Using Enzymes and Organic Acids in Broiler Diets

Innovative high digestibility protein feed materials reducing environmental impact through improved nitrogen-use efficiency in sustainable agriculture

Sustainable development in agriculture brings both environmental and economic benefits. Contemporary agriculture is also about increasing nutrient use efficiency, especially nitrogen, as the critical nutrient causing the most significant environmental pressure. This creates the need to produce highly digestible protein feed with high bioavailability, reducing losses of biogenic elements to feces. In this review, the latest trends and the potential for their implementation in sustainable agriculture have been compared, as well as the need to reduce the negative environmental impact of agriculture has been demonstrated. Applying local protein sources to feed animals reduces greenhouse gas emissions associated with transportation. The production of highly digestible fodder leads to a reduction in environmental pollution caused by excessive nitrogen outflows. Another approach indecreasing ammonia emissions from livestock farming is feed protein reduction and amino acid supplementation. All of the aforementioned approaches may result in beneficial long-term changes, contributing to environmental safety, animal welfare and human health.

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

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.