No abstract

Eighteen male lambs (8-9 months of age, 25.00 +/- 0.90 kg body weight) were divided into three groups of six animals in each and fed a total mixed ration (TMR) containing concentrate mixture (30% maize grain, 27% soybean meal, 40% wheat bran, 2% mineral mixture, and 1% common salt) and wheat straw in 65:35 ratio and supplemented with selenium (Se) as sodium selenite at 0 (T1, control), 0.15 (T2), and 0.30 ppm (T3) levels. Experimental feeding was done for a period of 90 days including a 6-day metabolism trial. To assess the growth performance, lambs were weighed every 15 days throughout the experimental period. All the lambs were intramuscularly inoculated with a single dose (2 ml) of haemorrhagic septicaemia oil adjuvant vaccine on 0 day to evaluate the humoral immune response. Blood samples were collected on 0 day and thereafter at 30 days interval. Results revealed that supplementation of Se both at 0.15 and 0.30 ppm levels had no significant (P > 0.05) effect on intake and digestibility of dry matter, organic matter, crude protein (CP), ether extract, neutral detergent fiber, acid detergent fiber, and hemicellulose; balances of calcium and phosphorus; and level and intake of digestible CP and total digestible nutrients. Se supplementation also had no significant (P > 0.05) effect on the levels of serum total cholesterol, total protein, albumin, globulin, albumin/globulin ratio, tri-iodothyronine (T(3)), thyroxine (T(4)), and T(4)/T(3) ratio; and serum glutamate oxaloacetate transaminase and serum glutamate pyruvate transaminase enzyme activity in the lambs. However, there was a significant (P < 0.05) increase in the plasma Se levels, red blood cell glutathione peroxidase enzyme activity, and humoral immune response in both the Se-supplemented groups. Feed (TMR) required per kilogram gain was less by 11.1% and 16.5% in groups T2 and T3, respectively, as compared to control (T1) group. Average daily gain was highest (108.5 g) in group T3, followed by group T2 (98.2 g), and lowest (89.06 g) in the control group (T1). These results indicated that supplementation of 0.15 and 0.3 ppm Se in the diet (having 0.19 ppm Se) of lambs significantly improves their immune response and antioxidant status.

To investigate the potential of RNA interference (RNAi) as antiviral agent against rabies, two small interfering RNAs (siRNAs) targeting rabies virus (RABV) nucleoprotein (N) and polymerase (L) genes were designed and evaluated. Both siRNAs knockdown or silenced the target RABV genes as evaluated in a plasmid based transient expression model. For efficient delivery, adenoviruses expressing the siRNAs were constructed and antiviral potential of the delivered siRNAs was investigated in BHK-21 cells. When cells treated with adenoviruses expressing siRNAs were challenged with RABV, there was 88.35±2.4% and 41.52±9.3% reduction in RABV multiplication in infected cells with siRNAs targeting RABV-N and L genes, respectively. Relative quantification of RABV transcripts using real-time PCR revealed knockdown of both RABV-N and L gene transcripts, however, significant reduction was observed only with adenovirus expressing siRNA against RABV-N. When mice treated intracerebrally with adenoviruses expressing siRNAs were challenged peripherally with lethal RABV by the intramuscular route in masseter muscle, there was 66.6% and 33.3% protection with adenoviruses expressing siRNAs against RABV-N and L genes, respectively. These results demonstrated that adenovirus expressing siRNA against RABV-N efficiently inhibited the RABV multiplication both, in vitro and in vivo and conferred significant protection against lethal RABV challenge. This supported the hypothesis that RNAi, based on siRNA targeting RABV-N gene can prevent RABV infection and holds the potential of RNAi as an approach to prevent rabies infection.

Forty weaned male guinea pigs of 208.20 +/- 6.62 g mean body weight were divided into 4 groups of 10 animals in a randomized block design. All of the guinea pigs were fed a basal diet [25% ground maize hay, 30% ground maize grain, 22% ground chickpea (Cicer arietinum L.), 9.5% deoiled rice bran, 6% soybean meal, 6% fish meal, 1.45% mineral supplement (without Zn) and 0.05% ascorbic acid] and available green fodder. Group I served as the control (no Zn supplementation), whereas 20 ppm Zn was added in the diet in groups II, III, and IV either as zinc sulfate (ZnSO(4)), zinc amino acid complex (ZAAC), and ZnSO4 + ZAAC in equal parts, respectively. Experimental feeding lasted for 70 d, including a 3-d digestibility trial. Blood was collected through cardiac puncture from four animals in each group at d 0 and subsequently at the end of experimental feeding. After 40 d of experimental feeding, four animals from each group were injected with 0.4 mL of Brucella abortus cotton strain-19 vaccine to assess the humoral immune response of the animals. After 10 wk of study, four animals from each group were sacrificed to study the concentration of Zn, Cu, Co, Fe, and Mn in the liver, pancreas and spleen. Results revealed no significant difference in the feed intake, body weight gain, and digestibility of the nutrients, except for crude protein (CP) digestibility, which was significantly (p < 0.05) lower in group IV. Although concentrations of serum glucose, Ca, and P and the albumin:globulin (A:G) ratio were similar in the different groups, the total protein, albumin, and serum alkaline phosphatase activity were higher in all of the Zn-supplemented groups on d 70. The serum Zn levels at the end of experimental feeding were significantly higher in groups II and III, whereas serum Mn levels were found to be significantly (p < 0.05) higher in groups III and IV. The organ weights (as percentage of body weights) did not show any differences among the treatment groups. Although the Mn concentration was significantly (p < 0.05) higher in the pancreas, the Cu concentration was significantly (p < 0.05) reduced in the spleen in all of the Zn-supplemented groups. The humoral immune response (antibody titer values) on d 14 of vaccination was significantly (p < 0.05) higher in all of the Zn-supplemented groups. It was concluded that the 20-ppm level of Zn in the diet might be adequate for growth and nutrient utilization in guinea pigs, but supplementation of 20-ppm zinc significantly improved the immune response and impact was more prominent with the ZAAC (organic source) compared to ZnSO(4) (inorganic source).