No abstract

The effect of organic acids as an alternative to antibiotics on the performance of broiler chickens was evaluated by meta-analysis, identifying and quantifying the main factors that influence results. A total of 51,960 broilers from 121 articles published between 1991 and 2016 were used. Interactions of additives [non-supplemented group (control), organic acids, and growth promoter antibiotics] with microbial challenge (with or without inoculation of pathogenic microorganisms) were studied on performance variables. Moreover, the effects of organic acids, used individually or in blends, were evaluated. Relative values of average daily gain (ADG) and average daily feed intake (ADFI) were obtained in relation to control: ΔADG and ΔADFI, respectively. Analysis of variance-covariance revealed lower ADG with organic acids when compared to antibiotics (P < 0.05). There was a significant interaction between the additives and the challenge on feed conversion ratio (FCR) (P < 0.01) and on viability (P < 0.05). Without challenge, organic acids improved broilers’ FCR (P < 0.01), presenting results similar to antibiotics (P > 0.05). Under challenge, the organic acids were again effective on FCR (−5.67% in relation to control, P < 0.05), but they did not match antibiotics (−13.40% in relation to control, P < 0.01). Viability was improved only under challenge conditions, and only by antibiotics (+4.39% in relation to control, P < 0.05). ADG (P < 0.05) and FCR (P < 0.01) were increased by blends of organic acids, but not by the organic acids used alone (P > 0.05). ADFI and production factor were not influenced by the treatments (P > 0.05). ΔADFI of organic-acid supplemented group showed a linear influence on ΔADG, which increases 0.64% at every 1% increase in ΔADFI. In conclusion, organic acids can be utilized as performance enhancing, but the results are lower than those found with antibiotics, particularly under microbial challenge. The blends of organic acids provide better results than the utilization of one organic acid alone.

The present study was carried out to evaluate the excretion of aflatoxin B1 residues in eggs of young laying hens fed aflatoxin B1-contaminated rations for 8 weeks. To this end, 96 twenty-week-old hens were randomly distributed into four experimental groups (24 birds per group) and given rations containing either 0 (controls), 100 micrograms, 300 micrograms or 500 micrograms aflatoxin B1/kg feed. Egg aflatoxin B1 residues were determined by thin layer chromatography; two samples per treatment per week were used for analysis. Egg production and average egg weights were not affected (p < 0.05) in the groups receiving aflatoxin B1-contaminated rations. Residues of aflatoxin B1 were detected only in the eggs of hens given 500 micrograms/kg feed, at levels that ranged from 0.05 to 0.16 microgram/kg (average: 0.10 microgram/kg). The results indicate that the feed to eggs aflatoxin B1 transmission ratio was approximately 5000:1, emphasizing the importance of controlling aflatoxin levels in rations for laying hens.

In the present study, 256 7-wk-old Japanese quail were randomly distributed into four experimental groups (64 birds per group) and given rations containing 0 (controls), 25, 50, or 100 (g aflatoxin B, (AFB1)/kg feed for 168 d. Each treatment consisted of four replicates of 16 quail. Egg production and individual egg weight were checked daily. Feed consumption and feed use were determined weekly. Eggs laid in the last day of each 28-d laying period were collected and subjected to individual analysis for specific gravity, Haugh units, shell thickness and percentage eggshell. Results showed that average egg production, feed use, and body weights were not affected (P > 0.05) by AFB1. However, feed consumption was lower (P < 0.05) for groups fed 50 or 100 microg AFB1/kg. Egg weight was significantly lower (P < 0.05) only for groups exposed to 50 and 100 microg AFB1/kg. Average egg specific gravity, Haugh units, and shell thickness were not affected (P > 0.05) by AFB1. Percentage eggshell was higher (P < 0.05) in the group fed the ration containing 100 microg AFB1/kg. Treatment associated lesions were observed only in the liver. Hepatic cell vacuolation with fatty infiltration was observed in all liver samples of quail fed AFB1-contaminated rations. Bile duct proliferation and trabecular disorder were found only in livers of quail on the 100-microg AFB1/kg treatment. Results indicated that chronic exposure to AFB1 at levels above 50 microg/kg could adversely affect quail performance, emphasizing the importance of controlling aflatoxin contamination in quail rations.

The effects of prolonged oral administration of aflatoxin B1 (AFB1) and fumonisin B1 (FB1) mycotoxins were evaluated in broiler chickens from 21 to 42 d of age. A total of 192 birds were housed in experimental batteries and assigned to 32 cages, 6 birds per cage. The following treatments were applied: 1) 0 mycotoxins (control), 2) 10 mg of FB1, 3) 50 microg of AFB1, 4) 50 microg of AFB1 + 10 mg of FB1, 5) 350 microg of AFB1, 6) 350 microg of AFB1 + 10 mg of FB1, 7) 2,450 microg of AFB1, 8) 2,450 microg of AFB1 + 10 mg of FB1/kg of feed. Each treatment consisted of 4 replicates of 6 birds each. At the end of the trial, blood samples from 12 birds per treatment were collected, and the birds were necropsied. Compared with controls, the percentage of heterophils was lower (P < 0.05) in birds from groups receiving 50 microg of AFB1/kg + 10 mg of FB1/ kg and 2450 microg of AFB1/kg alone or in combination with FB1. A higher percentage of lymphocytes (P < 0.05) was observed in birds fed 50 microg of AFB1/kg + 10 mg of FB1/ kg, 350 microg of AFB1/kg, and 2,450 microg of AFB1/kg. A decrease in plasma albumin was observed only in birds fed 2,450 microg of AFB1/kg + 10 mg of FB1/kg. The liver of AFB1-treated birds had focal areas of necrosis and inflammatory infiltrates. In birds fed rations containing only 10 mg of FB1/kg, bile duct hyperplasia with fibrosis and a mononuclear infiltrate accompanied by trabecular derangement were observed. In contrast, in treatments in which FB1 was administered in combination, hepatic vacuolar degeneration was observed, and renal tissue presented corpuscles with increased cellular agglomeration, characterizing glomerulonephritis, and a clearly visible tubular epithelium with areas of degeneration and necrosis. The FB1 residues were detected in liver and in excreta of all FB1-treated groups, at levels that ranged from 0.013 to 0.051 mg/kg and from 1.19 to 2.79 mg/kg, respectively. Results indicated that FB1 and AFB1, singly or in combination at the levels evaluated, do not change markedly the hematological and serological parameters of broiler chickens, but may cause relevant lesions in liver and in kidneys.

