The poultry industry suffers from various diseases or stresses. In poultry, apart from being antipyretic, acetylsalicylic acid (ASA) is widely used to cope with different issues including heat stress, and respiratory and digestive orders. This study evaluated the beneficial and toxic effects of ASA at different dose levels in broiler birds. To evaluate these toxic and beneficial effects it is necessary to examine the physical and serum biochemical parameters as well as the histopathological changes with tissue sections taken from broiler birds under experimental trial. This study was conducted on 60 one-day-old broiler chicks purchased from a local market in Faisalabad. Chicks were reared for the first 14 days under similar conditions. On the 15th day, birds were randomly divided into 4 groups (1-4) with 15 birds in each group. Group 4 was kept as control, while groups 1, 2, and 3 were treated with ASA at the dose of 300, 600, and 1200 mg/L of drinking water for 21 days. There were 3 samplings performed at 21, 28, and 35 days post-treatment. The live body weight and carcass weight were noted on each sampling. All the visceral organs were recorded for gross pathological changes. The serum samples were collected for biochemical evaluation. Histopathology of all the visceral organs was performed to observe the microscopic changes. A significant (P<0.05) increase in live body weight at a 300mg/L dose was noted after the first 2 samplings. A significant (P<0.05) increase in the relative organ weight was recorded at 1200 mg/L. The groups treated with ASA 600 and 1200 mg/L showed increased (P<0.05) AST, ALT, and creatinine levels from that of the control group. The group treated with 1200 mg/L of ASA showed increased (P<0.05) urea, serum total protein, and albumin level in all the samplings. Histopathological changes revealed swollen hepatocytes, increased sinusoidal spaces in the liver, congestion and abnormal glomerular spaces in the kidney, congestion and alveolar disruption in the lungs, and generation of villi and cellular degeneration in the intestine in a high-dose group. The study concluded that ASA at a low dose can be used for a long time in broilers and has a growth promontory role, while high-level doses cause hepatorenal toxicity.

In this study, 50 vaccinated broiler and one layer flock from Beni-Suef, Fayoum and Minia governorates were investigated. Necropsy lesions were suggestive of LPAI-H9N2 or NDV. Samples of tracheal swabs and organs were subjected for viral isolation and molecular characterization. Specific RT-PCR for the NDV F-gene and the HA gene of the LPAI-H9N2 viruses was used. Virus isolation and primary identification using HI test revealed 37.5 and 43.3-46.2% prevalence for LPAI-H9N2 and NDV viruses, respectively. Phylogenetic analysis of partial sequences of the F gene showed that NDV viruses belong to genotype II and VII-1.1. as indicated by the F0 protein proteolytic cleavage site motifs (aa112-117) of the NDV strains F-gene. The vNDV isolates were 98.7-99.3% and 96.6-98.9% identical to each other based on nucleotide and amino acid identities, respectively. Compared to their counterpart isolates; the lentogenic strains shared 98-99.2% and 96.3-98.1% nucleotide and amino acid identities to the LaSota reference strain. The LPAI-H9N2 phylogeny of the HA gene showed that the 2 isolates obtained in this study are related to each other and related to recent 2016-2018 Egyptian H9N2 strains. Notably, the 2 strains showed higher identity (≥99%) to recent Israeli 2018 isolates with several amino acid changes. The current study revealed wide spread of both NDV and LPAI-H9N2 viruses. The vaccine failure and the mismatch between the vaccine and circulating NDV viruses is the most probable cause of current outbreaks. The LPAI-H9N2 viruses are divergent form their ancestral viruses in Egypt indicating continuous circulation and vaccine pressure induced mutations

This study was carried out on serum samples collected from broiler breeder chicken flocks vaccinated with avian influenza (AI) H5N1 inactivated vaccine. These flocks included 23 flocks aged 13 to 47 weeks reared in close houses in 7 sites; two vaccinated breeder flocks for HI antibody monitoring by 5 weeks interval samples and 8 flocks aged 41 weeks reared in different sites with identified females and males samples. The vaccine was used in a dose of 0.2 ml at 1 day in hatchery and revaccinated with 0.5 ml at age of 18 days, 19- 20 weeks and 40 weeks. Hemagglutination inhibition (HI) test was carried out against homologous antigen. The study pointed out that AI H5N1 inactivated vaccine under field application induced irregular and low HI titres following the 1st two doses ranged from log 2 0.0 to 4.15 with great variation between flocks, where samples with titre 0-2 ranged from 20 to 100%. The 3rd dose at 19-20 weeks was essential to elevate HI titres 3.25 to 7.44 with more homogenizes flock immunity and lower percentage of titres 0-2 ( 0-20 %) and as measured by HI test. Revaccination of layer flocks at 40 weeks (fourth dose) improves flock immunity facing stress of egg production as evaluated by HI (5.52 - 6.33) and lower negative percentage (5.5-11.7%). Monitoring of breeder flock every 5 weeks is essential to detect proper time of revaccination as each flock has its HI antibody curve. There was a difference in HI tit re rang log 2 0.33 to 1.2 between male and female chicks reared in the same house, but this variation not affecting flock mean. Birds at aged 41 weeks having titres < log2 3 (Seronegative) were protected when exposed to contact with infected flock as showed no clinical signs or change in HI titres after 12 days. In conclusion the usage of homologous inactivated H5N1 vaccine in 4 doses in layer flocks was of value in improving chicken immunity to AI H5N1 wild strain circulate in our field

