52a Reunião Anual da Sociedade Brasileira de
Zootecnia
Zootecnia: Otimizando Recursos e Potencialidades
Belo Horizonte – MG, 19 a 23 de Julho de 2015
Efeito da inclusão de L-glutamina e L-ácido glutâmico e do ambiente térmico sobre o rendimento de carcaça,
peso relativo de órgãos e morfometria intestinal de leitões de 28 aos 65 dias de idade1
Edilson Paes Saraiva2, Adriano Leite da Silva3, Terezinha Domiciano Dantas4, Vinicius França de Carvalho
Fonseca3, Raniere de Sá Paulino5, Thiago de Assis Moraes5, Jorge Luiz Santos de Almeida6
1
Parte da dissertação do segundo autor
Professor do Departamento de Zootecnia – CCA/UFPB, Areia/PB, Brasil. E-mail: [email protected]
3
Doutorando do Programa de Doutorado Integrado em Zootecnia –PDIZ/UFPB, Areia/PB, Brasil
4
Professor do Departamento de Agropecuária - CCHSA/UFPB, Bananeiras/PB, Brasil
5
Graduando em Zootecnia – CCA/UFPB, Areia/PB, Brasil
6
Graduando em Ciências Agrárias – CCHSA/UFPB, Bananeiras/PB, Brasil
2
Resumo: Objetivou-se avaliar o efeito da inclusão de L-glutamina e L-ácido glutâmico e do ambiente térmico sobre
o rendimento de carcaça, peso de órgão e morfometria intestinal de leitões de 28 aos 65 dias de idade. Utilizou 64
leitões machos e fêmeas desmamados aos 25 dias de idade de linhagem comercial Agroceres®. O delineamento
experimental utilizado foi inteiramente casualizado, esquema fatorial com animais distribuídos em dois ambientes
térmicos (conforto/estresse por frio), recebendo uma dieta controle e outra com inclusão de 1% L-glutamina e Lácido glutâmico fornecidas ad libitum, sendo oito repetições por tratamento e a unidade experimental formada por
um macho castrado e uma fêmea. Os animais foram pesados antes e posterior ao abate, mensurando o peso da
carcaça eviscerada, o peso dos órgãos e comprimento do intestino delgado para obtenção do peso relativo, assim
como colhidas amostras de tecido do duodeno para análise morfométrica. Observou-se o pior rendimento de
carcaça e maiores peso de órgãos no ambiente de estresse por frio, a dieta contendo L-glutamina e L-ácido
glutâmico apresentaram órgãos mais pesados, maiores altura de Vilosidade, profundidades de cripta e melhor
relação vilosidade:cripta. Leitões de 28 aos 65 dias de idade criado em ambiente de conforto térmico e consumindo
ração com a inclusão de L-glutamina e L-ácido glutâmico apresentarão melhores rendimentos de carcaça e
constituição intestino delgado.
Palavras-chave: estresse, suinocultura, vilosidade
Effect of including L-glutamine and L-glutamic acid and the thermal environment on the carcass yield,
relative weight of organs and intestinal morphology of piglets from 28 to 65 days old
Abstract: This study aimed to evaluate the effect of inclusion of L-glutamine and L-glutamic acid and the thermal
environment on the carcass yield, intestinal organ weight and intestinal morphology of piglets from 28 to 65 days
old. It used 64 male and female piglets weaned at 25 days of age Agroceres® commercial line. The experimental
design was completely randomized factorial with animals over two thermal environments (comfort/cold stress).
They received a control diet and the other with inclusion of 1% L-glutamine and L-glutamic acid, provided ad
libitum, eight replicates per treatment and the experimental unit comprised of a castrated male and one female. The
animals were weighed before and after the slaughter, measured eviscerated carcass weight, the weight of the organs
and length of the small intestine to obtain the relative weight, and harvested duodenal tissue samples for
morphometric analysis. The cold stress environment showed the worst carcass yield and higher weight of organs.
The diet containing L-glutamine and L-glutamic acid showed heavier bodies, higher villus height, crypt depth and
best relationship villus:crypt. Piglets from 28 to 65 days old raised in thermal comfort and receiving the treatment
of L-glutamine and L-glutamic acid, presented better carcass yield and small intestine constitution.
