TGI: FUNCION PRINCIPAL

• Desde el punto de vista de la Nutrición Animal El aparatodigestivo puede presentar múltiples variantesmorfológicas; pero el proceso digestivo tiene el mismopropósito en todos los animales:propósito en todos los animales:

LIBERAR LOS GLÚCIDOS, LÍPIDOS Y PROTEÍNAS DEL ALIMENTO INGERIDO Y REDUCIRLOS EN SUS UNIDADES BASICAS MAS SENCILLAS, POR MEDIO DE

LOS MECANISMOS Y FACTORES INVOLUCRADOS EN LA DIGESTIÓN y ASEGURAR UNA EFICIENTE ABSORCION

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DIGESTIÓN

- INGESTIÓN- DIGESTIÓN (accion mecanica por masticacion, accion quimica por HCl,

enzimas).- TRANSPORTE DE DIGESTA (contracciones peristalticas).- ABSORCIÓN (transporte activo, pasivo,) nutrientes a la sangre).- ABSORCIÓN (transporte activo, pasivo,) nutrientes a la sangre).- SINTESIS (proteinas verdaderas, acidos grasos, carbohidratos, vitaminas).- EXCRECIÓN ( productos de desecho: por la bilis se excreta toxinas,

microbios, etc y por el recto se excreta calcio, magnesio y fosforo)

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IMPORTANCIA DE LA SALIVACION

• FUNCIONES DE LA SALIVA :

- SOLUBILIZACION de alimento seco

- LUBRICACIÓN Liga el alimento formando bolo alimenticio.

- ENZIMÁTICA (Amilasa).- ENZIMÁTICA (Amilasa).

- BUFFER (Bicarbonato de Sodio)

- HIGIENE Oral

- ENFRIAMIENTO EVAPORATIVO de algunas especies animales.

- CONTROL DE SECRECIÓN (volumen y tipo) dependiente de sistema nervioso central

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DIGESTION: ENZIMAS

• Carbohidratos→ monosacaridos (Amilasa salival (boca)amilasa pancreática (intestino delgado),disacaridasas(intestino delgado)

• Proteinas→ peptidos pequeños y aminoacidos (Pepsina en elestómago. Endopeptidasas de origen pancreático y

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estómago. Endopeptidasas de origen pancreático yExopeptidasas (carboxipeptidasa de origen pancreático

• Lipidos→monogliceridos y acidos grasos (Lipasa pancreática.Requiere de la presencia de bilis.

ACCION Y DESARROLLO DE ENZIMAS

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(unids/kg p.v. en intestino a los 10 días de edad

DIGESTION EN VARIOS NIVELES

• DIGESTIÓN GÁSTRICA:

• Ac. Clorhídrico

• Pepsina: Proteínas = polipéptidos + péptidos + peptonas

• Cuajo o renina: en lactantes, coagulación para facilitar la digestión

• (nata, caseína y lactosa) y el suero: (lactosa, lactoalbúminas, NNP y sales minerales)

• Lipasa: Actividad limitada por el bajo pH: Ac. Grasos + Glicerina• Lipasa: Actividad limitada por el bajo pH: Ac. Grasos + Glicerina

• DIGESTION INTESTINAL :

• Bilis hepática: sin fermentos emulsiona grasas. Es rico en Na y K. Favorece el peristaltismo intestinal, rebaja la tensiónsuperficial del quimo, favorece la hidrólisis, impide la proliferación de bacterias de la putrefacción y otros m.o.perjudiciales.

• Jugo entérico: Amilasas, Proteasas y Lipasas

• Jugo pancreática: Tripsina: Proteínas y péptidos en AA

• Amilasa: Almidón e H.C. en azúcares

• Lipasa: descompone grasas en a. grasos y glicerina. Máxima actividad con pH 8

• DIGESTION INTESTINO GRUESO ??

