Revista Brasileira de Zootecnia
versão On-line ISSN 1806-9290
ORLANDO, Uislei Antonio Dias et al. Crude protein levels and amino acid supplementation in diets of gilts maintained in a high environmental temperature from 60 to 100 kg. R. Bras. Zootec. [online]. 2007, vol.36, n.4, suppl., pp.1069-1075. ISSN 1806-9290. http://dx.doi.org/10.1590/S1516-35982007000500012.
This experiment was conduced to determine the level of CP with amino acid supplementation in diets to gilts under high environmental temperature in finishing phase. Thirty-five crossbreed gilts (Landrace x Large White) with an average initial weight of 60.3 kg were allotted in a randomized experimental design with five diets (17.3, 16, 14.7, 13.4, and 12.1% CP) seven replications and one animal by experimental unity. The experimental diets were supplied ad libitum until the end of the experiment when the animals reached the average weight of 100.3 kg. The average temperature inside the room was kept in 30.6ºC and the relative humidity in 71%. The black globe humidity index calculated in the period was 81. Not effect was observed for the reduction of CP level of the diet on the studied performance characteristics (feed intake, weight gain and feed gain ratio). The carcass characteristics (carcass length; loin eye area; backfat thickness and yield of carcass, lean meat, fat and ham) also were not influenced by the CP reduction in the diets. The CP levels and supplementation of amino acids in the dieta influenced the relative and absolute weight of intestine. Smaller values were observed in animals fed diet with smaller level of CP (12.1%). The reduction of CP level in the diet from 17.3 to 12.1% did not harms the performance of gilts maintained in a high environmental temperature from 60 to 100 kg since the diets are properly supplemented with limiting essential amino acids.
Palavras-chave : amino acids; gilts; high environmental temperature; nutrition.