Saccharomyces cerevisiae Y SU IMPACTO SOBRE LA CAPACIDAD FERMENTATIVA MICROBIANA EN HERBÍVOROS

La incorporación de microorganismos directamente a la alimentación, ofrece un gran potencial para la manipulación de la fermentación ruminal y Saccharomyces cerevisiae es un organismo especialmente atractivo. Se ha reportado que la incorporación de S. cerevisiae aumenta el valor nutricional de los forrajes de baja calidad. La presente tesis de investigación, en tres experimentos, tuvo como objetivo evaluar el impacto de Saccharomyces cerevisiae sobre el valor nutritivo de algunos forrajes de baja calidad, así como también sobre raciones integrales con diferente concentración de proteína cruda en la alimentación animal (rumiantes y equinos). Los resultados de los tres experimentos fueron publicados en revistas científicas indexadas con factor de impacto. Del primer experimento, sus resultados fueron publicados como un trabajo de investigación original en el Journal of Equine Veterinary Science 34 (2014), 619-625, y tuvo como objetivo evaluar in vitro la capacidad fermentativa de inoculos fecales equinos sobre nueve forrajes fibrosos en presencia de Saccharomyces cerevisiae. Los alimentos fibrosos fueron: rastrojo de maíz (Zea mays), paja de avena (Avena sativa), bagazo y hojas de caña de azúcar (Saccharum officinarum), hojas de pasto llanero (Andropogon gayanus), hojas de pasto Taiwán (Pennisetum purpureum), paja de sorgo (Sorghum vulgare) y hojas de pasto estrella (Cyinodon plectostachyus). Las Muestras de piensos fibrosos se incubaron con varias dosis de S. cerevisiae; 0 (control), 1.25 (baja), 2.5 mg (medio) y 5.0 (alto) mg / g de MS de un producto de levadura comercial que contiene 1 × 1010 UFC/ gramo. El inóculo fecal se obtuvo de cuatro caballos adultos alimentado ad libitum con un concentrado comercial que contiene heno de alfalfa. La producción de gas (PG) se registró a las 2, 4, 6, 8, 10, 12, 24 y 48 h después de la inoculación. Se observó una interacción entre los alimentos y la dosis de levadura para el pH fecal (P <0.01), la asintótica de PG (b, ml / g MS); tasa de PG (c, / h); retraso inicial previo a la PG (L, h), PG en 4 h y 48 h (P <0.01), PG a las 8 h (p <0.01), y a las 24 h (P <0.01). Diferencias en la capacidad de fermentación fecal entre los forrajes tropicales y templados (P <0,05) ocurrieron para el pH fecal, c y PG durante las primeras 12 horas, así mismo, se presentaron diferencias (P <0,05) entre los subproductos de la agricultura y los pastos para el pH fecal, b, y PG a partir de 8 a 48 h. La capacidad de fermentación entre los forrajes fibrosos frente a los no fibrosos (P <0,05) difirió para el pH fecal, b, y PG después de 12 h. La adición de S. cerevisiae al rastrojo de Z. mays reduce (P <0.01) el pH fecal y la fracción c con una mayor (P <0.01) fracción b en comparación con los otros alimentos. A partir de 4 a 24 horas, el bagazo de S. officinarum aumento la PG a los valores más altos en comparación con las hojas de S. officinarum. Después de 24 h, el rastrojo de Z. mays tuvo la más alta PG, mientras que las hojas de C. plectostachyus fue la más baja PG. No hubo diferencias entre las dosis de levadura para todos los parámetros medidos con la excepción de los valores de L (efecto lineal; P <0,01). El rastrojo de Z. mays tuvo el mayor valor nutritivo en comparación con los otros alimentos fibrosos. Sin embargo, la adición de S. cerevisiae en 2,5 a 5,0 g / kg MS ha mejorado la capacidad de fermentación fecal de forrajes de baja calidad. Los resultados del segundo experimento fueron publicados en la revista Italian Journal of Animal Science 13 (2014), 295-301 y evaluaron los efectos de Saccharomyces cerevisiae en la producción de gas in vitro (PG) y la degradabilidad de rastrojo de maíz, paja de avena, bagazo de caña y paja de sorgo. Los alimentos se incubaron con diferentes dosis de levadura (0, 4, 8 y 12 mg / g de MS) en adición directa