52a Reunião Anual da Sociedade Brasileira de
Zootecnia
Zootecnia: Otimizando Recursos e Potencialidades
Belo Horizonte – MG, 19 a 23 de Julho de 2015
Influence of metabolizable energy: sulfur amino acids in hepatic steatosis of light pullets during the growing¹
Sarah Gomes Pinheiro1,4, Fernando Guilherme Perazzo Costa2, Ricardo Romão Guerra3, Lavosier Enéas
Cavalcante5, Pedro José Rodrigues Neto6, Alberto Jefferson da Silva Macêdo 6, Harlan Emanuel Vieira Rocha6
1
Section Thesis in Animal Science UFPB, Areia, PB-Brasil. e-mail: [email protected]
Teacher at the Federal University of Paraíba (UFPB), CCA, Areia, PB-Brasil.
3
Veterinary Teacher at the Federal University of Paraíba (UFPB), CCA, Areia, PB-Brasil.
4
Doctoral Student in Animal Science, UFPB
5
Master Student in Animal Science, UFPB
6
Graduated Student in Animal Science, UFPB
2
Abstract: The aim was to determine the ideal relationship between the level of recommendation of metabolizable
energy (ME) and methionine+cystine digestible (M+C dig.) for light pullets. The experimental design was
completely randomized distributed in factorial: 4 (levels of digestible M + C) x 3 (levels ME), totaling 12
treatments each. The diets had two recommendation bases for M+C dig.: 100% of the recommendation proposed
Figueiredo Jr. (2013) (0.732, 0.522, 0.689 and 0.610%); other for 100% of the recommendation proposed Rostagno
et al. 2011 (0.640, 0.497, 0.670 and 0.617%), and which can meet the proposed varied ± 10% of this
recommendation. For ME were suggested three levels, one being the recommendation of literature (2,900 kcal/kg)
and other varying ± 5% (2,755 and 3,045 kcal/kg). In liver histopathology was observed severe changes to the
degree of steatosis. From 1 to 6 weeks wasn’t found lipid vacuoles. In phase 7 to 12 weeks, were found grades 0
and 1, characterized in vacuoles absence or low concentration of the lipids, respectively. It is recommended to use
0.667% M+C dig. associated with a level of 2755 kcal/kg ME in the diet for pullets between 1 and 6 weeks of age,
which corresponds to a daily intake of 184 mg M+C dig./pullet. In phase 7 to 12 weeks, the recommendation is
0.497% M+C dig. associated 2,755 kcal/kg ME, which corresponds to a daily intake of 136 mg of M+C dig./pullet.
Keywords: energy, interaction, lipid liver, methionine + cystine, pullets
Influência da relação energia metabolizável: aminoácidos sulfurosos na esteatose hepática das aves leves nas
fases de crescimento
Resumo: O objetivo foi determinar a relação ideal entre o nível de recomendação de energia metabolizável (EM) e
metionina + cistina digestíveis (M+C dig.) para frangas leves. O delineamento experimental foi inteiramente
casualizado, distribuído em esquema fatorial: 4 (níveis de digerível M + C) x 3 (níveis EM), totalizando 12
tratamentos. As dietas tinha duas bases recomendação para M+C dig.: 100% da recomendação proposta Figueiredo
Jr. (2013) (0,732, 0,522, 0,689 e 0,610%); outro para 100% da recomendação proposta Rostagno et al. 2011 (0,640,
0,497, 0,670 e 0,617%), e proporções percentuais de 10% desta recomendação. Para EM foram sugeridos três
níveis: a recomendação da literatura (2.900 kcal / kg) e outra variando 5% (2.755 e 3.045 kcal/kg). No exame
histopatológico hepático não foi observado alterações severas para o grau de esteatose. Na fase de 1 a 6 semanas
não foram encontrados vacúolos lipídicos. Na fase de 7 a 12 semanas, os graus encontrados foram de 0 e 1,
caracterizando ausência ou vacúolos com baixa concentração de lipídeos, respectivamente. Recomenda-se a
utilização de 0,667% de metionina+cistina digestível associado a um nível de 2.755 kcal/kg de energia
metabolizável na dieta para as aves entre 1 e 6 semanas de idade, correspondendo a um consumo diário de 184 mg
de M+C dig/ave. E para a fase de 7 a 12 semanas, a recomendação é de 0,497% de metionina+cistina digestível,
2.755 kcal/kg de energia metabolizável, que corresponde a um consumo diário de 136 mg de M+C dig./ave.
Palavras–chave: aves de reposição, energético, interação, fígado lipídico, metionina+cistina
Introduction
Currently, to determine the optimal recommendation of amino acids and energy for laying hens requires not
only the evaluation of the performance variables, as well as weight of organs (Barbosa et al., 2010), besides the
histomorphometric characteristics of the organs and enzyme activity present on blood serum, which demonstrates
the efficiency of absorption and metabolism of amino acids.
Acioli (2012) affirms that the development of the digestive tract organs depends on the normal growth of the
pullets in the initial phase, with the liver being considered the most relevant, since it centralizes the general
metabolism by changing your weight and metabolic activities when there are dietary changes.
