nutrition and gastrointestinal parasitism in ruminant production

14 Pages·2009·0.06 MB·English

REVISIÓN BIBLIOGRÁFICA
NUTRITION AND GASTROINTESTINAL PARASITISM IN
RUMINANT PRODUCTION
NUTRICIÓN Y PARASITISMO GASTROINTESTINAL EN PRODUCCIÓN DE RUMIANTES
Basabe, J.1,2 *, D.F. Eiras1,2 and J.R. Romero1,3
1Cátedra de Parasitología y Enfermedades Parasitarias. Departamento de Epizootiología y Salud Pública.
Facultad de Ciencias Veterinarias. Universidad Nacional de La Plata. CC 296 (B1900AVW). La Plata.
Argentina. *Corresponding author: [email protected]
2Laboratorio DIAP. Inca 109 (B1836BBC) Llavallol. Buenos Aires. Argentina.
3Centro de Diagnóstico e Investigaciones Veterinarias (CEDIVE). Alvear y Salta (B7130AGC). Chascomús.
Buenos Aires. Argentina.
ADDITIONAL KEYWORDS PALABRAS CLAVE ADICIONALES
Ruminant production. Parasitism. Producción de rumiantes. Parasitismo.
SUMMARY
In order to increase ruminant performance, trol de los parásitos. Los parásitos producen
producers have to deal with two main obstacles: alteraciones que afectan desde el consumo de
health and nutrition. Resistance to traditional alimentos hasta la utilización de los nutrientes
anthelmintic drugs and the increasing "organic ingeridos, interfiriendo gravemente en la produc-
production" of food are demanding alternative ción. La "inmunonutrición", se considera una me-
parasite control methods. When cattle parasites dida potencial y sustentable de control antipara-
alter food intake and cause a lower use of the sitario. La disponibilidad de proteínas, vitaminas y
absorbed nutrients, they greatly interfere with minerales es un importante factor para optimizar
productivity. "Immunonutrition" is considered a la productividad y la resistencia del hospedador a
potential and sustainable method of antiparasitical ciertas parasitosis. Los metabolitos secundarios
control. Protein, vitamin and mineral availability are de algunas plantas pueden tener efectos
important factors to optimize production and the antiparasitarios para los animales que las pasto-
resistance of the host to certain parasites. rean. El objetivo del presente trabajo es, basado
Secondary substances of some plants can have en revisiones de trabajos de investigaciones pre-
antiparasitical effects in animals grazing on them. vias, señalar algunas de las interacciones exis-
The purpose of this work is to, based on a review tentes entre nutrición y parasitismo en rumiantes
of previous research studies, point out some of y mostrar cómo un manejo nutricional racional
the existing interactions between nutrition and puede ser considerado un método eficiente de
parasitism in ruminants, and to show how a control antiparasitario.
rational nutritional management can be seen as an
efficient antiparasitical control method.
INTRODUCTION
RESUMEN Demographic growth, particularly seen
in developing countries, needs a parallel
En pos de aumentar el rendimiento animal, los
and compensatory growth in food produc-
productores se enfrentan con dos grandes obstá-
tion systems. This expansion in animal
culos: sanidad y nutrición. La resistencia a las
production has to be based not upon raising
drogas antihelmínticas tradicionales y el incre-
mento en la producción orgánica de alimentos the number of animals or on increasing the
están llevando a buscar alternativas para el con- amount of forage given to them but on
Recibido: 25-8-08. Aceptado: 15-9-09. Arch. Zootec. 58 (R): 131-144. 2009.
BASABE, EIRAS AND ROMERO
improving the efficiency of production with rotation, supplementary feeding to improve
the given resources. Increasing cattle the nutritional condition or the utilization of
production has generally two main obstacles: alternative forages with antiparasitical
nutrition and health. Depending on the effects (Coop and Kyriazakis, 2001; Hoste
environment, malnutrition or parasitic et al., 2006).
