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As the world population increases, there will be an increase in demand for poultry meat. To satisfy this requirement, sustainably will be a significant challenge as different countries in the world face different health problems. Additionally, for decades, poultry nutritionists have worked on sustainability in broiler manufacturing plants. The usage of short- and medium-chain fatty acids (MCFAs), which have positive effects as growth promoters and immunostimulants, is a pioneering way to decrease the cost of diets and improve environmentally friendly and sustainable production in this critical era. This study aimed at evaluating the influences of alpha-monoglyceride (alpha-monolaurin) on the growth performance, biochemical parameters, lipid profiles, liver oxidative stress, and immune response in broilers. Alpha-monolaurin was included at the levels of 0 (control), 0.25, 0.5, and 1 g/kg in broiler diets. After 33 days, dietary supplementation of alpha-monolaurin showed no impact on the feed intake, however, broilers fed 0.5 g/kg feed displayed a significantly reduced food conversion ratio, as compared to the control (p ≤ 0.05). However, body weight and body weight gain tended to increase after 0.25 g/kg alpha-monolaurin supplementation, as compared to other groups. The highest European production efficiency factor (EPEF) was obtained with 0.25 g/kg alpha-monolaurin supplementation. The ether extract utilization and spleen weight were improved substantially (p ≤ 0.05) by alpha-monolaurin supplementation, but muscle and other organ weights were not affected. Plasma alanine transaminase (ALT) was decreased significantly by alpha-monolaurin supplementation, while plasma total protein and albumin were enhanced (p ≤ 0.05). Interestingly, broilers fed alpha-monolaurin displayed an increased antibody titer of the Newcastle disease (ND) virus and muscle unsaturated fatty acid content, and a decreased liver content of malondialdehyde (MDA). It could be assumed that dietary supplementation of alpha-monolaurin positively impacts birds’ feed efficiency and immune response and can be applied as a natural immune enhancer in the broiler industry.

The use of antibiotic growth promoters (AGP) is common practice to improve broiler production and performance. The use of AGP is under discussion as it can induce bacterial resistance. The purpose of this study was to determine the impact of removing AGP from broiler feed and study the effect of feed additives. For those countries where in-feed AGP are still permitted, the effect of the products in the presence of AGP was evaluated. Half the number of male broilers received a diet free of AGP, whereas the other half received a diet supplemented with zinc bacitracin at 0.5 g/kg. Both diets were either without additional additives or combined with a coated sodium butyrate, α-monolaurin or a combination of these additives. Raised under optimal conditions, the incorporation of AGP had no effect on broiler performance, but negatively affected villi height and villi height to crypt depth (VH:CD) ratio in the duodenum. In the absence of AGP, butyric acid and α-monolaurin had a positive effect on villi height. In the presence of AGP, α-monolaurin resulted in the lowest feed conversion ratio and improved VH:CD ratio in the duodenum, jejunum and ileum. Both feed additives had minimal effect on performance parameters but showed small positive effects on gut health in the absence of AGP and could play a role in the strategy to replace AGP.

The objective of this study was to determine the in vitro antimicrobial activity of several organic acids and their derivatives against Gram-positive (G+) and Gram-negative (G&minus, ) bacteria. Butyric acid, valeric acid, monopropionin, monobutyrin, monovalerin, monolaurin, sodium formate, and ProPhorce&mdash, a mixture of sodium formate and formic acid (40:60 w/v)&mdash, were tested at 8 to 16 concentrations from 10 to 50,000 mg/L. The tested bacteria included G&minus, bacteria (Escherichia coli, Salmonella enterica Typhimurium, and Campylobacter jejuni) and G+ bacteria (Enterococcus faecalis, Clostridium perfringens, Streptococcus pneumoniae, and Streptococcus suis). Antimicrobial activity was expressed as minimum inhibitory concentration (MIC) of tested compounds that prevented growth of tested bacteria in treated culture broth. The MICs of butyric acid, valeric acid, and ProPhorce varied among bacterial strains with the lowest MIC of 500&ndash, 1000 mg/L on two strains of Campylobacter. Sodium formate at highest tested concentrations (20,000 mg/L) did not inhibit the growth of Escherichia coli, Salmonella Typhimurium, and Enterococcus faecalis, but sodium formate inhibited the growth of other tested bacteria with MIC values from 2000 to 18,800 mg/L. The MIC values of monovalerin, monolaurin, and monobutyrin ranged from 2500 to 15,000 mg/L in the majority of bacterial strains. Monopropionin did not inhibit the growth of all tested bacteria, with the exception that the MIC of monopropionin was 11,300 mg/L on Clostridia perfringens. Monolaurin strongly inhibited G+ bacteria, with the MIC value of 10 mg/L against Streptococcus pneumoniae. The MIC tests indicated that organic acids and their derivatives exhibit promising antimicrobial effects in vitro against G&minus, and G+ bacteria that are resistant to antimicrobial drugs. The acid forms had stronger in vitro antimicrobial activities than ester forms, except that the medium chain fatty acid ester monolaurin exhibited strong inhibitory effects on G+ bacteria.