TRACTO GASTRO INTESTINAL : TGI

10/09/2012
TRACTO GASTRO INTESTINAL : TGI
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INGESTION
DIGESTION (accion mecanica por masticacion, accion quimica
por HCl, enzimas).
TRANSPORTE DE DIGESTA (contracciones peristalticas).
ABSORCION (transporte activo, pasivo,) nutrientes a la
sangre).
SINTESIS (proteinas verdaderas, acidos grasos, carbohidratos,
vitaminas).
EXCRECION ( 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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GLANDULAS SALIVALES Y SALIVA
Las unidades básicas de secreción son conjunto de
células: acini.
Contiene
agua,
electrolitos,
muco
y
enzimas(Secreción primaria) las cuales fluyen a
ductos salivares donde sufren alteración (Sodio es
reabsorbido, Potasio y bicarbonato secretado).
La mayoría de animales tienen tres pares de glándulas
salivares que difieren histológicamente
-Parótidas
Serosa y fluida
-Submaxilares
Serosa y mucosa
-Sublinguales
Mucosa
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SALIVACION EN CERDOS
FUNCIONES DE LA SALIVA :
- SOLUBILIZACION de alimento seco
- LUBRICACIÓN Liga el alimento
formando bolo alimenticio.
- 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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SECRECION DE SALIVA & AGUA
Cantidad y composición de la
saliva varia considerablemente
entre especíes.
Cantidad relacionada al nivel
de actividad de masticar
Cantidad de secreción:
- PERROS
minima
(lubricacion, no enzimas).
- OVEJAS
3-10 litros/d
- CABALLO 10-12 litros/d
- VACUNO
130-180 litros/d
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FUNCION PRINCIPAL DEL TGI
Desde el punto de vista de la Nutrición Animal El
aparato digestivo puede presentar múltiples
variantes morfológicas; pero el proceso digestivo
tiene el mismo 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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DIGESTION
•
•
•
Carbohidratos→ monosacaridos (Amilasa salival
(boca)
amilasa
pancreática
(intestino
delgado), disacaridasas(intestino delgado)
Proteinas→ peptidos pequeños y aminoacidos
(Pepsina en el estómago. Endopeptidasas de
origen
pancreático
y
Exopeptidasas
(carboxipeptidasa de origen pancreático
Lipidos→monogliceridos y acidos grasos (Lipasa
pancreática. Requiere de la presencia de
bilis.
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DIGESTION EN VARIOS NIVELES
DIGESTION INTESTINAL :
Bilis hepática: sin fermentos emulsiona grasas. Es rico en Na y K. Favorece el peristaltismo
intestinal, rebaja la tensión superficial 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
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
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DIGESTION INTESTINO GRUESO :
- Fermentación microbiana (formación de vitaminas del complejo B y K).
- Absorción de agua.
35% MS en porcino y 25% de MS en equino
- Producción de heces: 10% p.v. en vacuno; 8% p.v. en porcino; y 6% p.v. en equino,
caprino y aves.
- En conejos dos tipos de heces: normales (leporinas): redondas, duras, oscuras y no
muy gruesas (día y noche)
- cecotrofos: pequeñas, blandas, húmedas, con mucus. Mucha riqueza proteica,
mineral y vitamínica. Ingestión directa del ano
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DESARROLLO DE ENZIMAS
LECHON
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DESARROLLO DE ENZIMAS
(UNIDS/KG P.V. EN INTESTINO A LOS 10 DÍAS DE EDAD)
POLLOS
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DIGESTION DE PROTEINAS
proteína del
alimento
polipéptido
diipéptido
proteína
indigestible
aa disponibles
masticación HCl pepsina tripsina quimiotripsina carboxipeptid. minopeptid. elastasas
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DIGESTION EN PERROS
Estomago simple, no capaz de utilizacion efectiva de dietas en base a
forrajes (alto en fibra)
Incapaz de digerir algunas sustancias en granos, frutas y vegetales.
Similar al gato.
Limitada fermentacion postgastrica
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DIGESTION EN CONEJOS
Reingestión
ALIMENTO
ABSORCIÓN
INTESTINO DELGADO
RESIDUO NO DIGERIDO
secreciones endógenas
partículas finas
CIEGO
partículas gruesas
AGV
HECES DURAS
HECES BLANDAS
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DIGESTION EN EQUINOS
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DIGESTION EN EQUINOS
Sistema digestivo y req. de nutrientes son mas similares al cerdo que al vacuno.
