trabalho completo - 52ª Reunião Anual da Sociedade Brasileira de

52a Reunião Anual da Sociedade Brasileira de
Zootecnia
Zootecnia: Otimizando Recursos e Potencialidades
Belo Horizonte – MG, 19 a 23 de Julho de 2015
Crescimento Tecidual e Turnover do 15N em Frangos de Corte1
Letícia Graziele Pacheco2, Nilva Kazue Sakomura3, Allan Reis Troni4, Daniel Mendes Borges Campos5, Rafael
Massami Suzuki4, Juliana Célia Denadai6, Hanay dos Santos Doreto7
1
Parte da tese de doutorado do estudante Allan Reis Troni, pesquisa financiada pela Fapesp, e-mail: [email protected]
Aluna de graduação Universidade Estadual Paulista (Unesp) – Campus Jaboticabal, e-mail: [email protected]
Professora titular da Unesp – Campus Jaboticabal
4
Aluno de Pós Graduação na Unesp – Campus Jaboticabal
5
Professor da Fundação Municipal de Ensino Superior de Bragança Paulista (FESB)
6
Professor colaborador do Dep. de Física e Biofísica do Instituto de Biociências, Unesp – Campus Botucatu
7
Zootecnista formada pela Unesp – Campus Jaboticabal
2
3
Resumo:As vias metabólicas podem ser estudadasutilizando traçadores biológicos, tais comoos isótopos estáveis.
O trabalho tem o objetivo de investigar o crescimento tecidual e turnover do traçador de nitrogênio (15N) em tecidos
de frangos de corte. Equações de crescimento e turnover foram desenvolvidas em músculo do peito, fígado e penas
em frangos machos por meiode abates sucessivos: 14, 15,16, 17, 19, 21, 23, 25, 28, 31, 35 e 42 dias de vida.O peso
a maturidade (Wm) foi: 2.097g, 93g e 175g; para o tempo de inflexão da curva de crescimento (T) foi: 44, 20 e 29
dias;e o coeficiente de deposição relativa ao peso tecidual (b) foi: 0,041; 0,059 e 0,08 para as peito, fígado e penas,
respectivamente. Os resultados de turnover do 15N são: Coeficiente de troca isotópica (k): 0,113; 0,235; 0,147; valor
de meia vida (50%): 6 dias;3 dias e 5 dias; e os valores de 99% da curva de substituição isotópica (99%): 40 dias;20
dias e 31 dias para peito, fígado e penas, respectivamente. Estes resultados demonstram a variação existente no
crescimento individual dos tecidos fornecendo maior conhecimento sobre o desenvolvimento tecidual em frangos
de corte. O uso dos isótopos estáveis como traçadores biológicos representa umamodernizaçãonos modelos
matemáticos, aliando a nutrição com conceitos fisiológicos e metabólicos.
Palavras–chave: fígado, isótopos estáveis, modelagem, músculo do peito, penas, traçadores biológicos
Tissue Growth and Turnover of 15N in Broiler Chickens
Abstract:Metabolic pathways can be productively studied using biological tracers such as stable isotopes. The aim
of this study was to investigate tissue growth and turnover of tracer nitrogen (15N) in broilers. Growth equations
were developed and tissue turnover was studied inbreast muscle, liver and feathers in male broilers and successively
slaughtering on: 14, 15, 16, 17, 19, 21, 23, 25, 28, 31, 35 and 42 days of life during the experiment period. Weight
at maturity (Wm) was 2.097 g, 93 g and 175 g; time of inflection of growth equation (T) was44, 20 and 29 days;
and coefficient deposition on tissue weight (b) was 0.041; 0.059 and 0.08 for breast, liver and feathers, respectively.
Results for turnover of 15N include the isotopic exchange coefficient (k) of 0.113; 0.235; 0.147; half-life value
(50%) of 6 days;3 days and 5 days; and 99% values of isotopic substitution curve (99%) of 40 days;20 days and31
days for breast, liver and feathers. These results demonstrate variability in the growth of individual tissues and add
to knowledge about tissue development in broilers. The use of stable isotopes as biological tracers leads to an
improvement in mathematical models, linking nutrition with physiological and metabolic concepts.
Keywords:biological tracers, breast,feathers,liver, modeling,stable isotopes
Introduction
The main biochemical systems involved in maintaining the balance of protein and amino acids in the body
are arrest and transport; oxidation and breakdown; and protein synthesis and degradation. These pathways can be
defined through the use of stable isotopes. The isotopes used as biological tracer make it possible to monitor the
nutrients in the system as well as the contribution of nutrients to the composition of tissues. This technique
facilitates the observation of the ongoing tissue renewal processes where there is interplay between biosynthesis and
degradation process known as turnover (Pimenta et al, 2014). Thus it becomes necessary to find an appropriate
response model which considers the tissue physiological differences, turnover and hierarchy nutrients for tissue
formation and degradation, allowing integration of these variables to provide a full response of the animal (Oviedo,
2007).
The present study was designed to compare specific issue growth equations and the turnover of 15N,
exploring the physiology of nitrogenin rapidly growing broilers.