In the present study, 288 8-wk-old Japanese quail were randomly distributed into 6 experimental groups (48 birds per group) and fed the following diets for 140 d: 1) 0 (control); 2) 10 mg of fumonisin B1 (FB1); 3) 50 microg of aflatoxin B1 (AFB1); 4) 50 microg of AFB1 + 10 mg of FB1; 5) 200 microg of AFB1; and 6) 200 microg of AFB1 + 10 mg of FB1/kg of feed. Each treatment consisted of 4 replicates of 12 quail. Egg production and individual egg weight were checked daily. Feed intake and feed conversion were determined weekly. Results showed that by the end of the fifth cycle, average egg weight was lower (P < 0.05) in groups fed 10 mg of FB1/kg, 50 microg of AFB1/kg, 200 microg of AFB1/kg, and 10 mg of FB1 + 50 microg of AFB1/kg of feed. Egg production decreased (P < 0.05) in birds fed 10 mg of FB1/kg by the third, fourth, and fifth cycles. Feed intake was lower (P < 0.05) in birds fed 10 mg of FB1/kg by the fourth and fifth cycles, and in birds fed 50 and 200 microg of AFB1/kg in the fifth cycle. Birds fed 10 mg of FB1 + 50 microg of AFB1/kg consumed less feed (P < 0.05) in the first, second, and fifth cycles. Results indicated that prolonged administration of FB1 and AFB1, singly or in combination at the levels evaluated, may cause economic losses to quail egg producers.

Three experiments with a 2 × 2 × 2 factorial arrangement were conducted to evaluate maize-based diets for broilers containing different lipid sources [soybean oil (S) or beef tallow (T)] supplemented with or without lysophospholipids and organic acids on nutrient balance (Experiment I, evaluation period of 10-14 d), on liver concentration of fat-soluble vitamins, on jejunal microbiota (Experiment II, sampling at d 14) and on performance (Experiment III, accumulated periods of 1-14, 1-21 and 1-42 d). A total of 1344 male chicks were used. In each experiment, the birds were allotted in a completely randomised design with 8 replications. The lysophospholipids were mainly composed of lysolecithins and the organic acids blend was constituted by lactic (40%), acetic (7%) and butyric acids (1%). An interaction between lipid sources and lysophospholipids was observed on faecal apparent digestibility of lipid (ADL), which improved with lysophospholipids addition in T diets. Broilers fed on S had higher ADL and faecal apparent digestibility of nitrogen-corrected gross energy (ADGE). It was not possible to demonstrate a significant treatment effect on the liver concentration of vitamins A and E, even with the differences in fatty acid profile between S and T. Enterobacteria values were below the detection threshold. Lysophospholipid supplementation reduced gram-positive cocci in T-fed birds. S diets promoted lower total anaerobe counts compared with T diets, independent of additives. S diets increased BW gain and feed:gain ratio in all evaluation periods. Lysophospholipids and organic acids improved feed:gain ratio at 1-21 d in T diets. Furthermore, main effects were observed for lysophospholipids and organic acids at 1-42 d, which increased BW gain and improved feed:gain ratio, respectively. No positive interactions between additives were found.

Detailed cleaning and disinfection programs aims to reduce infection pressure from microorganisms from one flock to the next. However, studies evaluating the benefits to poultry performance, the sanitary status of the facilities, and the sanitary quality of the meat are rarely found. Thus, this study was designed to evaluate 2 cleaning and disinfecting programs regarding their influence on productive performance, elimination of Campylobacter, and characterization of Campylobacter jejuni strains when applied to broiler chickens’ facilities. Two subsequent flocks with 960 birds each were distributed into 32 pens containing 30 birds each. In the first, the whole flock was inoculated with a known strain of Campylobacter jejuni in order to contaminate the environment. In the second flock, performance and microbiological evaluations were done, characterizing an observational study between 2 cleaning and disinfection programs, regular and proposed. The regular program consisted of sweeping facilities, washing equipment and environment with water and neutral detergent. The proposed cleaning program consisted of dry and wet cleaning, application of 2 detergents (one acid and one basic) and 2 disinfectants (250 g/L glutaraldehyde and 185 g/L formaldehyde at 0.5% and 210 g/L para-chloro-meta-cresol at 4%). Total microorganism count in the environment and Campylobacter spp. identification were done for the microbiological assessment of the environment and carcasses. The positive samples were submitted to molecular identification of Campylobacter spp. and posterior genetic sequencing of the species identified as Campylobacter jejuni. The birds housed in the facilities and submitted to the proposed treatment had better performance when compared to the ones in the regular treatment, most likely because there was a smaller total microorganism count on the floor, walls, feeders and drinkers. The proposed program also resulted in a reduction of Campylobacter spp. on floors, drinkers and birds. Moreover, it was possible to identify 6 different Campylobacter jejuni strains in the facilities. The proposed treatment resulted in a positive influence on the birds’ performance and reduction of environment contamination for broiler chickens.