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

Abstract

For reasons of aspired naturalness and cost reduction, vitamin additions should be kept low in organic livestock systems. To define safe lower threshold levels of riboflavin supplementation in organic poultry feeding, 135 hybrid layers were allocated to three dietary treatments supplemented with either 4.5 (R4.5), 3.0 (R3.0) or 1.5 mg (R1.5) GMO-free riboflavin added per kg feed. This resulted in total measured concentration averages of 5.0, 4.5, and 3.1 mg kg −1 feed for R4.5, R3.0 and R1.5, respectively. For 18 weeks, each treatment was replicated in three groups of 15 hens. Feed consumption, laying performance, egg quality, riboflavin concentration in the yolk, and clinical health scores were assessed. Two hens per group (six per treatment) were slaughtered in weeks 11 and 18, respectively, for measurement of pancreas, spleen, liver and heart weights, and determination of liver riboflavin. No treatment effects on feed consumption, body weight, laying performance, egg weights, eggshell strength and yolk colour or plumage and keel bone integrity were observed. No symptoms of lameness or footpad damage were found. The riboflavin concentration in egg yolks in R1.5 was lower than in other treatments. Liver riboflavin concentration increased between week 11 and 18 in all treatments, but it was also lower in R1.5. Based on these results, the addition of 3 mg riboflavin kg −1 feed appeared to be sufficient with respect to the health and performance of laying hens. Supplementation with only 1.5 mg kg −1 resulted in some metabolic signs of deficiency. These results apply only to organic winter diets.

Effects of immersing Japanese quail eggs in various doses of riboflavin on reproductive, growth performance traits, blood indices and economics

“…However, the control group revealed the lowest BWG (1,711.75g). These findings are consistent with a study of Florian et al (2021) , who showed that chickens given varying doses of vitamin B2 revealed the highest LBW and BWG relative to the control group.…”

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

“…Therefore, this paper contributes to the current discourse with additional knowledge on the current use of these six inputs and their alternatives in Europe by summarizing the results of six internal reports [48][49][50][51][52][53] of the RELACS project. The results of some of these reports were published [54,55] while others are publications in progress [56,57]. The results presented here and in the RELACS reports fill in the gaps of European and national databases which to this day still lack consolidate information on the actual use of these inputs.…”

“…Here, a clear lack of data was identified which needs to be experimentally produced in the future. This has been started in the case of vitamin B2 in poultry [55,95]. The specific situation for lipophilic vitamins on one hand, and B vitamins on the other, can be illustrated with the examples of vitamin E and vitamin B2.…”

“…However, since the GMO-free production is expensive to a relevant degree, mitigation of supplements is desirable. Based on current experimental work [39,55,95] it appears to be safe to reduce riboflavin supplements to poultry by approximately 30-50% compared to FEFANA recommendations. The safe levels depend on the animal category; sufficient supplements are especially essential for parent animals and chicks.…”

“…Here, a clear lack of data was identified which needs to be experimentally produced in the future. This has been started in the case of vitamin B2 in poultry [55,95].…”