o con 72 h de pre-incubación. La PG fue registrada a las 2, 4, 6, 8, 10, 12, 14, 24, 30, 48, 54 y 72 h de incubación. Después de 72 h, el pH y el metano se determinaron y los residuos se filtraron para determinar la degradabilidad de MS, fibra detergente neutro (FDN) y fibra detergente ácido (FDA). Existieron interacciones (P <0.001) entre las especies fibrosos × el método de aplicación × los niveles de levadura para todos los parámetros medidos de PG y degradabilidad ruminal. La adición directa o con 72 h de pre-incubación de S. cerevisiae al rastrojo de maíz mejoró (P <0.05) la PG y la producción de metano y redujo (P <0.05) el tiempo de retraso para el inicio de la fermentacón (L) y la degradabilidad de la FDN (DFDN). La adición directa de S. cerevisiae a la paja de avena aumentó (P <0.05) la tasa de PG (c) y disminuyó (P <0.05) la asintótica de PG (b). Sin embargo, la pre-incubación de 72 h aumentó (P <0.05) la tasa c una disminución lineal de b, de la degradabilidad de la MS (DMS) y DFDN. La aplicación de S. cerevisiae durante 72 h pre-incubación disminuyó (P <0.001) las emisiones de metano. La adición directa o la pre-incubación a 72 h con S. cerevisiae a la paja de sorgo aumentó (P <0.05), las fracciones b, c, L, así como la DMS y DFDN. En general, el efecto de la dosis varió entre los diferentes piensos y diferentes métodos de aplicación. Los resultados sugieren que la adición directa de 4 a 12 g de S. cerevisiae / kg MS puede mejorar la fermentación ruminal de los forrajes de baja calidad. El tercer experimento de investigación ha sido aceptado para su publicación en el Journal of Applied Animal Research – (ID JAAR-2015-0012) y su objetivo fue evaluar si el efecto de Saccharomyces cerevisiae (SC) sobre la fermentación in vitro puede ser afectado por el contenido de proteína cruda (PC) de la ración. Se probaron tres cultivos comerciales de Saccharomyces cerevisiae (SC): Biocell F53®, Procreatin 7® y Biosaf SC47® para evaluar niveles de 0 (SC0), 2 (SC2) y 4 (SC4) mg / g de MS de sustrato. Dos raciones niveles bajo 13% (BPC) y alto 16% de PC (APC) fueron utilizados como sustratos. La producción de Gas (GP) y metano (CH4) se registraron a las 2, 4, 6, 8, 10, 12, 14, 24, y 48 h de incubación. No se observaron interacciones (P <0.05) entre la ración × cultivo de levadura × dosis de levadura para PG, producción de CH4, y la cinética de la fermentación. La ración APC aumentó (P = 0.05) la asintótica de PG, la producción de CH4, y los parámetros de fermentación. Biocell F53® y Biosaf SC47® aumentaron la asintótica de PG (P <0.05) en las raciones de APC y BPC con un mejor efecto a la dosis de 2 mg / g MS de sustrato para APC (p <0,05) y dosis de 4 mg de levadura/ g MS de sustrato para BPC. Se observó la mayor producción de CH4 (P <0.05) con Procreatin 7®. Por otra parte, Procreatin 7® a 2 mg / g MS mejoró (P <0.05) la cinética de fermentación de la ración APC que las otras dosis de los otros cultivos de levadura, mientras que con la ración BPC, la dosis de 2 mg / g de MS de Biocell F53 ® tuvo la mejor cinética de fermentación (P <0.05). Podría concluirse que la ración APC mejoró la PG comparada con la ración BPC. Por otra parte, la adición de Biocell F53® y Biosaf SC47® a un nivel de 2 mg / g de MS mejora la cinética de fermentación y la degradabilidad de los nutrientes. Como conclusión general, la adición de S. cerevisiae puede aumentar la fermentación ruminal de forrajes de baja calidad mejorando la cinética de fermentación ruminal y la producción de gas, así como también, reduciendo la producción de metano. Las raciones con alto contenido de proteína cruda produjeron mayor cantidad de gas y disminuyeron la producción de metano en comparación con las dietas de bajo contenido en proteína cruda. El efecto de S. cerevisiae sobre la fermentación de alimentos depende de la composición química de estos, especialmente su contenido en fibra y proteína cruda

