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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
Efeito do plano nutricional prévio sobre o consumo e digestibilidade aparente dos nutrientes1
Gutierrez José de Freitas Assis2, Matheus Custódio da Silva2, Débora Evelyn de Freitas Assis2, Mauricio Miguel
Estrada3, Luiz Henrique Pereira Silva3, Pedro Veiga Rodrigues Paulino4, Mario Luiz Chizzotti5
1
Parte da dissertação de mestrado do quinto autor.
Graduando em Zootecnia da UFV,Viçosa - MG, Brasil.
Estudantes do Programa de Pós-Graduação em Zootecnia da UFV, Viçosa - MG, Brasil, Bolsista doCNPq. e-mail: [email protected]
4
Gerente Global de Tecnologia de Bovinos de Corte da Cargill/Nutron, Goiânia - GO, Brasil.
5
Professor Adjunto I do Departamento de Zootecnia da UFV, Viçosa - MG, Brasil.
2
3
Resumo: Objetivou-se com este trabalho avaliar o efeito do plano nutricional prévio sobre o consumo e a
digestibilidade aparente dos nutrientes de tourinhos Nelore. Foram utilizados 17 machos Nelores, não castrados,
com idade média de 8,4 ± 0,3 meses e peso inicial de 230,4 ± 5,6 kg. Os animais foram aleatoriamente distribuídos
nos tratamentos que consistiram de: baixo ganho na fase de crescimento e alto na terminação (BA, n = 5), médio
ganho na fase de crescimento e alto na terminação (MA, n = 6) e alto ganho em ambas fases (AA, n = 6). O
consumo de nutrientes não foi afetado (P>0,05) pelo plano nutricional prévio. O consumo relativo de FDNcp foi
maior (P<0,01) para os animais previamente restritos. O coeficiente de digestibilidade aparente dos nutrientes não
foi afetado (P>0,05) pelo plano nutricional prévio. O consumo absoluto dos nutrientes, bem como o coeficiente de
digestibilidade aparente, não é alterado durante o crescimento compensatório.
Palavras–chave: crescimento compensatório, terminação, zebu
Effect of previous nutritional plan on consumption and apparent digestibility of nutrients
Abstract: The aim of the present study was to evaluate the effect of previous nutritional plan on feed intake and
nutrients apparent digestibility. 17 Nellore young bulls were used, with average 8.4 ± 0.3 months old and initial
body weight of 230.4 ± 5.6 kg. The animals were randomly assigned to the following experimental treatments: low
body weight gain during the growing phase and high body weight gain during the finishing phase (LH; n = 5),
medium body weight gain during the growing phase and high body weight gain during the finishing phase (MH; n =
6), and high gain in both growing and finishing phases (HH; n = 6). The intake of nutrients was not affected
(P>0.05) by previous nutritional plan. The NDFap intake relative to body weight was higher (P<0.01) in previously
restricted animals from the treatments LH and MH. The apparent digestibility coefficients of the nutrients was not
affected (P>0.05) by previous nutritional plan. The absolute consumption of nutrients and the apparent digestibility
coefficient do not change during compensatory growth.
Keywords: compensatory growth, finishing phase, zebu cattle
Introduction
Compensatory growth is defined as a weight gain rate higher than normal and it is presented by animals after
a period of time where the growth pattern was under its genetic potential. In order to compensatory gain to occur, it
is necessary the animal to suffer a reduction in its growth. The causes are diseases, adverse environmental
conditions or feed restriction. Compensatory gain is justified by many alterations: increasing in feed intake,
differential guts growth, changing in maintenance energy requirement, endocrine variation, muscle turn-over
variation and weight gain composition. However, there is a lack of studies regarding nutrients digestibility
alterations during compensatory gain. Thus, this study aimed to evaluate the effect of previous nutritional plan on
feed intake and nutrients apparent digestibility during compensatory growth.
