الفهرس 
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Abstract
The current study was done as a trial to find effective chemical disinfectants against unsporulated and sporulated E. tenella oocysts and to define their best application conditions.
Efficiency of four commercial disinfectants commonly used in poultry farms including ammonium hydroxide, phenol, Zixvirox and Eco.Bio was evaluated against E. tenella oocysts that were obtained from naturally infected birds with ceccal coccidiosis then propagated in broiler chicks reared on wire cage and fed anticoccidial free starter ration from day one of rearing till the end of experiment.
For evaluation of the effect of concentration and contact time on the efficacy of disinfectants, three dilutions of each disinfectant was prepared as follow: Ammonium hydroxide (2.5%, 5% and 10%), Phenol (5%, 10% and 20%), Zixvirox (2%, 4% and 6%) and Eco.Bio (5%, 10% and 20%) each concentration was added to the parasite at different contact times (10, 30, 60 and 90 minutes and 24 hours). Also, the selected disinfectants were evaluated at different temperature degrees (4 ºC, 10 ºC, 20 ºC, 30 ºC and 40 ºC) and different pH degrees (Ammonium hydroxide at pH 8.6, 94, 10, 11 and 12, Phenol and Eco.Bio at pH 2, 5, 7, 9 and 11 and Zixvirox at pH 2, 5, 7, 9 and 11.4) in addition to evaluation of the disinfectant efficacy in absence and presence of source of organic matter (10% chicken faeces).
Efficacy of disinfectants against unsporulated E. tenella oocysts were evaluated by calculation of percentage of sporulation inhibition (IA %), while their efficacy against sporulated oocysts were evaluated through disinfection of sporulated oocysts by each of the selected disinfectants then inoculation of these oocysts into the crop of experimental broiler birds at the 14th day of age then some measures were calculated as: lesion scoring, mortality rate, feed consumption, body weight gain and feed conversion ratio.
The obtained results revealed the following:
7.1. Ammonium hydroxide:
• Usage of ammonium hydroxide 5% and 10% resulted in IA 100% within 24 hours CT.
• At concentration 10% the IA were 97% and 96.2% at exposure time of 90 and 60 minutes, respectively that still accepted result.
• At concentration 5% the IA were 95.8% and 96.4% within 60 and 90 minutes, respectively that still also accepted result.
• The study proved also that efficacy of ammonium hydroxide 10% not affected by presence of source of organic matter, as its efficacy reduced only by 2%.
• By rising the solution temperature to 40 ºC it needed only 15 minutes to reach IA 100%.
• It was clear that efficacy of Ammonium hydroxide 10% increased by increasing the solution alkalinity; as the highest efficacy (IA 96%) was reached at pH 12.
• The practical experiment proved that Ammonium hydroxide 10% was the most effective disinfectant against sporulated E. tenella oocysts; as it resulted in zero mortality percentage and zero lesion scoring.
• The results indicated a significant increase in feed consumption in experimental birds used to evaluate Ammonium hydroxide 10% solution above the feed consumption of those of control positive group during the first week post infection, while there were no significant differences within the following two weeks.
• There was a significant increase in body weight gain in experimental birds used to evaluate Ammonium hydroxide 10% solution above the body weight gain of those of control positive group during the first week post infection, while there were no significant differences within the following two weeks.
• There was a significant increase in feed conversion rate in experimental birds used to evaluate Ammonium hydroxide 10% solution above the rate of those of control positive group during the first week post infection, while there were no significant differences within the following two weeks. Also, there were non-significant differences in feed conversion rate between experimental birds used to evaluate Ammonium hydroxide 10% solution and those of control negative group through out the experiment period.
7.2. Phenol:
• IA of 100% was achieved at concentration of 10% and 20% within 24 hours.
• When the contact time was decreased to 90 minutes the achieved results was not accepted, as the highest IA of the highest concentration (20%) was 83.2%.
• The presence of organic matter not affect the efficacy of phenol 10% as the IA in the absence of organic matter recorded 42.1%, while in presence of 10% chicken faeces it was 48.6%.
• By rising the solution temperature the efficacy of Phenol 10% was increased to reach its maximum at 30 ºC where the IA was 73.5%.
• The efficacy of Phenol 10% against E. tenella oocysts increased by increasing the solution acidity; as the highest efficacy (IA 41.7%) was reached at pH 2.
• By disinfection of sporulated E. tenella oocysts by Phenol 10% and then inoculating them into experimental birds; it was noticed that there was no mortalities.
• Phenol 10% failed to prevent caecum lesions in experimental birds as it recorded lesion scoring of 2.00±0.58.
• The results indicated a significant increase in feed consumption in experimental birds used to evaluate Phenol 10% solution above the feed consumption of those of control positive group during the first week post infection, while there were no significant differences within the following two weeks.
