Acidic stress caused by dietary administration of citric acid in broiler chickens

Abstract

Abstract. Citric acid (CA) is commonly used in poultry diets to promote growth by acidifying the gastrointestinal contents, improving nutrient digestibility, and reducing pathogen loads; therefore, this study was conducted to demonstrate the effects of 0, 30 and 60 g of CA per kilogramme of diet on productive performance, selected blood metabolites, immune response and certain gut-related variables in broiler chickens using 150, 7-day-old Ross 308 male broiler chicks in five replicates of 10 birds each per diet. Growth performance, daily feed intake and tibia phosphorous (P) retention were significantly improved by the diets containing 30 g kg −1 of CA (P < 0.01) but were suppressed as CA increased to 60 g kg −1 . Dietary CA increased proventriculus, gizzard and ileum percentage and villus length, crypt depth and goblet cell number in duodenum, jejunum and ileum as well as ileal digestibility of crude protein, apparent metabolisable energy and total phosphorus while it decreased the pH of contents in the gut segments concerned (P < 0.01). Diets containing 60 g kg −1 of CA significantly reduced plasma P and Fe levels as well as cholesterol level and Alkaline phosphatase activity (P < 0.05) while increasing the aspartate aminotransferase and lactate dehydrogenase activities (P < 0.01) in the blood serum of the birds at day 42 of age. The percentage of bursa and thymus was greater in the birds fed on diets containing 60 and 30 g kg −1 of CA, respectively (P < 0.01). It was concluded that inclusion of 60 g kg −1 of CA in the diet resulted in a severe reduction in performance, nutrient digestion and absorption and liver dysfunctions in broiler chickens, a phenomenon we call as acidic stress.

Effect of dietary supplementation of formic acid, butyric acid or their combination on carcass and meat characteristics of broiler chickens

“…It has been documented that muscle myoglobin damage was attributable to the change in broiler meat colour, in that myoglobin destruction resulted in increased lightness and decreased redness values of broiler meat (Mir et al, 2017). Apart from its benefits on host defence against pathogens, organic acid may act as stressor leading to physiological deterioration and internal organ disruption (including skeletal muscle) in poultry and other monogastric animals (Nourmohammadi andKhosravinia, 2015: Suiryanrayna andRamana, 2015). In the case of formic acid, the high acidity of this compound seemed to induce the damage of myoglobin in skeletal muscle (Nourmohammadi and Khosravinia, 2015) and thereby increased the lightness values of FORM compared to other meats.…”

“…Apart from its benefits on host defence against pathogens, organic acid may act as stressor leading to physiological deterioration and internal organ disruption (including skeletal muscle) in poultry and other monogastric animals (Nourmohammadi andKhosravinia, 2015: Suiryanrayna andRamana, 2015). In the case of formic acid, the high acidity of this compound seemed to induce the damage of myoglobin in skeletal muscle (Nourmohammadi and Khosravinia, 2015) and thereby increased the lightness values of FORM compared to other meats. Considering the lower lightness values of BUTR and FORM+BUTR compared to CONT and FORM meats, it was therefore most likely that butyric acid and combination of formic and butyric acids were capable of preventing myoglobin destruction in the muscle and thereby reducing and increasing the lightness and redness values of meat, respectively.…”

Effect of dietary supplementation of salts of organic acids on gut morphology and meat quality of broilers

“…Greatest effect on the ratio of Height: Depth of intestinal crypts was recorded in the T 3 which were significantly differ with the control group. Nourmohammadi et al (2015) also reported that dietary citric acid increased the villus length, crypt depth and goblet cell number in duodenum, jejunum and ileum as well as it decreased the pH of contents in the gut segments significantly (P < 0.01). Formic acid supplementation significantly (P<0.05) reduced gut wall thickness and increased villus height, villus width and crypt depth in birds (Adeniji et al, 2015).…”

Effect of acidified turmeric and/or black pepper on growth performance and meat quality of broiler chickens

“…The acidic stress due to the dietary supplementation of acidified herbs seemed to be responsible for the lacking effect of acidified herbs on broiler chicken growth. Indeed, over-acidification due to organic acids may compromise nutrient digestibility and alter physiological conditions leading to retarded growth rate of broilers [30]. With regard to citric acid (the most dominant acid in A. bilimbi fruit filtrate [26]), Nourmohammadi and Khosravinia [30] documented that while dietary supplementation of 30 g/kg citric acid improved growth performance, the citric acid supplementation at the level of 60 g/kg retarded growth rate of broilers.…”