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Revista Brasileira de Zootecnia
On-line version ISSN 1806-9290
FERREIRA, Rony Antonio et al. Reduction of dietary crude protein levels and amino acid supplementation for 30 to 60 kg barrows maintained in a high environmental temperature. R. Bras. Zootec. [online]. 2007, vol.36, n.4, pp. 818-824. ISSN 1806-9290. http://dx.doi.org/10.1590/S1516-35982007000400010.
This experiment was carried out to evaluate the influence of the reduction of dietary CP levels and amino acid supplementation on performance of barrows maintained in a high environmental temperature. A total of sixty crossbreed (Landrace x Large White) piglets (average body weight = 29.8 kg) was allotted in a completely randomized experimental design with five treatments (17, 16, 15, 14 and 13% CP), six replications and two animals per experimental unit. Diets and water were suplied ad libitum until the end of the experimental period, when the animals reached the average weight of 59.9 kg. The average temperature in the room was maintained at 32.2ºC and the relative humidity at 74.4%, corresponding to a Black Globe-Humidity Index of 82.8. The reduction of dietary CP level affected weight gain (WG). The animals fed 14% CP diet showed significant WG reduction. Feed intake (FI) also was affected by CP level, and the animals fed 14% CP diet showed smaller FI values than those fed 16 and 13% CP diets. Feed:gain ratio was not affected by treatments. The animals fed the diet with 14% CP showed the smallest values of protein and fat deposition rates in the carcass. The animals fed the diet with 17% CP showed higher kidneys weights. It was concluded that dietary CP level for barrows from 30 to 60 kg body weight, maintained in a high environmental temperature, can be reduced from 17 to 13% with no effect on performance and protein deposition rate in carcass since diets are supplemented with essential amino acids.
Keywords : amino acids; high environmental temperature; nutrition; swine.