Background: This study evaluated the effect of adding dried Bacillus subtilisculture (BSC) with Periserrula leucophryna-derived ferritin to the feed of laying hens after 90 weeks of age, focusing on productivity and egg quality. 
 
Methods: An experiment was conducted using 36,000 90-week-old ISA Brown hens, fed either a control diet or a diet supplemented with 0.1% ferritin-transferred BSC for 10 weeks. Two treatments with three replicates were tested. Productivity (mortality, egg production rate, egg weight) and egg quality (eggshell thickness, strength, color; yolk color, index; Haugh unit) were measured. 
 
Result: Mortality did not differ before and after BSC feeding. Egg production remained stable until week 6, then declined. Egg weight increased initially (p&lt;0.05) but later decreased due to a higher proportion of smaller eggs. Eggshell strength and thickness were maintained and shell color showed a slight, non-significant improvement. Yolk color increased slightly at weeks 6-8, while the yolk index improved significantly (p&lt;0.05). Haugh units remained stable, indicating preserved freshness. These findings suggest BSC supplementation helped maintain productivity and egg quality in aging hens, with potential economic benefits.

Effects of Feeding Dried Culture of Bacillus subtilis&nbsp;Transformed with Ferritin Gene on Productivity and Egg Quality of Laying Hens After 90 Weeks of Age

Background: The 60-day experimental study investigated the expression of iron regulatory genes, namely ferritin, transferrin, and hepcidin, in Clarias magur fingerlings fed diets supplemented with two dietary iron sources. The experimental study comprised two groups in which C. magur fingerlings received diets supplemented with ferrous or ferric citrate at doses of 0, 15, 30, and 45 mg Fe/kg above the minimum dietary iron requirement of 30 mg Fe/kg diet, respectively. 
 
Methods: Ferritin, transferrin, hepcidin expression levels in fish intestine, liver, muscle and gill tissues were determined using quantitative-real time PCR (qRT-PCR). Regardless of the dietary iron source, all tissues exhibited expression of the three genes under investigation, however, the degree of expression varied amongst tissues. 
 
Result: Liver showed highest ferritin mRNA expression among all tissues under both iron sources. Maximum expression (6.77-fold) was observed at 45 mg/kg ferrous citrate. Muscle showed modest changes while gill exhibited the lowest ferritin expression. In intestine, under ferrous citrate supplementation, transferrin expression increased with increasing iron level. Maximum expression (4.21&plusmn;0.14) was recorded at 45 mg/kg iron supplementation. Liver transferrin expression increased with increasing ferrous citrate. Highest expression was observed at T3&nbsp;(3.31&plusmn;0.07). In intestine, the highest hepcidin expression occurred at T1&nbsp;(5.62&plusmn;0.01). Ferric citrate showed comparatively lower expression in all treatments. Liver showed the highest hepcidin expression among all tissues. Expression increased significantly with increasing iron supplementation. Maximum expression (7.99&plusmn;0.06) was observed in fish fed 45 mg/kg ferrous citrate (T3).

Effects of Feeding Dried Culture of Bacillus subtilis Transformed with Ferritin Gene on Productivity and Egg Quality of Laying Hens After 90 Weeks of Age

Impact of Graded Levels of Dietary Ferrous and Ferric Citrate Supplementation on Expression of Iron Regulatory Genes in Clarias magur