Keywords: stress, swine, villus
Introduction
The piglets weaned and housed in an environment that give them cold stress, had a delay in their
development, since they are more susceptible to this injury, which can affect performance and therefore the carcass
yield. Thus, it is essential to know the effect of heat stress by cold and search tools to try to reduce the damage
caused [(Pandorfi et al, 2005).
The industrial use of amino acids is increasingly higher in the feed formulation, allowing the piglets present
better performance. In this context, the objective was to evaluate the effect of inclusion of L-glutamine and Lglutamic acid and the thermal environment on the carcass yield, duodenal organ weight and morphology of 28 to 65
days old piglets.
Material e Methods
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52a Reunião Anual da Sociedade Brasileira de
Zootecnia
Zootecnia: Otimizando Recursos e Potencialidades
Belo Horizonte – MG, 19 a 23 de Julho de 2015
The experiment was conducted at the Poultry Laboratory in the Centro de Ciências Humanas, Sociais e
Agrárias (CCHSA) of Universidade Federal da Paraíba (UFPB) in Bananeiras-PB. Sixty-four weaned piglets
(castrated males and females) were used, at 25 days of age with average initial weight of 7.003±0.586 kg of
Agroceres® commercial line, with trial period of 28 to 65 days of life.
The animals were divided into two rooms with controlled temperature reproducing a situation of comfort,
25ºC for the period of 28 to 49 days of age, and adjusted to 20°C in 50 to 65 days of age. In the other room, cold
stress, the temperature was maintained at 20°C for animals 28-49 days-old and 15°C for piglets of 50-65 days of
age. Two experimental diets were formulated as recommended by ROSTAGNO et al. (2011) to meet the
requirements of pigs in pre-initial phase (7-15 kg), initial phase (15-30 kg). They were one control diet and another
with inclusion of L-glutamine and L-glutamic acid (G+GA) to 1%, provided ad libitum to the animals.
The experimental design was completely randomized in a factorial design with two thermal environments
(comfort and cold stress) and two diets (control diet and diet with addition of 1% L-glutamine and L-glutamic acid).
Eight repetitions were used per treatment and two animals (a castrated male and one female) formed the
experimental unit.
In their 65 days of age, the piglets were kept without water intake for 12 hours, weighed, and slaughtered.
They were then eviscerated, following carcass and organs weighted: heart, liver, lung, stomach, kidneys, pancreas,
spleen and small intestine, the latter being the length measured by tape measure. After weighing, it was calculated
the relationship carcass weight / live weight at slaughter, organ weight / carcass weight, and length of the gut /
carcass weight, for the proceeds thereof.
To evaluate the development of the intestinal mucosa tissue fragments were collected from about 3 cm², the
medial portion of the duodenum and subjected to normal histological routine. The morphometric study was
conducted using an image analyzer (Image J®). They were determined villus height, crypt depth, and villous:crypt.
The data were submitted to variance analysis, when significant, were compared by Tukey test at 5%
probability. For organ weight data, it used the fast body weight as a covariate. The statistical software (SAS, 2003)
was used for calculation.
Results and Discussion
There was no significant interaction between factors, so they were analyzed separately. The worst (P <0.05)
carcass yield was observed in the stress environment by cold (Table 1), which is related to the greater weight of
organs in this environment, associated with the likely energy deflect to maintaining their thermoregulation.