This study was carried out to evaluate the immunomodulating effects of, inactivated cells of Propionibacterium acnes and cell wall lipopolysaccharide (LPS) of the a pathogenic E. coli (INMUNAIR® 17.5) 0.5ml/ L and 1-3, 1-6 β-glucans (BETAPOLO®) 1 ml / L on the immune response of chickens to Newcastle disease (ND) vaccine. The results showed that administration of IMR before vaccination was resulted in food conversion rate (FCR) higher than after vaccination . Significantly higher NDV HI antibody titers in IMR and Betapolo medicated groups as compared with control groups which in turn induce high protection rate in challenge test .Thymus, spleen and bursal indices of control negative showed significantly lower values than vaccinated medicated and non- vaccinatedmedicated groups (P≤ 0.05).

The effect of 10 times (10x) overdose of enrofloxacin was studied in broiler chickens. One hundred and eighty chicks were classified in 3 equal groups. The first group received normal theurapeutic dose of enrofloxacin (1x) in drinking water for the first 5 consecutive days of age and repeated again at 24th -28th day of age. The second group received 10x (overdose) at the same ages. The third group was left non-medicated as a control group. Blood samples were taken on the 6th, 14th, 29th and 34th day of age for different laboratory tests. Enrofloxacin at 10x caused a decrease in the value of the following parameters: HI antibody titers to NDV vaccine at the 14th and the 34th day of age, serum albumin at the 10th day of age, hemoglobin at the 29th and the 34th day, lymphocytic count and IBDV ELISA titers at 29th day of age, uric acid at 29th day, phagocytic activity at 34th day, Lactobacillus spp. count in duodenum, feed conversion efficiency and body weight gain. The 10x (overdose) increased serum urea and creatinine at 29th day of age, serum AST and ALT at 29th and 34th day of age, and heterophilic count. Histopathological degeneration in liver, spleen, kidneys, bursa of Fabricius and thymus were demonstrated by 10x (overdose) of enrofloxacin. Challenge with vNDV caused 66.6% mortality in birds received the 10x (overdose) compared with 33.3% in the vaccinated non treated control group.

This study was carried out to evaluate the efficacy of water soluble formulation of diclazuril (1%) in the prevention and control of mixed Eimeria infection in two experimental (semifield) trials and testing efficacy of this medicament in controlling of natural field case of mixed Eimeria infection. The experimental (semifield) trials carried out each on 150-day-old broiler chicks, as they were divided into 3 equal separate subgroups. Infected groups were orally received 1ml of an inoculum containing 50.000 sporulated oocysts of Eimeria tenella, E. acervulina and E. necatrix/ chick at 14 days of age. Diclazuril (1%) liquid at dose of 1 ml / 4 liter of drinking water for 2 successive days just after appearance of bloody dropping (at the 5th day post infection). Birds were given prophylactic diclazuril dose (1 ml / 8 liter) at the 7th day before the experimental inoculation. In both trials were oocyst count (shedding) in the dropping, dropping score, lesion score, body weight gain % and mortality rate were evaluated. Groups treated with diclazuril either in the prophylactic and curative studies gave significant and satisfactory improvement in the assessment criteria when compared with infected non medicated groups. A field trial was conducted 2 commercial broiler chicken farm consisted of 2 flocks aged 33 days; 6000 birds each. Flock (1) was kept as control positive infected non medicated group, whereas flock (2) was medicated with diclazuril (1%) at dose of 1 ml / 4 liter of the drinking water for 2 successive days. The results revealed more reduction in total oocyst count, lesion score and the mortality rate in the medicated than the infected non-treated group. The results proved that diclazuril (1%) liquid is effective in prevention and control of both experimental and field infection field circulating Eimeria species still sensitive to the drug.

