Protection of chicken against very virulent IBDV provided by in ovo priming with DNA vaccine and boosting with killed vaccine and the adjuvant effects of plasmid-encoded chicken interleukin-2 and interferon-��

The aim of this study was to examine the efficacy of in ovo prime-boost vaccination against infectious bursal disease virus (IBDV) using a DNA vaccine to prime in ovo followed by a killed-vaccine boost post hatching. In addition, the adjuvant effects of plasmid-encoded chicken interleukin-2 and chicken interferon-γ were tested in conjunction with the vaccine. A plasmid DNA vaccine (pcDNA-VP243) encoding the VP2, VP4, and VP3 proteins of the very virulent IBDV (vvIBDV) SH/92 strain was injected into the amniotic sac alone or in combination with a plasmid encoding chicken IL-2 (ChIL-2) or chicken IFN-γ (ChIFN-γ) at embryonation day 18, followed by an intramuscular injection of a commercial killed IBD vaccine at 1 week of age. The chickens were orally challenged with the vvIBDV SH/92 strain at 3 weeks of age and observed for 10 days. In ovo DNA immunization followed by a killed-vaccine boost provided significantly better immunity than the other options. No mortality was observed in this group after a challenge with the vvIBDV. The prime-boost strategy was moderately effective against bursal damage, which was measured by the bursa weight/body weight ratio, the presence of IBDV RNA, and the bursal lesion score. In ovo DNA vaccination with no boost did not provide sufficient immunity, and the addition of ChIL-2 or ChIFN-γ did not enhance protective immunity. In the ConA-induced lymphocyte proliferation assay of peripheral blood lymphocyte collected 10 days post-challenge, there was greater proliferation responses in the DNA vaccine plus boost and DNA vaccine with ChIL-2 plus boost groups compared to the other groups. These findings suggest that priming with DNA vaccine and boosting with killed vaccine is an effective strategy for protecting chickens against vvIBDV.     

The effect of Eucommia ulmoides leaf supplementation on the growth performance, blood and meat quality parameters in growing and finishing pigs

The aim of the present study was to investigate the effect of Eucommia ulmoides leaf (EUL) supplementation on the growth performance, blood and meat quality parameters in growing and finishing pigs. Ninety gilts (L × LW × D, 20 kg initialBW) were housed 10 per pen in a front‐open building with three replicate pens per treatment. Experimental treatment was started from the beginning of the growing stage (20 ± 3 kg) by supplementing EUL at 0(C), 3(T1) and 5% (T2) to the growing and finishing diet. Pigs were slaughtered by electrical stunning at 105 ± 3 kg live weight. Average daily feed intake (ADFI, kg/day) decreased (P < 0.05) by addition of EUL in growth performance, average daily gain (ADG, kg/day) was lower (P < 0.05) in T1 and T2 than in C. In hematology, leukocytes (WBC, 10³/mm³) decreased (P < 0.05) in T1 and T2 than in C. Erythrocytes (RBC, 10⁶/mm³), hemoglobin (HGB, g/dL) and hematocrit (HCT, %) increased (P < 0.05) in T1 and T2 than in C. Platelet (PLT, 10³/mm³) was lower (P < 0.05) in T2 than in C and T1. In biochemical composition of serum, total protein (g/dL), r‐GTP (μ/L), total cholesterol (mg/dL) and triglycerides (mg/dL) were lower (P < 0.05) in T1 and T2 than in C. On longissimus dorsi muscle, crude protein was higher (P < 0.05) in T1 than in C. Crude ash was higher (P < 0.05) in T1 and T2 than in C. Yellow to blue color scale (CIE b*) in meat color was higher (P < 0.05) in T2 than in C. CIE b* in back fat color was higher (P < 0.05) in T2 than in the other treatments. In sensory evaluation scores for fresh meat, the values of meat color, fat color, drip loss and marbling were not significantly affected by addition of EUL. In cooked meat, the values of chewiness and overall acceptability were higher (P < 0.05) in T1 and T2 than in C. The results indicate that the addition of EUL affected growth performance, blood parameters and meat quality parameters in growing and finishing pigs.     

Hypolipidemic effect of soluble fiber isolated from seeds of Cassia tora Linn. in rats fed a high-cholesterol diet

Soluble fibers isolated from the seeds of Cassia tora Linn. (SFC) have attracted considerable attention in recent years due to their phenomenal rheological behavior. In this study were investigated the effects of SFC on lipid metabolism. Male Sprague-Dawley rats were fed one of three experimental diets, a normal diet, a high-cholesterol diet, or a high-cholesterol diet with 5% SFC, for 5 weeks. The serum concentration of total cholesterol in rats fed SFC was 27% lower (p < 0.05) compared to that of the control group, but the serum high-density lipoprotein cholesterol level was increased in the SFC group. Liver total cholesterol and triglyceride levels were reduced significantly (p < 0.05) in rats fed the SFC diet. In addition, fecal bile acid and lipid excretion was significantly increased by SFC consumption. These results indicate that SFC enhances fecal lipid excretion and may cause a reduction in serum and hepatic lipid concentrations in rats.     

The effect of glycyrrhizin on rainbow trout, Oncorhynchus mykiss (Walbaum), leucocyte responses

Abstract. Treatment of rainbow trout macrophages with glycyrrhizin (GL), an aqueous extract of licorice, Glycyrrhiza glabra , enhanced their respiratory burst activity. Maximal effects were seen using concentrations of 10–100 μml⁻¹. GL also modulated trout lymphocytes, increasing proliferation responses to the mitogen phytohaemagglutinin some two-fold over a range of GL concentrations. In addition, GL elicited the release of a macrophage activating factor (MAF) from head kidney leucocytes, as assessed by the ability of generated supernatants to increase respiratory burst activity of target macrophages. MAF activity was most apparent using 100 μg ml⁻¹ GL to induce MAF release and a 48-h incubation period with the target macrophages. Finally, GL was shown to enhance the release of MAF in response to the mitogen concanavalin A. The possible use of GL as a stimulant of fish innate defences is discussed.