الفهرس 
Cover Page Title in EnglishOnly 14 pages are availabe for public view
 |  | from | 162 |  |  |
| | | from | 162 | | |
Abstract
The present and future challenge is to get safe, cheap and environmentally friendly alternative pesticide so the current work was planned to evaluate the efficacy of two commercially available insecticides (Butox® 50% and Diazinon 15%) widely used in the Egyptian veterinary field against the different developmental stages of R. (Boophilus) annulatus tick, evaluate the efficacy of Achook® insecticide (a product of agricultural application only) derived from neem (Azadirachta indica) seed oil extract against the different developmental stages of R. (B.) annulatus tick. In addition, a comparative study between the efficacies of the investigated insecticides against the different developmental stages of R. (B.) annulatus tick was conducted. Finally, study the toxic effects of the investigated insecticides on the experimental animals in a trail to predict the side effects of application on cattle. R. (B.) annulatus (an example of cattle tick) engorged females were obtained from naturally infested cattle reared in a private farm in Rashid city, Behera province and each insecticide was evaluated at two dilutions as follow: Butox® 50% (1 ml/l and 2 ml/l), diazinon 15% (4 ml/l and 8 ml/l) and Achook (0.15% and 0.075%) each concentration was added to engorged females, eggs and unfed larvae for one minute contact time. The efficacy of insecticides against R. (B.) annulatus engorged females was evaluated by estimation of the mortality percentage and evaluation of reproductive performance upon calculation of females reproductive indices and percentage of oviposition inhibition, while their efficacy against tick eggs was evaluated through estimation of percentage of eggs hatchability and egg hatching inhibition. Finally, insecticides efficacy against unfed larvae was evaluated by estimation of larval mortality percentage. In addition, each investigated insecticide was orally administrated to total number of 10 albino male rats for four weeks, six days per week at doses of 0.6, 12.8 and 9 mg/kg of rat’s body weight of Butox® 50%, diazinon and Achook insecticides, respectively for assessing the toxic effect of the tested insecticides. The insecticides toxicity was evaluated on basis of signs of toxicity, changes of hematological and biochemical parameters of animal’s blood in addition to histopathological findings observed in examined internal organs of intoxicated animals. The obtained results revealed the following: 7.1. Effects of tested insecticides on engorged females of R. annulatus ticks: It was found that the highest mortality rate was observed on using Diazinon 15% (4 ml/l) and Achook (0.15% azadirachtin) (86.66%) followed by Butox 50% (1 ml/l, 5% deltamethrin) (73.33%). On contrary, the lowest mortality was observed on using Butox 50% (2 ml/l) (40%). In addition, statistical analysis showed highly significant association between the tested insecticides and the control group (29.58*** P<0.0001) while there was non-significant association between using different dilutions of the same insecticide. It was clear that Butox® 50% and diazinon 15% were highly effective in lowering the reproductive index to zero and completely inhibiting the egg laying by adult females at the two investigated dilutions (100% oviposition inhibition). Concerning Achook insecticide, there were differences between the tested dilutions as the lower concentration (0.075%) decreased the reproductive index of females and achieved higher oviposition inhibition (75%). This result indicated its failure in complete inhibition of laying egg compared to Butox® and diazinon. 7.2. Effect of tested insecticides on eggs of R. (Boophilus) annulatus ticks: It was noticed that the lowest hatchability (0%) was achieved in Achook treated groups at both concentrations 0.15% and 0.075% azadirachtin which led to the highest recorded hatching inhibition (100%) among the tested groups with no signs of hatching were noticed completely. On contrary, the highest hatchability % of eggs was recorded in diazinon groups especially group treated by 4 ml/l dilution that was translated in turn to 1.14% hatching inhibition, while Butox® 50% led to 0.66% and 0.83% hatchability for dilutions of 1 ml/l and 2 ml/l, respectively that reflected hatching inhibition values of 98% and 97.5%, respectively.7.3. Effect of tested insecticides on larvae of R. (Boophilus) annulatus ticks: It was observed that larvae of R. (B.) annulatus were highly affected by tested insecticides than adult females. In addition, azadirachtin and diazinon proved their superiority over deltamethrin in its effect on larvae as they led to 100% mortality of larvae as compared with Butox® 50% (93.3%). Moreover, Azadirachtin killed larvae within the first 24 hours post treatment at both concentrations 0.15% and 0.075%.
Finally, it was noticed that Achook was the most potent insecticide affecting the developmental stages (eggs and unfed larvae) of R. (B.) annulatus when compared to Butox® 50% and diazinon 15% as it achieved 100% hatching inhibition of eggs and 100% mortality in unfed larvae within 24 hours at both tested concentrations. 7.4. Effects of tested insecticides on experimental albino rats: 7.4.1. Effects of tested insecticides on body weight: Statistical analysis clarified that the total body weight of Butox® 50% and Diazinon 15% treated groups had a significant increase than the weight of control group. On contrary, Achook 0.15% insecticide did not have any significant effect on the body weight as weight did not changed when compared with control group.