diseases and sometimes both together can Apart from the nutritional value of plants,
limit production efficiency (Knox and Steel, there are substances in some of them that
1996). can have beneficial or undesirable effects
Parasites, especially gastrointestinal for animals feeding on them (Hoste et al.,
nematodes, can be considered one of the 2006). The effects of certain plants' compo-
main threats for health and production of nents on parasites and on animal perfor-
cattle in extensive production systems mance are being investigated (Nguyena et
(Coop and Kyriazakis, 2001; Louvandini et al., 2005; Suleiman et al., 2005; Tzamaloukas
al., 2002; Suleiman et al., 2005). They cause et al., 2005; Knox et al., 2006). Tannins are
considerable losses in the production in the secondary metabolites associated to the
whole world, mainly in young animals and defence mechanisms of plants against
periparturent females (Larsson et al., 2006). insects and mammals and, though they can
Economic losses are related to a decrease in have negative effects for the animal that
fertility, in food intake and in weight gain consumes them, ruminants can take
but also to the lower milk production, to advantage of the presence of these
more expensive treatments and control compounds (Athanasiadou et al., 2001).
methods and to the death of severely The nutritive status of the animals can
parasitised animals (Romero and Fonrouge, influence their resistance to parasitosis
1987; Knox et al., 2006). (Bricarello et al., 2005; Muturi et al., 2005).
Due to the economical losses caused by An improvement in immunocompetence due
parasites it is necessary to establish to an adequate diet (immunonutrition) is
effective control methods. Traditionally, considered a sustainable potential control
pharmacological products have been used method (Muturi et al., 2005). On the other
to control parasites (Athanasiadou et al., hand, the degree of each animal's genetic
2000; Min and Hart, 2003; Muturi et al., resistance influences the effect that
2005). These methods, however, offer some supplementation may have in its response
difficulties because of the growing resistan- to infections (Bricarello et al., 2005).
ce to the commonly used anthelmintic drugs. Independently of their localization, all
Furthermore, the high costs of the phar- parasites may have an indirect impact on the
macological products and the increasing host's nutritional status; the gastrointestinal
demand of the population to be provided parasites are, however, those that provoke
with food without residues, mainly those more notorious consequences because of
that could be toxic for the environment, their direct contact with nutrients.
stimulate to look for alternative non- Ruminants acquire the infecting forms
chemical strategies to control parasites of the gastrointestinal parasites while they
(Coop and Kyriazakis, 1999, 2001; Kyriazakis feed, which constitutes the beginning of a
and Houdijk, 2006). Non-pharmacological complex interrelation between two factors:
tools are based on the use of vaccines, nutrition and parasites (Hutchings et al.,
breeding of resistant genotypes, biological 2001).
control, (Van Hountert and Sykes, 1996), Two different approaches can be made
grazing of alternative hosts, manual removal to the interaction between parasitism and
of faeces, frequent and rational pasture nutrition. On the one hand, the influence of
Archivos de zootecnia vol. 58(R), p. 132.
NUTRITION AND GASTROINTESTINAL PARASITISM IN RUMINANT PRODUCTION
parasites on the host's metabolism and on digestibility, nitrogen retention and
the other, the effect of nutrition on parasite protein, mineral and energy metabolism
populations and on the ability of the animal and utilization (Rossanigo et al., 1992;
to face and get over the infection (Coop and Muturi et al., 2005) resulting in a lower
Holmes, 1996; Coop and Kyriazakis, 1999). performance of animal production. In
In this review, we have analyzed parasited animals the processes leading to
information obtained mostly by experimen- preserve the homeostasis, such as the
tal means and based on studies performed plasmatic protein synthesis, mucus produc-
generally on gastrointestinal parasites of tion, reparation of the gastrointestinal tract
sheep. However, the general concepts can and immunocompetence, are privileged over
be applied to other animals and other parasite other functions such as skeletal growth
species (Coop and Kyriazakis, 1999; (Muturi et al., 2005), soft tissue deposition
Kastelic, 2006). and milk production (Coop and Kyriazakis,
The aim of the present study is to 1999).