Comparado al vacuno, los caballos necesitan menos fibra, proteina de alta calidad y
abastecer de vitaminas del complejo B.
Donde no hay pastura disponible, un caballo de 1,000 pound consume alrededor de
25 lbs/dia de heno y grano, o alrededor de 4,6 toneladas por año.
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DIGESTION EN RUMIANTES
Producción diaria de saliva: VACUNO:
150 l.; OVINO: 10 l.
CONTENIDO RUMINAL: en 3 Fases:
- Inferior: líquida y finas partículas
· Superior: más seca y partículas
groseras
· Agua: 850-930 g./Kg. MS
DIGESTIÓN QUÍMICA Y FÍSICA
· Masticación: 40-50 veces
· Tiempo de masticación: 8 h.
· Tiempo de rumia: 8 h.
FERMENTACIÓN DE ALIMENTO
Microorganismos anaerobios
Condiciones homeostáticas:
— pH: 5,5-6,5 (fosfato y bicarbonato de
la saliva y rápida absorción de
ácidos).
— Presión osmótica: próxima a la
sangre (iones)
— Anaerobiosis: consumo rápido de
oxígeno
— Temperatura: 38-42 ºC
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DIGESTION EN RUMIANTES
PRINCIPALES MICROORGANISMOS
ANAEROBIOS DEL RUMEN :
1. BACTERIAS
109-1010 por ml.
Más de 60 especies
Número y proporción según dieta
2. PROTOZOOS
106 por ml.
Mayor tamaño
Ciliados
- Grupos:
ISOTRICHIDAE U HOLÓTRICOS
· Isotricha y Dasytricha
· Ovalados
· No ingieren partículas ni celulosa
OPHYOSCOLECIDAE U OLIGÓTRICOS
· Entodinium, Diplodinium, Epidinium y
Ophryuoscolex
· Tamaño y forma variable
· Ingieren partículas y celulosa
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RUMIACION
Rumia Comprende un ciclo de actividad de 4 fases : la regurgitación de la
ingesta seguida de una remasticación, reensalivación y nueva deglución.
Ocurre principalmente cuando el animal descansa y no come.
Importancia?
Disminuir el tamaño de partícula del alimento y aumentar la superficie para la
fermentación microbiana.
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QUE HACEN LOS M.O.
Funciones de los m.o. :
-digiere la fibra a AGV
-fabrica proteina
-fabrica vitamins K and B complex
La funcion del rumen es alojar microorganismos, similar en conejos, caballos
y cuy,
Sintetiza todas las vitaminas del complejo B, excepto vitamin B12, que requiere Co para
su sintesis
Sintetiza todas las vitaminas del complejo B, excepto vitamin B12, que requiere Co para
su sintesis
Produce amonio: Utilizado por los m.o. para formar AA´s, pueden absorver AA´s para
formar proteinas, pero parcialmente, satisfacen las necesidades de proteinas por digerir
algunos m.o. Esto ocurre en el abomaso e intestino delgado
Microorganismos en estomago convierte celulas vegetales en energia utilizable.
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Celulosa es degradado por accion
microbiana.
Los Acidos Grasos Volatiles de Cadena
Corta (AGVCC) Aportan con el 60-80%
de la energia dietaria de rumiantes
(dependiendo de la dieta).
Grandemente absorvidos desde el
estomago en la circulacion portal
hepatica.
Pricipales SCFAs:
› Propionato: utilizado por el
higado (gluconeogenesis)
› Acetato utilizado para energia y
formar grasas
› Butirato utilizado para energia
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DIGESTION FERMENTATIVA (FERMENTACION)
Todos los mamiferos tienen alguna capacidad fermentativa que les permite la
utilizacion de la fibra ingerida.
La importancia comparativa de la fermentacion esta relacionada a la fraccion de la
digesta total contenido en los compartamentos fermentativos del TGI i
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•
Bacterias anaerobicas, protozoa y hongos producen enzymas que degradan
la cellulosa, hemicellulosa y pectina
Productos de la digestion fermentativa :
› Acidos grasos de cadena corta (SCFAs), tambien llamados acidos grasos
volatiles (VFAs)
› Gas metano
› CO2
› Amoniaco (NH3)
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FERMENTACION EN MONOGASTRICOS
Limitada fermentación post gástrica (colon, recto y ciego)
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TIEMPO DE TRANSITO EN EL TGI
Cantidad de tiempo que toma el
material para viajar de una parte
del intestino a otra.
