Abstract

Background and Aim: The global ban on antibiotic growth promoters (AGPs) in livestock production has increased the search for safe and effective natural alternatives that can maintain productivity and support animal health. Phytogenic feed additives from medicinal plants are gaining more attention because of their antimicrobial, antioxidant, and immunomodulatory properties. Garlic (Allium sativum) and caraway (Carum carvi) contain bioactive compounds that can enhance digestive function and intestinal health in monogastric animals. Replacement gilts are a critical group in pig production, as their growth and intestinal development during rearing influence their reproductive longevity and herd productivity. However, limited information is available on how phytogenic additives affect intestinal structure and performance in replacement gilts. Therefore, this study aimed to assess the effects of a garlic-based phytogenic additive, “Imunochasnyk,” on growth performance, feed efficiency, survival rate, and small intestine histomorphology of replacement gilts under commercial production conditions.

Materials and Methods: A controlled feeding trial was conducted on 160 clinically healthy crossbred replacement gilts (Large White × Landrace) aged 11–28 weeks under commercial conditions in southern Ukraine. Animals were randomly assigned to two groups: a control group receiving a basal diet (BD) and an experimental group receiving BD supplemented with 0.10% phytogenic additive “Imunochasnyk,” which contains A. sativum and C. carvi (1000 g/ton). Each group included 80 animals. Growth performance parameters, including live weight, average daily gain (ADG), feed conversion ratio (FCR), and survival rate, were monitored throughout the experimental period. At 190 days of age, five representative gilts from each group were selected for histological examination of the jejunum. Morphometric analyses of enterocyte dimensions, nucleus-to-cytoplasm (N:C) ratio, and structural characteristics of villi, crypts, goblet cells, and Paneth cells were performed. Data were expressed as mean ± standard error of the mean and analyzed statistically, with significance set at p < 0.05.

Results: Dietary supplementation with the phytogenic additive significantly enhanced the productive performance of replacement gilts. Starting from week 17, the experimental group showed greater live weight and higher ADG than the control group. At 28 weeks of age, the final live weight reached 128.52 kg in the supplemented group compared to 118.64 kg in the control group (p < 0.001). The FCR decreased by 8%–11% during intensive growth phases, indicating improved feed utilization efficiency. The survival rate increased to 95.0% in the supplemented group compared to 85.0% in the control group. Histological analysis revealed notable intestinal adaptations in supplemented gilts, including a 19.6% increase in enterocyte area and a 31.0% increase in nuclear area, leading to a higher N:C ratio (p < 0.01). Additionally, increased villus tortuosity, enlarged crypt lumina, higher goblet cell density, and activation of Paneth cells were observed, suggesting enhanced absorptive capacity and strengthened mucosal defense mechanisms.

Conclusion: Including the garlic-based phytogenic additive “Imunochasnyk” at 0.10% in the diet significantly enhanced growth performance, feed efficiency, and intestinal structure in replacement gilts. The additive stimulated epithelial metabolic activity, boosted mucosal defenses, and improved nutrient absorption, ultimately increasing productivity and survivability. These results support the use of garlic-based phytogenic additives as sustainable alternatives to antibiotics in intensive pig production systems.

Keywords: antibiotic-free pig production, feed efficiency, garlic phytogenic additive, intestinal histomorphology, phytogenic feed additives, replacement gilts, small intestine morphology, swine nutrition.