establish some of the existing connections There seems to be a threshold of
between nutrition and parasitism in rumi- exposition beneath which there is no
nants, considering both the influence that significant reduction of appetite (Kyriazakis
parasites might have on the host's nutrition et al., 1998; Nari and Fiel, 1994). In a study
and the predisposition to parasitism in conducted by Rossanigo et al. (1988) a
different nutritional situations and to show reduction of 15% in food intake was recorded
why a rational nutritional management can in parasited calves with gastrointestinal
be used as an efficient antiparasitical con- nematode burdens lower than 300 eggs per
trol method. gram (epg) compared to non-parasited
animals and of 18% in animals with more
EFFECTS OF PARASITES ON THE than 300 epg compared to controls. A
HOST reduction of food intake is believed to take
place with burdens above 150 epg. In another
Gastrointestinal parasitoses are wides- study from Rossanigo et al. (1992), a
pread and appear in ruminants of all ages reduction of 8.36% in the dry matter intake
(Rossanigo et al., 1992) although it is was proved in parasited animals compared
generally accepted that adults are relatively to a control group. After 329 days the non-
resistant to internal parasites. Very young parasited animals had gained 26 kg more
animals are generally more affected by than the parasited ones. The appetite
coccidia, Cryptosporidium and Giardia depression can vary between 15-20%
than by gastrointestinal nematodes (Lardy according to Coop and Kyriazakis (1999),
and Stoltenow, 2001). Infections can present while other authors state that reductions of
a variety of clinical signs, that range from no up to 30% (Van Hountert and Sykes, 1996)
clinical manifestation at all to diarrhoea, or even 50% (Knox et al., 2006) can exist.
anorexia and weight loss leading to an Several hypotheses have been sugges-
impairment growth, decrease in productivity ted to explain the reduction in food
and, in severe cases, to death. Subclinical ingestion. On the one hand, the lesions
infections represent the majority of cases could produce certain pain and digestive
and cause economical losses due to the discomfort, which would have a negative
suboptimal performance of the animals. intake impact (Knox et al., 2006; Rossanigo
As a consequence of the action of the et al., 1988). On the other hand, the damage
parasites and of the immune response of the produced by the parasites could be located
host, several nutritional parameters can be in areas related to the tension regulation
modified, such as food intake and nutrient and feeling of plenitude which reduces the
Archivos de zootecnia vol. 58(R), p. 133.
BASABE, EIRAS AND ROMERO
ingestion. The alterations in the composition suggests the presence of some inhibitors,
of the food and the protein-energy relation amongst which the CRF has been mentioned
in the absorbed nutrients, in the availability (Van Hountert and Sykes, 1996).
of amino acids, in the intestinal pH, in the Armour et al. (1974) studied the effect of
reticulo-ruminal motility and in the hormo- parasites on the stomach secretion. The
nal metabolism of the digestive tube would injuries in the stomach produced by O.
also favour a lower intake of food (Rossanigo circumcincta and T. axei alter the normal
et al., 1988; Coop and Holmes, 1996; Knox function of the glands. This decreases the
et al., 2006). production of hydrochloric acid (HCl),
Amongst the gastrointestinal hormones, increasing the gastric pH and not allowing
the colecistocinine (CCC) is considered one the activation of the pepsinogen, with the
of the most important factors in the concomitant absence of protein digestion
alimentary behaviour (Nari and Fiel, 1994). (Min and Hart, 2003). The decrease in the
This hormone is produced by the cells that production of HCl can cause some delay in
cover the first part of the small intestine. It the abomasal flow, as acidity is an important
is released at the stimulus produced by the stimulus for the rumino-reticular contraction
presence of food; it produces the contraction (Nari and Fiel, 1994). Studies performed in
of the gall bladder and a plenitude feeling at cattle experimentally infected with O.
the central nervous system (Rossanigo et ostertagi have shown a relation between
al., 1988; Van Hountert and Sykes, 1996). the reductions in food consumption, the
The cellular damages caused by parasites increase in the concentration of blood
can produce a great release of CCC reducing gastrine and the decrease in the food
appetite. However, this is not the only passage. The increase of gastrine reduces
mechanism involved in anorexia induced by the reticular-ruminal motility producing
parasites as a reduction in appetite is also stasis of food and reduction of appetite
mentioned in sheep parasited by Fasciola (Coop and Holmes, 1996).
hepatica and bovines with Haemonchus During infections two classes of proteins
placei which are parasites not located in the are lost with the faeces: the exogenous not
small intestine (Rossanigo et al., 1988). absorbed proteins and, most important, the
The cytokines cascade associated to endogenous (the corporal protein) as cells
the immune response can also be related to coming from the desquamation of the
anorexia (Knox et al., 2006). It is known that epithelial cover or as plasmatic proteins of
in laboratory animals the tumoral necrosis high biological value (specially albumins
factor (TNF) and the interleukin 1 produce and globulins) that escape from the blood
anorexia. The hypothalamus is an important vessels towards the gastrointestinal lumen
place of integration of central and periferical through the damaged zone, because of the
signals involved in the control of ingestion. lack of sealing of the intercellular bridges
Several neuropeptides would be involved (Coop and Holmes, 1996; Knox and Steel,
in the appetite control, such as neuropeptide 1996; Knox et al., 2006). Some parasites,
Y, strong appetite stimulator, and the such as H. contortus, can produce an
corticotrophin release factor (CRF) as an important loss of plasma proteins as a
inhibitor (Coop and Holmes, 1996). It has consequence of their haematophagic habits.