Cuando el material viaja a traves del
intestino muy rapido, disminuye el
tiempo de transito intestinal.
Cuando el material viaja a traves del
intestino lento, se incrementa el
tiempo de transito intestinal.
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ESTRUCTURA DEL ILEON: BASE DE LA ABSORCION
The villi increase the surface area
of the ileum for the absorption.
The villi are finger like projections
into the lumen of the gut. The
villi increase the available surface
area by ten times.
The crypts contain the secretory
cells of intestinal secretion.
Mucosa is a mucus secreting
membrane.
The circular and longitudinal
muscles combine to create the
contractions known as peristalsis
that maintains the movement of
chyme along the alimentary
canal.
The serosa is a tough outer
membrane 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 ABSORCION
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DIFUSION FACILITADA
Facilitated diffusion: possible water soluble minerals and vitamins
•Larger molecules move passively through the membrane via channel proteins
•These proteins have large globular structures and complex 3d-shapes
•The shapes provide a channel through the middle of the protein, the 'pore'
•The channel 'shields' the diffusing molecule from the non-charged regions of the
membrane.
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TRANSPORTE ACTIVO
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.
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ENDOCITOSIS
Endocytosis: probably pinocytosis
The formation of tiny vesicles by endocytosis is normally referred to as pinocytosis.
This increases the surface area for the processes of active transport and diffusion.
This should not be confused with fatty acids absorption which in which the micelle
fuses with the cell membrane. The absorption of actual lipids would occur passively
across the cell membrane.
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PARTICULARIDADES DE LA ABSORCION
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 by
different 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 the
ileum
•Dietary monosaccharides are absorbed by active transport in the ileum
•Water is absorbed by osmosis in the ileum and colon.
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IMPORTANCIA DE LA EGESTION
- Cellulose is an undigested insoluble polysaccharide which forms the
fibre in the diet.
-Bile Pigments colour the egested faeces and are eliminated.
-The composition of these pigments often reflect liver function and are
sometimes used as a diagnostic for that organs function.
-The gut retains its own bacterial populations with their own ecology.
-There is evidence to believe that normal digestion requires the presence
of these populations and that factors that affect these populations
(antibiotics) can lead to digestive disorders.
-Intestinal cells are constantly removed from the lining of the gut.
-Gut epithelium has a structure similar to that of skin, with which it
shares a common embryological origin. Such cells are egested. An
interesting aside is that the collection of animal spoor (faeces) has aided
the genetic study of populations like lions. This is because the animals
DNA can be extracted from the epithelial gut cells within the faeces.
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CLASIFICACION DE LOS ANIMALES POR SU INGESTA DE
ALIMENTOS PREFERIDO
1. Monogastricos ó norumiantes
2. Rumiantes o:
- Pre-gastrico
fermentacion (craneal)
- Post-gastrico
fermentacion (caudal)
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FERMENTADORES PREGASTRICO
Clases
Rumiantes
Especies
Vacuno, oveja
Ciervo, antilope,
camello
Norumiantes
Mono colobine,
hamster
Kangaroo, hippo
Habito dietario
herbivoros q pastan
herbivoros selectivos,
incluyendo folivores and
frugivores
herbivores selectivos
Herbivores selectivos y que
pastan
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VENTAJAS FER.
PREGASTRICO
•
•
•
•
Hacen un mejor uso de los nutrientes
alternativos
– Cellulosa
– Nitrogeno no proteico
Capacidad para detoxificar algunos
componentes venenosos:
– Oxalatos, cyanide, alkaloides
Uso mas efectivo de los productos
finales de fermentacion
– AGV, proteina microbial,
vitaminas complejo B
Permite a los animales salvajes
comer y correr.
DESVENTAJAS FER.
PREGASTRICO
Fermentacion es ineficiente: La energia
es perdida como % del valor calorico
totaL. 5-8 % de energia se pierde como
Metano, como calor de fermentacion (5-6
%).
Eficiencia relativa es dependiente de la
NDF de la dieta.
Proteina: Algo de amonio resulta de la
degradacion microbial que podria ser
absorbido y excretado. 20% del
nitrogeno en los microbios esta en la
forma de acidos nucleicos.
-Rumiantes son susceptibles a toxinas
producidos por los microbios del rumen
– Nitratos a nitritos
– urea a amonio
– Carbohidratos no estructurales a acido
lactico.
