الفهرس Only 14 pages are availabe for public view
 |  | from | 216 |  |  |
| | | from | 216 | | |
Abstract
Summary
In this study total number of 450 Ross chicks of both sexes at age of one day old were used and obtained from Assiut National Company of poultry and eggs and housed in Veterinary Teaching Hospital at Assiut University. The routine system of feeding, watering, warming, ventilation and vaccination was applied allover the period of experiment.
Chickens were divided into two main groups (A and B), each contain (225) broiler chickens.
Group (A):
Chickens were fed on OTC free ration and drinking tap water from day one. After 31 days age, these birds were divided into three sub-groups (A1, A2 and A3) each contained 72 birds and treated as follow:
Sub-group A1: was left as control till the end of the experiment.
Sub-group A2: was given therapeutic concentration (3g OTC/L tap water) for 5 successive days.
Sub-group A3: given over concentration of OTC (6g OTC/L Double therapeutic concentration) for 5 successive days.
Group (B):
These birds were fed the same OTC free ration and drank tap water as group A in addition to 0.1 ppm cadmium chloride, which added to drinking water from day one till the end of experiment. These birds were also divided into three sub-groups after 31 days age; each contained 72 chicks and treated as follow:
Sub-group B1: was kept as control for group B.
Sub-group B2: was given OTC therapeutic concentration (3g OTC/L tap water) for 5 successive days in drinking water.
Sup-group B3: was given over concentration of OTC for (6g OTC/L Double therapeutic concentration) 5successive days in drinking water.
Samples of Blood, pectoral muscles, thigh muscles, liver, kidneys, spleen, bursa of fabricius and bone samples were obtained from each bird in all groups daily just after stopping of OTC) administration. At age of 37th days the samples were taken every 48 hours till the end of experiment.
Blood samples were used for estimation of (RBCs count, Hemoglobin concentration and PCV percentage).
Serum was separated and used for liver and kidney function assays as determination of ALT, AST activities and creatinine level.
*Specimens from different organs as liver, spleen, kidneys and bursa of fabricius were obtained for histopathology and kept in neutral formalin.
Other samples from pectoral muscles, thigh muscles, and liver and bone were obtained and kept in - 20°C till used for (OTC) and cadmium residue level estimation by HPLC.
The results of present study revealed that the recovery rate of oxytetracycline in pectoral, thigh muscles was 80% while in the liver was 80.06%.
The obtained findings revealed that the total reduction rate of OTC residues in pectoral muscles was 98.3% in group A2; 70.26% in group A3; 95 % in group B2 and 71.1% in group B3. In thigh muscles it was 64.8% in group A2 ;79.9% in group A3 ; 82.9 % in group B2 and 48.% in group B3. In livers the total reduction rate was 48.4% in group A2; 56.4% in group A3; 97.9 % in group B2 and 35.3% in group B3. Regarding the total reduction rate in the studied muscles and livers it was evident that the residual levels of OTC in pectoral muscle at 11- 21 days post exposing was within the permissible limits. However, the thigh muscles in-group A2 and B2 are not within the limit and highly exceed the MRLs in livers of all studied groups.
The highest Cd level in the kidney was recorded in group B3 (4.306 ± 0.385) at the 19th day post exposure, and significant increase in cadmium levels was showed in group B2 and B3. In comparison with B1 the interaction between studied groups showed significant values between group A3 and B3.
The highest Cd level in the liver was recorded in group B3 (1.040 ± 0.082) at the 15th day post exposure and significant increase in cadmium levels was showed in group B3 in comparison with B1. The interaction between studied groups showed a significant variation between groups A2xB2 as well as between A3xB3.
The highest Cd level of pectoral muscle was recorded in group B3 (0.056 ± 0.004) at the 17th and 23rd day post exposure. And significant increase in cadmium levels was showed in group B3 in comparison with B1. The interaction between studied groups showed a significant variation between groups A3xB3.
