Tolerance and safety evaluation of N, N-dimethylglycine, a naturally occurring organic compound, as a feed additive in broiler diets

N, N-dimethylglycine (DMG) is a tertiary amino acid that naturally occurs as an intermediate metabolite in choline-to-glycine metabolism. The objective of the present trial was to evaluate tolerance, safety and bioaccumulation of dietary DMG in broilers when supplemented at 1 g and 10 g Na-DMG/kg. A feeding trial was conducted using 480 1-d-old broiler chicks that were randomly allocated to twenty-four pens and fed one of three test diets added with 0, 1 or 10 g Na-DMG/kg during a 39 d growth period. Production performance was recorded to assess tolerance and efficacy of the supplement. At the end of the trial, toxicity was evaluated by means of haematology, plasma biochemistry and histopathology of liver, kidney and heart (n 12), whereas bioaccumulation was assessed on breast meat, liver, blood, kidney and adipose tissue (n 8). Carcass traits were similar between the control and 1 g Na-DMG/kg feed groups (P>0·05), but the feed:gain ratio was significantly improved at 1 g Na-DMG/kg feed compared with the control or the 10-fold dose (P = 0·008). Histological examinations showed no pathological effects and results of haematology and plasma biochemistry revealed similar values between the test groups (P>0·05). Bioaccumulation occurred at the 10-fold dose, but the resulting DMG content in breast meat was comparable with, for instance, wheat bran and much lower than uncooked spinach. In conclusion, DMG at 1 g Na-DMG/kg improved the feed:gain ratio in broilers without DMG being accumulated in consumer parts. Furthermore, dietary supplementation with DMG up to 10 g Na-DMG/kg did not induce toxicity or impaired performance in broilers

Efficacy and safety of dietary N,N-dimethylglycine in broiler production

N,N-dimethylglycine (DMG), the dimethyl derivative of the amino acid glycine, is a naturally occurring intermediary metabolite in the choline to glycine metabolism. The molecule was first reported in 1943 and is currently used for a variety of applications, including the enhancement of athletic performances in both man and racing animals. With respect to its biological activities, DMG is for instance suggested to enhance oxygen utilisation and to posses non-enzymatic anti-oxidant properties. The studies described in this thesis aimed to evaluate DMG as a feed additive in chickens for fattening. In a pilot study, broilers were challenged with both cold stress and a high energy feed in order to incite broiler ascites syndrome. This metabolic disease results from an imbalance between oxygen requirement and supply, and is an important cause of financial losses and a major welfare issue in the modern broiler industry. A low dosage of dietary DMG effectively attenuated progression towards ascites. We hypothesize that this effect results from reduction in endothelial damage and dysfunction caused by plasma free fatty acids, which were substantially lowered by DMG supplementation. Furthermore, DMG improved nutrient digestibility and reduced nitrogen emission, which can be attributed to an emulsifying effect of DMG at the gut level. A subsequent trial revealed dose-dependent effects of dietary DMG on technical performance, carcass yield, oxidative stress parameters and broiler ascites syndrome. However, the nature and magnitude of the effects depended on fatty acid profile of the basal ration. Herein, effects were most pronounced when fed a diet rich in poly-unsaturated fatty acids. Generally, effects showed a linear relationship with dose, except for progression towards broiler ascites syndrome, which showed a quadratic relationship with dietary DMG content. Next, a series of efficacy trials were performed on farms at different European locations, using broiler strains and rearing conditions common to each region. Basal flock efficiency showed a wide range between trials; still, DMG systematically improved broiler performance. Finally, a safety and tolerance trial demonstrated a wide safety range of DMG in the target species. Moreover, DMG did not accumulate in consumer parts of broilers when included in diets at the recommended dosage, and bioaccumulation in meat at tenfold dosage did not exceed DMG content in for instance spinach. In conclusion, current investigations clearly demonstrate a wide applicability of DMG as a new feed additive in broiler production, in which both economic efficiency and environmental load as well as animal welfare is enhanced without compromising consumer safety. </p

Tolerance and safety evaluation of N, N-dimethylglycine, a naturally occurring organic compound, as a feed additive in broiler diets

