Background: This experiment was designed to investigate how replacing antibiotics with postbiotics and paraprobiotics could affect growth performance, small intestine morphology, immune status, and hepatic growth gene expression in broiler chickens. Methods: The experiment followed a completely randomized design (CRD) in which eight treatments were replicated six times with seven birds per replicate. A total of 336, one-day-old (COBB 500) chicks were fed with the eight treatment diets, which include T1 = negative control (Basal diet), T2 = positive control (Basal diet + 0.01% (w/w) Oxytetracycline), T3 = Basal diet + 0.2% (v/w) postbiotic TL1, T4 = Basal diet + 0.2% (v/w) postbiotic RS5, T5 = Basal diet + 0.2% (v/w) paraprobiotic RG11, T6 = Basal diet + 0.2% (v/w) postbiotic RI11, T7 = Basal diet + 0.2% (v/w) paraprobiotic RG14, T8 = Basal diet + 0.2% (v/w) paraprobiotic RI11, for 35 days in a closed house system. Results: The growth performance indicators (final body weight, cumulative weight gain, and feed conversion ratio) were not significantly (p > 0.05) affected by the dietary treatments. However, feed intake recorded a significant (p < 0.05) change in the starter and finisher phases across the dietary treatments. Paraprobiotic RG14 had significantly (p < 0.05) lower abdominal fat and intestines. Villi heights were significantly (p < 0.05) increased, while the crypt depth decreased significantly due to dietary treatments. The dietary treatments significantly influenced colon mucosa sIgA (p < 0.05). Similarly, plasma immunoglobulin IgM level recorded significant (p < 0.05) changes at the finisher phase. In this current study, the hepatic GHR and IGF-1 expressions were significantly (p < 0.05) increased by postbiotics and paraprobiotics supplementation. Conclusions: Therefore, it was concluded that postbiotics and paraprobiotics differ in their effect on broiler chickens. However, they can replace antibiotics without compromising the growth performance, carcass yield, and immune status of broiler chickens.

The study was designed to analyze the effects of brown seaweed (BS) and green seaweed (GS) on blood plasma antioxidant enzyme activities, hepatic antioxidant genes expression, blood plasma lipid profile, breast meat quality, and chemical composition in broiler chickens. The dietary treatment groups contained basal diet [negative control (NC)], basal diet + vitamin E (100 mg/kg feed) [positive control (PC)], basal diet + 0.25, 0.50, 0.75, 1, and 1.25% BS and GS supplements separately. The findings showed that both BS and GS exhibited remarkable antioxidant activity. In contrast, the maximum antioxidant activity was recorded by BS (55.19%), which was significantly higher than the GS (25.74%). Results showed that various levels of BS and GS had no significant effects on broiler blood plasma catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) enzyme activities. The hepatic superoxide dismutase 1 (SOD1) gene mRNA expression was significantly higher for birds fed 0.50% and 0.75% BS. Regarding the plasma lipid profile, the total cholesterol (TC) and high-density lipoprotein (HDL) levels were higher (p < 0.05) for birds fed 0.75 and 1% BS compared to the negative and positive control groups. The findings showed that different levels of BS and GS had significantly higher breast meat crude protein (CP) content.

This study was conducted to investigate the effects of feeding postbiotics and paraprobiotics on the immune response of broiler chickens. A total of 336 COBB 500 one-day-old chicks were randomly divided into eight treatment groups (T1, T2, T3, T4, T5, T6, T7, and T8). The treatments were as follows: T1(Negative control)=Basal diet, T2 (Positive control)=Basal diet + 0.01% oxytetracycline, T3= Basal diet + 0.2% postbiotic TL1, T4=Basal diet + 0.2% postbiotic RS5, T5=Basal diet + 0.2% paraprobiotic RG11, T6=Basal diet + 0.2% postbiotic RI11, T7=Basal diet + 0.2% paraprobiotic RG14 and T8=Basal diet + 0.2% paraprobiotic RI11. The ileal cytokines expression using Real-Time polymerase chain reaction (RT-PCR) showed that pro-inflammatory cytokines (IL-1β, IL-6, IL-8, and IFN-α) were (p<0.05) downregulated by postbiotics, paraprobiotics, and the positive control. While the mRNA expression of the anti-inflammatory cytokine IL-10 was increased. In conclusion, postbiotics and paraprobiotics were found to be effective in modulating and improving the immunity of broiler chickens against infections that are due to intestinal inflammation thereby creating a healthy gut for better nutrient absorption and overall improvement of the growth of broiler chickens.