Effects of Dietaiy Betaine and Protein Levels on Performance, Blood Composition, Abdominal Fat and Liver Ami no Acid Concentration in Laying Hens

摘要

An experiment was conducted to investigate the effects of dietary betaine and protein levels on performance, internal egg quality, blood composition, abdominal fat and liver amino acid concentration in laying hens. A total of 432 ISA-Brown laying henswere randomly allotted to four treatments with six replications for twenty four weeks. Treatments were factorially designed with two levels of crude protein(14.5 and 16.5%) and two levels of betaine(0 and 600ppm). The egg production was increased by feeding 16.5% protein-fed group compared to that of 14.5% protein-fed groups(P<0.05), but was different from betaine supplementation. Increasing protein and betaine supplementation to diets improved egg weight, egg mass and feed conversion(P<0.05). Eggshellbreaking strength, thickness and Haugh unit were not influenced by either dietary betaine or protein levels. Dietary betaine did not affect serum total protein, albumin and uric acid concentration, whereas uric acid concentration was increased in 16.5%protein-fed groups(P<0.05). The deposition of abdominal fat was lower in 600ppm betaine groups compared to those fed on Oppm betaine groups(P<0.05). Concentration of the most hepatic amino acids were affected by dietary protein levels and betaine supplementation. There were synergistic effect between dietary protein and betaine. These results suggested that dietary betaine can improve the egg weight, mass, feed conversion and decrease the abdominal fat, but increase the hepatic amino acid contents.