N, N-dimethylglycine (DMG) is a tertiary amino acid that naturally occurs as an intermediate metabolite in choline-to-glycine metabolism. The objective of the present trial was to evaluate tolerance, safety and bioaccumulation of dietary DMG in broilers when supplemented at 1 g and 10 g Na-DMG/kg. A feeding trial was conducted using 480 1-d-old broiler chicks that were randomly allocated to twenty-four pens and fed one of three test diets added with 0, 1 or 10 g Na-DMG/kg during a 39 d growth period. Production performance was recorded to assess tolerance and efficacy of the supplement. At the end of the trial, toxicity was evaluated by means of haematology, plasma biochemistry and histopathology of liver, kidney and heart (n 12), whereas bioaccumulation was assessed on breast meat, liver, blood, kidney and adipose tissue (n 8). Carcass traits were similar between the control and 1 g Na-DMG/kg feed groups (P>0·05), but the feed:gain ratio was significantly improved at 1 g Na-DMG/kg feed compared with the control or the 10-fold dose (P = 0·008). Histological examinations showed no pathological effects and results of haematology and plasma biochemistry revealed similar values between the test groups (P>0·05). Bioaccumulation occurred at the 10-fold dose, but the resulting DMG content in breast meat was comparable with, for instance, wheat bran and much lower than uncooked spinach. In conclusion, DMG at 1 g Na-DMG/kg improved the feed:gain ratio in broilers without DMG being accumulated in consumer parts. Furthermore, dietary supplementation with DMG up to 10 g Na-DMG/kg did not induce toxicity or impaired performance in broilers

Dietary supplementation with dimethylglycine affects broiler performance and plasma metabolites depending on dose and dietary fatty acid profile

The effect of dietary supplementation with N,N-dimethylglycine sodium salt (Na-DMG) was evaluated in a feeding trial with 1500 1-day-old broiler chicks (Cobb 500). DMG was supplemented at 0, 0.1, 0.2, 0.5 or 1 g Na-DMG/kg feed to a ration with either animal fat (chicken fat) or vegetal fat (soy oil) as main fat source. In the vegetal fat diets, production value was significantly linearly improved by supplementation with DMG up to 11%. Irrespective of dietary fat source, abdominal fat percentage was significantly linearly reduced up to 24% and meat yield tended to increase linearly with DMG level up to 4%. In the vegetal fat groups, DMG significantly lowered abdominal fat pad by up to 38% and tended to increase meat yield up to 6% at the highest dose. Fasted non-esterified fatty acid level significantly decreased with increasing DMG level up to 36% and thiobarbituric acid reactive species (TBARS) decreased with a statistical trend up to 46% at the highest dose. In vegetal fat diets, addition of DMG resulted in significant lower TBARS level by 56% at the highest dose. Finally, a significant quadratic effect on ascites heart index was present in the vegetal fat diets, with a minimal value at 0.5 g Na-DMG/kg. In conclusion, dietary supplementation with DMG may improve technical and slaughter performance, and may reduce oxidative stress and pulmonary hypertension, but the degree of effects is modulated by fatty acid profile of the diet. Herewith, effects are more pronounced in a diet rich in polyunsaturated fatty acids compared with a diet rich in saturated and monounsaturated fatty acids

Efficacy of dimethylglycine as a feed additive to improve broiler production

Dimethylglycine (DMG) is a naturally occurring glycine derivative, which is useful as additive to broiler diets as it improves nutrient digestibility and reduces the development of broiler ascites syndrome. This study evaluated the efficacy of dietary DMG to enhance performance of broiler chickens. Three trials were conducted to evaluate the effect of dietary supplementation with 1 g Na DMG/kg on growth performance and carcass characteristics. In Trial 1, the effect of sex was also assessed in a 2×2 factorial arrangement of treatments. In Trials 1 (Germany), 2 (Austria), and 3 (Italy), each treatment consisted of 6, 12, and 11 replicate pens with 20, 15, and 16 one-day-old broiler chickens per pen, respectively. Dietary DMG supplementation resulted in improved feed conversion ratio (FCR) in the starter phase by 8.8% (P=0.004), 6.4% (P=0.001), and 4.8% (P=0.006) compared with the control diet in Trials 1, 2, and 3, respectively. The overall FCR improved in broiler chickens fed the diets supplemented with DMG by 3.8% and 4.1% in Trials 1 (P=0.007) and 3 (P=0.006), respectively. In addition, final body weight increased by 5.5% (P=0.001) in Trial 2 and production value improved by 6.8% (P=0.015) in Trial 1 by dietary DMG supplementation. Mortality in all trials was similar between dietary treatments. In all 3 trials, cold carcass weight and total meat yield were as well similar between broiler chickens fed the control and DMG diets. In Trial 1, dietary DMG had no effect on breast meat yield in male broiler chickens, but it increased breast meat yield in female broiler chickens (diet×sex, P=0.004). Organoleptic quality of roasted breast meat assessed only in Trial 2 was not affected by dietary treatments. In conclusion, dietary supplementation of DMG at 1 g Na DMG/kg can considerably improve s production performance in broiler chickens