A Survey On Quality Of Feed-Grade Choline Chloride In China Feed Market And The Hazard Of Its Trimethylamine Residuals

Fifty-nine feed-grade Choline Chloride samples were collected in china feed marketduring Feb. 2005 to Jan. 2006. Choline Chloride content was determinated by Reineckatemethod and silver nitrate titration. The trimethylamine residual was determined bydistillation under NaOH and Na₂PO₄-NaOH buffer respectively. The results indicated that,according to Choline Chloride content determined by Reineckate method, 24% samplecouldn't meet the criterion of national standard on feed-grade Choline Chloride product(HG2941-2004). The trimethylamine residual of 85% sample was higher than 1000 mg/kg,which is the maximum permited level of national standard (HG2941-2004). The highesttrimethylamine residual was 33506 mg/kg. It implied the product quality of feed-gradeCholine Chloride in china, as to the content of Choline Chloride, was improved after thenew official analysis method put into effect. However, much attention should be paid to thetrimethylamine residual.The trimythylamine residuals of 17 samples, simultaneously determined by Keldahland Na₂HPO₄-NaOH buffer distillation, were compared. The mean residual of Keldahlmethod was significantly higher than that of buffer method (202 mg/kg vs 107 mg/kg,P＜0.01). The same result was occurred as to five repeat analyses of corn flake—thecommon used carrier of choline chloride products (530 mg/kg vs 242 mg/kg, P＜0.001).The serious decomposition of nitrogenous compounds other than trimethylamine inproducts and carrier under saturated caustic soda solution was the possible reason.According to the result of this survey, two animal trials were conducted to verifywhether the high trimethylamine residuals in choline chloride would interfere with weanedpiglet's daily feed intake. In trail 1, 90 Duroc x (Landrace·Large white) crossbred weanedpiglets average weighted 7.3 kg were divided into 10 groups randomly. The trial diet hadthe same ingredient composition with control diet except a 22000mg/kg trimethylamine hydrochloride addition. Five groups of animal were randomly assigned to test or controldiet. After 8 days, it was demonstrated that the average daily feed intake of test groups wassteadily less than that of control groups(291 g/p/d vs 382 g/p/d), especially at the beginningstage of trial, 0～3 day (213 g/p/d vs 313 g/p/d, P＜0.05). Twenty-four piglets, as above,were divided into 6 groups in the second trial. Both the trial diet and control diet weregiven simultaneously to each group. After 10 days, it was demonstrated that the intake oftest feed was less than control in 5～10 day and whole test days (202 g/p/d vs 305 g/p/d; 179g/p/d vs 287g/p/d, P＜0.05).It concluded that the high residual of trimethylamine in cholinehydrochloride products had an adverse effect on feed intake of weaned piglet.