ABSTRACT
Aim: This study was carried out to investigate the effect of dietary metabolic energy on growth performance, homeostasis of blood biochemical parameters, immunoglobulin G (IgG), and corticosterone in meat duck exposed to heat stress.Methodology: A total of 320 meat ducks (Cherry valley, Anas platyrhynchos) were randomly allotted into five groups. In all experimental treatment groups, dietary crude protein content was fixed at 18%. metabolic energy level for the control group (thermononeutral temperature, 26°C) was set at 3000 kcal kg-1, while metabolic energy levels for heat stress groups were set at 2900, 3000, 3100 or 3200 kcal kg-1. Heat stress conditions were artificially induced at 36°C with relative humidity of 70% once daily (from 11:00 to 16:00 hr) during finisher periods (day 22 to 42). Results: Compared to control group, heat stress groups with different metabolic energy showed significant decrease in body weight gain, feed intake, red blood cell, and platelets. Heat stress groups with different metabolic energies showed significant increase in feed conversion ratio, blood lipid profiles, aspartate aminotransferase, alanine transferase, electrolytes, pH, gas concentration, immunoglobulin G, and corticosterone compared to the control group.Among heat stress groups, red blood cells and platelets were significantly higher in the heat stress group with metabolic energy of 3000 compared to those in other groups. Blood IgG and corticosterone levels were significantly lower in 2900 and 3000 groups than those in heat stress groups with metabolic energy of 3100 and 3200. Interpretation: The results of this study suggest that dietary metabolic energy 3000 kcal kg-1 level can improve the growth performance of meat duck exposed to heat stress by modulating homeostasis of blood biochemical parameters.
ABSTRACT
Aim: To determine the effect of feeding flaxseed on Omega-6 to Omega-3 ratio (n-6/n-3) in Korean native steers (Hanwoo) and effect of flaxseed-fed beef consumption on reducing blood lipid profile and glucose in normal human. Methodology: A total of 60 Hanwoo steers (750 kg b.wt.) were assigned three treatments (20 per treatment). Each treatment group was divided into C (control, feeding basal diets without flaxseed for 40 days before slaughter), FS5 (feeding 5% flaxseed for 60 days before slaughter), and FS7.4 (feeding 7.4% flaxseed for 40 days before slaughter). Fatty acid composition from Hanwoow jugular vein and beef loin were analyzed. Clinical trials were carried out to investigate the effect of consumption of flaxseed-fed beef loin on blood lipid profile and glucose in twenty human subjects. Results: n-6/n-3 ratio in the blood and beef loin of Hanwoo steers were lowered to 2.26-2.27 and 3.67-3.71 in the FS group, respectively, compared with the other groups. Oleic acid level in the blood and beef loin of Hanwoo steers increased to 40.12-42.01 and 52.27-52.79%, respectively, compared with other groups. Blood triacylglycerol, total cholesterol, and low-density lipoprotein-cholesterol levels in normal human fed with FS beef loin reduced by 25.35, 5.22, and 17.59%, compared to those before intake of beef loin. Blood high density lipoprotein-cholesterol (HDL-C) level in normal human fed with FS beef loin was increased by 6.07%. In human subjects fed with FS and C beef loin, blood glucose level was decreased by 6.42 and 11.82%, respectively. Interpretation: The results demonstrated that feeding 5 and 7.4% flaxseed to Hanwoo steers for 40 to 60 days before slaughter could lower n-6 to n-3 ratio and inhance oleic acid in the blood and beef loin. Further, consumption of flaxseed-fed beef loin by human subjects could improve blood lipid profile.