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proteína delalimento polipéptido

diipéptido

proteínaindigestible

DIGESTION DE PROTEINAS

aa disponibles

masticación HCl pepsina tripsina quimiotripsina carboxipeptid. minopeptid. elastasas

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ALIMENTO

RESIDUO NO DIGERIDO

INTESTINO DELGADO ABSORCIÓN

secreciones endógenas

Reingestión

DIGESTION EN CONEJOS

partículas gruesas

HECES DURAS

partículas finas

CIEGO

HECES BLANDAS

AGV

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DIGESTION EN EQUINOS

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DIGESTION EN RUMIANTES

- Producción de saliva: Vacuno: 150 l/d

- Capacidad rumen: 55-60 gal. (25-30 gal normal)

- Contenido ruminal : en 3 capas

- Consumo de agua: 850-930 g./Kg. MS

- Digestión física, química, microbiológica

(fermentación)(fermentación)

- Masticación: 40-50 veces

- Tiempo de masticación y rumia: 8 h. c/u.

(regurgitación remasticación, reensalivación y

nueva deglución, para disminuir el tamaño de

partícula del alimento y aumentar la superficie

para la fermentación microbiana

- pH= 5.5-6.5; T°= 38-42 °C

- Bacterias: más de 60 especies, número y % según

dieta.

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FERMENTACIÓN MICROBIANA

- Funciones de los m.o.:

1. digiere la fibra a AGV: convierte celulas vegetales en energiautilizable. Los AGV de Cadena Corta (AGVCC) aportan con el 60-80% de la energia dietaria de rumiantes (dependiendo de ladieta).

2. fabrica proteina: produce amonio: Utilizado por los m.o. para formarAA´s, pueden absorver AA´s para formar proteinas, peroAA´s, pueden absorver AA´s para formar proteinas, peroparcialmente, satisfacen las necesidades de proteinas por digeriralgunos m.o. Esto ocurre en el abomaso e intestino delgado

- 3. fabrica vitamins K and B complex (Sintetiza todas las vitaminasdel complejo B, excepto vitamin B12, que requiere Co para susintesis).

� Productos de la digestion fermentativa : AGVCC =SCFAs =VFAs, CH4, CO2 y NH3

• Pricipales SCFAs: Propionato: utilizado por el higado(gluconeogenesis) , Acetato utilizado para energia y formargrasas y Butirato utilizado para energia

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FERMENTACION COMPARATIVA POR ESPECIES

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FERMENTACION EN MONOGASTRICOS

• Limitada fermentación post gástrica (colon, recto y ciego)

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ESTRUCTURA DE VILLI: BASE DE LA ABSORCIÓN- The villi increase the surface areaof the ileum for the absorption. Thevilli are finger like projections into thelumen of the gut. The villi increase theavailable surface area by ten times.- The crypts contain the secretorycells of intestinal secretion.

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cells of intestinal secretion.- Mucosa is a mucus secretingmembrane.- The circular and longitudinalmuscles combine to create thecontractions known as peristalsisthat maintains the movement ofchyme along the alimentary canal.- The serosa is a tough outermembrane composed of collagen.

ABSORCION EN EL TGI

El proceso de transporte de los productos finales de la digestion atravieza las paredes gastrointestinal e ingresa al torrente sanguineo, vasos linfaticos y

celulas del tejido

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MECANISMO DE ABSORCIÓN

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Active Transport : Glucose absorption and Amino acids absorption into the epithelial cells. •Active mean that the membrane protein 'pump' requires energy to function •The source of energy is ATP from respiration •This moves the molecules from low to high concentration against the concentration gradient •The energy causes a shape change in the protein that allows it to move the molecule to the other side of the membrane.

ABSORCIÓN: TRANSPORTE ACTIVO

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Many substances in the diet are composed of small molecules that need little or no digestion. These include sugars, mineral ions, vitamins and water. These are absorbed bydifferent transport mechanisms:

•Cholesterol and the fat-soluble vitamins (A, D, E, K) are absorbed into the epithelial cells of the ileum by lipid diffusion

•Mineral ions and water-soluble vitamins are absorbed by passive transport in theileum•Dietary monosaccharides are absorbed by active transport in the ileum

•Water is absorbed by osmosis in the ileum and colon.

