Mércia Barros

Dr. Mércia Barros


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 November 2023 in Animals
Verified
Journal Article
Open access
PDF file
WMWaleska R. L. Medeiros-Ventura
Waleska R. L. Medeiros-Ventura
CRCarlos Bôa-Viagem Rabello
Carlos Bôa-Viagem Rabello
MSMarcos Jose Batista dos Santos
Marcos Jose Batista dos Santos
Mércia BarrosMércia Barros
Mércia Barros
RJRogério V. Silva Junior
Rogério V. Silva Junior
AFAlba Fireman
Alba Fireman
A study was conducted to evaluate the effects of different sources and levels of supplemental amino acid-complexed minerals (AACM), with and without enzyme phytase (EZ). A total of 512 Dekalb White laying hens at 67 weeks of age were used in a 2 × 3 + 2 factorial arrangement of 8 treatments and 8 replications each. The main effects included EZ supplementation (10,000 FTU kg−1) and AACM inclusion level (100, 70, and 40% of inorganic mineral recommendations), plus 2 control treatments. The group of hens fed AACM-100 showed lower feed intake than the inorganic mineral (IM) group. The diet containing AACM-EZ-70 provided a higher (p < 0.05) laying percentage and a lower (p < 0.05) feed conversion ratio than both the IM and IM-EZ diets. The groups fed AACM-EZ-40, AACM-EZ-100, and AACM-70 produced heavier yolks (p < 0.05). Hens fed IM laid eggs with the lowest yolk and albumen weights (p < 0.05). Layers fed with AACM-100 and AACM-70 produced the most resistant eggshells to breakage (p < 0.05). In diets containing phytase, the optimal AACM recommendations for better performance and egg quality in older laying hens are: 42, 49, 5.6, 28, 0.175, and 0.70 mg kg−1 for Zn, Mn, Cu, Fe, Se, and I, respectively.

7 February 2025 in Plants
Verified
Journal Article
Open access
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NSNataly Diniz de Lima Santos
Nataly Diniz de Lima Santos
PSPatryck dos Santos
Patryck dos Santos
TLThiago Lucas da Silva Lira
Thiago Lucas da Silva Lira
ASAline Rodrigues da Silva Santos
Aline Rodrigues da Silva Santos
JSJuliane Nancy de Oliveira Silva
Juliane Nancy de Oliveira Silva
EPEmmanuel Pontual
Emmanuel Pontual
The lesser mealworm, Alphitobius diaperinus, is a widespread pest in poultry farming, causing economic losses and facilitating the spread of pathogens. Current control methods rely heavily on synthetic insecticides, which raise environmental concerns and contribute to resistance. This study investigated the insecticidal potential of Moringa oleifera seed preparations, including an aqueous extract (AE), a protein-enriched fraction (PF), and an isolated lectin (WSMoL), against A. diaperinus. Contact assays demonstrated that AE and PF reduced adult survival by up to 90% and 100%, respectively, while WSMoL was effective only against larvae, causing 48% mortality. Ingestion assays showed that AE and PF reduced adult survival by 60% and 30%, respectively; impaired diet utilization; and caused significant weight loss. WSMoL exhibited antinutritional effects, including a 94% reduction in trypsin-like activity, but did not cause lethality, although it may impair long-term survival. Midgut histological analysis revealed epithelial disorganization, vacuolization, and nuclear condensation in the treated insects. These findings suggest that M. oleifera seed preparations are promising candidates for sustainable pest control, offering both lethal and sublethal effects on A. diaperinus. Future research should focus on the development of formulations and long-term impact assessments on pest populations and non-target organisms, paving the way for eco-friendly alternatives in integrated pest management.

