Digestible methionine+cysteine in the diet of commercial layers and its influence on the performance, quality, and amino acid profile of eggs and economic evaluation.

This work aimed at evaluating the effects of 4 digestible Met+Cys levels on the diet of commercial layers and their influence on the productive performance, quality, and amino acid profile of eggs and economic viability of the activity. A total of 576 white Lohmann LSL-Lite layers was distributed into 6 replicates of 24 birds for each diet. The experimental design was completely randomized, with 4 treatments defined by levels evaluated in the feed (0.465, 0.540, 0.581, and 0.647%). The productive performance was measured for 30 weeks. The quality (34 and 50 wk old) and the amino acid profile of eggs (43 wk old) also were evaluated. A linear positive response was observed at higher Met+Cys levels for feed intake, number of eggs per housed bird, and digestible Met+Cys intake. Egg production, egg weight, egg mass, feed efficiency, and weight gain had their optimal values determined by the quadratic regression model at 0.638, 0.654, 0.647, 0.644, and 0.613% digestible Met+Cys, respectively. In the 34th wk, eggshell thickness decreased linearly at higher Met+Cys levels. In the 50th week, the optimal levels detected for eggshell thickness and percentage were 0.571 and 0.570% digestible Met+Cys, respectively. The percentages of proteins, branched-chain amino acids (leucine, isoleucine, and valine), histidine, and proline in eggs (albumen+yolk) showed a linear negative response in function of higher Met+Cys levels. Higher digestible Met+Cys levels (>0.630%) led to a good performance of layers, while lower Met+Cys levels improved the eggshell quality of layers in peak production. Optimal Met+Cys levels may change according to the price of the synthetic amino acid.

Effects of Anacardium humile leaf extracts on the development of gastrointestinal nematode larvae of sheep.

The rapid development of nematode resistance to anthelmintics has limited the success of small ruminant gastrointestinal helminthiasis control in several countries, stimulating the search for alternatives. The aim of this work was to evaluate the in vitro anthelmintic activity of Anacardium humile (Anacardiaceae) on gastrointestinal nematodes of sheep. Aqueous and ethanolic extracts of A. humile leaves were evaluated by the larval development inhibition assay at concentrations of: 187.5, 150, 100, 50, and 30 mg ml(-1); and 100, 80, 60, 40, and 20 mg ml(-1), respectively. Phytochemical analysis demonstrated the presence of tannins, flavenoids, and alkaloids in the leaves. The LD(50) was 10.14 mg ml(-1) for the aqueous extract and 23.24 mg ml(-1) for the ethanolic extract, providing evidence for the potential of this plant in the endoparasite control.