CAPACIDAD DIGESTIVA COMPARATIVA

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TGI DEL AVE: FUNCION Y ESTRUCTURA

• To improve gut health, a clear understanding of the STRUCTURE AND FUNCTIONALITY OF THEGUT is important..

• Birds also have high numbers of intestinal villi and high EPITHELIAL TURNOVER RATE (48 to96 h), and rapid inflammatory response (less than 12 hours, as compared to 3-4 days inmammals), which makes them more susceptible to disturbances in absorptive capacity thanmammals.

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Transit time and pH in poultry GIT

GIT Segment Transit Time(Min) pH

Crop 50 5.5

Proventriculus / gizzard 90 2.5-3.5

Duodenum 5-8 5-6

Jejunum 20-30 6.5-7.0

Ileum 50-70 7.0-7.5

Colon 25 8.0

Source: R.Gauthier(2002)

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The caeca are a pair of tubes that allow fermentation ofundigested food to take place. This is emptied every 24hours (3 VECES) or so and is a light brown (mustardcolour) froth. This can often be confused as diarrhoeaby the novice

CRECIMIENTO ALOMETRICO

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Intestinal Integrity in Broilers Frederic J. Hoerr, DVM, PhD

Auburn University, Auburn, Alabama, USA

• The term “intestinal integrity” is difficult to define.

• THE EFFICIENCY OF NUTRIENT DIGESTION AND ABSORPTION IS LIMITED BY THEFUNCTIONAL SURFACE AREA OF THE INTESTINAL TRACT WHICH IS ITSELF DEPENDANT ONTHE DEVELOPMENT AND MAINTENANCE OF A HEALTHY INTESTINAL LINING.

• Intestinal integrity for commercial poultry can be defined as the maintenance of intestinalhealth to enable the expression of the full genetic potential for growth and yield and tohealth to enable the expression of the full genetic potential for growth and yield and tofully utilize the dietary nutrients.

• Evaluation of intestinal integrity in broiler production involves multiple approaches that involveassessment of production records, clinical examination of the flock, necropsy examination, andhistopathology. Additional assessments are applied for research purposes.

• Evaluation of intestinal integrity should be an ongoing activity within a broiler productionprogram.

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ECUACIÓN

ALTURA DE VILLI + DENSIDAD DE VILLI + AREA

ABSORTIVA + EQUILIBRIO M.O.

A superfície de absorção (SA) foi calculada de

acordo com a fórmula (Hardin et al., 1999):acordo com a fórmula (Hardin et al., 1999):

SA (mm2) = altura do vilo (mm) x largura a 50% de altura do vilo (mm)

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IPE

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SALUD INTESTINAL (SI)– NUTRICIÓN

• La SI tiene una gran influencia sobre el performance del crecimiento de las aves: Afecta ladigestión de alimento, absorción de nutrientes, y utilización de proteína y energía.

• La SI y la nutrición son estrictamente dependiente uno del otro. La óptima utilización denutrientes de la dieta no puede ser realizado a menos que el intestino este en un estadosaludable.

• Algunos factores dietarios pueden predisponer a las aves a una pobre salud intestinal o• Algunos factores dietarios pueden predisponer a las aves a una pobre salud intestinal oexacerbar un problema de salud intestinal.

• A causa que la calidad del alimento y la SI están estrictamente asociados uno del otro, losAVICULTORES y los VETERINARIOS tienden a “point fingers” en los fabricantes de alimentos ynutricionistas (o viceversa) siempre que los problemas de salud intestinal surjan.

• Los factores que afectan la salud intestinal incluyen: ENFERMEDADES ENTERICAS, ESTRÉSAMBIENTAL, APETITO, FORMA DEL ALIMENTO, TOXINAS EN EL ALIMENTO, EXCESIVO NIVELES DENUTRIENTES ó FACTORES ANTINUTRICIONALES, ETC. (Peter Ferket, 2002).

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Tabla 1: Ingredientes y problemas potenciales en dietas para pollos sobre la salud intestinal

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INTEGRIDAD DEL INTESTINO & INMUNIDAD

• El TGI constituye una extensa superficie en la que se produce un CONTACTO ÍNTIMO entre elorganismo y las substancias de la dieta, microorganismos, parásitos y toxinas exógenas.