Effect of glucoamylase enzyme extract on in vitro gas production and degradability of two diets with 25% of corn or sorghum grains

The optimal use of starch is fundamental in improving performance of ruminants fed high grain diets (Huntington 1997, Rojo et al. 2000). Many strategies were developed to increase starch digestion rate and grain energetic value such as ground, dry rolled and steamed, and harvest of grains with high moisture content (Owens et al. 1997). Amylolytic enzymes in the rumen are extracellular or cell-bound (Thurn and Kotarsky 1987), and the extracellular enzymes are the most important in the group of amylolytic bacteria (Cotta 1988). Amylases are present in protozoa (Mendoza et al. 1993 1995) and ruminal fungi (Yanke et al. 1993). Exogenous amylolytic enzymes are obtained from controlled fermentation of bacteria or fungi (Declerk et al. 1997) and they are used in the food industry for starch hydrolysis (Reilly 1985).The objective of this study was to evaluate the effect of glucoamylase enzyme (GEZ) extract on the in vitro ruminal gas production (GP) and degradability of 2 total mixed rations (TMR) of 25% of corn and other of 25% of sorghum grains. The 2 diets were treated with 0, 1.5 and 3 g of GEZ protein (65% of protein) per kg of grain in diet. Diets GP were measured at 2, 4, 6, 8, 10, 12, 24, 48 and 72 h of incubation. Incubations were stopped after 72 h where pH was measured and supernatant was filtered to determine in vitro dry matter (DMD), neutral detergent fiber (NDFD), and acid detergent fiber (ADFD) degradabilities. Addition of GEZ to corn diet had no effect on kinetics of GP, whereas GEZ added to sorghum diet, at the high dose of the enzyme (3 g/kg DM), was traduced by an increase of the rhythm of GP (c) and the volume of GP at 2, 4 and 6 h of incubation. Likewise, effect of GEZ was not affected either on the DMD or cell wall (NDFD and ADFD) of both diets (sorghum or corn). Irrespective to enzyme supply, kinetics of GP and pattern of degradation of corn were generally higher than those of sorghum. A net effect of the diet and the interactions between diet and enzyme were recorded for the volume of GP at different incubation times. The use of high doses of GEZ should be tested on the pattern rumen fermentation

Effects of exogenous enzymes on nutrient digestibility, ruminal fermentation and growth performance in beef steers

Forty crossbred steers (Baladi Friesian, average BW 15375.14 kg) were used to evaluate the effects of exogenous enzyme (ENZ) addition on nutrient intake, digestion, ruminal fermentation and feed conversion in beef steers. Steers were randomly assigned to two groups of 20 animals and fed individually a total mixed ration (TMR) without (CTRL) or with addition of 40 g/hd/d of an enzyme mixture (ZADOs). The ENZ mixture was added for 220 days and in vivo apparent digestibility was measured on days 210–220. Enzyme addition did not affect (P¼0.1) DM intake, whereas it increased (Po0.05) total tract apparent digestibility of all nutrients. The magnitude of improvement in digestibility varied among nutrients, with the highest improvement occurring in digestibility of NDF and ADF (21.8% and 26.7%, respectively). Addition of ENZ also increased (Po0.05) concentrations of rumen ammonia N and total short chain fatty acids (SCFA) before and 3 h post-feeding. Allantoin concentration total purine derivates were increased (P¼0.04) with enzyme addition while uric acid was not affected (P¼0.05). Live-weight gain was also higher (Po0.01) in steers supplemented with ENZ. In conclusion, adding the exogenous enzyme product increased live-weight gain by 16% due to increased nutrient digestibility

