17 T. L. de Sena2 S. C. Bastos-Leite A. M. de Vasconcelos C. de C. Goulart M. R. S. de Farias J. de S.Maranguape Journal of Animal and Plant Sciences JAPS 20192019/02/01 29 1 33-40 1018-7081 N/A <p>The aim of this study was to evaluate the physiological parameters and thermal comfort indices of commercial layers<br>fed diets containing different levels of vegetable glycerin. A total of 378 Hy-Line White layers at 32 weeks of age were<br>housed in a shed at nine birds per cage. The experiment lasted 84 days. Treatments consisted of a control diet (without<br>glycerin) plus five diets with increasing levels of vegetable glycerin (3, 6, 9, 12, and 15%). The black globe humidity<br>index (BGHI) and radiant heat load (RHL) were out of the thermal comfort zone and were higher in the afternoon period<br>in all production cycles. Respiratory frequency was lower in the morning, when 3% glycerin were added to the diet. The<br>surface temperatures of comb, wattle, back, wings, head, and feet did not differ with the glycerin levels and were higher<br>in the 2nd cycle, but within the range recommended for the species. Glycerin inclusion levels of up to 12% can be used<br>to partially replace corn in diets for layers housed in sheds covered with ceramic tiles without compromising their<br>thermoregulation in a hot environment.</p> Alternative Feeds. Homeothermy. Poultry Farming. Thermal Environment. Pakistan Agricultural Scientists Forum https://thejaps.org.pk/AbstractView.aspx?mid=AS-17-0200