1. The effects of dietary aflatoxin (AF, 0.5, 1.0 and 2.0 mg/kg), ochratoxin (OA, 1.0, 2.0 and 4.0 mg/kg) or combinations of these on body weight gain, feed efficiency, organ weights and immune response were studied in broilers. 2. Significant growth depression, reduced food consumption and poor food conversion efficiency were recorded in broilers fed a diet containing the greater concentrations of AF (1 and 2 mg/kg) and OA (2 and 4 mg/kg). 3. The combination of 2 mg/kg AF and 4 mg/kg OA exerted the maximum adverse effect on growth, feed intake and feed efficiency, indicating a synergistic effect on performance. 4. AF at 2 mg/kg in the diet caused a significant increase in the relative weight of liver, whereas the relative weight of kidney was significantly increased at 4 mg/kg of OA. A significant decrease in the relative weight of the bursa of Fabricius was noted at the highest concentration of AF (2 mg/kg) and combinations of 1 and 2 mg/kg AF and 2 and 4 mg/kg OA. 5. Cell mediated immunity (CMI), in terms of mean skin thickness (MST) sensitive to dinitrochlorobenzene (DNCB), was significantly reduced in chicks given the combination of 2 mg/kg AF and 4 mg/kg OA. Haemagglutination (HA) titre against sheep red blood cells (SRBCs) peaked at 42 d of age. At 42 and 47 d of age, a significant decrease in HA titres was recorded in chicks given 4 mg/kg OA or a combination of AF (1 or 2 mg/kg) and OA (2 or 4 mg/kg). 6. AF at a dietary concentration of 1 mg/kg or more and OA at 2 mg/kg or more, either alone or in combination, caused severe reductions in growth and immune response.

Studies were conducted to evaluate protein and energy utilisation in broilers fed diets containing various levels of aflatoxin (AF; 0, 0.5, 1 and 2 mg kg À1 ) and ochratoxin A (OA; 0, 1, 2 and 4 mg kg À1 ) either singly or in different combinations. Total protein efficiency (TPE) was reduced by 50.97, 76.52 and 132.75% at 2 mg kg À1 AF and 2 and 4 mg kg À1 OA respectively. Co-toxicity at two levels, 1 mg kg À1 AF þ 2 mg kg À1 OA and 2 mg kg À1 AF þ 4 mg kg À1 OA, resulted in significant reductions of 78.58 and 127.43% respectively in TPE. AF at all three levels and OA at 2 and 4 mg kg À1 caused significant decreases in net protein utilisation (NPU). Co-toxicity at all three levels led to significantly lower NPU. The reduction in NPU ranged from 18.68% at 0.5 mg kg À1 AF to 75.12% at 2 mg kg À1 AF þ 4 mg kg À1 OA. Significant reductions in metabolisable energy (ME) content were recorded at 1 and 2 mg kg À1 AF and all three levels of OA. ME content was reduced drastically when both toxins were fed simultaneously. It is suggested that both AF and OA adversely affect energy and protein utilisation in broilers, and this effect is exacerbated when both toxins are fed simultaneously. INTRODUCTIONNet protein utilisation (NPU) was found to be significantly lower and urinary nitrogen excretion significantly higher in ducklings fed a diet containing 30 mgkg À1 aflatoxin (AF) in comparison with those fed a toxin-free diet. 1 There was also a decrease in metabolisable energy (ME) content. 1 Graded levels of AF (1, 2 and 3 mg kg À1 ) significantly reduced the protein efficiency ratio and nitrogen absorbability in broilers. 2 It was also reported that ME was poorly utilised with 2 and 3 mg kg À1 dietary AF. 2 Dietary AF at a level of 1 mg kg À1 did not affect the digestibility of protein but caused a reduction in nitrogen utilisation from 31 to 43% and lowered the plasma concentration of methionine and cystine. 3 Ochratoxin A (OA) also caused malabsorption of nutrients. 4 Feeding of maize artificially contaminated with Penicillium spp and Aspergillus ochraceus to chicks resulted in reductions in dry matter and amino acid digestibility and energy utilisation. 5 AF at a rate of 1-2 mg kg À1 feed did not affect feed intake, protein digestibility or the absorption of amino acids, but reduced the utilisation of proteins. 6 Cereals can be contaminated by AFB 1 and OA and their metabolites before or during harvest or gradually during storage and processing. 7 The toxicity of individual mycotoxins can be enhanced or decreased when they occur as co-contaminants of feed,

