Valor nutritivo do resíduo de algodoeira submetido a tratamento químico

Abstract

The objective was to evaluate the effects of urea and sodium hydroxide (NaOH), in different concentrations and days of exposure, on cottonseed residue, on its bromatological composition. Two experimental trials were conducted in the Laboratory of Animal Nutrition of the Nucleus for Study and Research in Animal Production - NEPPA, campus IX of the University of the State of Bahia, in Barreiras - BA. For both experiments an entirely randomized design (DIC) was adopted, in a 4x4 factorial scheme (four levels of chemical additives and four opening times), with four repetitions each. In the first trial, the treatments were different concentrations of urea in cottonseed residue: 0; 2; 4 and 6% based on dry matter (DM). In the second trial, different concentrations of NaOH in cottonseed residue were used: 0; 1.5; 3.0 and 4.5%, based on dry matter (DM). For both, openings were made at 7, 14, 28 and 56 days after the applications. The variables neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose (HEM) and in vitro dry matter digestibility (IVDMD) showed no significant interaction with respect to the days of treatment and urea dose used. However, for dry matter (DM), mineral matter (MM) and crude protein (CP) there was a significant interaction. When NaOH was used, it was observed that there was no interaction between the applied doses and treatment times for crude protein (CP), fiber in neutral detergent (FDN), fiber in acid detergent (FDA), hemicellulose (HEM) and in vitro dry matter digestibility (DIVMS). However, there was an interaction between days of openings and levels used for dry matter (DM) and mineral matter (MM). Given the above, the use of urea and sodium hydroxide are effective in the chemical treatment of cottonseed residue, providing reduction of fibrous components (FDN AND FDA), improving the quality of the fibrous fraction and increasing the digestibility of dry matter. It is recommended 4 to 6% urea, based on dry matter, to treat cottonseed residue for a period of 14 and 28 days. For sodium hydroxide, a level of 4.5%, based on dry matter, is recommended for the treatment of cottonseed residue for a period of seven days. Therefore, following the recommendations is of fundamental importance for a better action of the chemical compound on the cottonseed residue without generating negative effects, in order to improve its nutritional value.