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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 da quantidade de leite e do fornecimento de ração concentrada sobre a composição corporal de
bezerros lactentes1
Marta Maria dos Santos Fontes2, Alex Lopes da Silva3, Lucas Faria Gomes4, Ariane Silveira e Silva4, Fabíola
Vasconcelos de Almeida4, Marcos Inácio Marcondes5
1
Parte da dissertação de mestrado do segundo autor, financiada pelo CNPq.
Estudante de graduação em Zootecnia - UFV,Viçosa, BRA. Bolsista Funarbic, e-mail:[email protected]
3
Doutorando do Programa de Pós-Graduação em Zootecnia – UFV, Viçosa, BRA, Bolsista da CAPES
4
Estudante de graduação em Zootecnia - UFV,Viçosa, BRA
5
Professor Associado do Departamento de Zootecnia, UFV, Viçosa, BRA
2
Resumo: Objetivou-se avaliar o efeito do fornecimento de diferentes níveis de leite, em combinação ou não com o
fornecimento de concentrado, sobre a composição corporal de bezerros mestiços Holandês×Gir lactentes, até os 64
dias de vida. Foram utilizados 39 bezerros mestiços com idade inicial de 4 dias e peso vivo médio inicial de 36±1
kg. Cinco animais foram designados como grupo referência e abatidos aos 4 dias de vida para estimar a composição
corporal dos animais mantidos em alimentação. Os demais animais foram distribuídos de acordo com um
delineamento inteiramente casualizado em esquema fatorial 3 × 2, consistindo de 3 níveis de leite (2, 4 e 8
litros/dia) e dois níveis de concentrado (presença ou ausência na dieta). Aos 64 dias de vida todos os animais foram
abatidos e os tecidos corporais foram amostrados para análises. Não foi observado efeito dos níveis de leite e a
inclusão de concentrado na composição corporal final dos animais. A deposição de gordura aumentou linearmente,
ao passo que os conteúdos de proteína e cinzas diminuíram linearmente com o aumento na oferta de leite. A
presença de concentrado foi responsável por aumento na teor corporal de gordura, mas não teve efeito sobre os
conteúdos de proteína e cinzas. Conclui-se que altos volumes de leite estão associados com uma maior deposição de
gordura, principalmente quando estão associados ao fornecimento de concentrado.
Palavras–chave: abate, consumo, gordura, proteína
The effects of amounts of milk and starter feed supply on body composition of suckling dairy calves
Abstract: The objective was to evaluate the effect of different levels of raw milk, alone or in combination with
access to a starter feed, on body composition of Holstein×Gyr crossbred suckling calves until 64 days of age.
Thirty-nine male calves aged 4 days with an average initial live weight of 36±1.0 kg were used. Five calves were
defined as a reference group and slaughtered at four days of age to estimate the initial body composition of the
animals. The other calves were distributed according to a completely randomized design in a 3 × 2 factorial
arrangement consisting of three levels of milk (2, 4 or 8 L/day) and two levels of starter feed (presence or absence
in diet). At 64 days of age, all animals were slaughtered and their body tissues were sampled for analyses. There
was no interaction effect between milk level and starter feed inclusion on the final body composition of animals. Fat
body content increased linearly, according to milk supply. On the other hand, protein and ash content decrease
linearly according to milk levels. The presence of starter feed was responsible for the increased body fat content,
but had no effect on protein or ash content. In conclusion, high amounts of milk are associated with greater fat
deposition in the empty body weight of calves, principally when starter feed is supplied.
Keywords: fat, intake, protein, slaughter
Introduction
Some strategies have been utilized to accelerate the growth rate of calves during suckling phase, such as
supply of greater amounts of milk, the alteration of milk replacer composition or even the supply of starter feed,
both strategies are used with the aim to increase nutrient intake and improve performance (Silva et al., 2015).
Although young animals have more tendency to deposit more protein than fat (Marcondes et al., 2015),
however, increases in body weight gain do not reflect gain of lean tissue and increases in fat deposition are
commonly observed (Hill et al., 2008).
Thus, this study was designed to evaluate the effect of supplying different amounts of milk, alone or in
combination with access to a starter feed, on body composition of Holstein×Gyr crossbred suckling calves until 64
days of age.
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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
Material e Methods
The experiment was approved by the Ethics Committee on Animal Use of Universidade Federal de Viçosa
(Viçosa, MG, Brazil), under protocol no. 049/2012.