7.4.2. Effects of tested insecticides on clinical signs and mortality: Butox® 50% did not produce any nervous manifestations characterizing pyrethroids toxicity reflecting the wider safety margin of the administrated dose. Moreover, no mortalities were recorded within experimental animals. On contrary, nervous overstimulation was observed at the 3rd week of the experiment as a result of oral administration of diazinon with 20% mortality occurred in rats. As Butox® 50%, azadirachtin caused no significant signs of toxicity or mortalities indicating high safety margin of azadirachtin on non-target organisms. 7.4.3. Effect of tested insecticides on blood biochemical parameters: Butox® 50%: Butox® 50% toxicity led to significant decrease of ALT, AST, ALP and LDH which may be a result of severe liver damage. In contrary a significant decrease in serum glucose level was noticed. Hypercholesterolemia was observed that may be due to the ability of pyrethroids to disrupt lipid metabolism in liver. Another increase was detected in serum protein and albumin levels indicating liver dysfunction as liver seemed unable to metabolize proteins. In contrary bilirubin, urea and creatinine levels were reduced in rat’s serum indicating dysfunction of hepatic and renal tissues. On the other hand, there was a significant reduction in AChE activity in serum. Testosterone did not changed significantly however the histological examination of testes showed pathological changes.
Diazinon:
Rat’s intoxication with diazinon resulted in a significant increase in serum liver enzymes including ALT, ALP and LDH while AST remained unchanged reflecting liver affection. While serum glucose level was significantly lower than the control group that may be due to acute pancreatitis caused directly by diazinon. Serum cholesterol level was increased that may be resulted from its toxic effect on hepatic tissue that impaired its ability to catabolize lipids. In addition, levels of serum total protein and albumin were increased reflecting the dysfunction state of liver and kidneys. The low bilirubin level detected in serum may be correlated to the pathological changes in liver that led to accelerated loss of bilirubin. Diazinon had an inhibitory effect on serum AChE activity while it stimulated testosterone hormone level in serum. Achook 0.15%: Achook intoxication resulted in an increase in ALP and LDH and decreased ALT and AST serum activities that may be an indication for the liver disorder. Also, serum glucose level was reduced significantly than the control group confirming the hypoglycemic effect of azadirachtin. The increased serum albumin level may be related to the pathological changes found in kidneys. In addition, the noticed reduction of serum bilirubin level may confirm kidney or liver affection. Serum AChE activity was increased significantly if compared with control group while the testosterone hormone level showed a significant reduction. Finally, there was a reverse relation between AChE and testosterone hormone was already observed in the results of the three tested insecticides and it is worth mentioning that Achook insecticide caused the highest increase in AChE and the lowest level of testosterone hormone when compared with the control group and other insecticide groups. 7.4.4. Effect of tested insecticides on the hematological parameters:
Butox® 50%: Administration of Butox® 50% to albino rats led to macrocytic anaemia that was indicated by decreased RBCs count and increased MCV value. Also, the increased values of MCV, MCH and MCHC confirmed the anemic condition. In addition, the increased platelets count may be resulted from defect in breakdown of thrombocytes by spleen. The reduced MPV and PDW values indicated that the majority of platelets were aged that characterized by small size. Finally, Butox® 50% intoxication did not affect the WBCs count. Diazinon 15%: Administration of diazinon has been led to macrocytic polychromic anaemia that indicated by increased MCV, MCH values and Hb concentration. The increased Hb may be returned to the state of dehydration or may be a response to tissue hypoxia induced by affected lungs. The increased Hct value confirmed the dehydration and may be due to the increased MCV value. Also, high values of platelets and plateletcrit emphasized dehydration state. Unlike Butox® 50%, diazinon intoxication resulted in significant increase in WBCs due to the tissue damage and inflammation. Achook 0.15%: Achook did not alter the values of RBCs and their indices, only RDW value was increased than control group that might indicate presence of RBCs of variable sizes. On the other hand, there were increases in platelets count and Pct value as well as WBCs that may be a response to the pathological changes in liver and kidneys as platelets and WBCs counts increase in case of inflammation. 7.4.5. Effect of tested insecticides on selected organs histopathology: The microscopic examination of selected tissues showed that the safest insecticide was Achook 0.15% as it led to the least alterations in liver and kidney tissues, in addition it did not produce any changes in histology of other organs as brain and testes unlike Butox® 50% and diazinon 15% insecticides.