Effection Growth Performance And Carcass Quality Of Betaine Instead Of Methionine In Low Crude Protein Diets On Growting-Finishing Pigs

Two experiments were conducted to investigate the effects of methionine replacemented with different amounts of betaine on growing-finishing pigs fed low crude protein diets.Experiment 1 contained 240 barrows (Duroc×Landrace Yorkshire) which were allotted to four treatments with six pens per treatment to determine the effects of different levels of dietary betaine on growth performance of grower pigs. Average initial body weight was 22.31±1.89 kg, the treatments consisted of the corn soybean control diet meeting the Nutrient Requirements of Swine (NRC,1998) and three test diets with the same low CP content, but three different betaine and methionine levels (betaine levels:0,400,800g/T;methionine levels:800,400,0g/T). Experiments showed that no adverse effects on growth performance in grower pigs fed the reduction of dietary CP at 4% and no significant difference was found in growth performance among the trial groups (P> 0.05)Experiment 2 contained 240 barrows (Duroc×Landrace×Yorkshire) which were allotted to four treatments with six pens per treatment to determine the effects of different levels of dietary betaine on growth performance of finishing pigs. Average initial body weight was 52.48±2.07 kg, the treatments consisted of the corn soybean control diet meeting the Nutrient Requirements of Swine (NRC,1998) and three test diets with the same low CP content, but three different betaine and methionine levels (betaine levels:0,300,600g/T; methionine levels:600,300,0g/T). Experiments showed that no adverse effects on growth performance in grower pigs fed the reduction of dietary CP at 4% and no significant difference was found in growth performance among the trial groups (P> 0.05). The slaughter trial after the experiment 2 show that no adverse effects on the percentage fat-free lean\the longissimus muscle area and tenth rib backfat. In conclusion, under the experimental conditions, methionine replacemented with 400g/T betaine on growing pigs and 600g/T betaine on finishing pigs was suitable feeding low crude protein diets.