been observed that in laboratory mice an The infiltration and inflammation of the
increase in the expression of the gene of the mucosa produced by some nematodes alters
neuropeptide Y occurred in a parasitic the continuity of the desmosomic unions
infection. The fact that no concomitant between the epithelial cells with the
increase in the food intake occurred concurrent passage of proteins towards the
Archivos de zootecnia vol. 58(R), p. 134.
NUTRITION AND GASTROINTESTINAL PARASITISM IN RUMINANT PRODUCTION
lumen of the organ and, eventually, the places of the lesions so there will not
pepsinogen to the plasma (Romero and necessarily be an altered nitrogen faecal
Boero, 2001). The absence of pepsin activity excretion. Moreover, the enteric protein
due to a pepsinogen loss or to a decrease in losses are balanced by an early increase
the secretion of the HCl necessary to in the hepatic synthesis of albumin.
activate pepsinogen into pepsin occurs not Afterwards, however, this synthesis decli-
in all nematodes but mainly in Ostertagia, nes and the protein losses produce hypo-
Haemonchus and Trichostrongylus. Another proteinemia (Nari and Fiel, 1994).
source of endogenous protein loss is the The hypoproteinemia and the nitrogen
increase in the production of mucopro- loss affect the protein deposition in the
teins (Rossanigo et al., 1988; Coop and growing animal, retarding the body deve-
Kyriazakis, 2001; Knox et al., 2006). These lopment (Rossanigo et al., 1988). The
losses can range from 20 to 125 g of protein reduction in the ingestion, incomplete
per day in infections by T. colubriformis absorption in the intestine and increase
in sheep (Coop and Kyriazakis, 1999). In protein turn-over, decrease the raw materials
this way, there is a net movement of proteins for the productive processes (Nari and Fiel,
from the productive processes such as 1994; Knox and Steel, 1996). The intestinal
production of meat, bone, milk and wool protein synthesis is increased as well as the
towards the synthesis of plasmatic proteins, plasmatic and structural protein synthesis,
reparation of the gastrointestinal tract and while muscle, milk and wool protein
mucus production (Coop and Holmes, 1996; synthesis are reduced (Knox and Steel,
Knox and Steel, 1996; Knox et al., 2006). The 1996).
protein recycling has an energetic cost (Van The average of exogenous proteins that
Hountert and Sykes, 1996; Coop and are absorbed is not much less than in non-
Kyriazakis, 1999, 2001), which goes in parasited animals as the intestine region not
detriment of the productive performance of affected is more active and compensates for
the animals. The increase in the mucus the lack of absorption of the affected part
production, rich in treonine, serine and (Rossanigo et al., 1988; Knox et al., 2006).
proline, can result in a deficiency of these Rossanigo et al. (1988) state that the poor
amino acids for other processes. On the absorption and the protein losses would
other hand, the mucus is resistant to not be enough to explain the low performan-
digestion and reabsorption; therefore, once ce. This increases the importance given to
its components are formed, they will not be anorexia in the parasitosis as the main cause
available for the synthesis of other proteins. of the lower productive performance.
The immune response that takes place It is estimated that to make up for the
against the infection requires certain amino protein losses of the infection 17 g/day of
acids, especially the sulphured ones and, metabolizable protein above the main-
therefore these will not be available for tenance requirements are needed, therefore
other processes if they are used for immune the effects of the parasitosis will be
purposes. The availability of amino acids worsened in times of protein shortage in the
for the body tissues can be reduced up to pastures, during pregnancy and lactation
30% because of the protein loss (Coop and (Knox et al., 2006).
Kyriazakis, 1999). Gastroenteritis caused by helmints can
Although the infections can cause local have severe consequences in the bone
changes that alter the gastrointestinal growth. The absorption and retention of
digestion and absorption functions, there phosphorus is severely reduced. There exists
are compensatory increases in the distal an endogen loss of calcium and a reduction
Archivos de zootecnia vol. 58(R), p. 135.
