Effects of N,N-dimethylglycine sodium salt on apparent digestibility, vitamin E absorption and serum proteins in broiler chickens fed high or low dietary fat level

The objective of this study was to assess the effect of supplementation with sodium salt of N,N-dimethylglycine (DMG-Na) on apparent digestibility (AD) in broiler chickens fed low and high fat diets. Twenty eight one-day old broiler chickens were fed one of the dietary treatments: a low fat diet (LF) or a high fat diet (HF) supplemented with or without 1000 mg/kg DMG-Na. Body weight and feed consumption were recorded at four different time points. Average daily gain, daily feed intake, and feed conversion ratio were calculated. The AD of dry matter (DM), organic matter (OM), crude protein (CP), total fat (TF), and ?-tocopheryl-acetate (?-TA) were assessed. Plasma alpha-tocopherol (?-TOC) concentration was assessed at 35 days of age. Final body weight, carcass, breast and spleen weight, and feed intake were higher in groups fed LF than HF diets (P=0.048, P=0.039, P<0.001, P=0.007, and P=0.001 respectively). Lower liver weight was observed in DMG-Na supplemented groups than controls (P=0.011) for both fat levels. The AD of DM (P=0.023), OM (P=0.033) and CP (P=0.030) during early age was higher in DMG-Na supplemented groups than controls. Digestibility of ?-TA was increased by DMG-Na supplementation (P=0.036). Digestibility of total fat was increased by DMG-Na supplementation in LF groups (P=0.038). A trend for improvement of digestibility was observed during finishing phase for DM (P=0.089), OM (P=0.051), and CP (P=0.063) in DMG-Na groups. Total serum protein was positively influenced by DMG-Na supplementation both in LF and HF diets (P=0.029). Plasma ?-TOC concentration was higher in groups fed LF than HF diets (P<0.001). At early age, positive effects of DMG-Na on AD in broiler chickens promote the reduction of nitrogen emission in low and high fat diets, and fat digestibility in LF diets. The DMG-Na supplementation enhanced digestibility of ?-TA at early age.