• El intestino permite el PASO DE SUSTANCIAS a la circulación sistémica, pero al mismo tiempoEXCLUYE COMPUESTOS PATÓGENOS (Gaskins, 1997).

• El TGI tiene múltiples MECANISMOS DE DEFENSA inespecíficos e inmunológicos.

• Los mecanismos no específicos incluyen producción de ácidos gástricos, peristaltismo, capa• Los mecanismos no específicos incluyen producción de ácidos gástricos, peristaltismo, capamucosa, estrecha unión entre las células epiteliales, proteo lisis, resistencia contra lacolonización por bacterias patógenas y el eje intestino hepático.

• La defensa inmunológica del intestino delgado incluye la PRODUCCIÓN DE INMUNOGLOBULINASsecretoras, células M y linfocitos (Madara et al. 1990; Walker y Owen, 1990; Deitch, 1993;Wang, 1995).

• Los INDICADORES comúnmente usados para evaluar la integridad intestinal son la longitud delas vellosidades, densidad y longitud intestinal y peso relativo del intestino,

profundidad de las criptas y número de células caliciformes, permeabilidad transepitelial,actividad enzimática de la superficie ciliada, inflamación y crecimiento del animal.

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INTEGRIDAD INTESTINAL (I.I.)(Cervantes, Phibro Animal Health Corp. EUA, 2011)

• Desarrollo completo, macroscópico y microscópico, a la integridad ininterrumpida y alfuncionamiento normal del tubo intestinal.

• La I.I. optima es, desde el nacimiento hasta el final del ciclo productivo, es esencial paraobtener el MÁXIMO POTENCIAL GENÉTICO de crecimiento y utilización eficiente de losnutrientes del alimento en base a un TGI saludable, una altura máxima de la villi, máximadensidad de la villi y máxima área absortiva.densidad de la villi y máxima área absortiva.

• Es necesario estimular un desarrollo temprano, integro y completo del aparato GTI, glándulas yórganos anexos para maximizar la digestión y absorción de nutrientes.

• Intestino intacto manteniendo su ESTRUCTURA Y FUNCIÓN o simplemente un intacto y sanointestino (Dr. Harish V. Dharne, head of Avitech’s).

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La buena II & TGI sano es esencial para:

• Optima digestión y absorción de nutrientes (Eficiencia de utilización de la dieta)

• Controlar el ingreso de los patógenos entéricos

• Lograr el máximo potencial de crecimiento

Lograr una pigmentación deseada

IMPORTANCIA DE LA II & TGI SANO

• Lograr una pigmentación deseada

• Resistencia al desgarramiento en el procesamiento del faenado

• Manejo de la cama (menos humedad)

• Mínimo olor sucio (foul odor )

• Provee resistencia contra m.o. entero patógenos

• Menos morbilidad y mortalidad

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Maintaining Gut IntegrityBy Dr. Harish V. Dharne, head of Avitech’s Business Promotion and

Knowledge Resource Centre

Nutrition and gut health are closely related in commercial poultry production.

• Diet formulation and feed management can have a marked effect on gut health greatlyinfluencing nutrient utilization and growth of the animal.

• Gut health problems arise due to improper nutrition and an unhygienic environmentespecially during the early stages of chick development.

• For cost effective and sustainable commercial operations there is need to:

1. Maintain natural gut health through proper nutrition and a clean environment, and

2. Effective treatment of an existing gut disorder.

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Factores QUE INFLUYEN SOBRE LA INTEGRIDAD INTESTINAL

a. Physical barriers: Intestinal integrity is compromised when the mucus layer is degraded;epithelial cells are effaced or destroyed, the vascular supply is interrupted, or the immunesystem is compromised. Viruses, bacteria, fungi, parasites, and toxins can damage this. +++

b. Stress factors: Gut environment is also altered by several stress factors to the birds likehandling, transportation, overcrowding, abrupt changes in environment etc.

c. Feed toxins and toxicants: Feed toxins and toxicants can also affect the gut integrity.c. Feed toxins and toxicants: Feed toxins and toxicants can also affect the gut integrity.

d. Dietary factors: Nutritional deficiency due to imbalance in ration formulation, grainengorgement, microbial load in feed etc. affect gut health. The nature of the diet, for examplepresence of non-starch polysaccharide (NSP) especially soluble fractions in the diet providesubstrate for the growth of undesirable bacteria and accumulation of fermentation productsaffecting the gut severely. Insoluble NSP is a major problem leading to soiling of litter.