BASABE, EIRAS AND ROMERO
in the absorption of this mineral due to a parturent females. Nutrition has the "power"
lower demand as the growth of the bones is to regulate the rate of acquisition and
reduced (Van Hountert and Sykes, 1996; expression of immunity. This way, immuno-
Knox et al., 2006). nutrition plays an important role in control
Van Hountert and Sykes (1996) state strategies, alone or associated with other
that the absorption of magnesium is not non-chemical strategies. Many studies that
altered, while Knox et al. (2006) mentions a relate the effects of nutrition to the immunity
decrease in the absorption of this mineral in are based on the metabolizable protein, as
gastrointestinal parasitoses. many of the immune system components
In the abomasal infections there is a are proteins in nature (Kyriazakis and
reduction in the copper absorption (Coop Houdijk, 2006), for instance the immunoglo-
and Holmes, 1996; Van Hountert and Sykes, bulins, mucoproteins and the interleukins.
1996). The infection by O. circumcincta in Once the requirements for growth are
sheep affects the metabolism of copper, satisfied, the immune response becomes
especially because of the increase of the more effective with the addition of
abomasal pH. The reduction of the abomasal supplementary protein. This would explain
acidity reduces the copper solubility and the relative immaturity in the parasited
therefore the captivity of the mineral by the young animals that have greater demands
liver (Coop and Holmes, 1996). (Coop and Holmes, 1996).
There is abundant evidence concerning
EFFECTS OF THE NUTRITION ON the importance of increasing the protein
PARASITES level more than the energetic one (Coop and
Kyriazakis, 1999, 2001), even though in
The effect of nutrition over the parasite-
animals severely affected by famine the
host relationship is an alternative to
increase in the energetic level will certainly
chemoprophylaxis. Nutrition can influence
help to overcome the infection. In an
the development and consequences of
experience done in sheep, it was observed
parasitism in three different ways: it can
that given two isoenergetic foods, the two
increase the ability of the host to overcome
sheep infected with T. colubriformis chose
the adverse consequences of parasitism; it
can increase the ability of the host to contain the one with the greater protein content,
and overcome the parasitism limiting the while the control animals did not do such
establishment, growth rate, fecundity and/ selection (Coop and Kyriazakis, 2001).
or persistence of the parasites population; The expression of the resistance to
last of all, it can directly affect the parasites gastrointestinal nematodes competes with
population through the ingestion of natural other functions when there is scarceness of
antiparasitical compounds (Coop and nutrients. It is expected that the animals will
Kyriazakis, 2001). privilege the maintenance of the corporal
It is known that the raise in the dietary protein in moments of shortage of food, as
protein enhances the resistance to the it ensures the survival in the short term.
infections through an increase in the This includes reparation and replacement
immunity to parasites, not allowing them of damaged tissues. Although the immune
to establish, reproduce and survive or at system was earlier considered as part of the
least reducing the consequences of the "maintenance" there are studies that
subclinical parasitosis. In times of protein demonstrate that there are aspects of the
shortage, the supplement in the diet can immunity that are sensitive to dietary
reduce the number of gastrointestinal changes. Once the maintenance necessities
nematodes in growing animals and peri- are covered, growth, reproduction and
Archivos de zootecnia vol. 58(R), p. 136.
NUTRITION AND GASTROINTESTINAL PARASITISM IN RUMINANT PRODUCTION
immunity to parasites will be privileged. In lambs in twin-sheep the count of epg and
young animals infected for the first time, the the parasite burden was reduced in one
acquisition of immunity will be privileged week and in more than 50%, reaching the
over growth; otherwise they would die from lowest levels of the supplemented sheep
the parasitosis before they can reach (Houdijk et al., 2006).
maturity age. Once immunity is acquired, The degree of genetic resistance of the
growth and reproduction are privileged over host can influence the response to food
immunity, as these functions will guarantee supplementation (Coop and Holmes, 1996;
the preservation of the genetic material Kahna et al., 2000). The benefits of a supe-
(Coop and Kyriazakis, 2001; Houdijk et al., rior genotype are not lost in a diet poor in
2003; Kyriazakis and Houdijk, 2006). The proteins while a diet rich in proteins can
initial establishment of nematodes and the help a sensitive genotype to overcome the
acquisition of immunity in young animals infection (Coop and Holmes, 1996). In a
are not influenced by supplementation, as study of Bricarello et al. (2005) it was
they already have more priority than growth. demonstrated that breeds of sheep that were
On the other hand, the expression of genetically more resistant reacted better
immunity is very much affected by the protein than the sensitive breeds to an increase in
content of the diet (Coop and Kyriazakis, the dietary protein when they were experi-
2001). Once the growth rate begins to decli- mentally infected with H. contortus.