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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 evaluation of hepatic steatosis level is important because it indicates the accumulation of fat vacuoles in
the liver, which can either increase the weight of the body as reflected in the production of hormones related to
reproduction.
Material and Methods
The project was developed at the Poultry Module Department of Animal Science of Agricultural Science
Center of the Federal University of Paraíba, Campus II, Areia - PB. Were used 1080 pullets of Dekalb White from
the first day of life, with an average initial weight of 38 grams; and at the 7th week of life, with an average weight
of 557 ± 1 gram. The experimental design was completely randomized distributed in a factorial 4 (methionine +
cystine - M+C dig.) x 3 (metabolizable energy-ME), totaling twelve treatments, six replicates of fifteen per each.
The diet of treatment 2 was formulated to meet the requirements of all nutrients, according to the recommendations
of Figueiredo Jr. (2013) and the diet of the treatment 8 to meet the recommendation of Rostagno et al. (2011). For
the other treatments percentage proportions were established levels of ME, varying 5% above and below of that
proposed by Rostagno et al. (2011), and M+C dig. ranging from 10% recommendation suggested by Rostagno et al.
(2011). To analyze the degree of hepatic steatosis is assigned a rating score for each analyzed liver of each animal
photomicrographs liver (10 animals/treatment), whereas the number and size of lipid cytoplasmic vacuoles in the
hepatocytes staining hematoxylin eosin, as follows: 0 (no steatosis), 1 (low steatosis), 2 (moderate steatosis) and 3
(advanced steatosis), following the Semi Quantitative Score of Ishak (Ishak et al., 1995). For each treatment was
obtained an average, which was submitted to the analysis of multinomial distribution, obtained from PROC
GLIMMIX SAS software (SAS Institute, 2011). All evaluations were performed by the same histologist to avoid
interpretative differences.
Results and Discussion
The degree hepatic steatosis in pullets has been reported, but the evaluated animals did not show any degree
of steatosis in phase 1-6 weeks.
Figure 1. Photomicrography of hepatic steatosis grade (grade 0) in pullets at 6 weeks of age (100 µm)
In phase 7 to 12 weeks, steatosis the levels found in most evident in Figure 2 are represented by 0 and 1
degrees.
According to D'Agostini et al. (2012), the digestible methionine + cystine associated with dietary
metabolizable energy level for replacement pullets are scarce. Thus, it is necessary to study to assess not only the
appropriate level of nutrients, for each phase, but adjust the energy density of the diet in different climates in which
these pullets are creates.
This result was expected, since replacement pullets tend not to present hepatic steatosis, as they are in
intensive development of body tissues and efficiently utilize the nutrients provided in the diet, especially within
hepatocytes, which are in intense cellular activity, with the excess accumulated energy as abdominal fat, if
applicable.
Acioli (2012) affirms that the weight of deficits and uniformity of the lot are not recovered in the posture
phase, so performance parameters such as persistence of production, egg mass and viability are penalized. Thus, the
development criteria achieved between 0 and 16 weeks are critical for maximum genetic potential expression of
pullets.
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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
Figure 2. Photomicrography of hepatic steatosis grade (A - grade 0 e B- grade 1) ) in pullets at 12 weeks of age (100 µm)
Following are represented in Figure 3 steatosis levels found in this study.
Figure 3. Frequency (%) 0-3 degrees of hepatic steatosis in pullets with 12 weeks submitted to diets containing different levels of
methionine + cystine (M + C dig.) and metabolizable energy (ME).
Conclusions
It is recommended to use 0.667% methionine + cystine digestible associated with a level of 2,755 kcal/kg of
metabolizable energy (ratio ME:M+C dig.of 4,130.43) in the diet for pullets between 1 and 6 weeks, which
corresponds to a daily intake of 184 mg M+C dig./pullet.
For pullets (7 and 12 weeks) the recommendation is 0.497% methionine + cystine digestible and 2,755
kcal/kg metabolizable energy (ratio ME:M+C dig. of 5,543.26), which corresponds to a daily intake 136 mg of
M+C dig./pullet.
Literature Cited
ACIOLI, M.I.L. The importance of quality pullet: the factors to influenced the performance of laying hens from
initial to the growth phase. Revista O Ovo, n.8, 2012. Available at: <www.avisite.com.br/revistadoovo/>
Accessed on: Nov. 24, 2012.
FIGUEIREDO Jr., J.P. Levels of methionine and cystine for light pullets in initial and growth phase. 132f.
Thesis (PhD in Animal Science) - Federal University of Paraíba, Areia-PB. 2013.
ISHAK, K .; BAPTIST, A .; Bianchi, L. et al. Histological grading and staging of chronic hepatitis. Journal of
Hepatology, v.22, p.696-699, 1995.
ROSTAGNO, H.S .; ALBINO, L.F.T .; DONZELE, J. L. et al. Brazilian Tables for poultry and swine: food
composition and nutritional requirements. 3rd ed. Lush: UFV, 252p. 2011.
SAS. SAS STAT 9.3. User’s’ Guide. Cary, NC: SAS Institute Inc. 8621p. 2011.
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