The highest Cd level of thigh muscle was recorded in group B3 (0.059 ± 0.004) at the 11th day post exposure. And significant increase in cadmium levels was showed in group A2 and A3 in comparison with A1. The interaction between studied groups showed a significant variation between groups A2xB2 and A3xB3.
The highest Cd level of bone tissue was recorded in group B3 (1.013 ± 0.155) at the 15th day post exposure. Significant increase in cadmium levels was observed in group B2 and B3 in comparison with B1. The interaction between studied groups showed a significant variation between groups A2 x B2 and A3 x B3.
Hematological Results (Red blood cells (RBCs) count, Hemoglobin (Hb) concentration, packed cell volume (PCV %), Mean corpuscular volume (MCV) and Mean corpuscular hemoglobin (MCH)] indicated that:
The highest level of Red blood cells (RBCs) was recorded in group B3 (2.73 ± 0.11) at the 23rd day post exposure. Group B3 showed significant increase in RBCs count in comparison with B1. The interaction between studied groups showed a significant variation between groups A3 x B3.
The highest level of Hemoglobin (Hb) concentration was recorded in group A1 (10.25 ± 0.21) at the 7thday post exposure. Significant increase in Hb concentration was showed in group B2 and B3 in comparison with B1.The interaction between studied groups showed a significant variation between groups A1xB1, A2x B2 and A3 x B3.
The highest Packed cell volume (PCV %) was recorded in group A1 (30.1 ± 0.6) at the 17thday post exposure. significant increase in PCV% was observed in group B2 and B3 in comparison with B1.The interaction between studied groups showed a significant variation between groups A1xB1, A2x B2 and A3 x B3.
The highest level of Mean corpuscular volume (MCV) was recorded in group B2 (132.4 ± 1.634) at the 21stday post exposure. Significant increase in MCV was observed in group B3 in comparison with B1.
The highest level of Mean corpuscular hemoglobin (MCH) was recorded in group B2 (42.8 ± 0.41) at the 7thday post exposure. Significant increase of MCH was showed in group B3 in comparison with B1. The interaction between studied groups showed a significant variation between groups A3 x B3.
Serobiochemical enzymes and Creatinine: Serum aspartate aminotransferase (AST), Serum alanine aminotransferase (ALT) and Creatinine.
The highest level of AST was recorded in group B2 (2.004 ± 0.261) at the 5thday post exposure. Significant increase of AST was showed in group B3 in comparison with B1. The interaction between studied groups showed a significant variation between groups A3 x B3.
The highest level of ALT was recorded in group B3 (0.705 ± 0.052) at the 3rdday post exposure. Significant increase in ALT was observed in group A2 and A3 in comparison with A1. The interaction between studied groups showed a significant variation between all groups.
The highest level of creatinine was recorded in group B3 (6.38 ± 0.48) at the 7th day post exposure. Significant increase of creatinine was showed in group B3 in comparison with B1.The interaction between studied groups showed a significant variation between groups A3 x B3.
The highest level of weight of broiler chickens was recorded in group A2 (3.110 ± 0.063) at the 23rdday post exposure significant decrease in weight was observed in group B3 in comparison with B1. The interaction between studied groups showed a significant variation between groups A3 x B3.
The histopathological changes of the investigated organs of broiler Chickens (liver, kidney, spleen and bursa of fabricius) revealed pronounced, mild to minimum changes or appeared more or less normal depending upon the various handled groups of the experiment and control.
The liver of groups A2 showed slight to mild hyperemia, degeneration, portal fibrosis and activation in Kuppfer cells. In group A2 changes include limited area of hepatic cell degeneration in some cases. Focal areas of hepatic necrosis and lymphoid cell reaction at portal tract in others (A2-17).
In group A3 the changes include focal areas of degeneration and cellular reaction around the central vein and in the portal tract in group (A3-17). Thrombosis in some of blood vessels of portal tract. In group (A3-23) the area of cellular reaction was wide with degenerative changes of the hepatic cells. Hyperplasia of bile duct epithelium dilated sinusoid , congestion of some blood vessels of the portal tract were observed in some cases of group A3.
