Dietary supplementation of betaine promotes lipolysis by regulating fatty acid metabolism in geese

Supplementation of betaine in the diet appears to regulate fatty acid metabolism and decrease fat deposition. This study aims to identify the effects of dietary supplementation of betaine on zootechnical performance, fatty acid synthesis, abdominal fat deposition, and morphology. Three hundred healthy, male, one-day-old Jiangnan White geese of similar body weight were randomly divided into 5 groups, with 6 replicates per treatment and 10 geese per replicate, and given the following amounts of supplementary betaine: 0 (group A), 600 mg/kg (group B), 1,200 mg/kg (group C), 1,800 mg/kg (group D), or 2,400 mg/kg (group E). Feed intake (FI), body weight (BW), abdominal fat and sebum thickness, clinical blood parameters, hepatic enzyme activity, and abdominal fat morphology were monitored during the experiment. All geese had free access to feed and water throughout the study. Our results indicate that supplementation of betaine increased zootechnical performance at 21 and 42 d of age. The percentage of abdominal fat and sebum thickness of geese at 63 d of age decreased linearly with the addition of betaine (P < 0.05). The triglyceride (TG) and total cholesterol (TCHOL) content of serum decreased with the increased level of betaine when measured at 63 d of age (P<0.05). Hormone sensitive lipase (HSL) increased with the level of betaine (P<0.05). However, dietary betaine appeared to decrease the activity of fatty acid synthase (FAS) in the geese at 42 d and 63 d of age (P<0.05). The percentage of total area of lipid droplet decreased with the increased level of betaine supplementation. In conclusion, dietary supplementation of betaine increased lipolysis and decreased fat deposition in the finishing period of geese via reducing feed intake. However, the precise mode-of–action is yet unclear and warrants further research.