Industrial egg residue as a calcium source in broiler feed: digestibility and growth performance.

Industrial egg residue (IER) possesses substantial concentrations of calcium and crude protein. The objective of this study was to measure the digestibility and performance of broilers when IER was added to the feed. Four treatments were tested, which caused increasing replacement of calcitic limestone by IER (0, 35, 70 and 100%) during a 42-day production cycle. First, total bird excreta were collected from broilers with and without IER, and we determined dry matter digestibility, apparent metabolizable energy (AME), calcium, and nitrogen retention. The IER presented 7.5% of crude protein, 31% of calcium, 209 kcal/kg of AME and the digestibility coefficients for dry matter, crude protein, and calcium were calculated at 83.95%, 86.20%, and 67%, respectively. After the digestibility test, the effects of IER on performance, carcass and meat yield were evaluated. No significant differences between the treatments were found in terms of performance (weight gain, feed conversion, consumption, and mortality), and no differences were found in terms of carcass or meat yield. A linear decrease in the percentage of abdominal fat was observed with increasing inclusion of IER in feed. These findings suggest that IER can totally replace limestone (calcium carbonate) in broiler diets.

Experimental infection with Escherichia coli in broilers: Impacts of the disease and benefits of preventive consumption of a stimulator of homeopathic immunity.

Colibacillosis is a disease caused by Escherichia coli that manifests itself when there are homeostatic imbalances or in the context of increased exposure, in which case the organism displays opportunistic behavior. To control this problem in poultry, antibiotics are used in the feed, because E. coli is component of the intestinal microbiota of birds. However, because of the changing dietary habits of the human population that seeks out healthier foods without antimicrobial residues, there have been many studies of alternatives to replace conventional antimicrobials as performance enhancers. Thus, the objective of the present study was to determine whether daily consumption of a homeopathic product (immune stimulator) by broilers stimulates immune responses and thereby minimizes the negative effects of experimental E. coli infection. We used 320 1-day-old Cobb 500 chicks, distributed in two groups with eight repetitions each, and 20 birds per repetition: control (CG) and homeopathy (HG). HG birds consumed doses of 0.02 mL/bird/day (1-7 d) via water, 0.01 ml/bird (8-21 d), 0.02 ml/bird (22-28 d), 0.01 mL/bird (29-35 d), and 0.02 mL/bird (35-45 d), as recommended by the manufacturer. At day 22 of the birds' life, the two groups were divided into four subgroups, with four repetitions per subgroup. On day 22, birds in CG1 and HG1 groups were infected intraperitoneally with 0.5 mL of inoculum containing 1.0 × 108 CFU of E. coli/mL. During the experimental period, data were collected for analysis of performance. On days 21 and 45 of age, we collected blood and feces. During the first 21 days of the experiment, we found that birds that consumed the immunostimulator had lower neutrophil counts and higher levels of globulins, however without significant difference between groups in terms of performance. Uninfected birds that consumed the homeopathic product in the water had less feed conversion (HG2) between days 1-35 and 1 to 45 compared to the other treatments. Mortality was higher in groups experimentally infected with E. coli (HG1 and CG1) from 22 to 35 days of life. There were greater numbers of lymphocytes in the HG2 group on day 45 than in CG1 and CG2; while numbers of neutrophils were lower at 42 days in birds of groups HG1 and HG2 than in CG1. Lower total bacterial counts, total coliforms and E. coli were observed in the feces of birds in the HG2 group compared to the other groups. Taken together, these findings suggest that inclusion of homeopathic product in the water of broilers had positive effects on the modulation of the immune response and on feed conversion in birds not challenged with E. coli. But the preventive protocol used in this study was not able to minimize the negative effects caused by the experimental E. coli intraperitoneal infection in broilers, featuring a substantial infectious challenge.

Impacts of Escherichia coli infection in young breeder chicks on the animal behavior and cerebral activity of purinergic and cholinergic enzymes involved in the regulation of molecules with neurotransmitter and neuromodulator function.

The objective of this study was to evaluate if infection by Escherichia coli in juvenile breeder chicks alters the activity of enzymes involved in neurotransmission and cerebral immunomodulation, including acetylcholinesterase (AChE), nucleoside triphosphate diphosphohydrolase (NTPDase), 5'-nucleotidase (5'NT) and adenosine deaminase (ADA), as well as their effects on the pathogenesis of the disease. We divided 20 growing breeder chicks into two groups (n = 10 per group). One group was experimentally infected with 1 mL of culture medium containing 1 × 108 CFU of E. coli intraperitoneally. The other was the negative control. On the tenth day after infection, the animals were euthanized and brain samples were collected. Macroscopically, pericarditis and hepatic congestion were observed in the birds, but without histopathological lesions in the encephalon although the bacterium was present in the cerebral cortex of all animals in the infected group (i.e., they were PCR-positive). The activity of AChE, NTPDase, 5'-NT and ADA were evaluated in the cerebral homogenates of the birds after 10 days of infection. AChE activity in the cerebral cortex was lower in the infected group than in the control; there was an increase in the activity of NTPDase, 5'-nucleotidase and ADA, possibly indicating greater hydrolysis of ATP (P < 0.001), ADP (P < 0.01) and AMP (P < 0.01), followed by increased adenosine deamination (P < 0.001). Despite these changes, no apparently diseased animals were observed throughout the experimental period. Therefore, such changes in enzymatic activity may affect the functioning of the central nervous system because these enzymes are responsible for extracellular regulation of molecules that act on neurotransmission and immunomodulation such as acetylcholine, ATP and adenosine.

Impact of Escherichia coli infection in broiler breeder chicks: The effect of oxidative stress on weight gain.

The aim of this study was to determine whether oxidative stress occurs in Escherichia coli-infected broiler breeder chicks, as well as the impact of this infection on bird growth. Twenty birds, 25-day-old female birds were divided into two groups (n = 10 per group): an intraperitoneally-infected group (1 mL containing 1.5 × 108 CFU of E. coli) and a control group that received 1 mL of culture medium (uninfected birds). Birds were weighed individually at the beginning and at the end of the experiment, and samples were collected on days 0, 5 and 10 post-infection (PI). No clinical signs were observed throughout the experimental period; nevertheless, on day 10 PI, there was lower growth and weight gain in infected birds than in the control group. The infected birds showed pericarditis and liver congestion, as well as moderate periportal inflammatory infiltrates with predominance of neutrophils. Significantly higher numbers of total leukocytes, lymphocytes, heterophils and monocytes were observed in the infected group on days 5 and 10 PI, as well as significantly higher total protein and globulin levels; albumin values significantly decreased over the same period. Levels of serum oxidative biomarkers (lipid peroxidation (TBARS) and free radicals (ROS)) were significantly higher at 10 PI, as was glutathione S-transferase (GST) activity during the same period. Hepatic ROS and protein thiol levels were significantly higher in E. coli-infected birds, as well as activities of the antioxidant enzymes catalase, superoxide dismutase. In the spleen, only GST activity was significantly higher for the infected group, unlike the brain, where SOD activity, ROS and non-protein thiol levels were significantly higher in infected birds than in the control group. These data suggested that colibacillosis causes oxidative stress in broiler breeder chicks, negatively affecting their weight gain.