Effect of Energy Restriction on Growth, Slaughter Performance, Serum Biochemical Parameters and Lpin2/WDTC1 mRNA Expression of Broilers in the Later Phase

Fifty 18-day-old broilers were used to investigate the effects of 30% energy restriction from 18∼48 d on growth and slaughter performance, serum biochemical parameters, and gene expression of WDTC1 and Lpin2 in hepatic tissue. Fifty 18-day-old Arbor Acres female broilers were randomly divided to ad libitum group (control) and energy restriction group (experimental) and housed individually. The ad libitum group broilers were fed ad libitum with control diet, while energy restriction broilers were subjected to 30% metabolizable energy restriction (the supply of other nutrients was the same as that of ad libitum broilers). The results showed that: (1) Energy restriction significantly increased the feed efficiency (gain/feed) of birds. The average daily gain, the relative weight gain and the feed efficiency of energy restriction broilers were lower than that of ad libitum broilers during the earlier stage of the experiment (from 18∼39 d). While at latter stage of experiment (from 40∼48 d), the average daily gain, the relative weight gain and the feed efficiency of energy restriction broilers were higher than that of ad libitum broilers. (2) Energy restriction significantly reduced the abdominal fat ratio and the subcutaneous fat thickness, increased the muscle stomach weight, muscle stomach ratio, glandular stomach ratio, pancreas ratio, spleen ratio and the bursa of Fabricius ratio. There was no significant difference in leg muscle ratio and breast muscle ratio between control and experimental groups. (3) Energy restriction significantly increased serum superoxide dismutase, alkaline phosphatase, and serum uric acid, decreased serum total cholesterol, high-density lipids, malondialdehyde, lactate dehydrogenase and blood urea nitrogen. (4) Energy restriction significantly elevated Lpin2 expression level in hepatic tissue, whereas it did not significantly affect the expression of chicken WDTC1 gene in hepatic tissue.