Abstract:The present study aimed to evaluate the effect of thermal processing, press throughput and roller-die gap on pellet physical quality, protein solubility and starch gelatinization in a corn-soybean based broiler diet. The different processing factors were combined in a 2 × 5 × 3 factorial arrangement with eight randomized block consisting of eight production series: two thermal processing treatments (conditioning-pelleting or conditioning-expanding-pelleting), five press throughput levels (18, 21, 24, 27 and 30 ton/h) and three roller-die gap (0.50, 0.75 and 1.00 mm), which resulted in 30 different processed feeds. For determination of pellet durability index (PDI), amount of intact pellets, degree of starch gelatinization and protein solubility, one composed feed sample was collected per treatment in each of eight production series, totaling eight replicates per treatment. Data concerning the amount of intact pellet and protein solubility in KOH were transformed using a variation of Box-Cox transformation in order to fit a normal distribution (P > 0.05). Pellet physical quality was enhanced by conditioning-expanding treatment (P < 0.01), narrower roller-die-gap (P < 0.01) and reduced press throughput (P < 0.01). Protein solubility in KOH was impaired (P < 0.01) in the expander treatment and larger roller-die distance (0.75 mm and 1.00 mm) (P < 0.01). Finally, greater starch gelatinization degree was achieved in expanded treatment (P < 0.01) and in 1.00 mm roller-die gap (P < 0.05). The factors evaluated in this study resulted in interactions and significant effects on physicochemical properties of broiler feed pellets.

-The objective of this work was to determine the correlation of the physical attributes of corn and the mycotoxins present in its grains with the severity of tongue lesions in broiler breeder roosters. The occurrence of the aflatoxin, vomitoxin, zearalenone, T-2 toxin, and fumonisin mycotoxins was detected in the corn grains used in the feed formulation for breeder chickens. The percentages of moisture and broken grains were positively correlated (Pearson's correlation) with the presence of aflatoxin. Milder lesions (grade 1) are positively correlated with aflatoxin and negatively correlated with fumonisin, and the most severe lesions (grade 3) are positively correlated with vomitoxin, fumonisin, and T-2 toxin.

Bird breeding is based on the use of grains that require quality for the processing of the rations. Among the possible contaminants that affect the success of the enterprise are mycotoxicoses caused by fungi, from the field to the storage of the ingredients present in the formulations of the diets. The toxins with the greatest impact on poultry farming are aflatoxin B1, ochratoxin A, T-2 toxin and diacetoxiscirpenol (DAS), vomitoxin and deoxynivalenol (DON), zearalenone and fumonisin B1. These compounds cause losses in production, as a result of lower feed intake, mainly for causing lesions in the oral route of the animals, which consequently decreases the weight gain, feed conversion, and meat and egg production, as well as metabolic disorders. Maize consists of a grain with a greater presence of these mycotoxins, being extremely important the monitoring of its qualification in order to offer rations with nutritional and sanitary safety, with success in the business and products of quality and food safety for human consumption.