Material and Methods
A total of 17 Nellore young bulls with averaging 8.4 ± 0.3 months of age and 230 ± 5.6 kg of body weight
were used. After weaning, the cattle were confined in collective pens with electronic head gate system (Calan Gate
type), to control individual consumption. Initially, animals were submitted to a 24 days of adaptation to
experimental conditions. After each animal was randomly assigned to one of the following experimental treatments:
low body weight gain during the growing phase and high body weight gain during the finishing phase (LH; n = 5),
medium body weight gain during the growing phase and high body weight gain during the finishing phase (MH; n =
6), and high gain in both growing and finishing phases (HH; n = 6). The growing phase was 90 days long. At 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
end of the growing phase the animals went through the transition phase (21 days for MH treatment, and 31 days for
HH and LH treatments) followed by a 112 days of finishing phase. To obtain the targeted body weight gains four
diets were formulated being three for the growing phase and only one for the finishing phase (Table 1). The
nutritional requirements were estimated using the model BR-CORTE (Valadares Filho et al., 2010).
Table 1. Composition of experimental diets (% DM).
Growing phase
Items
Finishing phase
1
HH
MH1
LH1
Sugar cane bagasse
16.13
Sugar cane silage
36.94
60.23
80.68
Corn
44.63
22.58
8.42
57.73
Soybean meal
14.24
12.90
5.54
10.42
Whole cottonseed
11.68
Urea
1.07
1.10
2.06
1.00
Dicalcium phosphate
0.12
0.30
Commercial premix
3.12
3.05
3.00
3.04
1
HH = high weight gain in both growing and finishing phase, MH = moderate gain
at growing phase and high gain at finishing phase, LH = low gain at growing phase
and high gain at finishing phase.
A digestibility test was made at the middle third of finishing phase in order to estimate apparent digestibility
coefficients. The feces samples were collected, during three consecutive days, from the ground after the animals’
defecation. The gathering was between 7am and 8am in the first Day, at noon in the second day and between 4pm
and 5pm in third day. Samples of feed and feed leftovers in the feed bunk were collected, weighted and sampled
during the day before, the first day and the second day of gathering.
The feed samples, bunk leftovers and feces were oven dried in a temperature of 55ºC during 72 hours. After,
all the samples were ground in Willey slicer with a 2 mm strainer to be incubated, posteriorly, in situ. Half of the 2
mm ground sample was ground in the same slicer in a 1 mm strainer to be analyzed according to Detmann et al.
(2012). The samples from the digestibility test were analyzed on their indigestible neutral detergent fiber (iNDF)
using F57 Ankom® filter bag (Detmann et al., 2012). Thus, it was possible estimate fecal dry matter (fDM) using
iNDF as intern marker. The fecal excretion of the nutrients was obtained multiplying the content of each nutrient in
fecal dry matter by fDM excretion. The apparent digestibility coefficients were obtained subtracting from the feed
intake amount the nutrients in fecal excretion, and the result was divided by the feed intake amount and multiplied
by 100.
The experiment was performed in a completely randomized design. The response variables were analyzed
using PROC GLM in SAS 9.0 (Statistical Analysis System Institute, Inc., Cary, NC, USA). To evaluate the effects
of previous nutritional plane on feed intake and apparent digestibility of nutrients, the data were submitted to
ANOVA and the least square means were compared using Tukey`s method at α = 0.05.
Results and Discussion
As was aimed, feed restriction during growing phase was not capable of generating difference (P<0.05) in
animals growth. During the growing phase, the average daily gain (ADG) by the animals from treatment LH, MH,
HH were -0.6, 0.67 and 1.09, respectively. This animals growth difference during growing phase impacted in
finishing phase, where the animals from LH treatment had compensatory growth, exhibiting higher (P<0.05) ADG1.45 kg/d. However, the ADG during finishing phase did not differ (P>0.05) between the animals from MH and HH
treatments, where their ADG were 1.12 and 0.91 kg/d, respectively.