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e. Health status: Diseases like coccidiosis and fowl plague are found to affect the gutintegrity severely. Infections, injuries etc. also affect gut health.

f. Gut micro flora:

The rich bacterial community that make up the gut micro flora play animportant role for the host through changes in the morphology of gut,nutrition, pathogenesis of enteric diseases, immune response and alterationsin colonization resistance.in colonization resistance.

The shift in composition of this microflora results in production and efficiencylosses often in the absence of any clinical signs. Useful microbes (commensalbacteria) in gut play a positive role in controlling the gut flora and stimulatethe development of the gut wall. Hence, microbial balance of gut is utmostimportant in maintaining gut integrity.

g. Beak deformity: Beak deformity preventing proper feed consumption may impair guthealth.

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a. Natural Physical Barriers that Help to Maintain Intestinal Integrity

• Physical barriers protect against the entry of foreign materials and organisms into the bloodstream andaccess to other viscera thus helping intestinal integrity. On occasion due to improper nutrition or anunhygienic environment, when the load of foreign invaders increase these barriers are breached.

1. Mucus (a protective1. Mucus: material secreted by intestinal cells) is a barrier to bacterial and fungalinvasion. It is broken by some enzymes (eg. mucinolytic, urease). Poultry feeds with under cooked soymeal may contain urease.meal may contain urease.

2. Gut epithelial cells (enterocytes): These cells form a semi-permeable surface that selectively allowspassage of fluid, electrolytes, and dissolved nutrients. Every epithelial cell in the digestive tract is part ofa continuous physical barrier. When organisms and toxic agents damage epithelial cells, the integrity ofthis protective barrier is broken.

3. Fluid secretion: fluid having large amounts of water mixed with electrolytes. The fluid in the upper smallintestine is protective and keeps bacteria in suspension and washes them downstream.

4. Vascular supply: supply under the gut epithelial layer serves to rapidly dilute and carry away any agentsor chemicals (endogenous or exogenous) that may breach the mucosal barrier.

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f. MICROORGANISMOS Y EL TGI

• Integridad anatómica y fisiológica (Estructura y Función).

• Microbiota del TGI: parte integral de la salud del TGI e influencia el desarrollo de la microanatomia, ayudaa los procesos digestivo, estimula el desarrollo del sistema inmune entérico y puede proteger contra lainvasión de patógenos.

• Sistema inmune mucosal: la mucosa intestinal tiene una función de barrera, pero también puede generaruna respuesta inmune protectiva contra patógenos.

• El TGI alberga el mas grande numero de células inmunes en el cuerpo.

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Fotos de: Collet, S. University of Georgia - 2008

Tabla 2. Cantidad de bacterias (log CFU/ g) en el tracto intestinal del pollo en diferentes edades.

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INTEGRIDAD INTESTINAL & MICROORGANISMOS: Dr. Jose Barragan, Poultry Nutrition Specialist and Consultant of Spain

• Because many factors can lead to changes in the bacterial population and to enteritis — ranging fromperistaltic movements to bacterial spores in the feed — it isn’t always easy to determine when nutrition iscontributing to the problem. However, one way to help identify diet as a contributor is to test the level ofprotein and fats in feces.

• “If you find an increase in the level of protein or fat in the feces, you know that you have a digestionproblem and you need to check your raw materials,” Barragan said. “The idea is to adapt dietaryformulations to the broiler gut. Don’t wait for broilers to adapt their gut to the diet.”formulations to the broiler gut. Don’t wait for broilers to adapt their gut to the diet.”

• Dr. Barragan, who described the broiler’s intestines as a “complex ecosystem,” said that it takes about 15days for the bird to develop a mature bacterial population.