ne, the immune function can be fulfilled in Although both breeds resisted better the
an efficient manner (Coop and Holmes, 1996). infection when increasing the protein in the
The increase in the metabolizable protein in diet, the resistant breed was the only one
sheep infected with O. circumcincta that showed a reduction in the parasite
increased the milk production at the burden.
beginning while the reduction in the parasite The nutritional levels that are poor in
burden took place only at the end (Houdijk energy and proteins affect the immune
et al., 2000; Kyriazakis and Houdijk, 2006). response mediated by cells. Both the number
The immune break down in the peri- and the morphology of the effector cells are
parturent females and during the beginning severely affected. In the nutritional levels
of lactation is explained by the priority that abruptly reduced as in those kept
reproduction has over immunity and in permanently low, a reduction in the
moments of insufficiency of food the former phagocytosis, in the complement system
is privileged. These females have great and in the opsonisation can be observed.
protein demands and the supplementation The alteration of the humoral immunity in
in these stages reduces the epg (Coop and malnutrition cases is the indirect result of
Kyriazakis, 2001). That is to say, the immune the depression in the cellular response (Nari
break down is caused by the greater and Fiel, 1994). In parasite infections, the
importance that reproduction has over im- role of the T helper lymphocytes seems to
munity. Therefore, if immunity is "penalized" be important in the immune response (Koski
in moments of deficiency, these functions and Scott, 2001).
will be benefited when supplemented with In an experimental work conducted by
proteins, reducing the epg, burden and Gennari et al. (1995), the group of calves
fecundity of parasites. The protein supple- that consumed a diet with high protein
mentation in these cases is clearly remarked content showed a lower parasite burden,
as a good antiparasitical non-chemical con- less clinical signs and less biochemical and
trol method. In an experimental study it was hematological alterations than the group of
observed that when removing one of the animals maintained with a low protein level.
Archivos de zootecnia vol. 58(R), p. 137.
BASABE, EIRAS AND ROMERO
Similar observations were made by Knox acquisition of the infection with T.
and Steel (1996) and by Coop and Kyriazakis colubriformis (Kahna et al., 2000). Besides,
(2001). The first authors observed, however, the establishment of the abomasal and in-
that more than the protein content in the testinal larvae seems to be independent
diet what seemed to have more influence from the protein offer (Coop and Holmes,
would be the immunity level previously 1996; Kahna et al., 2000). Chronical
acquired. Despite this, the level of proteins haemonchosis during periods of poor
in the diet would indeed be important in alimentation would indicate that there exists
sheep parasited by F. hepatica and H. an association between nutrition and the
contortus. already established infections. Animals to
The reduction of immunity around which the protein level of the diet was
parturition has nutritional bases. As the improved showed a clinical improvement;
immune functions are expected to use they reduced the epg count and were more
metabolizable protein, a breakdown of resistant to re-infection than those that were
immunity is produced in shortage moments. kept on a basal diet (Coop and Holmes,
Females around parturition privilege milk 1996).
production to the expression in immunity The emergence of the "arrested" larvae
(Houdijk et al., 2003, 2005). In a work in the abomasum could have nutritional
conducted by Houdijk et al. (2003), it was basis, as it occurs in a moment when the
observed that increasing the protein value forage offer is poorer, which leads to a lower
from 190 to 330 g/day in lactating ewes expression of immunity (Coop and
infected with O. circumcinta the count of Kyriazakis, 2001).
epg declined but not the total parasite The protein supplementation affects
burden, while in 2005 the same author various effectors of the immune response.
performed an experiment in which an In parasited animals that are supplemented
increase in the supplementation with with proteins, the number of eosinophils
metabolizable protein in sheep in the period and other leukocytes, mast cells and
next to parturition reduced the count of epg proteases from the mast cells increase in the
in the faeces and the parasite burden. A 5% mucosa of the gastrointestinal tract. Some
difference in the dry matter intake was components of the immune response such
observed, with the associated reduction in as mucoproteins, leukotrienes, cytokines
the ingestion of metabolizable energy when and immunoglobulins have a dispropor-
comparing animals fed with food with high tionate demand of certain amino acids. The
and low protein value. The milk production intestinal mucus is rich in serine, threonine
improved with the first increase of metaboli- and proline, while leukotrienes are rich in
zable proteins (from 184 to 273 g/day) but cysteine. Sheep that were parasited with T.
