Pathological and immunological studies on dietary T-2 toxin with concurrent e. coli infection in chickens and some relevant control trial

Abstract EN

This study was conducted to assess the effect of T-2 toxin on Escherichia coli-challenged broiler chickens from varies aspects (health per-romance, biochemical, immunological, bacterial clearance rate, lymphocyte proliferation assay and histopathologically alterations) and to study possible protective effects of antioxidant preparation.

A total of 214 one day-old broiler chicks were used in two experiments.

On day one, 190 chicks were separated into two groups, with one group fed a control commercial ration, and the other fed a commercial ration containing 2 ppm T-2 toxin.

On day 14, each group was fur-ther separated into two subgroups, one subgroup1 supplemented with antioxidant preparations as 1m / l in drinking water and other subgroup was not supple-minted.

On day 21 each subgroup was further separated into two division, with one division inoculated with E.

coli O78 (4 x 106 colony-forming units / 0.5 ml), while the other division was not inoculated with E.

coli.

Five chickens from each group were randomly selected, weighed bled at 14, 21, 28 and 35days.

In experiment two, 24 day old chicks were randomly allotted to 4 dietary treat-mints as control, fed 2ppm T-2 toxin, fed 2ppm T-2 toxin plus antioxidant and antioxidant preparation 1ml / l of drinking water.

At 3 weeks old, all groups were intravenously injected with E.

coli 4 x 106 colony-forming units / 0.5 ml.

Blood sample were collected at 60,120 and 180 min.

post injection while, the liver, spleen and lung were collected 180 minutes P.I.

Numbers of CFU per ml of blood and per gram harvested tissues were calculated.

Escherichia coli infection caused dullness, depression, huddling, and respiratory signs, wet eyes and diarrhea.

Tracheid's, airsaculitis, pericarditis and perihepa-titis was seen at postmortem.

Mortality was (12 %) in chicks infected with E.

coli and increased up to 40% in chicks fed T-2 and infected with E.

coli.

Decreased body weight and reduced feed intake were observed in chicks fed T-2, and the effects were more pronounced in chicks fed T-2 and infected with E.

coli.

Increased serum levels of aspartate aminotransferase, alanine aminotransferase, urea, uric acid, and cretonne and decreased levels of total proteins, albumin, globulins and cholesterol were observed in T-2 -fed birds.

T-2 toxin significantly lowering lymphocyte proliferation and delay systemic clearance of E.

coli from circulation with a significant increase persistence of E.

coli in tissues .Escherichia coli infection alone or in combination with T-2 adversely affects all biochemical parameters and lymphocyte proliferation rate.

The presence of T-2 toxin in ration even in a minimum amount could decrease the bird resistance and predisposed to certain diseases.

In addition, will prolong the carrier state of chicken which results in prolonged shedding of the microorganism.

T-2 toxin provokes dystrophic and necrotic changes in chicken's liver and kidney, differ-ent lesions in other internal organs as well as lymphocytic depletion and necro-sis of the lymphoid tissue.

These lesions increased in severity with E.

coli infection and decrease in severity by using the antioxidant.

The inclusion of Antioxidant preparation Toxnil as feed additives, might improve feed intake and body performance and could be able to counteract the T-2 adverse effects on biochemical parameters, immunity and pathological alterations.

Poultry feed need to be screened regularly for the presence of mycotoxin T-2 under field conditions.