Growth performance of broiler chickens fed on feeds with varying mixing homogeneity.

In feed manufacturing, the need for an effective combination of ingredients to produce a complete feed for animals is well known. However, limited quantitative data illustrate the effect of low homogeneity on the performance of animals. This study was conducted to determine the coefficient of variation (CV) of feed mixtures produced with different mixing times and the effects of these feeds with varying homogeneity consumed by 1-40-day-old broilers on their feed intake, body weight gain, feed conversion, mortality, and body weight uniformity. The mixing times used were 30, 60, 90, and 120 s, and the CV obtained from the feeds ranged from 49.5% to 5.4%. A linear decrease was observed in the feed CV with increasing mixing time, but sometimes, a longer mixing time did not present the lowest CV. The influence of the lack of feed homogeneity on the performance of broilers was mainly observed in body weight gain and, in some cases, in feed conversion. The effects on feed intake were more consistent for broilers older than 22 days, increasing body weight gain without affecting feed conversion. Our results suggest that feeds with CVs up to 22.6% had no adverse effects on the performance of broilers older than 12 days, and the lack of uniformity in broiler body weight was not influenced by feed homogeneity.

Combined effect of using near-infrared spectroscopy for nutritional evaluation of feed ingredients and non-starch polysaccharide carbohydrase complex on performance of broiler chickens.

This study was carried out to evaluate the combined effect of using near-infrared spectroscopy (NIRS) for nutritional evaluation of feed ingredients and the addition of non-starch polysaccharide carbohydrase complex (NSP enzymes) on the growth performance of broilers fed diets produced with low-quality wheat and soybean meal. A 2 × 2 trial design was performed, with seven replicates of 40 male Ross 308 broilers per treatment, evaluating the effect of the addition of NSP enzymes and the ingredients' nutritional matrix based on table values or NIRS values. Diets without added enzymes were formulated to reach nutritional requirements, whereas diets with enzymes were reformulated, reducing the apparent metabolizable energy (AME) by 85 kcal/kg. In the overall period (days 0-35), broilers fed diets formulated using NIRS values had higher (P < 0.001) average daily gain (+11.3%) and daily feed intake (+7.2%), and a lower (P < 0.001) feed conversion ratio (-5.3%) compared to those fed diets formulated using table values. When formulating diets for broilers with low-quality feed ingredients, performance can be improved by considering NIRS values and by the addition of NSP enzymes, even with a reduction of AME. These nutritional approaches are efficient in improving broilers' performances by themselves and even more so when they are combined.

Next-generation non-starch polysaccharide-degrading, multi-carbohydrase complex rich in xylanase and arabinofuranosidase to enhance broiler feed digestibility.

This study was carried out to evaluate the effect of a multi-carbohydrase complex (MCC) rich in xylanase (Xyl) and arabinofuranosidase (Abf) on overall broiler feed digestibility in broilers. Energy utilization and digestibility of dry matter (DM), organic matter (OM), protein, starch, fat, and insoluble and soluble fibers were measured using the mass-balance method. The experiment was carried out on 120 broilers (3-week-old chickens). Broilers were distributed over 8 treatments to evaluate the effect of the dietary arabinoxylan content and nutrient density with and without MCC (Rovabio® Advance). The graded content of arabinoxylan (AX) was obtained using different raw materials (wheat, rye, barley, and dried distillers' wheat). Diet-energy density was modified with added fat. Measurements indicated that nutrient density and AX content had a significant effect on most digestibility parameters. Apparent metabolizable energy (AME) was significantly increased (265 kcal kg-1) by MCC. The addition of MCC also resulted in significant improvement in the digestibility of all evaluated nutrients, with average improvements of 3.0, 3.3, 3.2, 3.0, 6.2, 2.9, 5.8, and 3.8% units for DM, OM, protein, starch, fat, insoluble and soluble fibers, and energy utilization, respectively. The interaction between MCC and diet composition was significant for the digestibility of OM, fat, protein, and energy. Nutrient digestibility and diet AME were negatively correlated with AX content (P < 0.001). However, the addition of MCC resulted in a reduction of this negative effect (P < 0.001). The AME of diets with and without the addition of MCC were successfully predicted by the diet digestible nutrient (i.e., starch, protein, fat, insoluble and soluble fibers) content with and without MCC (R2 = 0.87; RSD = 78 kcal kg-1). This study confirms that the presence of AX in wheat-based diets and wheat-based diets with other cereals and cereal by-products reduces nutrient digestibility in broiler chickens. Furthermore, the dietary addition of MCC, which is rich in Xyn and Abf, reduced deleterious effect of fiber and improved overall nutrient digestibility in broiler diets.

Changes in the microbiological quality of mangrove oysters (Crassostrea brasiliana) during different storage conditions.

This study aimed to determine the effect of temperature and period of postharvest storage on the microbiological quality and shelf life of raw mangrove oysters, Crassostrea brasiliana. A total of 150 dozen oysters were collected directly from the points of extraction or cultivation in southern Brazil, and in the laboratory, they were stored raw at 5, 10, 15, 20, and 25°C for 1, 4, 8, 11, and 15 days. On each of these days, the oysters were subjected to microbiological analyses of aerobic mesophilic count, total coliforms, enterococci, Escherichia coli, Staphylococcus aureus, and Salmonella. None of the tested samples under any storage condition showed contamination levels above those allowed by Brazilian legislation for E. coli, S. aureus, and Salmonella, and there was no change (P > 0.05) in the counts of these microorganisms due to the temperature and/or period of oyster storage. Counts of enterococci and total coliforms showed a tendency to increase (P < 0.05) among the different temperatures tested. Raw mangrove oysters remain in safe microbiological conditions for consumption up to 8 days after harvesting, regardless of temperature, and their shelf life may be extended to 15 days if they are stored at temperatures not exceeding 15°C.