Effect of probiotic supplementation on serum/yolk cholesterol and on egg shell thickness in layers

1. The effect of probiotic supplementation on egg production, on serum and yolk cholesterol and on egg shell thickness in 24 White Leghorn layers was studied from 28–38 weeks of age.

2. In 3 treatments the diet was supplemented with 0, 100 and 150 mg probiotic/kg food.

3. In the 100 mg probiotic group, egg production improved by 5%, and shell thickness improved slightly, with fewer thin‐shelled eggs than in the control (8.6% compared to 18.6%).

4. The initial serum cholesterol concentration of 170.2 mg/dl in control birds remained similar throughout the 10‐week experimental period, whereas in the 150 mg group the initial value of 176.5 mg/dl decreased to 114.3 mg by week 10.

5. Yolk cholesterol concentration was 14.69 mg in the control group and 11.28 and 11.37 mg/g in the 100 and 150 mg probiotic groups respectively. Overall mean total egg cholesterol was thus reduced by probiotic supplementation.     

A Single-chain Fragment Variable Recombinant Antibody against F5 Fimbria of Enterotoxigenic <Emphasis Type="Italic">Escherichia coli</Emphasis> Inhibits Agglutination of Horse Red Blood Cells Induced by F5 Protein

Bovine colibacillosis caused by enterotoxigenic Escherichia coli (ETEC) is a worldwide problem. Adhesion of ETEC to intestinal cell receptors mediated by the surface protein F5 fimbriae is the initial step in the establishment of colibacillosis. Prevention of ETEC F5⁺ adhesion to enterocytes protects newborn calves against collibacillosis. On the enterocytes, the F5 fimbriae bind to a ganglioside that is also found on horse red blood cells. Thus, the presence of F5 fimbriae induces haemagglutination, which is useful as an indicator in a functional assay system. In this study, recombinant anti-F5 scFv antibody fragment produced in E. coli HB2151 reacted with F5 fimbriae in ELISA and Western immunoblot, and prevented haemagglutination induced by the binding of the F5 fimbriae to its natural host receptors on horse red blood cells. Given the ease with which recombinant antibodies can be mass-produced, the presently described scFv may hold promise as a prophylactic agent for colibacillosis.     

Experimental insight of trace metal environmental pollution problems in mussel farming

A survey was made on the content of nine trace metals in waters of 12 predetermined coastal stations in the Island of Penang, Malaysia, with the object of establishing mussel culture farms in the near future. The results indicated low concentrations of these trace elements except for Cr and Ni, which ranged from trace level to 35 ppm and BDL (below detectable level) to 2.07 ppm, respectively. These values are slightly above the upper limits (Cr, 0.05 and Ni, 1.0 ppm) set by the national Division of Environment, Ministry of Science, Technology and Environment, under the Environmental Quality (Sewage and Industrial Effluents) Regulations 1978.Investigations on tissue level bioaccumulated trace metal contents in mussel from an experimental culture farm indicated BDL values for As in all tissues, Cd highest in the intestines and stomach (6.24 ppm), Co in the mantle (59.85 ppm), Cr in the siphon (1869.85 ppm), Cu in the mantle (23.94 ppm), Fe in the intestines and stomach (218.82 ppm), Mn in the style (365.28 ppm), Ni in the mantle (23.94 ppm), Pb in the mantle (279.3 ppm) and Zn in the style (152.2 ppm). However, culture experiments at 10 ppm concentration stresses of the different trace elements over a 48-h period did not result in a similar tendency in tissue bioconcentration, except for Cd (378.35 ppm) and Fe (419.66 ppm) in the intestine and stomach, and Mn (748.5 ppm) in the style. Co was highest in the style (187.35 ppm), Cr in the gill (2924.91 ppm), Cu in the gill (457.22 ppm), Ni in the intestines and stomach (222.44 ppm), Pb in the gill (1897.2 ppm), and Zn in the mantle (1077.73 ppm).Short-term stress studies over a 48-h period with trace metal concentrations ranging between 10 and 300 ppm indicated the patterns of biodeposition for Cd, Cr, Co, Pb, Mn and Zn to be closely related even though their toxicity levels varied. Cu indicated a bioaccumulation maximum after 12 h of incubation followed by a regulatory mechanism, while Fe and Ni demonstrated a drastic spiked absorption after 6 h exposure followed by the normal trend of biodeposition as observable for the other trace metals. The biodeposition factors at most instances, were highest for the 10 ppm concentration cultures of 48 h.     

