1Department of Animal Science, National Chiayi University, Chiayi City, Taiwan
2Division of Animal Industry, Animal Technology Laboratories, Agricultural Technology Research Institute, Miaoli, Taiwan
*Corresponding Author: Jhy-Ming Li, Department of Animal Science, National Chiayi University, Chiayi City, Taiwan, Email: jml@mail.ncyu.edu.tw
**Chean-Ping Wu, Department of Animal Science, National Chiayi University, Chiayi City, Taiwan, wcp@mail.ncyu.edu.tw
Online published on 23 January, 2026.
This study examined the effects of a diet supplemented with peanut skin and bromelain on egg production, egg quality, blood parameters and fat accumulation in middle-aged and aged laying hens.
In Trial 1, 120, 62-week-old Hisex Brown laying hens were grouped into five treatments: A control and high and low concentrations of peanut skin and bromelain groups. In Trial 2, 96, 93-week-old Hisex Brown laying hens were grouped into four groups: control, high concentrations of peanut skin and bromelain and a peanut skin and bromelain combination. Egg production and quality were monitored over an 8-w period and included egg weight, shell thickness and yolk color. Blood samples were analyzed for lipid profiles and liver function. Fat accumulation was observed in the abdominal cavity.
Egg production of hens receiving supplementation of peanut skin and bromelain improved substantially in 62-w-old hens (but not in 93-w-old hens) compared with the control group. Substantially reduced blood glucose levels and beneficial changes in yolk color were observed in the supplemented groups. The addition of peanut skin and bromelain to the diet positively affects the productivity and health of middle-aged laying hens.
Bromelain, Dietary supplementation, Laying hens, Peanut skin