The liver of chickens from group B1 showed mild hyperemia, degenerative changes included vaculation of liver cells and mild portal fibrosis.
The livers of group B2 (B2-11 and B2-17 and B2-23) showed large focal area of cellular reaction, diffused degeneration of hepatic cell, thrombosis of central vein ,dilated hepatic sinusoids, and fibroblastic reaction in the portal area . A focal areas of lymphoid and monolocular cell reaction were observed in most cases of this group.
The liver of group B3 showed hepatocellular degeneration and necrosis, which sometime accompanied with a focal area of lymphoid cell reaction, hyperplasia of the bile duct, thrombosis of blood vessels in portal tract and central vein in subgroup B3-17 and B3-23.
Micromorphological examination of the kidney from group A2-11 showed focal necrosis of glomerular tuft and mild tubular degenerative changes. In subgroup A2-17 tubular dilation with atrophy or loss of their epithelium, congested intertubular blood vessels and focal area of lymphoid cells reaction was observed. Focal areas of fibroblastic reaction were seen in subgroup (A2-23).
The kidneys from group A3 (A3-23) showed Lesions of degenerative and necrotic nature in the tubular epithelium, some areas of Hemorrhage, mild increase in cellularity of the glomerular tuft and focal areas of interstitial reaction.
In group B1-1 and B1-11 the kidney showed glomerular hypercellularity, degenerative or necrotic changes in epithelium of the renal tubules, cystic dilation of some of the tubules and areas of interstitial reaction. In B1-17 and B1-23 the kidney showed focal areas of hyperemia, and cystic adenoma in collecting tubules. In subgroup B2-1 the renal tubular epithelium was hyperplasic. In group (B2-11) the kidney showed nephrosis and proliferations in the interstitial tissue, mononuclear cell infiltration, thrombosis of blood vessels and hypercellularity of glomerular tuft as well as necrosis of endothelium of blood vessels and gloremuli of subgroup B2-17 and B2-23. In group B3 (B3-11, B3-17) the kidney showed degeneration of renal tubular epithelium and some of glomeruli in addition to necrosis or hypercellularity of glomerular tuft in subgroup B3-23.
The histomorphological studies of the spleen from the broiler chickens of group A2 and A3 revealed that the structural changes were observed in some cases as limited very mild depletion of lymphoid cell population of the white pulp. Spleen from group B1 showed severe decrease in the number of the lymphoid cells in some follicles of the white pulp B1-11, B1-23. The red pulp of the spleen was severely congested and hemorrhagic. In group B2 the spleen showed moderate to severe necrotic changes of the white pulp and congestion of blood vessels of red pulp. In subgroup B3 (B3-1, B3-17) the spleen showed mild depletion of lymphoid cell population of white pulp, congestion of red pulp with formation of compensatory lymphoid nodule along the sheath of the splenic artery.
Spleen of (B3-23) showed severe depletion of lymphoid cell population of the white pulp which is replaced by proliferation of the reticuloendothelial system cells.
The histopathological studies of the bursa of Fabricius from group B1 showed that the amount of lymphocytes in some follicles diminished and hyperplasia was seen in other lymphoid follicles. In group (A2) the changes were more or less not sever as these of chicken of group A3. Decrease in the size and number of bursal follicles lymphocytes were prominently decreased in group A3 if compared to the control group. In chicken of (A3-11) a mild focal depletion of lymphoid cell population was showed in some bursa follicles. In group (A3-23) the bursa structures appear normal with exhaustion of lymphoid cell population. Chicken of subgroup B1-17 showed little pathological changes and appeared normal. Bursa of fabricius from chickens of group B3 showed partial necrosis of some of its follicle, prominent depletion of lymphoid cells population fibrotic changes were observed in bursa of this group. In some birds of this group the Bursa of fabricius showed moderate to sever decrease in the lymphoid cells in its bursal follicle.