Desempenho, comportamento e composição corporal de touros da raça nelore classificados pelo consumo alimentar residual
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Data
2014-02-24
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Universidade Federal de Goiás
Resumo
The residual feed intake is a measure of feed efficiency that is independent of weight
gain and adult weight. With this you can select efficient animals without
compromising the size at maturity of the animals. Faced with the need to understand
the factors that influence the variability in efficiency of feed utilization by cattle, aimed
to evaluate the performance, behavior and estimated body composition of Bos
Indicus . Hundred and nineteen Nellore with a mean age of 18 months (±36 days)
and average weight of 392 kg (±47kg) for the classification of animals of high,
medium and low feed efficiency were used . The experimental design was completely
randomized and the criterion for classification of animals for residual feed intake
(RFI) used was 0,5 standard deviations above or below the average, which showed a
percentage of 32 % of the total for better efficiency (low RFI), 43,7 % average and
24,3 % showed low efficiency (high RFI). The animals were housed in individual pens
for 83 days provided with feed trough and drinking fountain. The supplied diet
contained 68,4 % total digestible nutrients (TDN) and 11,3 % crude protein (CP) in a
ratio of 62,6 % concentrate and 37,4 % forage. The consumption ratio and the
predicted dry matter intake observed showed a coefficient of determination of 0,5462.
Metabolic mean body weight of the animals, the average daily gain, initial body
weight, final and metabolizable energy intake showed no significant association with
residual feed intake (P>0,05). Significant correlations between the CAR and dry
matter intake (DMI) (r= 0,57), feed conversion (FC) (r=-0,38) and feed efficiency (EA)
(r=0,42) were found. The less efficient animals that were older than those with the
highest efficiency (P<0,05). As for the ultrasound measurements (loin eye area, fat
thickness and rump fat thickness) and also for body composition (muscle tissue, fat
and bone) there was no significant difference (P<0,05) between the classes CAR.
The first evaluation of escape velocity (V1) showed a significant difference (P< 0,05)
between classes of CAR, as well as the time lying ruminating (P<0,05). Selected for
low RFI animals have better efficiency in the use of food without compromising body
composition, and present more docile animals at the end of the study.
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ALMEIDA, Thiago Santos. Desempenho, comportamento e composição corporal de touros da raça nelore classificados pelo consumo alimentar residual. 2014. 40 f. Dissertação (Mestrado em Ciência Animal) - Universidade Federal de Goiás, Goiânia, 2014.