The nutritional plan which the animals were submitted during growing phase did not affect (P>0.05)
nutrients intake expressed in kg/d during the finishing phase (Table 2). The metabolizable energy intake was not
affected (P=0.620) by previous nutritional plan. However, fiber intake (NDFap) was affected (P<0.01) by previous
nutritional plan when it was expressed in relation to body weight. Feed intake variation might be explained by diet
composition and animal feed intake capacity. However, during finishing phase all the animals were under the same
diet (Table1). This way, the possible differences found might be explained for variation in animals feed intake
capacity. Feed intake capacity of the animals from MH and LH during finishing phase was higher. It was observed
because, even though organic matter (OM) and the nutrients intake did not differ among the treatments, the animals
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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
from LH and MH exhibited lower body weight due their feed restriction during growing phase. Thus, when
expressing NDFap intake in relation to body weight, it was observed a higher value for the previously restricted
animals.
Table 2- Feed intake average and nutrients apparent digestibility coefficient obtained during
finishing phase.
1
Variables
Treatments2
SEM3
P-value
HH
MH
LH
Feed Intake
(n=6)
(n=6)
(n=5)
OM (kg/d)
CP (kg/d)
EE (kg/d)
NFCap (kg/d)
NDFap (kg/d)
NDFap (g/kg PC)
EM (Mcal/d)
Apparent Digestibility Coefficient
7.39
1.33
0.41
3.56
2.09
5.07b
20.01
7.94
1.43
0.44
3.81
2.26
5.94ª
21.63
7.59
1.37
0.42
3.64
2.16
6.22ª
21.20
0.491
0.087
0.027
0.227
0.138
0.173
1.310
0.663
0.679
0.683
0.695
0.618
<0.001
0.620
68.08
68.43
70.14
2.632
0.833
OM
78.56
78.86
79.86
1.190
0.710
CP
86.31
88.86
87.90
1.434
0.405
EE
72.37
73.56
72.06
2.705
0.907
NFCap
50.42
49.68
57.70
4.354
0.361
NDFap
1
MO = organic matter, NDFap = neutral detergent insoluble fiber corrected for ash and protein, CP =
crude protein, EE = ether extract, NFCap = non fiber carbohydrates corrected for ash and protein, ME =
metabolizable energy. 2HH = high gain in both growing and finishing phases, MH = medium body
weight gain during the growing phase and high body weight gain during the finishing phase, LH = low
body weight gain during the growing phase and high body weight gain during the finishing phase.
3
SEM = standard error of the mean. Means differ from each other by Tukey´s method (P<0.05).
Nutritional plan did not affect (P>0.05) nutrients apparent digestibility coefficient. It is known that animals
under compensatory growth present higher efficiency in feed conversion in relation to body weight. This higher
efficiency might be from digestion improvement. However, as it was observed, animals that went through
compensatory gain- LH treatment- did not present a higher apparent digestibility coefficient. On the other hand, the
studies that have evaluated diet digestibility from animals under compensatory gain exhibited controversial results.
Hayden et al. (1993) found a lower DM apparent digestibility coefficient for animals that went through
compensatory gain.
Conclusion
Feed intake and nutrients apparent digestibility were not affected during compensatory gain.
Acknowledgements
Author thanks to FAPEMIG and CNPq for funding support.
References
Detmann, E., Souza, M. A., Valadares Filho, S. C., Queiroz, A. C., Berchielli, T. T., Saliba, E.O. S., Cabral, L. S.,
Pina, D. S., Ladeira, M. M., Azevedo, J.A.G. (2012).Métodos para Análise de Alimentos. Viçosa, MG, Brazil
(1nd ed., p. 214). Visconde do Rio Branco-MG: Suprme Gráfica LTDA.
Hayden, J. M., Williams, J. E., Collier, R.J. (1993). Plasma growth hormone, insulin-like growth factor, insulin, and
thyroid hormone association with body protein and fat accretion in steers undergoing compensatory gain after
dietary energy restriction. Journal of Animal Science 71(12):3327–3338.
Valadares Filho, S.C., Marcondes, M. I., Chizzotti, M. L., & Paulino, P. V. R. (2010). Exigências nutricionais de
zebuínos puros e cruzados-BR CORTE.
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