Study On The Effect Of Cotton Meal And Cottonseed Shell On Urolithiasis Of Male Fine Wool Sheep

Object: Studying urolithiasis of male wool sheep induced by cotton meal and cottonseed shell, in order to explore the inducing factors and the basic reason of urolithiasis of male wool sheep in cotton areas, investigate the prevalence situation, analysis the effect of free gossypol and mineral elements that exist in cotton meal and cottonseed shell on the formation of sheep urinary calculi, and also observe and study pathological tissues of urinary system, thus to investigate the formation mechanism of urolithiasis of male wool sheep under feeding them with cotton meal and cottonseed shell.Methods: The paper consists of 6 experiments. Experiment 1: determination of gossypol and calcium, phosphorus, potassium and magnesium in feed. Atomic absorption spectrometry determine the content of calcium, potassium and magnesium in cotton meal , cottonseed shell and soybean meal, and using aniline method to determine free gossypol. Experiment 2: Urolithiasis of male wool sheep induced by cotton meal and cottonseed shell. By observing sheep urinary stone symptoms to verificate the feasibility that using cotton meal and cottonseed shell to induce urolithiasis of male wool sheep, in order to provide experiment animal model for studying sheep urinary stone. Moreover, dectect pathogenetic sheep's serum and urine biochemical index by automatic biochemical analyzer. Experiment 3: the effect of cotton meal and cottonseed shell on urine pH and urine crystallization of male wool sheep. At different experiment period (0d, 30d, 60d, 90d, 120d) deterimine the urine pH and observe the morphology, quantity and type of crystallization of all groups. Experiment 4: the effect of cotton meal and cottonseed shell on calcium, phosphorus, potassium and magnesium in serum of male wool sheep. Detecting pathogenetic sheep's serum calcium, phosphorus, potassium and magnesium by automatic biochemical analyzer, and stone elements by X-ray mass spectrometer, and then analysis the correlation between serum and stone component. Experiment 5: study on the damage in urinary system that caused by cotton meal and cottonseed sell (at the treatment day 30, 60, 90, 120 and the pathogenetic sheep). Making the tissue section of urinary system, and observing histopathologic change by microscope in order to analysis the urine system damage mechanism of stone's male wool sheep. Experiment 6: look into stone's microstructure and analysis its components. X-ray diffraction analysis, X-ray mass spectronmetric, scanning electron microscope method and infrared spectroscopy were used to assay stone's components and its microstructure.Results: Low dose cotton meal and cottonseed shell couldn't initiate urinary calculi of male wool sheep, but high dose could, and in the experiment there were 5 stone sheep. Cotton meal and cottonseed shell has no significant effect on urine pH, but has significant effect on urine crystallization. By analyzing the correlation about phosphorus, potassium and magnesium, which exist in stone components and serum, and the results are R_P=0.750 (moderately correlated), R_K=0.959 (significant correlation), R_Mg=0.883 (high correlation). The reason that cotton meal and cottonseed shell can induce urinary stone is there are phosphorus, potassium, magnesium and free gossypol in them, and gossypol injures glomerular and renal tubular. Then crystallization obstructs renal tubular, making it swell and epithelia break (at 60d), and minuteness granule flow into the renal tubular, ultimately lead to urine concretion. In the test MgKPO₄, MgKPO₄·6H₂O and Mg₂P₂O₇ were analyzed.Conclusion: Urinary stone caused by high dose cotton meal and cottonseed shell in male wool sheep is a kind of gossypol chronic poisoning mineral nutritional diseases. The study adequately proved that stone was caused by cotton meal and cottonseed shell in cotton areas, and the main factor is that there are a lot free gossypol and high dose of phosphorus, potassium, magnesium. The free gossypol can result in the damage of glomerular and renal tubular. By analyzing the correlation about the component of stone and serum, we obtained that high dose of phosphorus, potassium and magnesium had close relationship with the stone formation. High dose phosphorus, potassium and magnesium bring on the metabolized mineral ion tending to saturation and crystal accretion at the same time, so leading to urinary system obstruct and finally stone come forth.