ABSTRACT The objective of this study was to evaluate the L-arginine supplemental effects for broilers in the final rearing phase (29 and 42 days), during which they were exposed to heat stress and fed diets with different metabolizable energy levels. Performance, carcass parameters, and physiological and biochemical parameters related to lipid metabolism were evaluated. A completely randomized design was used, in a 3 × 2 factorial arrangement, corresponding to three metabolizable energy levels (3000, 3150, and 3300 kcal/kg) in diets supplemented or not with L-arginine (0.66%). Eight replicates composed by eight broilers each (experimental units; boxes) per treatment were evaluated, totaling 48 experimental units. Performance was evaluated in the period from 29 to 42 days old, and carcass and blood parameters were measured at 42 days old. L-arginine supplementation improved feed conversion and blood profile, mainly due to the reduction of total and LDL-cholesterol levels. Broilers that received 3300 kcal/kg of metabolizable energy showed the greatest weight gain, regardless of supplementation or not with arginine. The dietary supplementation with 0.66% of L-arginine for heat-stressed broilers can be recommended, regardless of the feed energy level. Larginine L arginine (2 4 days, , days) used arrangement 3000, 3000 (3000 3150 330 kcalkg kcal kg 0.66%. 066 . 0 66 (0.66%) units boxes old profile LDLcholesterol LDL cholesterol gain 0.66 heatstressed stressed recommended level ( 300 (300 315 33 06 6 (0.66% 0.6 30 (30 31 (0.66 0. (3 (0.6 (0. (0

ABSTRACT Two experiments were carried with broilers from 29 to 42 days of age for the nutritional evaluation of dietary chia. Thus, the nitrogen-corrected apparent metabolizable energy (AMEn) and the apparent metabolizability coefficients of gross energy and ether extract of chia seeds and oil, toasted soybean grain (TSG), and soybean oil were determined in the experiment I, by total excreta collection method, using 120 broilers. Each experimental diet (reference diet [RD] and four diets with the tested feedstuffs) was evaluated in eight replicates of three broilers. The TSG and chia seeds replaced the RD in 250 g/kg, whereas soybean and chia oils replaced the RD in 100 g/kg. Simultaneously, a second experiment was carried subdivided into two trials. In the performance trial, we evaluated the dietary feedstuffs effects on performance, carcass and cut yields, blood parameters, and activity of lipogenic enzymes. The nutrient metabolizability coefficients and AMEn were evaluated in the metabolism trial. The AMEn values of 37.49, 37.35, 15.85, and 8.43 MJ/kg of dry matter were determined for chia oil, soybean oil, TSG, and chia seeds, respectively (experiment I). In the second experiment, the best feed conversion was observed in broilers fed diets containing chia oil and TSG. However, the diet formulated with chia seeds worsened broiler feed conversion, exhibited the smaller energy value and apparent metabolizability coefficient of the ether extract, and increased the activity of the malic enzyme and serum total cholesterol level. There was no difference for glucose-6-phosphate dehydrogenase activity and high-density lipoprotein cholesterol level. In general, chia oil showed to be efficient in replacing soybean oil in broiler diets.

ABSTRACT The present study examined the effect of aflatoxin (AFB1) and fumonisin (FB1) at the levels of 2 mg kg−1 AFB1 and 100 mg kg−1 FB1 and the efficiency of use of different levels of adsorbent based on sodium and calcium aluminosilicate on growth performance, hematological parameters, and biochemical parameters of broilers. A total of 1,440 Cobb broilers were distributed into the following treatments: positive control (PC) - no mycotoxin and adsorbent (AD); PC+3AD - no mycotoxin, with 3 g kg−1 adsorbent in feed; negative control (NC) - only mycotoxin; NC+1AD - with mycotoxin and 1 g kg−1 adsorbent in feed; NC+2AD - with mycotoxin and 2 g kg−1 adsorbent in feed; and NC+3AD - with mycotoxin and 3 g kg−1 adsorbent in feed. The amounts of AFB1 and FB1 added to NC reduced weight gain (35%) and feed intake (50%) compared with PC; however, inclusion of 2 or 3 g kg−1 adsorbent to NC alleviated such losses. Birds fed NC showed anemia, immunosuppression, and impaired liver function, observed by reduced cholesterol and increased gamma glutamyl-transferase activity compared with PC; values returned to normal levels when 2 or 3 g kg−1 of the adsorbent (as fed) were used. Mycotoxins cause adverse effects on most of the parameters studied, and the use of adsorbent at the levels of 2 and 3 g kg−1 of the adsorbent as fed partially negates the adverse effect of mycotoxicosis.