The Effects of Different Levels of Citric Acid on Growth Performance, Nutrient Digestibility and Gastrointestinal pH of Weaned Piglets

Background: This study was conducted to evaluate the effects of different levels of citric acid (CA) on the growth performance, nutrient digestibility and gastrointestinal pH of weaned piglets. Methods: A total of 120 weaned piglets with an initial BW of 7.15±0.01 kg, were randomly divided into four groups including control treatment each with three replicates of 10 piglets each. Each group was supplemented with 0.5% (control group), 1%, 1.5% and 2% CA in the basal diet, respectively. Result: The results showed that the average daily feed intake (ADFI) and average daily gain (ADG) of added 1% CA group were significantly higher than that of 0.5% group (P less than 0.05). Dietary CA significantly improved the utilization rates of crude protein, calcium and phosphorus (P less than 0.05), while there was no significant difference between adding 1% and 1.5% CA (P greater than 0.05). Compared with the control group, adding CA effectively reduced the pH of the stomach, duodenum jejunum and ileum contents and adding 2% CA were significantly lower than those in other groups (P less than 0.05). Therefore, the addition of 1.0% CA in the diets of weaned piglets is suitable.

A Review of the Effect of Formic Acid and Its Salts on the Gastrointestinal Microbiota and Performance of Pigs

Out of the alternatives to antibiotics and zinc oxide, organic acids, or simply acidifiers, play significant roles, especially in ensuring gut health and the growth performance of pigs. Regarding acidifiers, formic acid and its salts have shown very promising results in weaning, growing and finishing pigs. Although it is known that the main mechanisms by which acidifiers can improve livestock performance and health are related to the regulation of gastrointestinal pH, an improvement in intestinal digestibility and mineral utilization, and their antimicrobial properties against specific pathogens has been observed, while poor consensus remains in relation to the effect of acidifers on bacteria and the complex microbiome. Therefore, the aim of the present review was to critically evaluate the effects of formic acid and its salts on the performance and the gastrointestinal microbiota balance of pigs.

Fluorescence lifetime imaging of upper gastrointestinal pH in vivo with a lanthanide based near-infrared τ probe

Lanthanide complex was successfully applied in the design of pH-responsive NIR τ probe for quantitative in vivo imaging.