– tryptofano a 3-methyl indol
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FERMENTADORES POSTGASTRICO
Clases
Especies
Digestores cecal Capybara
Conejo
Rata, raton
digestores
colonicos
Sacculados
Unsacculated
Elephant, caballo, zebra
Monos del nuevo mundo
cerdo, humano
Panda
Perro, gato
habito dietario
Pastan
herbivores selectivos
Omnivoros
Pastan
Folivoros
Omnivoros
Herbivoros
Carnivoros
FERMENTACION COMPARATIVA POR ESPECIES
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CAPACIDAD DIGESTIVA COMPARATIVA
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TGI DE LAS AVES
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ORGANOS ACCESORIOS DEL TGI EN AVES
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TGI: FUNCION Y ESTRUCTURA
To improve gut health, a clear understanding of the STRUCTURE AND FUNCTIONALITY OF
THE GUT is important..
Birds also have high numbers of intestinal villi and high EPITHELIAL TURNOVER RATE (48 TO
96 H), and rapid inflammatory response (less than 12 hours, as compared to 3-4 days in
mammals), which makes them more susceptible to disturbances in absorptive capacity than
mammals.
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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CRECIMIENTO ALOMETRICO
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SALUD INTESTINAL – NUTRICION
La salud intestinal tiene una gran influencia sobre el performance del
crecimiento de las aves, ya que afecta la digestión de alimento, absorción de
nutrientes, y utilización de proteína y energía. La salud intestinal y la nutrición
son estrictamente dependiente uno del otro. La óptima utilización de
nutrientes de la dieta no puede ser realizado a menos que el intestino este en
un estado saludable. Sin embargo, algunos factores dietarios pueden
predisponer a las aves a una pobre salud intestinal o exacerbar un problema de
salud intestinal. A causa que la calidad del alimento y la salud intestinal están
estrictamente asociados uno del otro, los AVICULTORES y los VETERINARIOS
tienden a “point fingers” en los fabricantes de alimentos y nutricionistas (o
viceversa) siempre que los problemas de salud intestinal surjan.
Los factores que afectan la salud intestinal incluyen: ENFERMEDADES
ENTERICAS, ESTRÉS AMBIENTAL, APETITO, FORMA DEL ALIMENTO, TOXINAS EN
EL ALIMENTO, EXCESIVO NIVELES
DE NUTRIENTES O 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
El TGI constituye una extensa superficie en la que se produce un CONTACTO ÍNTIMO entre
el organismo 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
tiempo EXCLUYE 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
mucosa, estrecha unión entre las células epiteliales, proteo lisis, resistencia contra la
colonización por bacterias patógenas y el eje intestino hepático.
La defensa inmunológica del intestino delgado incluye la PRODUCCIÓN DE
INMUNOGLOBULINAS secretoras, 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
de las vellosidades, 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 al funcionamiento normal del tubo intestinal.
La I.I. optima es, desde el nacimiento hasta el final del ciclo productivo, es
esencial para obtener el MÁXIMO POTENCIAL GENÉTICO de crecimiento
y utilización eficiente de los nutrientes del alimento en base a un TGI
saludable, una altura máxima de la villi, maxima densidad de la villi y
máxima área absortiva.
Es necesario estimular un desarrollo temprano, integro y completo del
aparato GTI, glándulas y órganos anexos para maximizar la digestión y
absorción de nutrientes.
intactness del intestino manteniendo su ESTRUCTURA Y FUNCIÓN o
simplemente un intacto y sano intestino (Dr. Harish V. Dharne, head of
Avitech’s).
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IMPORTANCIA DE LA INTEGRIDAD INTESTINAL (I.I.)
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MANTENER UN TGI SANO, ASEGURA:
Proper digestion and absorption of valuable feed nutrients
Less wastage of nutrients
Minimum foul odor
Provides resistance against entero-pathogens
Checks mortality and morbidity losses
Optimizes feed conversion ratio
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INTEGRIDAD DEL INTESTINO
El TGI constituye una extensa superficie en la que se produce un CONTACTO ÍNTIMO entre
el organismo 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
tiempo EXCLUYE 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
mucosa, estrecha unión entre las células epiteliales, proteo lisis, resistencia contra la
colonización por bacterias patógenas y el eje intestino hepático.
