Production and metabolic consequences of high-energy and low-crude-protein diet fed to 49-wk-old Shaver white leghorn without or with top-dressed organic selenium

摘要

Production and metabolic consequences of feeding 49-wk-old Shaver white hens a high-energy low-crude-protein (HELP) diet were investigated over 6 wk. The test diets included standard diet [2750 kcal kg(-1) apparent metabolizable energy (AME) and 17.5% crude protein (CP)], HELP (3000 kcal kg(-1) of AME and 13.0% CP) diet, and HELP top dressed with selenium (HELP + Se). All diets had 0.3 mg Se kg(-1) as part of premix. Hens (33) were procured, three birds necropsied for baseline liver samples, and the rest placed in individual cages and allocated diets (n = 10). Feed intake (FI), hen day egg production (HDEP), and egg weight (EW) were monitored weekly. Plasma and liver samples were collected from all birds. Birds fed standard and HELP diets had similar (P > 0.05) FI (with exception of weeks 4 and 5) and HDEP, whereas HELP + Se depressed (P 0.05) feed and nutrient intake at weeks 5 and 6, HDEP, and EW. There were no (P > 0.05) diet effects on hepatic weight and crude fat content. Birds fed HELP diets had lower (P > 0.05) concentration of plasma total protein, macrominerals, and some enzymes. Overall, HELP diet had minimal impact on production and metabolism; however, addition of Se had negative effects on hen performance.