Effect of Supplemental Manganese on Carcass Traits, Meat Quality, and Relative Enzyme Activities in Broilers

摘要

An experiment was conducted using a total of 288 day-old Arbor Acres male broilers to study the effect of supplemental manganese (Mn) levels on carcass traits, meat quality, and relative enzyme activity in the muscles and abdominal fat of the broilers. Birds were randomly allotted by body weight to one of six treatments in a completely randomized design. They were fed either a Mn-unsupplemented corn-soybean meal basal diet or fed basal diets supplemented with 100 mg/kg, 200 mg/kg, 300 mg/kg, 400 mg/kg or 500mg/kg Mn as Mn sulfate (MnSO_4) for a duration of 42 days. The supplemental Mn had no effect (P > 0.11) on ADG, ADFI, F/G, incidence of leg abnormality, percentage of eviscerate, percentages of breast and leg muscles, water-holding capacity, L~* value , a~* value, shear force, and intramuscular fat in breast and leg muscles, pH values in leg muscles, malondiadehyde content (MDA), Mn-containing superoxide dismutase (MnSOD) activity in breast muscle, or malic dehydrogenase activity and hormone sensitive lipase activity in abdominal fat. However, the addition of 100 mg/kg, 200 mg/kg, 300 mg/kg or 400 mg/kg Mn did result in a decrease in abdominal fat percentage (P < 0.03), and broilers fed on the 100 mg/kg Mn had a higher pH (P < 0.05) in breast muscle than those on the other Mn treatments. The addition of 200 mg/kg, 300 mg/kg, 400 mg/kg or 500 mg/kg Mn decreased b~* value in the leg muscle (P < 0.10). The addition of 100 mg/kg, 200 mg/kg, 300 mg/kg or 500 mg/kg Mn decreased MDA content in leg muscle (P < 0.06) and lipoprotein lipase (LPL) activity in abdominal fat (P < 0.08), and increased the activity of MnSOD in leg muscle (P < 0.08). The results from this study indicate that the addition of Mn to broiler diets might decrease the percentage of abdominal fat by reducing LPL activity in abdominal fat, and decrease MDA content in leg muscle by increasing MnSOD activity in leg muscle.