Development of cashew-alginate microbeads and powdered dose forms: prospects for oral vaccine delivery in chickens.

Conventional oral vaccine delivery in poultry is challenging due to vaccine degradation in the gastrointestinal (GI) environment and the need for cold-chain storage. Microencapsulation offers a solution by protecting vaccines from GI degradation and improving stability. Natural polymers like alginate and cashew gum have mucoadhesive properties, making them promising candidates for oral vaccine delivery. This study developed cashew-alginate microbeads and a powdered dose form for oral vaccine delivery in chickens. The microbeads were created using ionotropic gelation, while the powdered form was obtained via freeze-drying. These formulations were characterized for size, shape, and stability using scanning electron microscopy (SEM), light microscopy, X-ray diffraction (XRD), and Energy Dispersive X-ray (EDX). Peak adhesion time (PAT) was determined using chicken intestinal and esophageal tissues, and antigenicity was assessed with in-vitro hemagglutination (HA) and hemagglutination inhibition (HI) assays. The microbeads exhibited a spherical shape with a porous structure, suggesting enhanced antigen accommodation. Hemagglutination Inhibition tests indicated that the experimental vaccine remained effective without cold-chain storage for three months. These findings suggest that cashew-alginate microbeads are promising for oral vaccine delivery in poultry.

Pathology and immunohistochemical evaluation of lungs of cattle slaughtered at metropolitan abattoirs in Nigeria and Ghana.

There was a dearth of information on pathology and causal agents of bovine pneumonia in West Africa. This cross-sectional study conducted at four major metropolitan abattoirs in Nigeria and Ghana was to evaluate the pathology and to immunohistochemically demonstrates viral and bacterial pathogens of bovine pneumonia in West Africa. Out of the 20,605 cattle lungs examined at post-mortem using standard inspection procedures, 136 samples grossly showed pneumonic lesions and 99 randomly selected lung samples were fixed in 10% neutral buffered formalin for histopathological and immunohistochemical examination. The overall prevalence of pneumonia was 0.66%, with 0.72% prevalence in Ibadan, Nigeria and 9.68% prevalence in Ghana. Age and breed were observed to be among the predisposing factors to pneumonia in cattle. Histologically, bronchopneumonia (0.65%), broncho-interstitial pneumonia (0.13%), and interstitial pneumonia (0.08%) were the prominent type of pneumonias observed. Immunohistochemically, 0.8% was positive for bovine PI-3, 0.9% for bovine RSV, 1.0% for Mannheimia haemolytica (MH), and 0.6% for Pasteurella multocida (PM). There were a few interactions of pathogens: PI3 and MH (0.01%), RSV and MH (0.01%), PM and MH (0.02%). This was the first study that immunohistochemically demonstrated bacterial and viral antigens in naturally occurring pneumonia in cattle in Nigeria and Ghana.

The effect of micronutrient supplementation on bioavailability, antioxidants activity, and weight gain in response to Infectious Bursal Disease vaccination in commercial broilers.

The effect of supplementing organic selenium and zinc on bioavailability, oxidative stress, weight gain in commercial broilers was studied. A total of 180-day-old chicks were divided into six groups: NSUV (Not supplemented, unvaccinated), NSV (Not supplemented, vaccinated), VS (vaccinated, supplemented selenium), VZ (vaccinated supplemented zinc), VSZ (vaccinated supplemented selenium and zinc), UVSZ (unvaccinated supplemented selenium and zinc). 1 mg/kg selenium and 60 mg/kg zinc were added to the feed of supplemented groups. The concentration of selenium (0.05 ± 0.00 mg/L) in VS and zinc (0.66 ± 0.13 mg/L) in VZ were lower on day 27 post-vaccination compared to day 10 (VS= 0.07 ± 0.01 mg/L; VZ= 1.46 ± 0.30 mg/L). Glutathione peroxidase and catalase concentrations were highest in the supplemented groups compared to unsupplemented groups on day 27 post vaccination, expressing a similar trend with the micronutrients. There was no difference (P ≥ 0.05) in the glutathione concentration between all groups except on day 27 post vaccination where SZV group was significantly higher (P=0.02) compared to the NSV group. Catalase concentration was significantly decreased in the NSV group compared to SZV (P=0.04) on day 27 post vaccination. The NSV group (1.64 ± 0.13 kg) weighed significantly lower (P=0.02) than the VSZ (2.00 ± 0.12 kg) in the fifth week, while on the sixth week, the SZV group gained the highest weight (2.04 ± 0.18 kg). The supplementation of organic selenium and zinc in broilers increased the serum micronutrients bioavailability, decreased oxidative stress, increased weight gain, thus, enhancing immunity in the broilers.