Dietary effects of Sclerocarya birrea caffra seed cake replacing soyabean meal on physiology, meat and bone quality of indigenous chickens.

This study investigated marula seed cake (MSC) as alternative protein source (APS) replacing soyabean meal (SBM) in indigenous chicken diets. Four hundred, 3-week-old Boschveld chicks were randomly allocated to 5 iso-energetic-nitrogenous maize and SBM-based grower diets with 0, 10, 15, 20, and 25 % MSC, each with 5 replicate pens of 16 birds, in a completely randomised design (CRD), for 9 weeks. Results showed that dietary MSC quadratically decreased bird overall feed intake (FI) (P < 0.001) and body weight gain (BWG) (P < 0.01) as it linearly decreased the weights of hot carcass (HCW; P < 0.05), spleen (P < 0.05), jejunum (P < 0.05), ileum (P < 0.001), and caecum (P < 0.001). In contrast, MSC increased chicken serum glucose (P < 0.05), cholesterol (P = 0.001) and phosphate (P < 0.05) as it decreased its amylase activity (P < 0.01). Also, it decreased bird meat lightness at 45 min (P < 0.05) and its yellowness at 45 min (P < 0.001) and 24 h (P < 0.001) whilst it increased its redness at 45 min (P < 0.01) and 24 h (P < 0.05) post-slaughter. In addition, MSC decreased chicken bone medial diaphysis (P < 0.05) as it induced no effects (P > 0.05) on overall feed conversion efficiency (FCE) and all other parameters. In conclusion, feeding of ≤ 15 % dietary MSC is nutritionally safe for indigenous chickens whilst detrimental on bird appetite, growth and meat yield, however without significantly affecting their physiology, at higher inclusion levels.

Pathological Role of Oxidative Stress in Aflatoxin-Induced Toxicity in Different Experimental Models and Protective Effect of Phytochemicals: A Review.

Aflatoxin B1 is a secondary metabolite with a potentially devastating effect in causing liver damage in broiler chickens, and this is mainly facilitated through the generation of oxidative stress and malonaldehyde build-up. In the past few years, significant progress has been made in controlling the invasion of aflatoxins. Phytochemicals are some of the commonly used molecules endowed with potential therapeutic effects to ameliorate aflatoxin, by inhibiting the production of reactive oxygen species and enhancing intracellular antioxidant enzymes. Experimental models involving cell cultures and broiler chickens exposed to aflatoxin or contaminated diet have been used to investigate the ameliorative effects of phytochemicals against aflatoxin toxicity. Electronic databases such as PubMed, Science Direct, and Google Scholar were used to identify relevant data sources. The retrieved information reported on the link between aflatoxin B1-included cytotoxicity and the ameliorative potential/role of phytochemicals in chickens. Importantly, retrieved data showed that phytochemicals may potentially protect against aflatoxin B1-induced cytotoxicity by ameliorating oxidative stress and enhancing intracellular antioxidants. Preclinical data indicate that activation of nuclear factor erythroid 2-related factor 2 (Nrf2), together with its downstream antioxidant genes, may be a potential therapeutic mechanism by which phytochemicals neutralize oxidative stress. This highlights the need for more research to determine whether phytochemicals can be considered a useful therapeutic intervention in controlling mycotoxins to improve broiler health and productivity.

Bacterial and yeast communities in raw milk from three dairy animal species in Nigeria.

The present study aimed to reveal the microbial (bacteria and yeast) composition of raw milk from dairy camel (n = 10), cow (n = 10) and goat (n = 10) in North-western Nigeria. High-throughput DNA metabarcoding was used to compare microbial compositions in raw milk among the three species. Although the three species had similar dominant bacterial (Firmicutes and Proteobacteria) and yeast (Ascomycota and Basidiomycota) phyla, their microbial compositions at the genus level were noticeably different. The top differentially abundant bacterial and yeast genera (percentage abundance) were Lactobacillus (36%), Streptococcus (34%), Enterococcus (12%), Kluyveromyces (28%), Saccharomyces (24%), and Candida (18%), respectively. Principal coordinate analysis based on unweighted UniFrac values revealed significant differences in the structure of bacterial communities and no differences in yeast communities in milk samples from the three species. This study provides insight into the rich and diverse bacterial and yeast communities in raw animal milk consumed in Nigeria, which could play beneficial roles or pose health threats to consumers. However, further research on the economic significance of the microbial community in animal milk consumed in Nigeria is required.

Biosynthesis of zinc oxide and silver/zinc oxide nanoparticles from Urginea epigea for antibacterial and antioxidant applications.

Zinc oxide (ZnO) and silver-zinc oxide (Ag/ZnO) nanocomposite were synthesized by a green method using Zn(CH3COO)2 and AgNO3 as precursors for zinc and silver respectively; and Urginea epigea bulb extract as a reducing/capping agent. The nanomaterials were characterized by X-ray diffraction (XRD) analysis, Fourier transform infrared spectrophotometer (FTIR), ultraviolet-visible spectrophotometer, scanning, and transmission electron microscopy (SEM and TEM). Their elemental composition was studied using EDX analysis, while elementary mapping was used to show the distribution of the constituent elements. The powder X-ray diffraction confirmed hexagonal phase ZnO, while the Ag/ZnO nanocomposites identified additional planes due to cubic phase Ag nanoparticles. The absorption spectrum of the nanocomposite indicated a red shifting of the absorption band of the metallic ZnO and a surface plasmon resonance (SPR) band's appearance in the visible region due to the metallic Ag nanoparticles. The analysis from the TEM image showed the particles were of spherical morphology with a mean size of 35 nm (ZnO) and 33.50 nm (Ag/ZnO). The biological activity of the nanoparticles was studied for their antibacterial and antioxidant capacity so as to assess their ability to hinder bacterial growth and capture radical species respectively. The results demonstrated that the modification of ZnO with silver nanoparticles enhanced the antibacterial potency but reduced the antioxidant activity. This biogenic method offers a facile approach to nanoparticles for biological purposes, and the strategy may be extended to other metal oxide and their composites with metallic silver nanoparticles as a more effective approach compared to the physical and chemical routes.