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Effects of Dietary Supplementation with Eucalyptus Essential Oil and Soy Isoflavones on the Growth Performance, Intestinal Health and Meat Quality of Weaned Meat Rabbits
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College of Animal Science and Technology, Henan Agricultural University, Zhengzhou 450046, China
2
College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
*
Author to whom correspondence should be addressed.
Animals 2025, 15(19), 2890; https://doi.org/10.3390/ani15192890
Submission received: 31 August 2025
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Revised: 28 September 2025
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Accepted: 1 October 2025
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Published: 2 October 2025
(This article belongs to the Special Issue Effects of Feed Additives on the Health and Performance of Monogastric Animals)
Simple Summary
The weaning period is a highly sensitive stage in meat rabbit production, where sudden dietary changes and environmental shifts may trigger gastrointestinal disorders, thereby impairing production performance. This study evaluated the effects of dietary supplementation with eucalyptus essential oil and soybean isoflavones in weaned meat rabbits. The results demonstrated that individual or combined supplementation of eucalyptus essential oil and soybean isoflavones improved growth performance, intestinal health and meat quality; enhanced slaughter yield and meat quality; and augmented antioxidant capacity. The most pronounced effects were observed with combined supplementation.
Abstract
This study investigated the effects of individual and combined supplementation of eucalyptus essential oil (EEO) and soy isoflavones (SI) on the growth performance, intestinal health and meat quality of weaned meat rabbits. A total of 120 Ira female rabbits were stratified by body weight (BW) and randomly allocated into four treatment groups. The rabbits were fed for 35 days using (a) basal diet (Control), (b) basal diet + 150 mg/kg EEO, (c) basal diet + 25 mg/kg SI, or (d) basal diet + 150 mg/kg EEO + 25 mg/kg SI. The results showed that supplementing EEO and SI in the diet had a synergistic effect on production performance by increasing BW and average daily gain and reducing the feed intake/gain ratio. The EEO + SI group exhibited the most pronounced improvement in growth performance. Compared with the Control group, individual or combined supplementation significantly increased both semi-clean slaughter and total eviscerated slaughter rates, and showed a synergistic effect when supplemented together. The antioxidant capacity of the rabbits was enhanced, with the EEO + SI group showing the largest improvement. Serum biochemical analysis revealed that the combined treatment improved hepatic and cardiovascular functions. Additionally, we observed that the combined addition of EEO and SI has a synergistic effect on increasing the height of intestinal villi and the villus height/crypt depth ratio. Moreover, EEO and SI synergistically improved meat quality by elevating pH value, water-holding capacity, tenderness, and fat proportion. Notably, supplementation of EEO and SI in the diet regulated the composition of the intestinal microbiota, demonstrating increased relative abundance of beneficial Bacteroides and Lachnospiraceae_NK4A136_group. In conclusion, the combination of EEO and SI outperformed individual supplements in promoting growth and intestinal barrier function, potentially through enhancing antioxidant activity, attenuating oxidative stress, protecting the hepatic/cardiovascular systems, and improving intestinal morphology and microbial composition, thereby collectively enhancing growth performance, slaughter traits, and meat quality.