5 July 2023 in Macromol
Verified
Journal Article
Open access
PDF file
NSNataly Diniz de Lima Santos
Nataly Diniz de Lima Santos
Lidiane Pereira de AlbuquerqueLidiane Pereira de Albuquerque
Lidiane Pereira de Albuquerque
MAMarcus Mello Rego de Amorim
Marcus Mello Rego de Amorim
JSJuliane Nancy de Oliveira Silva
Juliane Nancy de Oliveira Silva
TPThamara Figueiredo Procópio
Thamara Figueiredo Procópio
EPEmmanuel Pontual
Emmanuel Pontual
In this study, we evaluated the susceptibility of Alphitobius diaperinus larvae and adults to saline extract (SE), lectin-rich fraction (FR), and isolated lectin (MvRL) from Microgramma vacciniifolia rhizomes. To determine immediate effects, larvae and adults were exposed to SE (10.5 mg/mL), FR (7.5 mg/mL), or MvRL (1.0 mg/mL) for 48 h. Live insects were evaluated for acetylcholinesterase (AChE) activity. The delayed effects of SE (10.5 mg/mL), FR (7.5 mg/mL), and MvRL (0.2 and 0.4 mg/mL) were checked by incubating the adults for 16 days with a diet containing the preparations. In vitro effects on gut digestive enzymes were investigated. All preparations showed immediate larvicidal effect but had no effect on adult survival. Extracts from FR-treated larvae showed higher AChE activity than control insects. In the delayed effect assay, the adults lost biomass after consuming SE and FR. FR was the most effective inhibitory agent of trypsin-like and amylase activities (88% and 65% inhibition, respectively). All preparations inhibited endoglucanase activity in 94–98%, while SE and FR inhibited exoglucanase activity in 93.2 and 94.1%, respectively. In conclusion, M. vacciniifolia rhizomes contain compounds (including MvRL) that affect the survival and physiology of A. diaperinus, acting as potential natural insecticides for controlling this pest.

12 November 2024 in Preprints.org
Verified
Preprint
Open access
PDF file
WSWebert Aurino Silva
Webert Aurino Silva
CRCarlos Bôa-Viagem Rabello
Carlos Bôa-Viagem Rabello
LSLilian Francisco Arantes de Souza
Lilian Francisco Arantes de Souza
JNJúlio Cézar dos Santos Nascimento
Júlio Cézar dos Santos Nascimento
MSMarcos Jose Batista dos Santos
Marcos Jose Batista dos Santos
SCSaruanna Millena dos Santos Clemente
Saruanna Millena dos Santos Clemente
This study evaluated the effects of replacing zinc bacitracin with a symbiotic diet on the biochemical profile, liver development, and Clostridium perfringens presence in laying hens at 90 weeks of age. A total of 165 Dekalb–White hens were assigned to six experimental diets: MBM (corn, soybean meal, and meat and bone meal), BAC (MBM + 0.05% zinc bacitracin), and SIMC (MBM + 0.1% symbiotic), provided from day 1 to 90 weeks. Additional treatments, SIMR and SIMP, received symbiotics from weeks 6 and 17, re-spectively. At 90 weeks, blood and tissue samples were analyzed. Results showed that symbiotic-treated hens had 20% heavier livers (P < 0.01) and lower concentrations of uric acid, total proteins, AST, ALT, and LDH (P < 0.01) compared to BAC-treated birds. Phosphorus, triglycerides, and HDL levels were better in symbiotic groups. C. perfringens counts and antibiotic resistance (ampicillin, erythromycin, aminoglyco-sides, lincomycin, tetracycline, bacitracin) were significantly higher in BAC groups (P < 0.01). Symbiotic supplementation improved intestinal health, reduced pathogenic bacterial colonization, and enhanced liver function compared to continuous antibiotic use, especially when administered from early life stages.

20 June 2024 in Animals
Verified
Journal Article
Open access
WMWaleska R. L. Medeiros-Ventura
Waleska R. L. Medeiros-Ventura
CRCarlos Bôa-Viagem Rabello
Carlos Bôa-Viagem Rabello
MSMarcos Jose Batista dos Santos
Marcos Jose Batista dos Santos
Mércia BarrosMércia Barros
Mércia Barros
RJRogério V. Silva Junior
Rogério V. Silva Junior
AFAlba Fireman
Alba Fireman
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