• There was a significant increase in body weight gain in experimental birds used to evaluate Phenol 10% solution above the body weight gain of those of control positive group during the first week post infection, while there were no significant differences within the following two weeks.
• There was a significant increase in feed conversion rate in experimental birds used to evaluate Phenol 10% solution above the rate of those of control positive group during the first week post infection, while there were no significant differences within the following two weeks. Also, there were non-significant differences in feed conversion rate between experimental birds used to evaluate Phenol 10% solution and those of control negative group throughout the experiment period.
7.3. Zixvirox:
• At concentration 2% (the recommended concentration by producer to kill Eimeria spp.) the IA were 4.5%, 5.3%, 23%, 24% at 10, 30, 60 and 90 minutes, respectively. Even after increasing the contact time to 24 hours the IA increased to 30.9% only, that still unaccepted result for classifying that product as oocysticidal one.
• The highest IA recorded by Zixvirox was 49.8% at concentration of 6% within contact time 24 hours.
• The IA of Zixvirox 4% was reduced by presence of organic matter by 52.9%, where IA reached 17.2% in absence of organic matter while in presence of 10% chicken faeces this efficacy reached 8.1% only.
• Rising the temperature degree seemed to have no effect on efficacy of Zixvirox 4% as the IA were 36.8 and 36.5 at 4 ºC and 40 ºC, respectively. While it reached 39.7%, 37.7% and 38.8% at 10 ºC, 20 ºC and 30 ºC, respectively.
• The highest efficacy of Zixvirox 4% was recorded at pH 5 as the IA reached 41.5%.
• By disinfection of sporulated E. tenella oocysts by Zixvirox 4% and then inoculating them into experimental birds; it was noticed that there was no mortalities.
• Zixvirox 4% failed to prevent caecum lesions in experimental birds as it recorded lesion scoring of 2.00±0.58.
• The results indicated a significant increase in feed consumption in experimental birds used to evaluate Zixvirox 4% solution above the feed consumption of those of control positive group during the first week post infection, while there were no significant differences within the following two weeks.
• There was a significant increase in body weight gain in experimental birds used to evaluate Zixvirox 4% solution above the body weight gain of those of control positive group during the first week post infection, while there were no significant differences within the following two weeks. Also, there was non significant difference in body weight gain between experimental birds used to evaluate Zixvirox 4% solution and those of control negative group through out the experiment period.
• There was a significant increase in feed conversion rate in experimental birds used to evaluate Zixvirox 4% solution above the rate of those of control positive group during the first week post infection, while there were no significant differences within the following two weeks. Also, there were non-significant differences in feed conversion rate between experimental birds used to evaluate Zixvirox 4% solution and those of control negative group through out the experiment period.
7.4. Eco.Bio:
• By increasing Eco.Bio concentration or increasing its contact time with the parasite its efficacy was increased, where the highest IA (76.2%) was obtained at concentration 20% within 24 hours contact time.
• The efficacy of Eco.Bio 10% was reduced in case of presence of organic matter by 47%. The IA was 16.8% in absence of organic matter that reduced to 8.9% in the presence of organic matter.
• The results clarified that Eco.bio 10% worked very well at 20 ºC, while its efficacy enhanced by very little degree by increasing the temperature to 40 ºC.
• Efficacy of Eco.Bio 10% was enhanced by increasing the solution alkalinity, as the highest IA was reached at pH 11.
• By disinfection of sporulated E. tenella oocysts by Eco.bio 10% and then inoculating them into experimental birds; it was noticed that there was no mortalities.
• Eco.bio 10% failed to prevent caecum lesions in experimental birds as it recorded lesion scoring of 3.33±0.33 that was the same as that of control positive group.
• The results indicated non significant differences in feed consumption in experimental birds used to evaluate Eco.bio 10% solution above the feed consumption of those of control positive group during the whole period of experiment.
• There was a significant increase in body weight gain in experimental birds used to evaluate Eco.bio 10% solution above the body weight gain of those of control positive group during the first week post infection, while there were no significant differences within the following two weeks.
• There was a significant increase in feed conversion rate in experimental birds used to evaluate Eco.bio 10% solution above the rate of those of control positive group during the first week post infection, while there were no significant differences within the following two weeks. Also, there were non significant differences between experimental birds used to evaluate Eco.bio 10% solution and those of control negative group through out the experiment period.
Finally, It was suggested that the usage of phenol 10% for 24 hours for disinfection of poultry house before entrance of new birds or between production cycles if there was a complain of coccidiosis invasion in the last production cycle, as Phenol able to eliminate E. tenella oocysts by 100% even in the presence of organic matter, also it is more safer than ammonium hydroxide that is an irritating, suffocating and corrosive product that has deleterious effect on general health and also lower the expected life time of the poultry house and its utensils and equipment. The temperature of water used to dilute Phenol should be adjusted at 30 ºC and the pH at 2.