This study was conducted to investigate the efficacy of the Newcastle disease (ND) live vaccines from different commercial sources used in different programs for vaccination of chicks having maternal antibodies against Mycoplasma infection. The immune response was estimated using HI and challenge tests. The effect on the chicken performance was estimated by the detection of the body weight gain. The role of vaccines in stimulating respiratory bacterial stress was pointed out by the lesion scores. Birds vaccinated with live vaccines from source (2) showed higher HI titers than those vaccinated with vaccine from source (1) and birds received the 2nd vaccination from heterologous source showed lower titers than those received from homologous source. Results of the challenge test indicated that birds vaccinated with live ND vaccines from one source and those vaccinated with Hitchner B1 at 33-days of age instead of La Sota showed 100% protection rate as compared with 95 % followed by vaccination with heterologous La Sota. Birdsreceived Hitchner B1 of vaccine source (1) showed only 85% protection rate. All vaccinated chicken groups showed feed conversion rates lower than the non-vaccinated control one. Groups received Hitchner B1 as a 3rd dose of the vaccine showed higher rates than those vaccinated with La Sota. Results of the lesion score for chronic respiratory disease (CRD) in vaccinated groups with different regimes revealed that birds received ND vaccinal strains from source (1) having higher scores than those received ND vaccines from the 2nd source. Administration of Hitchner B1 vaccine at 33-days of age showed lower scores. Hitchner B1 can be recommended in vaccination of chickens derived from Mycoplasma infected hens.

An unusual fowl pox outbreak has been diagnosed in 40 days-old-unvaccinatedbroilers farm in Dakahlia Governorate during summer, 2004. The most characteristicobservation of this outbreak was that the pox signs and lesions were observed on the feathered parts of the body mainly in the posterior dorsal area of the chickens.Classical pox lesions were also seen in the mouth, comb, wattle, eyelids and shank of some chickens. Samples were collected from affected birds for virus isolation andhistopathological studies. The isolated virus on the chorioallantoic membrane (CAM)was serologically confirmed. Histopathological examination revealed characteristicintracytoplasmic eosinophilic inclusion bodies in affected chicken tissues and CAM.This outbreak caused severe economic losses due to cutaneous lesions in the feathered area of the body that resulted in high condemnation rate at processing plant beside to high mortality which reached upto25%.

A total of 90 one-day-old male broiler chicks were fed on balanced ration for 15 days and then divided into 3 equal groups. Control group fed ration probiotic free, group 2 and 3 fed ration supplemented with probiotic at concentration levels 0.5 and 1.0g/kg ration respectively for 4 weeks.It was found that probiotic improve body weight gain and feed conversion ratio. Relative organs weights were not altered in groups of birds fed ration mixed with probiotic. Serum values of biochemical parameter (AST, ALT, ALP, total protein, A/G ratio, Ph) were not significantly changed in comparison to control group. Probiotic enhance the immune response of broiler chickens in a dose dependent relation as documented by increasing the serumNDHI antibody geometric mean titres to ND vaccine, phagocyte percentage and phagocytic index of peripheral blood monocyte of broiler chickens. We concluded that probiotic composed of 3 strains of bacteria (Pediococcus acidilactici, Pediococaoccus pentosaceus and Bacillus Amylolique- faciens) in addition to 2 strains of yeast( Pichia farinose and Dekera anomala ) enhance body weight gain, feed conversion, growth performance and Newcastle disease antibody titres in broiler chickens. Moreover, probiotic was safe as proved by serum biochemical profile and relative organ weight of male broiler chickens.

In 9 weeks field study, a total of 14100 (Ross broiler breeders) 51 weeks-old chickens fed on the same ration, placed in 2 houses (6600 female + 450 male / house). Birds of house 1 were treated with antimycotoxin adsorbent aluminum silicate (G-V-tox®) 5 kgm/ ton, while those of house 2 were kept as non treated controls. Productivity and reproductivety parameters were calculated for comparison. Treated flock showed improved average egg production (Average 62.2%/week) compared with non treated (Average 61.7%/week), but all still lower than farm stander (Average 76.4%/week). Marked improvement was in the 1st 3 weeks (51-53) of treatment only. Total 9 weeks production declined was 5.5% and 8.4% in control and silicate treated flock; with weekly average of 0.61, and 0.93; respectively. Control flock was slower in decline of production (0.61%/week) than treated flock (0.93%/week). Average weekly egg production and hatching eggs/ hen in treated flock was lower than standard and higher than non treated. Hatchery parameters of treated were improved in treated at the first 3 weeks post treatment. The fertility was higher in aluminum silicate treated group (77.2%), than the untreated one (72.19%). The hatchability was in silicate treated (63.66%) versus (62.25%) in the untreated control. Culls % in hatched chicks was 1.91% in treated flock and lower than in non treated (2.85%). Difference percentage between fertility and hatchability of G.V. tox treated chickens was (10.84%) higher than untreated control (16%). The number of marketable chicks l100 was also improved in treated than non treated. In conclusion, our field study cleared that administration of Silicate in ration for treatment of broiler breeders resulted in an improved production and hatchery performance as compared with non medicated control. However; it did not restore it to the farm stander. Consequently the results indicated that we still in need for more effective products to be used to control mycotoxins in breeder chicken.