Table 1 -the effect of inclusion of L-glutamine and L-glutamic acid¹ (G + GA) and the thermal environment on
the carcass yield, relative weight of organs and relative length of the small intestine
Environment
Diet
CV (%)
Comfort
Cold
Without G+GA G+GA
Carcass (%)
75.48a
73.52b
74.61a
74.43a
3.85
Heart (%)
0.67b
0.72a
0.67a
0.71a
4.70
Liver (%)
3.34b
3.83a
3.54a
3.63a
11.13
Lung (%)
1.42b
1.93a
1.69a
1.65a
10.46
Stomach (%)
1.19a
1.13a
1.18a
1.14a
7.79
Kidneys (%)
0.73b
0.81a
0.73b
0.79a
4.61
Pancreas (%)
0.36a
0.37a
0.36a
0.37a
5.42
Spleen (%)
0.26b
0.34a
0.28b
0.35a
4.84
Small intestine (%)
4.55a
4.51a
4.46b
4.58a
7.58
Small intestine (m/kg PV²)
0.76a
0.77a
0.74a
0.78a
7.41
The different letters in the same line differ significantly by Tukey test at 5% probability; Commercial product
containing L-glutamine and L-glutamic acid (95% min.); ²Meters per kilogram of body weight; CV =
coefficient of variation.
Organs
There was no difference in the carcass weight due to the effect of diets with or without G+GA (Table 1). For
each pig-rearing phase, there is an optimal temperature range, without increase in metabolic activity and energy
expenditure for heating or cooling the animal (Rodrigues et al. 2010).
The most metabolically active organs (heart, liver, lung, kidney and spleen) showed greater relative weight
in cold conditions and it may be explained by the increased metabolic rate of them to increase thermogenesis. The
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52a Reunião Anual da Sociedade Brasileira de
Zootecnia
Zootecnia: Otimizando Recursos e Potencialidades
Belo Horizonte – MG, 19 a 23 de Julho de 2015
ration with G+GA gave higher relative weight of the kidneys, spleen, and small intestine, since these amino acids
serve as a source of energy and grouping amine to rapidly dividing cells. The small intestine length was not
influenced by the environment and not by the type of diet offered.
There was interaction of the factors (thermal environment and diet) on the variables villus height, crypt
depth and villous:crypt, which were then analyzed together. The villus height was greater in general for animals fed
with G+GA, being lower for animals fed without G+GA in by cold stress environment. This can be explained by
the fact that these amino acids are the main energy substrate for enterocytes (Caldara et al., 2010). The lower crypt
depth was observed in thermal comfort that did not receive addition of G+GA (Table 2).
Table 2 – Effect of addition of L-glutamine and L-glutamic acid¹ (G+GA) and the thermal environment on villus
height (µm), crypt depth (µm) and relationship villus:crypt (µm) of duodenum piglets at 65 days of age.
Variables
Diet
Environment
CV (%)
Without G+GA G+GA
Comfort
349.63 bA
432.17 aA
Villus Height (µm)
10.01
Cold
326.34 bB
434.98 aA
Comfort
94.64 bB
101.76 aA
Crypt Depth (µm)
12.92
Cold
99.67 aA
9.87 aA
Comfort
3.72 bA
4.25 aB
Relationship villus: crypt (µm)
4.15
Cold
3.30 bB
4.40 aA
The different letters in the same line (lower case) and spine (upper case) differ significantly by Tukey test at 5%
probability; ¹ commercial product containing L-glutamine and L-glutamic acid (95% min.); CV = coefficient of
variation.
According Arouca et al. (2012) the depth of the crypt indicates the compensation of epithelial cells,
multiplying the number of cells stimulated by aggression diets increasing the size of tissues.
Most villus:crypt ratio was found in animals receiving G+GA and environmental stress by cold, since this
promoted greater villus height, providing second Arouca et al. (2012) better absorption of nutrients.
Conclusions
The cold stress worsens the carcass yield, without it being affected by the use of L-glutamine and L-glutamic
acid in piglets from 28 to 65 days old. The inclusion of L-glutamine and L-glutamic acid enhances the development
of duodenal mucosa in cold stress as well as comfortable conditions.
References
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PEREIRA, F.M. Desempenho, morfometria de órgãos e histologia intestinal de suínos na fase de terminação
tardia alimentados com cana-de-açúcar. Revista Brasileira Saúde Produção Animal, v.13, n.4, p.1074-1083,
2012.
CALDARA, F. R; DUCATTI, C; BERTO, D.A; DENADAI, J.C; GARCIA, R.G; FERREIRA, V.M.O.S.
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térmico. Revista Eletronica Nutritime, v.7, n. 02 p.1197-1211, 2010.
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