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The experiment was conducted to study the growth suppression mechanism of chicken stunt and immunosupression syndrome virus(tentative name CSISV)for broilers.A total of 240 ROSS308 broilers ( male and female are half and half),1day age,were divided into two groups according to redidue respectively,Ⅰwas the control group,Ⅱwas the experiment group, each group contained 6 repetitions.3 repetitions in each group that every repetition included 10 chickens performed the growth experiment; 3 repetitions in each group that every repetition included 30 chickens performed the slaughters experiment continuously.On 2nd age,physiological saline 1.2mLwas poured into every broiler of groupⅠ, CSISV 1.2mL was poured into every broiler of groupⅡ. The trial lasted 6 weeks (0～3weeks and 4～6weeks).CSISV corrected pathogenicity of broilers.12hour post inoculation(hpi),to begin with,enteron was pathopoiesised,the results were showed: proventriculus,rough endoplasmic reticulum of epithelial cell which assumed vesicule dilated and edemaed, mitochondrial was immediate karyotheca,further, mitochondrial swelling, rough endoplasmic reticulum reduced, ribosome exfoliated, dilatation and small vesicules of Golgi complex reduced,and massive virus in nucleus. slight epithelial cell of Glandular cavity, gland acorn tube, three levels of tubes and gland Dou exfoliated and necrotized;swelling and erosion of nipple of proventriculus, the mucilage secretion increased.The small intestine,24hpi, mitochondrial of epithelial cell swelling、dilated and a few vacuoles,mitochondrial matrix damaged,degranulatiom of rough endoplasmic reticulum,formation hydropic bodies;intestinal villus became short、blunt and reduced,absorptive cell reduced, goblet cells increased,epithelial cell on the top of intestinal villus exfoliated, lamina propria exposed、connective tissue hyperplasia of lamina propria,ymphocyte infiltration, a part of necrosis stoves were formed.The intestines mucous membrane swelling,epithelial exfoliated,the reduction of the folds and became short,blunt,smooth and reduced of intestinal villus,and overall surface area reduction.Liver,48hpi,hpimitochondrial swelling,granular degeneration and a few vacuoles, degranulatiom of rough endoplasmic reticulum, glycogen increased;cell swelling and pyknosis, vacuolar degenercdion and bacame reticulation for massive vacuole,cell membrane was destroyed, reticulation of glycogen dissolution of cell serous, perisinusoidal pace narrowed, connective tissue hyperplasia;liver swelling,extravasated blood and blooding,with the disease development, the white or yellow secretion on the liver.Kidney,120hpi, microvillus in the absorptive cells broke、shorten and staved, mitochondrial reduced staved and ring-shaped,reduced and serious degranulatiom of rough endoplasmic reticulum, smooth endoplasmic reticulum swelling and dilated, dilatation,primary lysosomes swelling,hydropic degeneration in the cytoplasm,and massive virus in nucleus;renal corpuscle extravasated blood and coagulated,renal capsule dilated, granular degeneration of epithelial cell of renal tubule、swelling and cavity pace narrowed formed vacuole degeneration, epithelial cell of collecting renal tubule happened vacuole degeneration, things of protein style has been coagulated in the cavity of renal tubule;tumescent、engorgement and hemorrhage of kidney.144hpi,dispersivity necrosis stove like“the piebald kidney”.Growth performance of broilers was affected by CSISV. The rate of dead of groupⅡ(50%)was higher than groupⅠ(3.33%);Average daily feed intake,average daily gain and meat material ratio of groupⅡhas decreased 23.38%(P<0.05),29.80%(P<0.01)and 7.27%(P>0.05) than groupⅠ.The result of production performance and viscera growth showed that:the live weight, dressed weight, eviscerated weight with giblet,eviscerated weight, leg weight, brisket weight, leg muscle weight of groupⅠwere extremely significantly higher than groupⅡ(P<0.01); percentage of eviscerated yield, brisket muscle weight, abdomen fat weight of groupⅠwere significantly higher than groupⅡ(P<0.01);dressing percentage, percentage of eviscerated with giblet,abdomen fat rate,brisket muscle rate, the rate of leg muscle were no significant (P>0.05). The result of metabolism showed that: crude protein apparent retention ratio of groupⅡwas slightly higher than groupⅠon 3th and 5th the age,afterwards, droped gradually, groupⅡwas extremely significantly lower than groupⅠafter 17th the age (P<0.01);crude fat apparent retention ratio of groupⅡwas extremely significantly lower than groupⅠduring the total phase except 15th the age (P<0.01); calcium apparent retention ratio of groupⅡwas lower than groupⅠon 3th, 5th,7th and 9th the age,afterwards, groupⅡwas extremely significantly lower than groupⅠafter 15th the age(except 19th the age) (P<0.01); phosphorus apparent retention ratio and calcium apparent retention ratio were basically same.Based on above all mentioned, pathological change of Proventriculus、Small intestine、Liver and Kidney after broilers were inoculated virus created the digestion and the uninary system function disorder,which leaded to the fact that organism physiology structure was destructed. Function of digestion and absorption reduced because absorptive cell reduced and goblet cells increased, and feed intake of broilers droped,and the intaked feed could not by the full effective digestion,the absorption.Intaking of protein, fat, calcium and phosphorus reduced or lossed from body.Pathological change of Liver and Kidney induced disorder of substance metabolism.Last,the body would been malnutrition, growth was significantly inhibited, or even caused death.
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