La defensa inmunológica del intestino delgado incluye la PRODUCCIÓN DE
INMUNOGLOBULINAS secretoras, 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
de las vellosidades, 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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FACTORES QUE AFECTAN LA I.I.
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MAINTAINING GUT INTEGRITY
BY 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 greatly influencing nutrient utilization and growth of the animal.
Gut health problems arise due to improper nutrition and an unhygienic
environment especially 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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NATURAL PHYSICAL BARRIERS THAT HELP TO MAINTAIN
INTESTINAL INTEGRITY
Physical barriers protect against the entry of foreign materials and organisms into the
bloodstream and access to other viscera thus helping intestinal integrity. On occasion due to
improper nutrition or an unhygienic 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
fungal invasion. It is broken by some enzymes (eg. mucinolytic, urease). Poultry feeds with
under cooked soy meal may contain urease.
2. Gut epithelial cells (enterocytes): These cells form a semi-permeable surface that selectively
allows passage of fluid, electrolytes, and dissolved nutrients. Every epithelial cell in the
digestive tract is part of a continuous physical barrier. When organisms and toxic agents
damage epithelial cells, the integrity of this protective barrier is broken.
3. Fluid secretion: fluid having large amounts of water mixed with electrolytes. The fluid in the
upper small intestine 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 agents or chemicals (endogenous or exogenous) that may breach the mucosal barrier.
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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
immune system 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 like
handling, transportation, overcrowding, abrupt changes in environment etc.
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, grain
engorgement, microbial load in feed etc. affect gut health. The nature of the diet, for
example presence of non-starch polysaccharide (NSP) especially soluble fractions in the
diet provide substrate for the growth of undesirable bacteria and accumulation of
fermentation products affecting 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 gut
integrity severely. Infections, injuries etc. also affect gut health.
f. Gut micro flora: The rich bacterial community that make up the gut micro flora play an
important role for the host through changes in the morphology of gut, nutrition,
pathogenesis of enteric diseases, immune response and alterations in colonization
resistance. The shift in composition of this microflora results in production and
efficiency losses often in the absence of any clinical signs. Useful microbes (commensal
bacteria) in gut play a positive role in controlling the gut flora and stimulate the
development of the gut wall. Hence, microbial balance of gut is utmost important in
maintaining gut integrity.
g. Beak deformity: Beak deformity preventing proper feed consumption may impair gut
health.
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CAUSA MAS COMUNES DE LA MALA I.I.
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AGENTES ETIOLOGICOS MAS COMUNES DE LA ENTERITIS
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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.
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 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-oligosaccharides (XOS), mannan-oligo-saccharides (MOS) and galacto-oligosaccharides (GOS).
4. 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 preand probiotics are termed as synbiotics.
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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, ayuda a los procesos digestivo, estimula el desarrollo del
sistema inmune entérico y puede proteger contra la invasión de patógenos.
Sistema inmune mucosal: la mucosa intestinal tiene una función de barrera, pero
también puede generar una respuesta inmune protectiva contra patógenos. El
TGI alberga el mas grande numero de células inmunes en el cuerpo.
Fotos de: Collet, S. University of Georgia - 2008
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TABLA 2. CANTIDAD DE BACTERIAS (LOG CFU/ G) EN EL TRACTO INTESTINAL DEL
POLLO EN DIFERENTES EDADES.
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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
Cervantes, Phibro Animal Health Corp. EUA, 2011
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VD was higher when probiotics based on Bacillus subtilis were used together with prebiotics
based on MOS, compared to the use of probiotics based on Bacillus sp alone. It was also
higher in the birds fed the probiotics containing a bacterial pool compared to those
containing only one culture (probiotic 1). The results suggest that, in order to obtain higher
VD (consequently higher nutrient absorption area), it is necessary to use MOS-based
saccharides when probiotics based in only one bacterial culture are used. On the other
hand, they would be not necessary if the probiotics has many bacterial cultures, as
observed for probiotic 2.
Cervantes, Phibro Animal Health Corp. EUA, 2011
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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 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 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 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 rapido de agua y alimento de buena calidad, para favorecer el desarrollo y
maduracion precoz del tubo intestinal .
Verificacion diaria del consumo (agua y alimento) mediante la palpacion del buche.
Uso de enzimas para mejorar digestibilidad y reducir la viscocidad de cereales con
contenido alto de polisacaridos no almidonados.
Verificacion y rechazo de materias primas para la fabricacion 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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NUTRICION 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:
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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ASISTENCIA OBLIGATORIA