尿素の毒性並びにその防除に関する研究-3-

概要

論文の詳細を見る
Goats, more than 6 months of age, fasting from the preceding day, were fed rations containing 1g of urea per kg of body weight (These feeding conditions of urea could bring animals to death by acute toxicosis, as previously reported.), and effects of molasses added to rations, upon the progress of urea toxication were investigated.1) When fed urea with 10 times as much molasses as urea, all 9 animals showed only trace symptoms of toxication and survived.2) When fed urea with 5 times as much molasses as urea, two animals died in 1 to 2 hours, one died after 15 hours, and eight survived showing various degrees of toxic symptoms for a few hours. One animal fed with 4 times as much molasses as urea also died.3) All animals fed urea without molasses died after showing acute toxicosis, with the progress similar to that described in the preliminary report.4) In animals which were fed rations with or without molasses and died eventually from urea toxication, NH3-N contents of their jugular vein blood increased very rapidly after feeding, reached the maximum levels at the dying stage which were more than 4mg per 100 cc blood and 10 times higher than those in normal animals. On the other hand, urea-N contents increased slowly and were only 2 to 3 times higher than those in normal animals at the same period.5) In animals surviving after feeding of urea with molasses, NH3-N contents of their jugular vein blood reached the maximum 1 to 2 hours after feeding and then decreased. This progress was almost parallel to the degree of toxic symptoms. The maximum value, on the average, was 0.5mg per 100 cc blood in animals fed 10 times as much molasses as urea and 1mg per 100 cc in those fed 5 times as much molasses, Urea-N contents of their jugular vein blood increased slowly, did not decrease during 7 hours after feeding, and showed no considerable difference between surviving and dying animals.6) When urea was substituted by the toxic lethel dose previously established of ammonium carbonate (equivalent to 0.8g of urea on N base perkg of body weight), and 10 times as much molasses as ammonium carbonate was added to rations, animals fed these rations survived. In this case, progressive changes of NHR3-N and urea-N in jugular vein blood were very similar to those in animals which survived after urea feeding.7) The blood concerning directly to the alimentary absorption contained more NH3-N than other blood, whereas no remarkable differences were shown among urea-N contents of blood in various veins of dead animals.8) Under experimental conditions, urea toxicosis was not influenced by pre-feeding of urea or cane molasses over long periods.
社団法人日本畜産学会の論文

尿素の毒性並びにその防除に関する研究-3-

スポンサーリンク

概要

著者

関連論文

スポンサーリンク