Studies On The Toxicity Of Free Gossypol To Layers

280 brown shell HaiLan layers, 43 weeks, were divided into 10 groups .There were two replications in each group and fourteen laying hens in one replication. The experimental hens was breeded ration containing free gossypol(FG): 0 mg/kg,10 mg/kg,20 mg/kg,30 mg/kg,40 mg/kg,50 mg/kg,70 mg/kg, 90 mg/kg, 120 mg/kg and 150mg/kg, respectively. After pre-breeding 7 days, the trial term lasted 10 weeks. The layers could drinking and feeding freely. 2 layers were selected to pump blood and kill. The blood was disparted two shares, one was accounted for RBC and WBC, the other share was determined for GOT & GPT activities. The layers were killed to select breast tissue(20g), live, kidney for contenting FG.. 2 eggs were selected randomly in each replication every week, also for contenting FG..The objective of the study was to realize the toxicity of FG in layers, and its residues of in tissues and eggs.The results would offer the data on the provide capacity of cottonseed cake in layer rational,and bird production safety and sanitation.The experimental results showed:1 .Effect on the rate of laying eggsIt wasn't remarkable that all groups(FG<70mg/kg) compared with the control group in the rate of laying eggs. But rate of laying eggs in those groups (containing FG: 90mg/kg, 120mg/kg, 150mg/kg) showed downtrend clearly.2.Effect on mean of egg weightThe mean of egg weight of all groups(FG<70mg/kg) only showed increased trend, but degressive trend along with increaseing content of FG., and this trend was significant at last phases(p<0.01).3. Effect on ADFIADFI in all groups weren't significant in preceding 6 weeks, but ADFI of 2 groups(containing FG:120mg/kg, 150mg/kg) degressed obviously.4.Effect on RBCThere weren't as near as makes no difference on amount of RBC of all groups(FG<70mg/kg) (p>0.05), but 3 groups(containing FG: 90mg/kg, 120mg/kg, 150mg/kg) showed clearly downtrend.5.Effect on WBCAmount of WBC of all groups fluctuated distinctly in preceding 2 weeks, whereas showed markedly increaseing respectively. In particular the increasing trend was wondrous in there groups(FG≥70mg/kg)(p<0.01).6.Effect on weight of layersThe weight of layers increased respectively in these groups (FG≤50mg/kg), however presented reduced trend in these groups(FG ≥ 70mg/kg),didn't showed clearly difference(p>0.05).7.Effect on rate of decrease & elimination in hens.The effect of rate of decease & elimination on hens wasn't obvious that affected by FG (p>0.05).8.Effect on GOP and GPT activiyiesThe activities of GOP and GPT in blood serum were steady whose there layers of the control group, but there layers of all trial team of feeding cottonseed cake in diets which the activity of GOT/GPT showed increase's trend(p<0.01) clearly.9. The FG residues in tissues and eggsFG could cumulate in tissues and eggs soon after, showed clearly trend of rise which increasing along with content in ration and trial period. The difference of all groups were the remarkablest(p < 0.01)...