Abstract
Background:
The nanoencapsulation technology has great potential as an innovation in animal feed, especially as a natural supplement to replace antibiotics and improve livestock health. With this technology, the bioactive benefits of mangosteen rind can be utilized more optimally, opening up new opportunities in the sustainable livestock industry especially in poultry nutrition.

Aim:
This study aimed to examine the effect of adding mangosteen rind extract nanocapsule (MREN) as a feed additive and to determine its optimal level to improve growth performance and blood lipid profile of broiler chicken.

Methods:
The research design used a completely randomized design with a one-way pattern. There were 300 DOC unsexed Cobb strain broiler chickens grouped into 5 feed treatments, namely T0:100% basal feed (PB) as a negative control, T1:100% PB + zinc-bacitracin 50 ppm (positive control), T2: PB + 0.1% MREN, T3: PB + 0.2% MREN, and T4: PB + 0.3% MREN. The treatment was repeated 6 times and each experimental cage was filled with 10 broiler chickens. The maintenance was conducted for 35 days to observe the growth performance and blood lipid profile of broiler chickens.

Results:
The results showed that the addition of mangosteen rind extract nanocapsule had a significant effect on the growth performance (body weight, body weight gain, and feed conversion) and blood lipid profile of broiler chickens (triglycerides and HDL). The feed treatments containing 0.1% and 0.2% mangosteen rind extract nanocapsules (T2 and T3) produced better growth performance and blood lipid profile compared to the T4 treatment with a higher dose (0.3%).

Conclusion:
The addition of mangosteen rind extract nanocapsule at low level (0.1% – 0.2%) is really recommended for broiler chickens to improve growth performance and blood lipid profile.

Key words: Blood lipid profile, Broiler chicken, Growth performance, Mangosteen rind extract nanocapsule