• “This is one of the reasons why broiler nutrition is so important during the first 15 days of life,” he said.

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Higher villi in the jejunum (p<0.01) were seen when Bacillus subtilis-based probiotics were used compared to diets without this additive

20/10/2013 Cervantes, Phibro Animal Health Corp. EUA, 2011

VD was higher when probiotics based on Bacillus subtilis were used together with prebioticsbased on MOS, compared to the use of probiotics based on Bacillus sp alone. It was alsohigher in the birds fed the probiotics containing a bacterial pool compared to thosecontaining only one culture (probiotic 1). The results suggest that, in order to obtain higherVD (consequently higher nutrient absorption area), it is necessary to use MOS-basedsaccharides when probiotics based in only one bacterial culture are used.On the other hand, they would be not necessary if the probiotics has many bacterialcultures, as observed for probiotic 2.

20/10/2013Cervantes, Phibro Animal Health Corp. EUA, 2011

• Coccidiosis y Enteritis necrótica (Clínicas o Subclínicas) son las causas mas comunes que derivan en unamala II. El daño es costoso, principalmente en su forma subclínica, pudiendo causar perdidas hasta de10.2 centavos de dólar por pollo de 2 kg (5.2 centavos por coccidiosis y 5 centavos por enteritisnecrótica).

• Otras causas de mala II son: Sindrome de retraso del crecimiento y enanismo, Reovirus, Ascaridiasis, Cestodosis, Colibacilosis entero patógena, Salmonelosis, Micotoxinas, Grasas rancias, Aminas biogénicas, Harina de soya mal procesada, Agua de bebida de mala calidad, etc.

CAUSA MAS COMUNES DE LA MALA II

Harina de soya mal procesada, Agua de bebida de mala calidad, etc.

• Agentes etiológicos y tipos mas comunes de la enteritis:

Protozoarios (Eimeria spp., Histomona spp., y de menor importancia cochlosoma, hexamita, trichomona y cryptosporidium)

Helmintos: Ascaridia spp., Capillaria spp.., y Heterakis spp.Cestodos: Raillietina spp.Bacterias: Clostridium perfringes, Escherichia coli enteropatogena y Salmonella spp.Virus: Coronavirus (sobre todo en pavos), rotavirus, astrovirus, reovirus, enterovirus y calicivirus.

Hongos: Levaduras, Candida albicansInfecciones mixtas: causadas concurrentemente por cualquiera de los agentes etiologicos arriba

mencionados20/10/2013

NUTRICIÓN TEMPRANA Y SALUD INTESTINAL

� Good start is an important factor in MAXIMIZING PROFITS from broiler operations.

� Early nutrition mainly in the first 7 days of life for broilers may program the birds' systems and set a

pattern for growth and productivity. A large percentage of early growth (2 to 5 times the growth rate of

other tissues) occurs in the digestive tract and those organs involved in digestion.

� If digestive growth is retarded during this time period, overall growth rate may be compromised. Further

newly hatched chicks are more prone to gut infections as its natural defense is yet to be strengthened. So

proper care should be taken during this time period.

� Feeding of chicks:Feeding of chicks:

� Access to nutrients post hatch has a major impact on the immediate and long-term development of the

chick.

� The immediate post hatch period is critical for the development of all systems in chicks including the

immune system.

� The development of bursa and spleen is responsive to environmental stress at an early age in chicks.

Delayed access to nutrients post hatch reduces the relative weight of bursa and spleen.

� The passage of feed that is not sterile, through TGI exposes the bursa to a variety of antigens. So the

earlier the chicks are fed post hatch, the sooner will the proliferation stem cell meet environmental

antigens. This clearly suggests that early nutrition is important in laying a strong foundation for the health

status of birds in a situation where little or no antibiotics are allowed in their feed. Suitable feed additives

should be added in the starter diet as precautionary measure that will ensure better health and

productivity.

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ROL DE FACTORES DIETARIOS – MEJORA DE LA INTEGRIDAD INTESTINAL

• Quality feed ingredients: Supplementation of quality feed ingredients helps in

maintaining natural gut health.