not with the last ones (from 273 to 376 g/ colubriformis, when fed with methionine
day). The epg count declined as the protein protected of ruminal degradation, showed
supplementation increased (Houdijk et al., an increase in the immune response by the
2003). The resistance to H. contortus can be increase in the mast cells and leukocytes
altered if the proteins offer is less than 30 (Coop and Kyriazakis, 2001).
g/kg of dry matter, which produces weight There is enough evidence to consider
loss at the beginning and later an im- that the macro-minerals and the trace
munological break down (Coop and Holmes, elements influence the parasite-host
1996). relationship. As it was previously men-
The increase in the offer of proteins tioned, the intestinal infections with
seems to affect the expulsion of already nematodes reduce the absorption of
established adults rather than to avoid the phosphorus, the retention of phosphorus
Archivos de zootecnia vol. 58(R), p. 138.
NUTRITION AND GASTROINTESTINAL PARASITISM IN RUMINANT PRODUCTION
and the mineralization of the skeleton. The and offers greater amounts of protein to
increase of this mineral in the diet of lambs digest and absorb in the intestine. The
that received L3 of T. vitrinus raised the inefficient ruminal function produces an
weight gain. The burden of T. vitrinus and increase in the heat production, which redu-
the epg count was greater in the animals that ces the intake of food. The supplementation
received the low phosphorus diet (Coop of low quality food with urea as a non-
and Holmes, 1996). The administration of proteinaceous nitrogen source can reduce
phosphorous to T. vitrinus-parasited sheep the level of infection and the effects of the
reduced the epg count in 55% and the total nematodes. This response is somehow due
parasite burden in 89% (Coop and to the urea stimulation effect over appetite.
Kyriazakis, 2001). Other studies have shown Urea also increases the microbial protein
that the administration of copper before the production and the degradation of organic
infection with H. contortus and O. circum- matter by the ruminal micro-organisms
cincta reduced the establishment of the (Coop and Holmes, 1996; Knox et al., 2006).
nematodes in 96 and 56%, respectively, The pathogenicity of H. contortus can be
although no effect was observed in the reduced by adding urea (60 g/kg of dry
establishment of T. colubriformis (Coop matter) to the basal ration. Coop and
and Holmes, 1996; Coop and Kyriazakis, Kyriazakis (2001) observed that parasited
1999). According to Dimander (2003), the animals whose diets were supplemented
administration of copper capsules to sheep with urea showed less parasite burdens and
reduced the establishment and development less biochemical and hematological altera-
of parasites in the abomasum. The ionic tions. Although the response is lower than
copper released by the acid of the mucosa that obtained with high quality protein, it is
would be the responsible of the anthelmintic to be considered in places where obtaining
effect. However, no increase in the parasite such proteins is impossible.
burden was observed in hypocupremic Plants used to feed animals can affect
animals (Coop and Kyriazakis, 1999). The their health not only as an alimentary source
addition of molybdenum to the diet of sheep but also as a source of certain antiparasitic
infected with T. vitrinus or H. contortus substances. It is well known that tannins
reduced the populations of these parasites can produce this effect; however, similar
in 23 and 78%, respectively. Molybdenum is results can be obtained with a variety of
an oligoelement that affects the parasite other substances. Xylopia aethiopica, a
populations disturbing the metabolism of tree found in Nigeria, is an example of this.
the parasites or indirectly increasing the An extract of its seeds is used as a vermifuge
immune response of the mucosa (Coop and of round worms. Doses of 0.8 g/kg, 1.0 g/kg,
Holmes, 1996; Coop and Kyriazakis, 2001). 1.2 g/kg, 1.4 g/kg, 1.7 g/kg and 2.0 g/kg of
The selenium deficiency does not seem such extract produce deparasitization of
to affect the resistance to parasites while 21%, 47%, 51%, 50%, 63% and 76%
the deficiency of cobalt induces greater epg respectively in treated rats, compared to
counts and increased levels of pepsinogen controls (Suleiman et al., 2005).
in lambs infected with O. circumcincta (Coop Tannins are found in many of the plants
and Holmes, 1996). Zinc is known to be an that are part of the diet of herbivores and
essential element that affects the develop- their concentration can affect the parasite
ment and integrity of the immune system population (Athanasiadou et al., 2005; Coop
(Brãzao et al., 2008; Coop and Kyriazakis, and Kyriazakis, 200; Nguyena et al., 2005;
2001). Tzamaloukas et al., 2005). Their concentra-
The optimization of the ruminal function tion ranges from 5% in some tropical
increases the microbial protein production leguminous to 50% of the dry matter in some
Archivos de zootecnia vol. 58(R), p. 139.
