Glycerol monolaurate in the diet of broiler chickens replacing conventional antimicrobials: Impact on health, performance and meat quality.

Glycerol monolaurate (GML), known as lauric acid, is a chemical compound formed from lauric acid and glycerol that presents strong antimicrobial activity. Therefore, our hypothesis is that MGL can replace conventional antimicrobials, being a new alternative to poultry farming. The aim of this study was to evaluate whether the addition of GML as a replacement for antibiotics could have positive effects on health and performance of broiler chickens. For this, 240, one-day-old, Cobb 500 broiler chicks were weighed and randomly distributed into four groups with four repetitions each (n = 15). The control group, T0, received a basal diet containing antibiotic (60 ppm of bacitracin), while the T100, T200, and T300 groups received a basal diet supplemented with 100, 200, and 300 mg/kg of GML, respectively. The birds were weighed at intervals of seven days, as well as at the end of the experiment (day 42). Blood samples were collected for evaluating animal health, stool for counting bacteria and coccidian, as well as muscle (chest) to measure meat quality, respectively. At the end of the experiment (day 42), body weight, weight gain, and daily weight gain of broiler chickens in the T300 group were higher than the T0 group (P < 0.05). Indeed, feed conversion was lower compared to T0. Animals that received diets containing GML showed lower amounts of Eimeria spp. oocysts on day 42 in comparison to the control group. Low total bacterial counts on day 21 of the experiment were also observed in the treated groups. Conversely, plasma levels of total protein, globulins, uric acid, and glucose were higher in animals that received GML when compared to the control group. It was also observed higher carcass yields in the breast muscle of the T100 group when compared to other groups. Lower water holding capacity was observed in breast meat of animals of the groups T100, T200, and T300 when compared to T0. Histopathological findings were compatible with coccidiosis, and the degree of these lesions did not differ among groups. Based on these results, GML in the diets of broiler chickens, showing potent antimicrobial effect, growth promoter capacity, and lack of toxicity. Therefore, GML is a promising alternative to replace conventional antimicrobials used in the diets of broiler chickens.

A prophylactic protocol to stimulate the immune response also controls infectious disease and, consequently, minimizes diarrhea in newborn heifers.

The immunostimulatory and immunomodulatory properties of selenium (Se), an essential trace element for animals, has increase its use because may prevent/or reduce the occurrence of infectious diseases. Thus, the aim of this study was to verify whether Se and vitamins (A and E) applied via subcutaneous associated with secnidazole via oral exert positive effects in the antioxidant and immune systems, as well as whether prevent infections caused by protozoan and bacteria, and consequently, reduce the number of cases of diarrhea in heifers. Thirty-two newborn Holstein heifers were divided into two groups with sixteen animals each: the control group and the treated group that received sodium selenite (0.2 mg/kg) and vitamins A (35 mg/kg) and E (1 mg/kg) with one day of life, and a second application associated with secnidazole (400 mg/animal) on day 10 of life. Sample collection (blood and feces) were performed on days 1, 15, 30, 45 and 60 of life. Heifers from the treated group showed higher hematocrit values compared to the control group on day 60 of life, while total serum protein levels were higher on days 15 and 30. The ceruloplasmin (days 15, 30 and 60), IgG of heavy chain (days 15, 30, 45 and 60), IgG of light chain (days 45 and 60) and haptoglobin (days 15, 30, 45 and 60) were higher in the treated group compared to the control group. Serum levels of glucose decreased in treated animals on day 60 of life, while serum levels of albumin, triglycerides, urea, cholesterol, thiobarbituric acid reactive substances, reactive oxygen species and glutathione S-transferase activity did not differ between groups. Secnidazole was able to prevent infections caused by Giardia duodenalis in the first few days of life, but no difference was observed between groups. Moreover, there was no difference on total bacteria count and the incidence of diarrhea between groups. No difference on weight gain was observed on day 60 of life, but on day 210 of life treated animals had higher weight gain compared to the control group. Based on these evidences, we concluded that the injectable application of Se and vitamins (A and E) associated to secnidazole can improve the immunological system, and consequently, favor animal's performance.

Aflatoxins produced by Aspergillus parasiticus present in the diet of quails increase the activities of cholinesterase and adenosine deaminase.

The aim of this study was to evaluate the effects of aflatoxins on cholinesterases (acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), and adenosine deaminase (ADA) activities in quails. For this, twenty male quails were randomly distributed into two groups (n = 10 each): the group A was composed by quails that received feed without aflatoxin (the control group); while the group B was composed by quails that received feed contaminated with 200 ppm/kg of feed of aflatoxin. On day 20, the animals were euthanized to measure the activities of AChE (total blood and brain), BChE (serum) and ADA (serum, liver, and brain), as well as for histopathological analyses (liver and intestine). AChE, BChE, and ADA levels increased in animals intoxicated by aflatoxin compared to the control group. The presence of aflatoxin lead to severe hydropic degeneration of hepatocytes and small focus of hepatocyte necrosis. In conclusion, aflatoxins poisoning increased AChE, BChE, and ADA activities, suggesting the involvement of these enzymes during this type of intoxication, in addition to the fact that they are well known molecules that participate in physiological and pathological events as inflammatory mediators. In summary, increased AChE, BChE and ADA activities contribute directly to the inflammatory process and tissue damage, and they might be involved in disease development.