ABSTRACT
The objectives of this study were to produce probiotic yogurt (5.0-7.0 log cfu/g) fortified with nanopowdered eggshell (NPES) at a rate of 0.02, 0.04, and 0.06 mg/ml, as well as, examine the effect of NPES on the physicochemical, microbial, sensory properties, and shelf-life of probiotic yogurt. The NPES was prepared by milling preboiled dried eggshell using a mortar grinder. The size of the milled powder was measured to assure that the diameter of the powder is 27 ± 1.7 nm. Yogurt was manufactured by dividing the pasteurized milk into four aliquots portions. The first portion was utilized as control (T1), while the other three portions were supplemented with 0.02 (T2), 0.04 (T3), and 0.06 (T4) mg/ml NPES. All treatments were inoculated with 5.11 log cfu of Lactobacillus delbruckii ssp. bulgaricus (Lb) and Streptococcus thermophilus (St) combined and 5 log cfu of Bifidobacterium bifidum (Bb) per kg of milk at 40°C until the pH of 4.6 was reached. The acidity, sensory properties, Bb count, total bacterial count (TBC), yeast, and mold counts were examined. The results showed that the acidity was increasing during storage, however, increasing NPES resulted in low acid development (p < .05). The shelf-life of control was ended after 8 d of storage at 4°C because molds were grown on the surface of the sample. The TBC significantly decreased (p < .05) as the concentration of NPES increased. Bb count in probiotic yogurt was also decreasing during storage. Yeast and molds were detected in control after 8 d; however, NPES did not result in molds even after 16 d of storage but yeast was exhibited. The NPES improved the sensory evaluation of probiotic yogurt slightly and increased the shelf-life of probiotic yogurt as compared to control.
ABSTRACT
The current experiment was designed to evaluate the effects of dietary supplementations of zinc oxide nanoparticles (ZONPs) on some behavioural, performance, welfare and histopathological changes in broilers exposed to multidrug resistant Staphylococcus aureus (MRSA)-induced footpad dermatitis (FPD). Eighty-four male Indian River (IR) broilers were randomly allotted to six different dietary treatments as follows: C-ve, C+ve, 10, 20, 30 and 40â ppm ZONPs from 7 to 49d of age. At day 28, broilers (n = 70) were sub-cutaneously injected with 0.5â ml of saline containing 5.3 × 107â CFU/ml of S. aureus (MRSA) in each metatarsal foot pad. Control (non-infected) broilers were given 0.5â ml of saline (n = 14). Results clarified that non-infected birds and ZONPs-fed birds had significantly higher standing and feeding activities and lower resting activities in comparison with the infected group. Also, the S. aureus infected group had significantly lower body weight gain (BWG) and higher feed conversion ratio (FCR) than the non-infected group. In addition, the non-infected birds and ZONPs groups had significantly lower object crossing and tonic immobility times (TI) and gait scores (GS) in comparison with the S. aureus group. Only ZONPs 30, 40â ppm and non-infected groups had a significantly higher latency to lie time (LLT) and lower serum cortisol level in comparison with the S. aureus group. Moreover, there were significant changes in the gross lesion score and histopathological lesions between the different groups. In conclusion, the dietary supplementation of ZONPs can reduce S. aureus-induced negative effects of FPD in broilers.
ABSTRACT
The current study investigated the effects of zinc oxide nanoparticles (ZONPs) and oxytetracycline (OTC) supplementation on broilers' behavior, performance, carcass quality, biochemical parameters, and intestinal microbial populations and birds' response to Newcastle disease (ND) vaccine. A total of 336 seven-day-old IR broiler chicks were randomly allotted to six dietary treatments containing 0, 10, 20, 30 and 40 ppm ZONPs or 50 ppm OTC. Each diet was fed to 7 replicates (8 birds/pen). The results clarified that 10 ppm ZONPs significantly improved the body weight gain and feed conversion in comparison to the control. No changes in behavior were recorded. The 10 ppm and 30 ppm ZONPs and OTC significantly reduced the gizzard weight in comparison to the control. While, 10 ppm ZONPs significantly increased the spleen weight, and all ZONPs doses increased bursa weight in comparison to the control and OTC groups. 20 ppm ZONPs increased the eviscerated yield and edible yield in comparison to the control and OTC groups. 40 ppm ZONPs increased pH, reduced meat color and overall acceptability in comparison to the control. In addition, results revealed that the 20 ppm ZONPs increased Calcium (Ca), High density low cholesterol (HDL-C), reduced urea (UA) and triglyceride (TG). Also, 40 ppm ZONPs and OTC increased creatinine (Cr) and reduced ND-HI titer in comparison to the control. For microbial population, OTC group was significantly lower than ZONPs groups in the total anaerobic, aerobic and lactobacilli count. In conclusion, the dietary inclusion of ZONPs can be applied as antibiotic growth promoter substitutions in broilers' diet. However, further investigations are still needed.