Moringa oleifera leaf meal as protein feed in goat’s diets: biomethane and carbon dioxide and fermentation kinetics”

Durante la fermentación ruminal de los piensos, se producen grandes cantidades de gases de efecto invernadero (GEI) que hace en el ganado uno de los productores de gases de efecto invernadero más importantes. La Organización de las Naciones Unidas para la agricultura y la alimentación (FAO, 2006) informó que el sector ganadero representa aproximadamente el 18% del metano (CH4) y el 9%de las producciones de dióxido de carbono (CO2). Se han hecho muchos intentos para mitigar la emisión de ch4 de rumiantes, incluyendo la inclusión de levaduras (Elghandour et.al., 2017), sal de ácidos orgánicos, enzimas exógenas y aceites esenciales con resultados prometedores

The perceptions of South African accounting practitioners on the post-implementation of IFRS for SMEs in an institutionalised environment

Orientation: Small and medium-sized entities (SMEs) play a crucial role in the South African economy. The financial reporting framework applicable to SMEs may contribute to the success of the SME. This study was exploratory in nature and followed an interpretive approach to seek an in-depth understanding of the application of the International Financial Reporting Standards for Small and Medium-Sized Entities (IFRS for SMEs) in South Africa. Research purpose: This article explores the perceptions of South African accounting practitioners regarding the post-implementation of the IFRS for SMEs in the South African SME sector. Motivation for the study: South African research on IFRS for SMEs is scarce. This study was designed to contribute to the scarce body of literature on IFRS for SMEs and will benefit both the South African and international accounting profession. Research approach/design and method: In-depth semi-structured interviews with 21 accounting practitioners were carried out during 2017 and 2018. An interpretive approach was adopted to analyse the data into themes providing the insight into the perceptions of South African practitioners. Main findings: Overall, there appears to be an approval of IFRS for SMEs. The uniformity associated with IFRS for SMEs is one of the significant advantages, while factors such as the age of the practitioners, the use of automated software systems and South African legislative requirements affect the relative merit of using the standard. Practical/managerial implications: The use of the interpretive style will assist professional accounting organisations, standard setters and regulators in understanding the various benefits and drawbacks of the IFRS for SME framework. Contribution/value-add: This article is the first to explore the in-depth views of accounting practitioners after IFRS for SMEs was adopted in South Africa. The article also highlights the challenges faced by accounting practitioners in developing economies that service SMEs

The effects of three total mixed rations with different concentrate to maize silage ratios and different levels of microalgae Chlorella vulgaris on in vitro total gas, methane and carbon dioxide production

The aim of the current study was to assess the effects of adding Chlorella vulgaris algae at different levels on in vitro gas production (GP) of three total mixed rations (TMR) with different concentrate (C): maize silage (S) ratios (25C : 75S, 50C : 50S, 75C : 25S). Chlorella vulgaris was added at 0, 20, 40 and 80 mg/g dry matter (DM) of the TMR and total gas, methane (CH4) and carbon dioxide (CO2) production were recorded after 2, 4, 6, 8, 10, 12, 24 and 48 h of incubation in three runs. Increasing concentrate portion in the TMR linearly increased the asymptotic GP and decreased the rate of GP without affecting the lag time. Addition of C. vulgaris at 20 mg/ g DM to the 25C : 75S TMR increased the asymptotic GP, CH4, CO2 and GP at 48 h. Addition of C. vulgaris to the 50C : 50S TMR decreased the asymptotic GP and GP at 48 h. Higher CH4 production was observed at 48 h of incubation when C. vulgaris was included at (per g DM): 20 mg for the 25C : 75S ration, 40 mg for the 50C : 50S ration and 80 mg for the 75C : 25S ration. Inclusion of C. vulgaris linearly increased CH4 production for the 50C : 50S ration and increased CO2 production at 10 and 12 h of incubation for the 50C : 50S ration, whereas 20 and 40 mg C. vulgaris/g DM of the 75C : 25S TMR decreased CO2 production. The 25C : 75S TMR had the highest in vitro DM disappearance with C. vulgaris addition. Chlorella vulgaris addition was more effective with rations high in fibre content than those high in concentrates. It can be concluded that the optimal level of C. vulgaris addition was 20 mg/g DM for improved ruminal fermentation of the 25C : 75S TMR

