Effects of ochratoxin and T-2 toxin combination on performance , biochemical and immune status of commercial broilers

Aim: To study the effects of Ochratoxin A (OA), T-2 toxin (T-2) and their combinations on the performance, biochemical and immune status of broiler chickens. Materials and Methods: 168 day-old Cobb broiler chicks, obtained from a commercial hatchery were divided by Complete Randomized Design into four groups of three replicates and fourteen chicks per replicate, with dietary treatments of 0.0 (control), 1 ppm OA, 2 ppm T-2 and their combination (1 ppm OA + 2.0 ppm T-2). The chicks were housed in deep litter independent conventional system with feed and water ad libitum throughout the experimental study. Body weight and feed intake were recorded weekly. At the end of the trial, blood was collected and was analyzed for total protein, serum albumin, uric acid and the activities of gamma glutamyl transferase (GGT) and alanine amino transferase (ALT) and antibody titers against ND and IBD using ELISA technique. Results: The toxin treated birds exhibited a significant (P<0.05) decrease in the body weights and weight of lymphoid organs. A significant (P<0.05) reduction in serum total protein, albumin and increase in serum uric acid levels were observed in toxin treated birds. The serum alanine amino transferase (ALT) and gamma glutamyl transferase (GGT) levels were decreased and antibody titers against Newcastle disease (ND) and Infectious Bursal Disease (IBD) were decreased significantly (P≤0.05). Conclusion: The presence of OA and T-2 in the diet showed depressing effects on performance, biochemical and immunological parameters indicating their adverse effects on the general health of broilers.


Introduction
found to be quite pronounced in young broiler chicks resulting in poor growth rate and poor feed efficiency.Feed ingredients and compounded feeds used in In addition, these toxins have been implicated in poultry production by virtue of their moisture content causing immunosuppression in young birds thereby are highly susceptible to the growth of mould, which resulting in economic losses to the poultry farmers.produces toxic metabolites during their growth Ochratoxin A and T-2 toxin affects immune function by referred to as mycotoxins.The fungal contamination of decreasing the size of vital immune organs, such as feedstuffs occurs at various stages of production, thymus, spleen, and lymph nodes, and several immune harvesting, handling, processing and storage.Cocells within these tissues thereby causing immunocontamination of feedstuffs with multiple mycotoxins suppression [4,5]. is a common scenario [1].
Hence, an attempt has been made in this study to T-2 is a highly toxic trichothecene mycotoxin evaluate the effect of Ochratoxin, T-2 toxin and their produced by different Fusarium species, mainly combination on performance, biochemical parameters Fusarium sporotrichoides to a lesser extent by F. poae and immune status in commercial broiler chicken.

Results and Discussion
agar and oatmeal agar, respectively.Then OA and T-2 The data of effect of different dietary treatments on toxin was extracted as described by [6,7] and quantified growth performance, organ weights, immune response by thin layer chromatography (TLC) as described by and biochemical parameters are presented in Table 1, 2 [8].and 3.

Diet formulation: Basal diet was formulated and
Growth performance: Body weights were significantly compounded to meet the nutrient requirements of (P<0.05)lower beginning with first week for OA and commercial broilers during the starter (0-3 wks) ( Organ weights: Compared with those of controls, were vaccinated against Newcastle Disease (ND) on relative weights of liver, kidney and gizzard were 7th day using F1 strain and against Infectious Bursal significantly (P<0.05)increased in the groups Disease (IBD) on 14th day using intermediate strain receiving Ochratoxin A or T-2 toxin, singly and in (Ventri's Biologicals, Bangalore, India).Both the combination, whereas relative weight of pancreas was vaccines were given by oculonasal and ocular routes.not altered.Ochratoxin A plus T-2 combination fed group showed significant (P<0.05)increase in relative Data collection: Body weight and feed intake were liver, kidney and gizzard weights followed by OA (and recorded weekly.At the end of the trial, blood was T-2 fed group, respectively).These findings agree with collected in non-heparinized tubes from six birds in the results of [18,19,20] for OA, [21,22] for T-2 and each treatment (3 males and 3 females) by puncturing [18,23] for OA plus T-2 combination treatments.The the brachial vein during 5th week of age.Serum was increase in relative weights of liver could be attributed separated after 8 to 10 hours as per the standard to increased lipid metabolism in liver due to impaired procedures [9] and was stored at -20 ºC for subsequent fat metabolism which brings appreciable changes in significant reduction of antibody titers against ND and the general functioning and gross appearance of liver.
IBD values in commercial broilers fed 3ppm T-2 toxin.The effects on gizzard are believed to be due to severe Serum biochemistry: A significant (P<0.05)reduction inflammation and the resultant thickening of the gastric in serum total protein, albumin and increase in serum mucosa [19].Increase in kidney weight was more uric acid levels were observed in OA alone and OA plus likely to be due to enlargement and hypertrophy of T-2 toxin combination fed groups.In T-2 toxin alone proximal convoluted tubules and infiltration of treated group, serum uric acid values significantly lymphoid cells as suggested by [24].
(P<0.05) reduced from control values at fifth week of Lymphoid organs: The relative weight of thymus was age (Table -3).The highest depression of serum total significantly (P<0.05)decreased in the groups protein, albumin and highest increased levels of serum receiving OA or T-2 toxin singly and in combination, uric acid was recorded in the group fed OA plus T-2 whereas relative weights of bursa and spleen were not toxin combination, followed by OA and T-2 toxin alone altered compared to that of control (Table -2).The fed groups.The mechanism by which these toxins relative weight of bursa and thymus were significantly cause decrease in serum protein levels is thought to be (P<0.05)depressed in the OA plus T-2 combination fed due to the impairment of protein synthesis by inhibiting group, followed by OA and T-2 alone fed groups as m-RNA transportation by binding to DNA.The compared to control group at fifth week of age.
findings of the present study were in agreement with Mycotoxins are known to cause immunosuppression in [18,22,31].chickens and concomitantly reduce the relative sizes of Serum enzyme activity: Serum GGT activity was bursa of Fabricius and thymus responsible for significantly (P<0.05)increased by OA and OA plus Timmunological competence [25].The reduction in size 2 toxin combination as compared to control group, but of lymphoid organs (bursa and thymus) might have the level of GGT was not altered by T-2 toxin alone been due to necrosis and cellular depletion by the treatment (Table -3).Highest level of serum GGT mycotoxins.The findings of the study were activity was recorded in OA plus T-2 combination comparable to the reports of [19,26]

Table - 1
. Effect of individual and combined toxicities of ochratoxin and T-2 toxin on body weight (g) of broiler chickens from 0-5 wks of age (Mean+SE)

Table - 2
. Effect of individual and combined toxicities of ochratoxin and T-2 toxin on organ weights (g/ kg live wt.) of Means within each column bearing common superscript do not differ significantly (P<0.05)

Table - 3
. Effect of individual and combined toxicities of ochratoxin and T-2 toxin on Immune and Biochemical parameters th of broiler chickens at 5 wk of age (Mean+SE) Means within each column bearing common superscript do not differ significantly (P<0.05)