• Processed feed: Many incriminating factors of feed are destroyed due to

processing. Extrusion is effective in reducing microbial contamination in feedstuffs

and in Salmonella control.

• Pelleted feed: Pelleting provides scope for utilization of high fibre feed resources.

Use of steam- pelleted feed seems to be of value in maintaining gut health.Use of steam- pelleted feed seems to be of value in maintaining gut health.

• FEED ADDITIVES: Commercial poultry production during the last 50 years has

benefited from pharmaceutical and biological products that enabled flock size to

increase, genetic potential and improved nutritional formulations to be realized,

and overall production to increase. Food animal agriculture is providing

wholesome poultry meat protein for consumption in the human diet at

unprecedented levels. Some feed additives that promote the gut health either

directly or by preventing the enteric pathogens are discussed below

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ADITIVOS QUE PROMUEVEN SALUD DEL TGI

1. ANTICOCCIDIALS AND IONOPHORES; coccidiosis, a managemental disease, causes devastating losses to the

poultry industry. The disease is characterised by an invasion and damage of the intestinal wall by the

parasite resulting in severe haemorrhage and mortality. For this reason, it is essentially added in most

poultry rearing situations during the rearing period to prevent illness and control infections. When used in

a structured and monitored programme, anticoccidial agents are very effective and permit the optimum

performance of the animal without compromising health status. No new anticoccidial agent has come

onto the market since the 1980s, which is in part a reflection of the success that the ionophores have

brought to the control of the disease. (GRUPO DE EST. PRA EXPERIMENTO FMVZ- LAB. INTERNACIONAL)

2. PROBIOTICS (DIRECT-FED MICROBIALS); “A probiotic is defined as a live microbial feed supplement which2. PROBIOTICS (DIRECT-FED MICROBIALS); “A probiotic is defined as a live microbial feed supplement which

beneficially affects the host animal by improving its INTESTINAL MICROBIAL BALANCE.”

Gut flora may be disturbed under several circumstances including the use of antibiotics or other drugs,

excess stress, disease, exposure to toxic substances, which allows harmful competitors to thrive in the gut.

Probiotics prevent such harmful bacteria (enteric pathogens) from growing in the gut and thus minimize

the disturbances caused by them, and also maintain host favourable bacteria. Thus Probiotics balance gut

microflora.

Probiotics are also used as an alternative to antibiotics. However, probiotics are not a substitute for

antibiotics in birds with serious infections but are useful in restoring the normal bacterial population that

was otherwise altered due to administration of antibiotics. If the conditions that originally caused damage

to the natural gut flora persist, the benefits obtained from probiotic supplements will be short lived.

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3. PREBIOTICS; are non-digestible food ingredients (readily fermentable

sugars), that beneficially affect the host by selectively stimulating the

growth and/or activity of one or a limited number of bacteria in the

colon, and thus improve host health. Most potential prebiotics are

carbohydrates (such as oligosaccharides). Prebiotic oligosaccharides may

be added to processed foods. Some prebiotics that are used in this

manner against pathogens are fructo-oligo-saccharides (FOS), xylo-oligo-

saccharides (XOS), mannan-oligo-saccharides (MOS) and galacto-oligo-

saccharides (GOS).

4. SYNBIOTICS; although use of probiotic formulations may well help in4. SYNBIOTICS; although use of probiotic formulations may well help in

achieving these benefits, it is also possible to increase and maintain a

healthy bacterial gut flora by increasing the amounts of prebiotics in the

diet such as inulin (naturally occurring oligosaccharides), raw oats, and

unrefined wheat. As probiotics are mainly active in the small intestine

and prebiotics are only effective in the large intestine, the combination

of the two gives a synergistic effect. Appropriate combinations of pre-

and probiotics are termed as synbiotics.

