Effects of a riboflavin source suitable for use in organic broiler diets on performance traits and health indicators

Abstract

Riboflavin (vitamin B2) is essential for monogastric animals. It is mainly produced by recombinant microorganisms (Candida famata, Bacillus subtilis and Ashbya gossypii). The availability of genetically modified organism (GMO)-free riboflavin, obligatory in European organic agriculture, is a major issue. Besides, requirements for organic livestock might differ from conventional production because other genotypes and feed formulations are used. The effects of a fermentation suspension with a high native content of riboflavin produced with unmodified A. gossypii by fermentation were investigated at graded dosages as an alternative to conventional (GMO-based) riboflavin in slow-growing broilers on performance traits and health and welfare indicators. In 2 runs with 800 animals each, Ranger Gold™ broilers were fed with 4 dietary treatments. For starter diets (day 1 to 18), treatments included a basal diet (1) without any riboflavin supplementation (negative control, N-C), (2) with conventional riboflavin supplementation (Cuxavit B2 80% riboflavin) at 9.6 mg/kg (positive control, P-C), (3) with riboflavin supplementation from the alternative source at 3.5 mg/kg (A-low) and (4) with riboflavin supplementation from the alternative source at 9.6 mg/kg (A-high). For the finisher diet (day 29 until slaughtering), P-C and A-high were supplemented with 8.0 mg/kg and A-low with 3.5 mg/kg. Diets were formulated according to organic regulations. Animals were kept in floor pens with 20 chickens per pen. Weekly, BW, feed and water consumption were recorded. Every second week, animal-based health and welfare indicators (feather score and footpad dermatitis) were scored. Slaughter traits were assessed for five males and females per pen at 62/63 days of age. Final body weight of A-high differed from N-C and A-low, but not from P-C. From week 2 until six years of age, A-high had a higher daily weight gain when compared to all other groups. With 74.4%, dressing percentage was higher in A-high compared with all other groups (73.3%). Breast percentage of A-low was lower than that of both control groups but did not differ from A-high. The highest frequency of liver scores indicating fatty liver syndrome was found in P-C, followed by N-C and A-low. Feather scores did not respond to treatment; the highest frequency of mild footpad dermatitis was observed in A-high, however at a low prevalence. In conclusion, the tested fermentation suspension with a high native content of riboflavin derived from fermentation of A. gossypii can be used at levels of commercial recommendations as alternative to riboflavin produced from GMO in broiler feeding. Further studies must verify whether riboflavin can be reduced without inducing riboflavin deficiency in slow-growing broilers.

Riboflavin for laying hens fed organic winter diets: effects of different supplementation rates on health, performance and egg quality

“…However, the true reason for the decrease in the present study remained unclear. In other experiments with similar diet formulations, conducted by some of the authors of this article, the riboflavin content of the feed was not found to decrease during a 10-months storage period (Lambertz et al 2020). It is important to note that, in the present study, from week 8 onwards, the difference in the riboflavin concentrations between R3.0 and R4.5 became rather small.…”

“…Riboflavin is generally not synthetically produced, but is derived from microorganisms like bacteria or yeasts, and in the current industrial processes, these microorganisms are usually genetically modified. However, organic production relies on inputs from non-GMO sources (Council of the European Union 2018; Lambertz et al 2020Lambertz et al , 2021. This is relevant as riboflavin is almost exclusively produced on the basis of genetically modified microorganisms, which implies safety issues, as occurred recently with respect to the spread of antibiotic resistant bacteria in riboflavin supplemented feed (Rychen et al 2018).…”

Chemical Constituents and Molecular Mechanism of the Yellow Phenotype of Yellow Mushroom (Floccularia luteovirens)

“…Riboflavin exists in various organs of the human body, promoting metabolism and normal vision [ 18 ]. Thus, riboflavin plays an important role in cell proliferation and growth [ 19 ]. Riboflavin is an isopropylamine derivative with a side chain of ribitol, mainly formed from the direct precursors GTP and ribulose 5-phosphate through a series of reactions catalyzed by riboflavin synthase [ 20 ].…”

The State of Play of Copper, Mineral Oil, External Nutrient Input, Anthelmintics, Antibiotics and Vitamin Usage and Available Reduction Strategies in Organic Farming across Europe

“…In order to avoid a lack of vitamin E in organic herds during winter feeding [98], such differentiated recommendations, which consider not only the animals' needs but also the varying provision by different feeds, urgently need to be developed. Riboflavin (vitamin B2) deficiency occurs for instance in livestock birds, especially in growing chicks and broilers, and symptoms are severe and relevant to health and welfare [39]. Therefore, non-supply is no option.…”

“…Another problem associated with B vitamins is that these are nowadays mostly produced by microorganisms that have been genetically modified [37] which is categorically forbidden in organic production. The lack of GM-free vitamin B manufacturing in Europe reinforces the vulnerability of the vitamin feed supply of organic farming [38,39].…”