BASABE, EIRAS AND ROMERO
other tropical plants (Coop and Kyriazakis, and Kyriazakis, 2001; Min and Hart, 2003).
2001). These substances are related to the The tannins in the plants have both
plants' defences against insects and direct and indirect effects over the gastro-
herbivores, and can cause either beneficial intestinal parasites (Coop and Kyriazakis,
or undesirable effects on those animals that 2001; Min and Hart, 2003; Hoste et al., 2006).
feed on them (Athanasiadou et al., 2000; The direct effects could be caused by the
Coop and Kyriazakis, 2001). The major benefit tannin-parasite interaction, affecting the
of the tannins of the plants is the protection parasite's physiology. The tannins extracted
of proteins against the ruminal degradation, from several forages reduce the total
enabling the digestion and absorption in nematode burden, the migration, the viability
the abomasum and intestine (Coop and of the larvae and the epg count. They can
Kyriazakis, 2001; Nguyena et al., 2005). They also interfere with the hatching of the eggs
are usually divided into hydrolysable and and the development of infective larval
condensed tannins (CT), although there are stages (Athanasiadou et al., 2001, 2005;
other types. The CT are relatively stable in Nguyena et al., 2005). The CT of quebracho
the digestive tract of the animals and they had a direct anthelmintic effect when they
rarely have toxic effects and are, therefore, were given to sheep parasited by T.
used to control parasite populations (Coop colubriformis. A reduction in the adult
and Kyriazakis, 2001). The CT are the most parasite burden, in the epg count and in the
frequent type of tannin found in leguminous parasite females' fecundity per capita was
and trees (Min et al., 2003). The tannins observed (Athanasiadou et al., 2000).
bind themselves to proteins and other Indirectly, tannins act improving the
compounds in a reversible way in relation to protein nutrition by binding themselves to
the pH (Coop and Kyriazakis, 2001; Muturi the proteins of the plants in the rumen and
et al., 2005). They can form complexes with preventing the microbial degradation, thus
proteins, polysaccharides, nuclear acids and increasing the offer of amino acids to the
minerals. Although they interact with duodenum (Athanasiadou et al., 2000;
carbohydrates, particularly with starch, their Coop and Kyriazakis, 2001; Nguyena et al.,
affinity for carbohydrates is lower than for 2005). The administration of quebracho
proteins. The complexes with proteins are extract during three days (8% of the intake)
influenced by the pH and the molecular reduced the epg count, the adult burden
weight of both. They bind to proteins in a and the fecundity of T. colubriformis
pH close to neutrality, which is the case of (Athanasiadou et al., 2001). The ideal tannin
the rumen, dissociating themselves in the concentration would be somewhere around
acid pH of the abomasum to be digested 20-40g/kg of dry matter, level in which they
(Muturi et al., 2005). The complexes also bind themselves to the diet proteins during
dissociate in the intestine due to the bile chewing. A tannin concentration higher than
acids that act as surfactants (Athanasiadou 50g/kg of dry matter can transform them into
et al., 2000). This reaction can be used to anti-nutritional factors with adverse effects
reduce the protein degradation in the rumen both on food ingestion and on ruminal
without reducing the microbial protein syn- function (Nguyena et al., 2005). Lambs
thesized. The tannins in Lotus corniculatus infected with T. colubriformis had higher
and Hedysarum coronarium can be used to daily live weight gains, lower epg counts
increase the absorption of essential amino and lower parasite burdens when they
acids in the intestine. Yet, not all of the pastured the Mediterranean leguminous H.
tannins found in plants produce such coronarium (12% CT) than when they
increase. This would be related to the pastured leguminous without CT. Similarly,
structure of the tannins themselves (Coop lambs naturally exposed to nematodes had
Archivos de zootecnia vol. 58(R), p. 140.