Fructooligosaccharide Supplementation Boosts Growth Performance, Antioxidant Status, and Cecal Microbiota Differently in Two Rabbit Breeds

Nutritional Value of Oregano-Based Products and Its Effect on Rabbit Performance and Health

Antimicrobials long been used to enhance the performance and immunity of rabbits, typically by adding them to feed or drinking water to prevent illness. However, increasing consumer concerns about antibiotic-resistant microorganisms have led to a shift toward natural, eco-friendly, non-antibiotic feed supplements that can improve rabbit health and productivity. Recently, aromatic herbs and their extracts have gained considerable attention as natural antioxidants with growth-promoting and health-boosting properties. Essential oils and secondary metabolites play a central role in these effects, with Origanum vulgare (oregano) emerging as a standout option. Compared to synthetic alternatives, oregano is a natural, residue-free feed supplement with fewer harmful side effects. Its key bioactive components, thymol and carvacrol, have been shown to deliver significant benefits when incorporated into rabbit diets, particularly in improving production performance, immunity, and antioxidant capacity. Supplementing rabbit diets and drinking water with oregano essential oil (OEO) has been found to enhance growth performance, feed efficiency, and meat quality, while also lowering cholesterol levels and boosting antioxidant activity. Despite these promising results, research on the use of oregano in rabbit farming remains limited. This review aims to provide an up-to-date overview of the potential effect of oregano supplements, on growth parameters, carcass and meat quality, hemato-biochemical parameters, antioxidant capacity, immunity response, gut health, and gene expression in rabbits.

Impact of bee venom supplement on productive performance, health status and economics of weaned male rabbits: Considering breed and dosage factors

The objectives of the present study were to investigate the potential effects of purified bee venom (BV) on various aspects of growth, carcass, antioxidant, intestinal bacterial count and economic considerations in rabbits. A total of 240 male rabbits, comprising two distinct breeds (V-Line and New Zealand White [NZW]), 5 weeks old, with an average live body weight (BW) of 680 ± 20 g, were randomly divided into six groups, each containing 30 rabbits. Each group had five replicates, with six rabbits in each replicate. The allocation of animals to the groups followed a fully factorial design, incorporating two factors: breed (V-Line and NZW) and four levels of purified BV derived from Apis Mellifera. The control group (G1) received a basal diet without additives. The other three groups (G2, G3 and G4) received the basal diet with BV supplementation in their drinking water at 0.5, 1 and 2 mg/L respectively. The study results indicated that NZW rabbits significantly enhanced feed conversion ratio while maintaining consistent carcass attributes compared to the V-Line breed. Despite variations in growth parameters being less pronounced, the supplementation of BV at levels of 1-2 mg/L demonstrated significant improvements in various other parameters. Notably, the interaction between the BV supplement and the breed factor (p < 0.001) yielded notable distinctions in most production metrics, encompassing BW, weight gain, feed conversion, carcass attributes and blood parameters. Increasing levels of BV supplementation, particularly at 1 mg/L, led to substantial improvements in serum and tissue metabolites. Moreover, the levels of total bacterial count and Escherichia coli in the jejunum and colon were significantly diminished, while the population of Lactobacilli in the colon was augmented (p < 0.001) in rabbits from both breeds receiving BV supplementation (1-2 mg/L) compared to the control group. The results underscore the potential of the BV supplement to enhance final weights, bolster antioxidant status and mitigate the presence of pathogenic bacteria, thereby contributing to enhanced economic efficiency in rabbits. Further inquiries are warranted to comprehensively investigate BV supplementation's potential advantages and limitations across different breeds and dosage levels.

Seasonal Variations in Production Performance, Health Status, and Gut Microbiota of Meat Rabbit Reared in Semi-Confined Conditions

In this study, we investigated the variations in production performance, health status, and gut microbiota of meat rabbits raised in the semi-confined barn during summer and winter. Compared to summer, rabbits reared in winter possessed significantly higher slaughter weight and carcass weight. Rabbits fed in the summer were more vulnerable to different stressors, which led to increased protein levels of HSP90, IL-1α, IL-1β, IL-2, and concentrations of MDA, but declined GSH and SOD activities. Additionally, significant differences in gut microbial communities were observed. Compared to the winter, rabbits fed in the summer had significantly lower and higher alpha and beta diversity. Both Firmicutes and Verrucomicrobiota were the dominant phyla, and they accounted for greater proportions in the winter than in the summer. At lower microbial taxa levels, several seasonal differentially enriched microbes were identified, such as Akkermansia muciniphila, the Oscillospiraceae NK4A214 group, the Christensenellaceae R-7 group, Alistipes, and Muribaculaceae. Functional capacities linked to microbial proliferation, nutrient metabolism, and environmental adaptive responses exhibited significantly different abundances between summer and winter. Moreover, strong interactions among different indicators were presented. Based on our findings, we not only proposed several potential strategies to ameliorate the undesirable effects of seasonal changes on the productivity and health of meat rabbits but also underscored the directions for future mechanistic studies of adaptation physiology.

