactação (0, 12, 24 e 36 horas) antes da ensilagem em minissilos. Houve efeito significativo (P<0,05) em relação aos MA e EX, para os teores de PB e NIDN, além de interação entre esses fatores para as variáveis pH, N-NH3 e NIDA. Devido à interação, a silagem feita no estádio GL produziu mais N-NH3 do que aquelas feitas no estádio GF. A interação entre os fatores MA e EX aumentam o valor médio de pH das silagens produzidas, porém com diferentes magnitudes. O manejo inadequado na ensilagem decorrente da demora no enchimento do silo aumenta a fração nitrogenada insolúvel, ou seja, diminui a degradabilidade protéica, porém afeta negativamente a digestibilidade e o valor nutritivo da silagem. Silagens de milho colhidas com grão leitoso comprometem a palatabilidade pelo maior teor de nitrogênio amoniacal.

This experiment was aimed at evaluating the effect of corn grain maturity and air exposure time prior to ensiling on the pH and nitrogenous fractions of corn silage from corn crop planted late in the season. A completely randomized 2 x 4 factorial arrangement was used to test the effect of two maturity stages at harvest (GL, milky kernel and GF, ½ milky ½ dough kernel) of maize crops and the effects of four periods of air exposure of chopped materials (zero, 12, 24 and 36 hours) previous to packing in mini-silos, on pH and N fractions of silages. There was a significant effect (P<0.05) related to stage of maturity and period of air exposure concerning the contents of crude protein and neutral detergent insoluble nitrogen, as well as an interaction between the main effects for ammonia nitrogen and acid detergent insoluble nitrogen. Due to the interaction, the maize silage harvested at the milky kernel stage resulted in higher pH value and ammonia nitrogen contents. A delayed packing procedure increases the insoluble nitrogen fractions and may affect negatively protein digestibility.

The Distribution of Ammonia Nitrogen in Groundwater of Shunyi and Its Influencing Factors / 环境与健康杂志

Objective To discover the distribution of ammonia nitrogen in groundwater of Shunyi District and its influencing factors. Methods 286 monitored points in low-flow period and 100 in high-flow period were chosen in 19 towns in Shunyi District. Concentrations of ammonia nitrogen, iron and manganese, and the total bacterial count of water samples were determined and evaluated based on the Guidelines for Drinking Water Quality and related standard during Jan.-Mar., Aug.-Sep., in 2005. Results All the monitored points were deep groundwater. The median of ammonia nitrogen concentration in groundwater was 0.010 mg/L in low-flow period, and 0.140 mg/L in high-flow period. The relativity was not found between the concentration of ammonia nitrogen,total bacterial count in water sample and pollution source around the well. However the concentration of ammonia nitrogen was positively correlated with the concentration of nitrite nitrogen(r=0.224, P

Analysis of NH3-N Concentration and the Influence Factors in Ground Water in the Country of Beijing / 环境与健康杂志

0.05), however, NH3-N among different sampling sites showed the significant difference (P