Rumen degradation and nutritive utilization of wheat straw, corn stalks and sugarcane bagasse ensiled with multienzymes

Agricultural wastes such as wheat straw, corn stalks and sugarcane bagasse are carbohydrate-rich materials with a large potential as a source of dietary energy for ruminants. However, such feeds have poor nutritional value with low nitrogen and high fibre content (Tang et al. 2013; Ghorbani et al. 2014; Kholif et al. 2014). Although ruminant production systems depend mainly on forages as the main nutritional components, the digestion of these fibrous forages in the rumen is limited by their high content of fibre and inefficient fibre degradation (Krause et al. 2003; Khattab et al. 2013), thus limiting their use as the sole feed for actively growing or high-performing ruminants (Dean et al. 2013). The high fibre content also prevents the access of ruminal hydrolytic enzymes to cellulose and hemicellulose (Chesson 1984).The aim of this study was to determine the effect of anaerobic ensiling of raw agricultural wastes with a fibrolytic enzyme cocktail (EZ) as a cleaner and sustainable biological product for animal feed. Ten 1-kg samples of wheat straw, corn stalks and sugarcane bagasse were chopped at 5 cm length and mixed with EZ at three levels of 0, 1 or 3 L enzyme/ton of feed, moistened to a relative humidity of approximately 50% and ensiled in plastic bales for 30 days. Additionally, fibrous samples were incubated for 72 h with rumen liquor to determine the digestion of dry matter (DM), neutral detergent fibre and acid detergent fibre. Increasing enzyme level lowered ether extract and nitrogen-free extract contents of fibrous feeds and increased the biodegradation of acid detergent lignin of wheat straw. Anaerobic ensiled corn stalks and sugarcane bagasse with EZ improved the biodegradation of DM and fibre fractions. It could be concluded that ensiling fibres of the three wastes with EZ improved and enhanced their ruminal digestion with the biodegradation rate at 3 L/ton and subsequently produced a cleaner product for animal feed from agriculture wastes

Anaerobic ensiling of raw agricultural waste with a fibrolytic enzyme cocktail as a cleaner and sustainable biological product

Global crop production is growing continuously, with large amounts of crop residues being produced. Besides, the high cost of concentrates and quality forages has raised the interest to include fibrous roughages in ruminant nutrition, as indicated by Alsersy et al. (2015) in their work on effect of Mediterranean saltbush (Atriplex halimus) ensilaging with two enzyme cocktails on feed intake, nutrient digestibility and ruminal fermentation in sheep.The increasing expansion of agricultural activities have resulted in an unending production of agricultural waste which constitutes environmental nuisance, if not properly disposed. In most developing countries, this waste is burnt causing environmental problems and health challenges. The utilization of biodegraded ensiled agricultural waste, as an energy source, in livestock nutrition is proposed as a viable solution of reducing pollution. Agricultural waste such as straws is carbohydrate-rich materials that have a large potential as a dietary energy source for ruminants. This study aimed to determine the effect of anaerobic ensiling of raw agricultural waste with a fibrolytic enzyme cocktail as a cleaner and sustainable biological product for animal feed. Ten samples of 1 kg each of wheat straw, corn stalks and sugarcane bagasse were ensiled with enzyme cocktail at 0, 1 or 3 mL/kg dry matter of feed. Before ensiling, feed samples were chopped at 5 cm and moistened to a relative humidity of approximately 50% and then kept for 30 d in plastic bales. Feed type enzyme level interactions were observed (P < 0.01) for nutrient contents and fermentation kinetics. Increasing the level of enzyme cocktail increased (P < 0.01) crude protein and ether extract contents but decreased organic matter and non-structural carbohydrates contents of the three feeds. The enzyme cocktail also decreased (P < 0.01) neutral detergent fiber, acid detergent fiber, cellulose and hemicellulose contents of corn stalks and sugarcane bagasse. The high level of the enzyme cocktail increased (P < 0.05) methane production from corn stalks but decreased it from sugarcane bagasse. Fermentation parameters response to ensiling differed among the ensiled feeds. It can be concluded that anaerobic fermentation of enzyme-treated agricultural waste and feeding it to livestock is one of the viable ways of utilizing this waste which otherwise could have constituted nuisance and pollution to the environment, if incinerated or improperly disposed