The effect of dietary aflatoxin B 1 (AF) at levels of 0.5, 1 and 2 mg kg −1 , ochratoxin A (OA) at levels of 1, 2 and 4 mg kg −1 and their corresponding combinations on protein and energy utilisation as well as energy partitioning was studied in white leghorn laying hens. Protein retention was adversely affected at all levels of AF and OA either singly or in combination, though the effect was more evident with OA and AF + OA. Minimum protein retention was recorded in hens fed the combination of toxins at their highest levels (2 mg kg −1 AF + 4 mg kg −1 OA). Aflatoxin at 1 and 2 mg kg −1 and OA and AF + OA at all levels caused a significant reduction in metabolisable energy (ME) value of the diets. The minimum ME value was recorded for the diet containing both toxins at their highest levels (2 mg kg −1 AF + 4 mg kg −1 OA). A significant depression in egg energy deposition was observed with dietary inclusion of 1 and 2 mg kg −1 AF, 2 and 4 mg kg −1 OA and all levels of AF + OA in period I. In period II the reduction in egg energy deposition was significant at all levels of toxins either singly or in combination. Body energy deposition was adversely affected in hens fed the highest levels of AF (2 mg kg −1 ) and OA (4 mg kg −1 ) and all levels of AF + OA in period I. However, in period II a significant decrease in body energy deposition was observed at all levels of toxins except 1 mg kg −1 OA. A significant increase in maintenance energy (ME m /W 0.75 day −1 ) requirement was recorded in hens fed 2 mg kg −1 AF, 4 mg kg −1 OA and all levels of AF + OA. It is suggested that AF and OA either singly or in combination affect not only protein and energy utilisation in laying hens but also energy partitioning i.e. egg and body energy deposition and maintenance energy requirement. However, the combination of toxins (AF +OA) has more severe adverse effects on all parameters than the individual toxins because of their synergistic toxicity effect.

A 50 day feeding trial was conducted with White Leghorn (WL) laying hens, 42 weeks old, to determine if feeding of varying levels of aflatoxin (AF), ochratoxin A (OA) or their combinations has any effect on their performance and egg quality parameters. Feeding of T 4, T 7, T 8, T 9 and T 10 caused significant reduction in feed intake of hens. Hen day egg productions were significantly reduced at all the levels of toxins except 0.5 ppm of AF. Maximum reduction in egg production was noticed at 2 and 4 ppm of AF and OA, respectively. Average body weight and egg weight were not affected by toxin feeding. The feed efficiency in terms of net feed efficiency and feed consumed per dozen egg produced was significantly reduced at higher levels of both the toxins and their combinations. Feed consumption for production of 1 kg egg mass remained uninfluenced due to aflatoxin feeding whereas significant increase in the value of the same was noticed at 4 ppm level of OA and combination of 1 and 2 ppm of AF and 2 and 4 ppm of OA (T 9 and T 10 ), respectively. Various levels of OA (1-4 ppm) and all the combination of two toxins (T 8, T 9 and T 10 ) significantly altered the shape index of eggs in laying hens. The shell thickness was significantly reduced by higher level of AF (2 ppm), OA (2 and 4 ppm) and their combination. Albumen index, Haugh Unit and yolk index remained unchanged due to incorporation of toxins in the diet. It is concluded that AF, OA either singly or in combination at higher levels could depress the performance in terms of egg production and feed efficiency significantly. The egg quality parameters i.e. shape index and shell thickness were also significantly affected.

Aim: Long-term use of sewage-sludge and improper management of agricultural lands can lead to an elevated heavy metal concentration in the soil resulting in barren soil. The present investigation was carried out to study the influence of different soil characteristics on the enrichment of Cd, Cr and Pb and their detoxification strategies in sewage irrigated soil profiles of Prayagraj region, India. Methodology: Di-acid mixture method used for soil analysis. The clean filtrate was used for the estimation of the heavy metals (Cd, Cr and Pb) by Atomic Absorption Spectrophotometer (AAS) (AAnalyst600, Perkin Elmer Inc., MA, USA). Isolation and identification of Cd, Cr and Pb Detoxifying microorganisms were isolated from the sewage-irrigated soils by nutrient agar medium. Results: It was observed that surface soils contained higher amount of DTPA- extractable heavy metals (Cd 3.00-3.20 mg kg-1,Cr 5.20-6.40 mg kg-1 and Pb 6.80-7.20 mg kg-1) and these amounts along with CEC (26.10 Cmol (p+) kg-1) and organic carbon (OC) Content (0.58%) decreased with the depth of soil profiles. Among the tested microorganisms, the highest accumulation of heavy metals in the sewage irrigated soils was observed in Citrobacter spp. to the extent of Cd 13.2%, Cr 36%, and Pb 42%. However, the lowest accumulation was observed in Escherichia coli to the extent of Cd 1.2%, Cr 8.4%, and Pb 10.2%. Conclusion: The horizons A of the studied soil profiles contain almost 12% more Cd, 9.11% more Cr, and 52% more Pb as compared to the contents of horizons B. Biological detoxification system metal uptake is largely influenced by the availability of metals. The highest accumulation of heavy metals was observed in the order of Pb > Cr > Cd by the selected microorganisms in the order of Citrobacter spp. >Bacillus spp. > Pseudomonas aerugia > Rhizopus arrhizus > Escherichia coli, resulting in the detoxification of the metals in the sewage irrigated soils. GRAPHICAL ABSTRACT