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Página - 1 - de 3
52a Reunião Anual da Sociedade Brasileira de
Zootecnia
Zootecnia: Otimizando Recursos e Potencialidades
Belo Horizonte – MG, 19 a 23 de Julho de 2015
Material and Methods
The study was conducted at the Poultry Science Laboratory, Department of Animal Science, Faculty of
Agriculture and Veterinary Sciences - UNESP - Jaboticabal/SP. The experiment used 136 male broilers 1-70 days
of age Cobb® 500. The birds were raised collectively until 13 days of age, receiving a standard diet based on corn
and soybean meal as described by Rostagno et al. (2011). At 14 days of age, birds were transferred to individual
metabolic cages and were given a diet based on rice, poultry meal and soybean meal, formulated based on the
nutritional requirements for this age.The tissues evaluated were chosen because of their importance in metabolism
(liver), value to agribusiness (breast muscle), and role in protection of the animal plus importance in nitrogen
utilization (feathers). To measure tissue 15N enrichment of the wing feathers, liver and breast muscle, groups of four
birds were slaughtered at 14, 15, 16, 17, 19, 21, 23, 25, 28, 31, 35, and 42 days of life. There were tissues
collections to until the 70th day with the aim of establishing growth equations. Samples were analyzed at the Center
of Stable Isotopes of the Biosciences Institute of Unesp, Botucatu. Data on 15N incorporation rate obtained by
isotopic analysis were analyzed using exponential equations and the sigmoidal Origin Pro 8.0 software.
Results and Discussion
As indicated in Figure 1 (upper panel), tissue growth (based on sigmoidal equation Gompertz, 1825) was
different in the three tissues studied. The liver matured more quickly than the other tissues, as indicated by the
stabilization of the curve or weight maturity (Wm, Table 1). In contrast, breast muscle growth had not stabilized
during the experimental period (70 d).
150
1200
800
400
100
50
0
200
160
120
80
40
0
0
0
14
28
42
56
70
0
14
28
42
56
0
70
3
2
1
0
1 5 N D e lt a ‰ F e a t h e r s
1 5 N D e lt a ‰ L iv e r
4
4
2
28
T im e (D a y s )
42
42
56
70
T im e (d a y s )
4
3
2
1
0
0
14
28
5
6
0
14
T im e (D a y s )
T im e (D a y s )
5
1 5 N D e lt a ‰ B r e a s t
240
F e a th e r s W e ig h t (g )
1600
L iv e r W e ig h t ( g )
B r e a s t W e ig h t ( g )
2000
0
14
28
T im e (D a y s )
42
0
14
28
42
T im e (D a y s )
Figure 1: Upper panel: growth curves based on the Gompertz equation (1825) for broiler breast muscle (○),
liver (□) and wing feathers (▲) over 70 days. Lower panel: tissue 15N enrichment curves for breast muscle (○),
liver (□) and wing feathers (▲) from 14 to 42 days of life, based on the equation Ducatti et al. (2002)
There has been a rapid stabilization of the nitrogen-15 enrichment in liver showing the rapid metabolism this
tissue, when compared to breast muscle and feathers. Interestingly, the coefficient of isotopic exchange (k, Table 1)
for wing feathers was higher than that for breast muscle. This is compatible with the rapid growth and utilization of
nitrogen by feathers to complete warping, which is important for protection of the broiler. This result is evident in
theweight maturity reached in Gompertz equation (Fig. 1).
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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
Table 1: Parameters of tissue growth equation 1-70 days of age and turnover equation 14-42 days of age
Growth
Tissues
Breast
Liver
Feathers
a
2,097.77
93.37
175.88
b
T (days)
43.95
20.52
29.17
c
b (/day)
0.041
0.059
0.080
R2k (%)
98.8
90.8
95.5
Wm (g)
Equation
𝑊𝑡 𝑖 = 𝑊𝑚∗ 𝑒 (−𝑒
−𝑏 ∗ 𝑡−𝑇
)
Turnover
Tissues
d
15
Ei (δ‰ N)
e
15
Breast
Liver
Feathers
2.15
2.28
2.13
Ef (δ‰ N)
4.04
5.17
3.73
k f(δ‰15N/t)
0.113
0.235
0.147
50%g
6.09
2.95
4.70
40.48
19.58
31.25
99%
h
Equation
δ15Ntj = Ef+(Ei - Ef)*e(-k*t)
2k
R (%)
95.1
95.0
94.7
a: Maturity weight (Wm); b:Inflection Gompertz equation (T); c: Maturity ratio (b); d:Initial
enrichment (Ei); e: Final enrichment (Ef); f: Isotopic exchange coefficient (k); g:Half-life (50%);
h:Incorporation of 99% of dietary signal (99%); i:Tissue weight in time chosen according to the
equation; j: Tissue enrichment value at the time chosen by the equation; k: Explanation of the data
provided by the model.
Conclusions
Our results show logical differences in growth and utilization of nitrogen by different broiler tissues which
are compatible with known functions of the tissues.
The use of stable isotopes can enhance at animal production experiments by adding measurable
physiological variables for nutritional models. Further studies using this methodology can generate utilization
efficiency data not only for protein and amino acids but also for carbohydrates and lipids and related to nutrient
flows between different tissues in production animals.
Acknowledgements
We thank colleagues in the Institute of Stable Isotopes (Unesp/Botucatu) for their knowledge and for doing
the isotopic analyses and FAPESP for funding the project.
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