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5. ACIDIFIERS/ORGANIC ACIDS; include short chain fatty acids, volatile fatty acids and

weak carboxylic acids that are only partly disassociated. They may play a role in

maintaining gut integrity in the way that they reduce the colonization of pathogens

(like Salmonella and E.coli) in intestinal wall by lowering the intestinal pH below 6.0,

and promoting the normal microflora growth. This condition also increases the

efficiency of all digestive enzymes. Daily application of short chain fatty acids such as

Butyric acids increases epithelial cell proliferation, quick repairing of the intestine,

increased villous height and in turn increased absorptive capacity. Alone or in

combination, these are beneficial to the animal's health.

6. ENZYMES; extra enzymes can add to the animals' own digestive capacity. Feeding high

viscosity cereal grains to broilers result in larger microbial populations in the ileum.

Viscosity reduces the passage rate of the feed leading to overall reductions inViscosity reduces the passage rate of the feed leading to overall reductions in

consumption and decreased performance, sticky droppings and dirty eggs. A viscous

environment slows down digestion processes, and encapsulates nutrients, making

them inaccessible to digestive enzymes. Viscous gels are formed in the digesta by

the soluble NSP, which are not digested by the animal's own enzymes. Thickening of

unstirred water layer due to gel formation also inhibit absorption. Thus non-starch

polysaccharides form a major target substrate for feed enzymes. The addition of

enzymes to address NSP viscosity can improve gut health, feed efficiency, improve

manure quality and facilitate the use of lower cost feed ingredients.

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7. TOXIN BINDERS; are used through feed to bind or adsorb deleterious

substances such as mold and fungi-borne mycotoxins. These are the

invisible thieves or a hidden danger in animal feed, to animal health and

production. They may also accumulate in animal products and contaminate

the human food chain.

8. ANTIBIOTIC GROWTH PROMOTERS; With the intensification of livestock

farming the use of antibiotics for growth promotion has become popular.

Antibiotic growth promoters are feed additives that are administered at a

low, sub therapeutic dose to suppress sensitive populations of bacteria in

the gut and improve growth and performance of bird. The reason is that a

reduction in gastrointestinal infections would result in the subsequentreduction in gastrointestinal infections would result in the subsequent

increase in muscle weight. It has been estimated that as much as 6 per cent

of the net energy in the diet could be lost due to microbial fermentation in

the intestine (Jensen, 1998) and stimulation of energy-consuming immune

responses. If the microbial population could be better controlled, it is

possible that the lost energy could be diverted to growth. Whatever the

mechanism of action, the result of the use of growth promoters is an

improvement in daily growth rates between 1 and 10 per cent resulting in

meat of a better quality, with less fat and increased protein content

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Limitaciones del uso de los antibióticos:

• An overuse of any antibiotic over a period of time may lead to the local

bacterial populations becoming RESISTANT TO THE ANTIBIOTIC.

• ANTIBIOTIC RESIDUES in the products may affect humans.

• Essentially, there are two main ways in which we can reduce our

dependence on antibiotic use in animals:

1. An obvious choice is the development of ALTERNATIVES TO ANTIBIOTICS1. An obvious choice is the development of ALTERNATIVES TO ANTIBIOTICS

that work via similar mechanisms, promoting growth whilst enhancing the

efficiency of feed conversion.

2. A more difficult route would be to IMPROVE ANIMAL HEALTH.

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RECOMENDACIONES NUTRICIONALES

• Acceso rápido de agua y alimento de buena calidad, para favorecer el

desarrollo y maduración precoz del tubo intestinal .

• Verificación diaria del consumo (agua y alimento) mediante la palpación

del buche.

• Uso de enzimas para mejorar digestibilidad y reducir la viscocidad de

cereales con contenido alto de polisacaridos no almidonados.cereales con contenido alto de polisacaridos no almidonados.

• Verificación y rechazo de materias primas para la fabricación de alimentos

contaminados con micotoxinas o aminas biogenicas.

• Evitar el uso de grasas rancias o no estabilizadas con antioxidantes o que

no cumplan con los requisitos de calidad.

• Evitar el uso de soya mal procesada con contenido alto de inhibidores de

tripsina.

•

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ACTIVIDADES

TRABAJO :

• Consiga una foto de un corte histológico de cualquier parte del TGIcomo consecuencia de una prueba en nutrición : sintetice y de suopinión critica.opinión critica.

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