Thirty-nine uncastrated crossbred male calves were used (½ to ¾ Holstein×Gyr) with an average initial body
weight of 36±1.0 kg. In total, five animals were used as a reference group, and were slaughtered at four days of age
and analyzed for body composition as described below. The other calves were distributed according to a completely
randomized design in a 3×2 factorial arrangement consisting of three levels of milk (2, 4 and 8 liters/day) and two
levels of starter feed (with and without free access). Milk was supplied to animals, using pails, in two daily meals:
at 0600h and 1500h, whereas starter feed (only for treatments that contained it) and water were available to animals
ad libitum.
At the end of the experiment, all animals were slaughtered after being deprived of solid feed for 14 hours.
The gastrointestinal tract were washed and weighted for quantify the empty body weight (EBW). The body
components of each animal were weighed and completely ground in an industrial grinder. The slaughter procedure
for the reference group was similar to that adopted for other animals.
Milk, starter feed and body components were analyzed for dry matter (DM), ash, crude protein (CP) and
ether extract (EE) contents (AOAC, 1995). While, starter feed was also evaluated for neutral detergent fiber (NDF).
The final body composition of animals was calculated as follows:
BC y 
Cy
EBW f
[1]
 100
where: BCy = body composition of protein, fat or ash (% on dry matter basis); Cy = protein, fat or ash constituent in
the final empty body weight (kg); and EBWf = final empty body weight (kg).
All statistical analyses were carried out by ANOVA using the PROC MIXED procedure of SAS (version
9.3) and significance of treatment effects was declared at P < 0.05.
Results and Discussion
There was no interaction effect (P > 0.05) between milk level and starter feed inclusion on the final body
composition of animals. Milk levels affected body content of protein and ash, showing a linear decrease, according
to the increased milk allowance (Table 1). In contrast, milk levels also linearly affected fat body content, showing
an increase according milk supply. The supply of starter only affected fat body content, with greater fat content
when starter was supplied compared with diets without starter, but starter had no effect on protein or ash content
(Table 1).
Table 1 – Body composition of dairy calves (n=34; reference group n=5) feeding different amounts of milk (2L, 2
L/d; 4L, 4 L/d; 8L, 8 L/d) and receiving starter feed (+S) or no starter feed.
P-Value
Treatments
Items
2L
4L
8L
2L+S
4L+S
8L+S
SD1
M2
S2
(% of EBW in dry matter basis)
Protein
67.40
65.30
59.22
66.04
62.72
59.38
1.2122
<0.001
0.135
Fat
15.40
20.19
28.23
18.44
23.74
28.24
1.2732
<0.001
0.016
Ash
17.19
12.91
12.54
15.50
Standard deviation.
2
L = milk levels effects and S = starter feed effect.
13.53
12.37
1.2015
0.002
0.616
1
Increase in body fat deposition is linked to an increased energy intake by animals (Mills et al., 2010), which
was achieved when milk supply was increased and starter feed was included in the diet. Thus, an decrease in body
protein content is likely related to the increased body fat content, which caused a dilution effect on protein content
(Labussiere et al., 2008)
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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
Conclusions
High amounts of milk are associated with greater fat deposition in the empty body weight of calves,
principally when starter feed is supplied.
Acknowledgements
We are grateful to CAPES, CNPq, FAPEMIG, INCT-CA and EMBRAPA-Gado de Leite for all help in this
study.
References
AOAC, Official methods of analysis. 1995. Association of Official Analysis Chemists, 16th edn Arlington,
VA.
Hill, S. R.; Knowlton, K. F.; Daniels, K. M.; James, R. E.; Pearson, R. E.; Capuco, a V; Akers, R. M., 2008:
Effects of milk replacer composition on growth, body composition, and nutrient excretion in preweaned Holstein
heifers. Journal of Dairy Science 91: 3145–3155.
Labussiere, E.; Dubois, S.; van Milgen, J.; Bertrand, G.; Noblet, J., 2008: Effects of dietary crude protein on
protein and fat deposition in milk-fed veal calves. Journal of Dairy Science 91: 4741–4754.
Marcondes, M. I.; Tedeschi, L. O.; Filho, S. de C. V.; Costa e Silva, L. F.; Silva, A. L., 2015: Using growth
and body composition to determine weight at maturity in Nellore cattle. Animal Production Science (In press).
Mills, J. K.; Ross, D. A.; Van Amburgh, M. E., 2010: The effects of feeding medium-chain triglycerides on the
growth, insulin responsiveness, and body composition of Holstein calves from birth to 85 kg of body weight.
Journal of Dairy Science 93:4262–4273.
Silva, A. L.; Marcondes, M. I.; Detmann, E.; Machado, F. S.; Valadares Filho, S. C.; Trece, A. S.; Dijkstra, J.,
2015: Effects of raw milk and starter feed on intake and body composition of Holstein × Gyr male calves up to 64
days of age. Journal of Dairy Science 98: 2641–2649.
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