الفهرس 
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Abstract
Mycotoxins Are Toxic Secondary Metabolites Produced By Fungi Before Harvest And During Storage Mainly Aspergillus And Penicillium spp Contaminating A Great Percentage Of Agriculture Products World Wide .For Food Derived from Animals The Hazard May Originate from A Number Of Source Including The Consumption Of Contaminated Feed By Livestock Resulting In Contaminated Animal Products . So The Problem Of Mycotoxins Doesn`t end in Feed Or Reduced Animal Performance . Many Are Transferred Into Meat Visceral Orangs Milk And Eggs . When Ingested Mycotoxin May Cause A Mycotoxicosis Which Result In An Acute Or chronic Disease Episode.Chronic Conditions Have A Much Greater Impact In Human Health Globally. Reduced Growth And Development Immunosuppression And Cancer Are chronic.
The present study was carried out at a private broiler farm in Damanhour city and the laboratory work was done at the Department of Animal and Poultry Production, Faculty of Agriculture, Damanhour Branch, Alexandria University, throughout the period from 2008 to 2009, an experiment was conducted to study the efficacy of some non-nutritive feed additives to eliminate the adverse effects of AF on the growth performance and the physiological parameters as judged by percentage of the internal organs, blood biochemical constituents, hematological and histopathology of the liver, bursa of fabricius and the thymus of Cobb broilers throughout the period from 1-42 day of age. The experimental period was divided into two phases, first period from 1-.21 day and the second from 21-42 day of age (withdrawal period). During the first period there were eight treatments consist of 2 levels of AF at 0 and 200ppb and 4 non-nutritive feed additives within each AF levels. These additives included MOS at 2g/kg diet, HSCAS at 2g/kg diet and Lacto at 2g/kg diet. Each diet was fed to three replicates of 11 chicks. During the recovery period (21-42 d of age), 210 broilers that left from phase 1 were continue in this period. AF was removed from the experimental diets at 21 d of age to study the effects of AF withdrawal on the growth performance and the physiological parameters as judged by percentage of the internal organs, blood biochemical constituents, hematological and histopathology of the liver responses of broilers. Each group except the control divided into two sub groups, one of them fed diet with different additive beside group that fed diet contaminated with AF without feed additives. The control groups fed diets without AF was also divided into two groups. Each treatment containing 3 replicates of five chickens. At 21 and 42 d of age, five chickens of each treatment were slaughtered to study dressing percentage and relative weight of body organs and glands.
Chicks were maintained on 24 hours light per day during the 1st day and kept at 23 hours light per day throughout the whole experimental period and housed in the floor pens (10 birds/m2). Water and mash form of the experimental diets were offered adlibitum.
The Results Could be Summarized in:
The First Phase (1- 21day of age);
1-There was a significant effect of AF and non-nutritive feed additives on BWG showed the negative effect of AF and the ability of additives especially Lactobacillus to eliminate the adverse effect especially during 1-7 and 8-14 d of age.
2- AF decreased feed intake and impaired FCR significantly and there was an insignificant improvement due to feed additives, thus complete recovery was not achieved.
3- AF caused a significant increase in the relative weight of liver and a significant decrease in the dressing and the relative weight of the intestine.
4- There was a significant interaction between AF and non-nutritive feed additives on the relative weights of liver, heart and intestine showing that feed additives especially Lactobacillus relief the negative effect of AF.
5- There were no significant effects due to the AF and the feed additives or the interaction between them on the relative weights of spleen, proventricullus, pancreas, bursa of fabricius and gizzard.
6- AF caused a significant decrease in WBC’s, RBC’s, Hgb and PCV but there was no significant effects of the feed additives or the interaction on these parameters.
7- AF caused a significant decrease in the serum total protein, albumin meanwhile, it increased in serum triglyceride level but there was no significant effect of the non-nutritive feed additives or the interaction on these parameters.
8- AF caused a significant increase in serum AST and ALT levels but there was no significant effect of the non-nutritive feed additives or the interaction on these parameters.
9- AF caused a significant decrease in neutrophils (%) and H/L ratio but increased the lymphocyte (%) and the monocyte (%) significantly. On the other hand, feed additives significantly decreased the lymphocyte (%) but increased the neutrophils% and the H/L ratio.
10- The histological study showed that AF during 1-21 d of age adversely affected liver, bursa and thymus cell histology at 21 day of age. However, feed additives eliminated the negative effects especially HSCAS followed by MOS then Lact.
Recovery Phase (21- 42 day of age):
1-Three weeks after AF withdrawal (42 d of age) BWG was still lower for the AF fed groups from 1-21 day of age. There was no significant differences of different feed additives although Lact. increased BWG.
2- There was a significant interaction between AF withdrawal and feed additives on BWG showing a beneficial effect of MOS on growth within AF withdrawal groups and the same due to Lact. within groups fed diet without AF from 1-42 d of age.
3- AF didn’t affect feed intake however, the HSCAS and the Lact. supplemented group decreased feed intake compared to the control and the MOS supplemented diet. MOS supplemented diet decreased the feed intake within AF withdrawal groups but increased feed intake within the groups fed diet without the AF from 1-42 d of age. In contrary, the HSCAS supplemented group increased the feed intake within the AF withdrawal groups however, decreased feed intake within the groups fed diet without the AF from 1-42 d of age.
4- AF and/ or feed additives didn’t affect FCR, although FCR of the control group was numerically better than that of the AF group after 21 d of AF withdrawal.
5- Three week after the AF withdrawal there were significant increase in the spleen relative weight and decrease in the liver relative weight in AF withdrawal group compared to the control group, showing chronic effect of AF however the non-nutritive feed additives didn’t affect any of the internal organs weight studied.
6- There was a significant interaction between the AF withdrawal and the feed additives on the dressing and the intestine relative weight showed that lact. supplemented group decreased dressing percentage within either AF withdrawal groups or within the groups fed diet without AF from 1-42 d of age. However, AF withdrawal group had significantly higher Intestine relative weight compared to the control group.
7- Three weeks after AF withdrawal there was a significant increase in the AST, ALP and triglycerides levels due to AF, showing chronic effect of AF on liver function.
8- The feed additives didn’t affect any of the serum biochemical parameters also the interaction between AF withdrawal was not significant, either.
9- Withdrawal of AF significantly decreased eosinophil (%) but, didn’t affect any of the other hematological parameter.
10- Lact. supplemented significantly increased the Hgb and the PCV compared to the control.
11- MOS supplementation up to 42 d of age within AF withdrawal groups significantly increased lymphocyte (%), basophile (%) and decreased H/L ratio compared to MOS removal at 21 day of age. However, within groups fed diet without AF from 1-42 d of age the MOS supplementation up to 42 d of age decreased lymphocyte (%) and increased H/L ratio compared to MOS removal at 21 d of age. Also HSCAS supplementation up to 42 d of age decreased lymphocyte (%) and basophile (%) meanwhile, increased H/L ratio compared to its removal at 21 d of age.
12- Histological study showed that liver of broilers fed diet contaminated with AF up to 21 day still had adverse effects showing chronic effect at 42 d of age. However, feed additives improved liver cell histology of the AF withdrawal groups.
In conclusion AF significantly decreased growth performance of broilers chickens during 1-21 d of age and still had a negative insignificant effect during the recovery period, indicating a chronic effect of AF. Meanwhile, Lact. and HSCAS relief the negative effect of AF period.
AF had a significant negative effect on the liver function and histology during the AF period and the recovery period. Meanwhile, HSCAS induced the best recovery.