ABSTRACT This work aimed to evaluate the performance and egg quality of lightweight laying hens supplemented with a high biological value mineral, carbo-amino-phospho-chelates (CAPC), compared with inorganic minerals (sulfates), at different recommended values. A total of 320 Dekalb White hens, between 53 and 77 weeks of age, were distributed in a completely randomized design into two treatments, 10 replicates of 16 birds each. The treatments consisted of a reference diet formulated according to breed manual recommendations, in which one group was supplemented with a trace mineral source, CAPC (Cu, 8.6; Fe, 43.7; Mn, 56.4; Se, 0.34; and Zn, 43.7 mg/kg) and the other with a sulfate source, using the levels recommended in the breed manual (Cu, 8; Fe, 60; Mn, 70; Se, 0.25; and Zn, 60 mg/kg). There was no effect of trace mineral supplementation on egg production variables, feed conversion ratio by mass or by dozen eggs, and eggs per housed bird. However, there was an increase in feed intake and weight and mass of eggs when birds fed diet supplemented with CAPC. Regarding egg quality, CAPC supplementation increased the albumen weight and percentage, shell weight, thickness, and strength, and Haugh unit. The eggs from birds fed CAPC supplementation showed higher levels of iron and zinc when compared with eggs from birds fed the sulfate source diet. Better quality rates were observed in variables related to shelf life for the group that received CAPC. Trace mineral sources and recommendations in the diets of high genetic potential laying hens need to be reassessed and allow us to conclude that totally replacing the sulfate for different recommendations of CAPC in laying hen diets helps to improve quality characteristics as well as the nutritional value of eggs.

ABSTRACT The effect of additives used in the feed of broilers on anaerobic bio-digestion of poultry litter was evaluated. Four diets were used: NC: negative control; DFM: NC + 500 ppm direct-fed microbials (DFM) containing Bacillus subtilis and Bacillus licheniformis; ENZ: diet formulated with an enzyme blend (20 ppm phytase, 200 ppm protease and 200 ppm xylanase); DFM+E: ENZ + DFM. Substrates for the anaerobic bio-digestion were prepared with litter from each treatment, containing 4 % total solids (TS). These were used in 16 continuous bio-digesters with a 2 kg d−1 load, to determine the production and potential biogas production and composition during an 85-day period. Influent and effluent samples were collected for the amounts of TS and volatile solids (VS), fiber fraction (neutral detergent fiber [NDF], acid detergent fiber [ADF] and lignin), nutrients (N, P and K), and total and thermotolerant coliforms to be determined. For all treatments a reduction in the following effluents was observed as follows: TS (49, 48, 48 and 50 %) VS (70, 54, 55 and 62 %) NDF (91, 90, 95 and 96 %) ADF (89, 88, 93 and 94 %) and lignin (80, 76, 89 and 88 %). The efficiency of the treatment for coliforms in bio-digesters was higher than 90 % in the 85-day period in all treatment groups. There was a reduction in biogas and methane production when DFM (5500 and 4000 mL) and DFM + E (5800 and 4100 mL) were used, compared to treatments NC (6300 mL and 4400) and ENZ (6400 and 4500 mL). The potential production of reduced TS and VS was higher in ENZ (1:00 and 1.74 106 mL kg−1) when compared to NC (0.88 and 1:02 106 mL kg−1), DFM (0.80 and 1:40 106 mL kg−1) and DFM + E (0.88 1:25 and 106 mL kg−1). The additives did not affect the percentage of methane production, and all treatments showed values higher than 70 %. Adding enzymes to the diet of broilers influences the litter characteristics and, as a consequence, increases biogas production. The addition of DFM and DFM + E to broiler diets reduced biogas and methane production.