Ramifications of Heat Stress on Rabbit Production and Role of Nutraceuticals in Alleviating Its Negative Impacts: An Updated Review

Heat stress has become a widespread concern worldwide, which is a major environmental stress that causes substantial economic loss in the rabbit industry. Compared to other agricultural animals, rabbits are more sensitive to heat stress as they have fewer sweat glands and a thicker coat of fur, increasing the heat dissipation complexity. Thus, heat stress hurts rabbits' productivity, meat quality, reproductive performance, antioxidative properties, immune responsiveness, intestinal histomorphology, and microbiome. Nutraceuticals include vitamins, minerals, antioxidants, organic acids, fatty acids, probiotics, prebiotics, synbiotics, enzymes, and medicinal plants due to the possible impacts on maintaining common biological situations, strengthening immune response, and preventing illness, which ultimately led to an increase in productivity. Nutraceuticals have recently attracted a lot of attention to alleviate the adverse impacts of heat stress in rabbit farms. The objective of the current review is to provide acquaintance with the recent findings about the impact of heat stress on rabbit productivity and the advantages of dietary supplementation of nutraceuticals in mitigating it.

Sow-Offspring Diets Supplemented with Probiotics and Synbiotics Are Associated with Offspring's Growth Performance and Meat Quality

Probiotics and synbiotics supplementation have been shown to play potential roles in animal production. The present study aimed to evaluate the effects of dietary probiotics and synbiotics supplementation to sows during gestation and lactation and to offspring pigs (sow-offspring) on offspring pigs' growth performance and meat quality. Sixty-four healthy Bama mini-pigs were selected and randomly allocated into four groups after mating: the control, antibiotics, probiotics, and synbiotics groups. After weaning, two offspring pigs per litter were selected, and four offspring pigs from two litters were merged into one pen. The offspring pigs were fed a basal diet and the same feed additive according to their corresponding sows, representing the control group (Con group), sow-offspring antibiotics group (S-OA group), sow-offspring probiotics group (S-OP group), and sow-offspring synbiotics group (S-OS group). Eight pigs per group were euthanized and sampled at 65, 95, and 125 d old for further analyses. Our findings showed that probiotics supplementation in sow-offspring diets promoted growth and feed intake of offspring pigs during 95-125 d old. Moreover, sow-offspring diets supplemented with probiotics and synbiotics altered meat quality (meat color, pH_45min, pH_24h, drip loss, cooking yield, and shear force), plasma UN and AMM levels, and gene expressions associated with muscle-fiber types (MyHCI, MyHCIIa, MyHCIIx, and MyHCIIb) and muscle growth and development (Myf5, Myf6, MyoD, and MyoG). This study provides a theoretical basis for the maternal-offspring integration regulation of meat quality by dietary probiotics and synbiotics supplementation.

Supplying Bee Pollen and Propolis to Growing Rabbits: Effects on Growth Performance, Blood Metabolites, and Meat Quality

The objective of this study was to evaluate the effect of supplementation with bee pollen (BP) and propolis (PRO) on productive performance, Eimeria oocyst counts in feces, blood metabolites, and the meat quality of growing rabbits. A total of 160 hybrid rabbits (California × New Zealand) of 30 days of age and 643 ± 8.0 g body weight (BW) were assigned to four treatments with 10 replicates each (four rabbits/replicate). The treatments were as follows: (1) CON: rabbits fed basal diet and not supplemented with BP or PRO; (2) BP500: CON + BP (500 mg/kg BW); (3) PRO50: CON + PRO (50 µL/kg BW); and (4) BP + PRO: CON + BP (500 mg/kg BW) + PRO (50 µL/kg BW). Higher daily weight gain (p = 0.04) and lower feed conversion rate (p = 0.03) were observed in rabbits supplemented with PRO50. In addition, supplementation with PRO50 and BP + PRO reduced the amount of Eimeria oocysts per gram of feces (p < 0.05). Most hematological and serum biochemical parameters were similar in rabbits of all treatments. Protein content, collagen, and meat color were similar between treatments. In conclusion, propolis supplementation (50 µL/kg BW) can prevent coccidiosis and act as a natural growth promoter in rabbits without affecting animal health and meat quality.