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The emergence of antibiotic-resistant bacteria in the intestinal microbiota of broiler chickens, and the possibility of antibiotic residues in meat and meat products are seen as a threat to animal and human health. The search for alternatives to conventional drugs, including natural compounds, is an interesting approach to prevent the adverse effects of antibiotics. Therefore, the aim of the present study was to evaluate whether the addition of tannin (as a quebracho extract) in the diet of broiler chickens could be used to replace in-feed antimicrobials and coccidiostatic drugs, to exert positive effects on animal health and performance. The use of tannin in the diet of broiler chicks as an additive (at 0.5% for 1–10-day-old birds; and 1.0% for 11–42-day-old broiler chickens) enhanced their bodyweight, weight gain and daily weight gain on Day 42 of life, compared with the untreated control group (P < 0.05). However, these findings were not observed when tannin was added at 0.5%. Moreover, broiler chickens fed with an extract containing tannins showed higher erythrocyte counts, as well as haemoglobin and haematocrit concentrations than did those in the control group, whereas counts of total leukocytes and lymphocytes were lower (P < 0.05). The use of a diet with tannins did not influence meat quality compared with a diet containing zinc bacitracin and salinomycin, which altered some parameters associated with meat colour. Moreover, the diet with tannins reduced (P < 0.05) the number of oocysts of Eimeria sp. (36-day-old broilers) and the total faecal bacterial counts (42-day-old broilers) compared with the control group. Finally, intestinal histopathology showed that the addition of tannins minimised the degree of lesions (Degree 1) compared with the control group (Degree 3). On the basis of these results, we concluded that the use of quebracho extract containing tannins can be a suitable approach to improve the performance of broiler chickens, replacing in-feed antibiotics and coccidiostatic drugs. The use of tannins did not change meat quality; however, it caused positive effects on the immune system, and exerted potent bactericidal and coccidiostatic properties, reinforcing its use as a replacement for conventional drugs.

Coccidiosis is a disease of great importance in industrial poultry. The correct diagnosis directs the poultry industry to its best treatment and control. Thus, a survey of Eimeria spp. was carried out in intestines of 64 broiler flocks, with an average age of 29 days. Eight broilers from each flock were randomly removed from the slaughter line, in a total of 512 samples. Macroscopic and histopathological lesions in the intestine were classified into Scores 0 to 4. Polymerase chain reaction (PCR) was used to research the oocysts from the seven species of Eimeria spp. in the intestinal content. The macroscopic evaluations showed that 59.4% (38/64) of the flocks were positive for E. acervulina, 32.8% (21/64) for E. maxima, 29.7% (19/64) for E. tenella, and 34.4% (22/64) for E. brunetti. The histopathological evaluation showed that 87.5% (56/64) of the flocks had at least one broiler with parasitic structures compatible with Eimeria spp. in the duodenum, 70.3% (45/64) in the jejunum, 18.8% (12/64) in the ileum, 46.9% (30/64) in the cecum, and 4.7% (3/64) in the colon. In PCR, 21.9% (14/64) of the flocks were positive for E. acervulina, 12.5% (8/64) for E. maxima, 3.1% (2/64) for E. mitis, and 32.8% (21/64) for E. tenella. The Kappa Cohen test between macroscopy, histopathology, and PCR demonstrated concordance ranging from weak to moderate with the exception of histopathology and PCR of the cecum, which was strong. In the comparison between macroscopy and histopathology, there were significative differences between Scores 0 and 1 (apart from the cecum). For Score 3, there were significative differences in duodenum, jejunum and cecum (p<0.05). In conclusion, the macroscopic diagnosis and PCR can generate false-negative results, and the histopathological exam proved to be effective, making it essential to associate different techniques for the correct diagnosis of Eimeria spp. in broiler chickens.

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Background:Immunocastration is a less invasive and painless procedure compared to surgical castration, which causes greater stress to animals, especially when performed improperly. Immunocastration stimulates the production of antibodies against Gonadotropin-Releasing Hormone (GnRH), temporarily blocking the hormone production by the male gonads. Anatomopathological evaluation of animals submitted to immunocastration with the establishment of different degrees of testicular degeneration helps to evaluate the efficacy of the different dose ranges used for this procedure. Because of the scarcity of information about this procedure in young bulls, the study aimed to compare the immunocastrated and noncastrated animals. Materials, Methods & Results:Eighteen Angus-Limousin bulls were used from weaning (7±1 months) to slaughtering (15±1 months) with the establishment of two groups composed of nine non-castrated (NC) and nine immunocastrated (IC) animals. In the IC group, three doses of GnRH synthesis inhibitor vaccine (Bopriva®) were applied on days 0 (weaning), 87 and 223. At slaughter, scrotal circumference, weight (kg), width (cm), length (cm) and total size (width x length) of the testicles were obtained, then were routinely processed for histopathological analysis. Four degrees of testicular degeneration was established: grade 0 (no changes), grade 1 (mild), grade 2 (moderate) and grade 3 (severe). Statistical analysis was performed using Student's t-test to compare the means of macroscopic variables. The scrotal circumference started to decrease in the IC animals on day 132, with a certain growth from day 194. There was a significant difference between the two groups for width (P = 0.001), length (P = 0.004), total size (P = 0.003) and scrotal circumference (P = 0.04). Testicles of the IC group tended to be lighter (P = 0.06). The final difference between the groups was 6.3 cm for scrotal perimeter, with respective averages of 27.44 cm and 33.77 cm for the IC and NC group, respectively. In the microscopic evaluation, NC animals obtained grade 0. In the IC animals, 33.33% (3/9) had degeneration grade 1 with slight basement membrane tortuosity and Sertoli cell atrophy, 33.33% (3/9) obtained grade 2 with moderate tortuosity and thickening of seminiferous tubules, Sertoli and Leydig cell atrophy, and absence of spermatogenesis and 33.33% (3/9) reached grade 3, with decreased seminiferous tubules and a severe and diffuse atrophy of Leydig and Sertoli cells and complete absence of spermatogenesis, with a 1:5 ratio in seminiferous tubule diameter between NC and IC grade 3 animals, respectively. Discussion: There was a significant difference in several testicular macroscopic aspects between the two groups, similar to values using eight months old field-bred animals, with a difference of 8.78 cm between groups, also with the use of three doses of Bopriva. The only macroscopic variable that showed just a tendency of difference between the groups was testicular weight, whereas, in a study with crossbred animals with nine mo...

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