Influence of Exogenous Enzymes on In Vitro Ruminal Degradation of Ensiled Rice Straw with DDGS

The objective of this study was to determine the effect of exogenous enzymes (ENZ) on nutrient profile and ruminal degradability of rice straw (RS), distillers dried grains with solubles (DDGS) and their mixture (RS with 10% DDGS). Ten samples of each fibrous feed were mixed with ZAD® (mixture of cellulases, xylanaxes, proteases and alpha amylase). ENZ was added at 0, 1 and 3 L to one ton of the fibrous feeds and the mixture was ensiled for 30 days. Feed samples were incubated for 72 h in rumen liquor of sheep to determine the degradability of DM, NDF and ADF. Pretreatment of feeds and their mixture (RS and DDGS) with ENZ at 3 L were increased (P<0.01) the degradation of NDF and ADF. Degradation fractions (a, b, (a+b) and c) of feeds were improved (P<0.01) at 3 L of ENZ, except the c of NDF and ADF of RS which were not affected by ENZ treatment. The results suggested a strong potential in improving digestion of RS and DDGS as well as their mixture with the pretreatment with ENZ. The dose of 3 L/ton of fibrous product improved the DM, NDF and ADF degradability

Effects of organic acid salts on ruminal biogas production and fermentation kinetics of total mixed rations with different maize silage to concentrate ratios

Methane is a major greenhouse gas (GHG) produced during the normal digestive process in ruminant animals (Blaxter and Clapperton, 1965) with a global warming potential, 25-fold that of carbon dioxide (IPCC, 2007). In addition to environmental implications, ruminant methanogenesis represents a loss of 2e12% of the gross energy intake (Johnson and Johnson, 1995; Soltanali et al., 2015) with a greater environmental impact from the confinement system compared with pasture-based system (O'Brien et al., 2012). A cow can produce 250 to 500 L of methane (CH4) per day depending on the quantity and quality of the feed which affects rate of digestion and rate of passage in the fermentation process (Johnson and Johnson, 1995). Furthermore, cattle consuming high fibre diets typically lose about 6% of gross dietary energy as methane (CH4), whereas those on high concentrate rations generally lose about 3% of dietary gross energy as CH4 (Mc Geough et al., 2012). According to the Food and Agriculture Organization of the United Nations, the livestock sector is responsible for about 18% of total global anthropogenic GHG emissionsRuminants are one of the major generators of methane, a greenhouse gas (GHG) with a global warming potential, 25-fold that of carbon dioxide. Methane production by ruminants also reduces the gross feed energy intake utilization by about 2e12%. The present study aimed to test the effects of different levels of a ruminal fermentation modulator (RFM) on in vitro ruminal fermentation and GHG production of five total mixed rations (TMR) with different silage (S) to-concentrate (C) ratios (0S:100C, 25S:75C, 50S:50C, 75S:25C, and 100S:0C). The RFM contained mainly calcium propionate and malate, and monopropylene glycol. The rumen inoculum was collected from a Brown Swiss cow fed a TMR of concentrate and alfalfa hay (1:1 dry matter (DM)) ad libitum. Gas production (GP) measurements were recorded up to 72 h of incubation. There were interactions (P 0.05) on methane production. The DM digestibility increased (linear effect; P ¼ 0.003) as silage level increased. Overall, increasing silage in the TMR lowered the asymptotic GP and DM digestibility. The asymptotic GP was higher with the addition of the RFM without any effect on fermentation kinetics. These results suggest that the RFM can be used as an environmental cleaner product in animal farming due to its ability to improve ruminal fermentation of feedstuffs and to reduce methane emission