Effect of Selenium Sources on Laying Performance, Egg Quality Characteristics, Intestinal Morphology, Microbial Population and Digesta Volatile Fatty Acids in Laying Hens

Abstract

The use of toxic and less bioavailable inorganic selenium can now be supplemented with an alternative organic source from bacterial species in nutrition for human and animal benefit. This study investigated the effects of selenium sources on laying performance, egg quality characteristics, intestinal morphology, caecum microbial population, and digesta volatile fatty acids in laying hens. One hundred and forty-four Lohman Brown Classic laying hens, at 23 weeks of age, were divided into four experimental groups (36 hens in each), differing in form of Se supplementation: no Se supplementation (Con), 0.3 mg/kg of inorganic Se in the form of sodium selenite (Na2SeO3), 0.3 mg/kg of organic Se from selenium yeast (Se-Yeast), and 0.3 mg/kg of organic Se from Stenotrophomonas maltophilia (bacterial organic Se, ADS18). The results showed that different dietary Se sources significantly affected laying rate, average egg weight, daily egg mass, feed conversion ratio (FCR), and live bodyweight (LBW) (p < 0.05). However, average daily feed intake and shell-less and broken eggs were unaffected (p > 0.05) among the treatment groups. The findings revealed that selenium sources had no (p > 0.05) effect on egg quality (external and internal) parameters. However, eggshell breaking strength and Haugh unit were significantly (p < 0.05) improved with organic (ADS18 or Se-yeast) Se-fed hens compared to the control group. In addition, egg yolk and breast tissue Se concentrations were higher (p < 0.05) in the dietary Se supplemented group compared to the control. Intestinal histomorphology revealed that hens fed ADS18 or Se-Yeast groups had significantly (p < 0.05) higher villi height in the duodenum and jejunum compared to those fed Na2SeO3 or a basal diet. However, when compared to organic Se fed (ADS18 or Se-Yeast) hens, the ileum villus height was higher (p < 0.05) in the basal diet group; with the lowest in the SS among the treatment groups. A significant increase (p < 0.05) of Lactobacilli spp. and Bifidobacteria spp., and a decrease of Escherichia coli and Salmonella spp. population were observed in the organic (ADS18 or Se-yeast) compared to inorganic supplemented and control hens. The individual digesta volatile fatty acid (VFA) was significantly different, but with no total VFA differences. Thus, bacterial selenoprotein or Se-yeast improved the performance index, egg quality characteristics, egg yolk and tissue Se contents, and intestinal villus height in laying hens. Moreover, caecum beneficial microbes increased with a decrease in the harmful microbe population and affected individual cecal volatile fatty acids without affecting the total VFA of the laying hens digesta.

Effects of dietary methyl sulfonyl methane and selenium on laying performance, egg quality, gut health indicators, and antioxidant capacity of laying hens

“…Egg quality is affected by genetic factors, diet, health, and environment [30]. However, dietary treatments here did not affect egg quality, which is in accordance with previous reports [14,22,30]. However, Se reduced the eggshell thickness.…”

“…The oxidative stability of yolk lipids was improved in hens fed diets enriched with sodium selenite [13]. In addition, Se-enriched eggs may be marketed as functional foods to increase human Se intake [14].…”

Bioactive compounds, antibiotics and heavy metals: Effects on the intestinal structure and microbiome of monogastric animals – a non-systematic review

“…In that study a strong relationship was also found between the metabolites and the profile of intestinal bacteriain particular the population size of Lactobacillus spp.was higher in mice supplemented with Se. A beneficial effect of the supplementation of Se on the microbiome's composition was also found by other researchers for mice (Callejón-Leblic et al, 2021) and laying hens (Muhammad et al, 2021).…”

The health benefits of selenium in food animals: a review

“…populations were observed in hens supplemented with organic Se [93]. Broiler chickens experimentally challenged with E. maxima and Clostridium perfringens and supplemented in ovo with sodium selenite had increased body weight, reduced intestinal lesions and oocyst production, increased levels of transcripts for interleukin-1-beta (IL-1β), interleukin-6 (IL-6) and interleukin-8 (IL-8) in intestine as well as increased serum antibody levels to C. perfringens α-toxin and NetB toxin [22]. Chickens inoculated with E. coli (serotype O1:K1) in the lower abdominal air sac had reduced mortality rate and air sac lesions when supplemented with inorganic Se [34].…”