Pyocyanin as a safe aquaculture drug for the control of vibriosis in shrimp recirculating aquaculture system (RAS)

Diseases are one of the most critical limiting factors in aquaculture. Recirculating aquaculture systems (RAS) are one of the most functionally viable sustainable aquaculture production systems adopted world over. In the event of any eventuality caused by bacterial pathogens, antibiotics or other antibacterial agents cannot be applied due to the vulnerability of biological filters which form an integral part of the RAS. Because of this, newer drugs are required for the effective control of diseases in RAS which would not interfere with the activity of nitrifying bacteria used in the biological filters. The antagonistic activity of pyocyanin, a bioactive compound produced by Pseudomonas aeruginosa, against vibrios is well established. The purpose of this study was to prove the effectiveness of pyocyanin as an aquaculture drug for application in RAS by employing a pilot-scale shrimp culture under RAS. It was noted that at the concentration of 5 mg L^?1, pyocyanin could significantly bring down the population of Vibrio spp. in RAS without affecting noticeably the other natural heterotrophic bacteria. Also, pyocyanin at this concentration did not inhibit the activity of nitrifying bacterial consortia used in the SBSBR (stringed bed suspended bioreactor) of RAS. The reared shrimp (Penaeus monodon) showed 100% survival after the application of pyocyanin, besides exhibiting normal health signs. Pyocyanin was non-toxic to the shrimp hybrid cell line (PmLyO-Sf9) at the concentration required for its application in disease management (IC₅₀?=?419.26 mg L^?1). The present study has demonstrated that pyocyanin is effective as an environment-friendly and safe aquaculture drug for the application in RAS-based shrimp culture to control Vibrio spp. without impeding nitrification established through the deployment of nitrifying bioreactors.

     

Effect of probiotic supplementation on growth,nitrogen utilisation and serum cholesterol in broilers

1. The effect of dietary probiotic supplementation on the growth, nitrogen utilisation and serum cholesterol content of broiler chickens was studied in 2 trials.

2. In experiment 1, the birds receiving the 0, 75, 100, 125 mg probiotic/kg diets had weight gains of 1204.0, 1272.0, 1268.3 and 1210.5 g, respectively at the end of 8 weeks of feeding. The group of birds fed on the 75 mg probiotic supplemented diet retained significantly (P<0.01) more nitrogen than the control birds. Serum cholesterol content was lower in the probiotic‐supplemented birds (93.3 mg/100 ml) compared to the control birds (132.2 mg/100 ml).

3. In the second experiment the probiotic plus antibiotic‐supplemented group of birds had the maximum weight gain (1148.5 g) followed by antibiotic (1141.3 g), probiotic‐supplemented (1128.4 g) and control birds (1045.6 g) after 6 weeks. Nitrogen retention was greatest in the antibiotic—(48.5%) followed by the probiotic—(46.5%), probiotic plus antibiotic‐supplemented groups (46.3%) compared to 40.2% in control birds.

4. The apparent metabolisable energy was greatest in birds receiving the probiotic plus antibiotic‐supplemented diet (12.37 MJ/kg) followed by antibiotic—(12.00 MJ/kg), probiotic‐supplemented birds (11.92 MJ/kg) than in control birds (11.62 MJ/kg). Serum cholesterol was significantly (P<0.01) lower in probiotic‐supplemented birds (86.1 mg/dl) compared to 118.4 mg/dl in control birds.     

Hypodermosis in cattle translocated to Tamil Nadu from Punjab

Tropical Animal Health and Production - Fifteen apparently healthy Kandari cross-bred cattle aged about 4&nbsp;years were purchased from Rurki, Patiala district of Punjab by a private dairy...     

Enterotoxigenic K99+ Escherichia coli attachment to host cell receptors inhibited by recombinant pili protein

Most enterotoxigenic Escherichia coli (ETEC) isolated from neonatal cattle with diarrhea (enteric colibacillosis) exhibit the colonization factor antigen, K99. The K99 pili are necessary for the bacteria to bind to a receptor, N-glycolylneuraminic acid-GM3 on the host cells in the small intestine where the bacteria multiply and secrete toxins that cause the diarrhea. When the attachment of the ETEC to host cell is inhibited, the bacteria do not accumulate sufficiently in the gut to cause disease. Since purified K99 pili block K99+ ETEC from binding to host epithelia, three recombinant K99 proteins of different sizes were developed and produced to demonstrate inhibition with in vitro competitive binding assays. The full-length recombinant protein, rK99-476 inhibited the binding of ETEC with an activity similar to that of the native purified K99, whereas the truncated recombinant K99 protein had no inhibitory activity. Thus this binding activity of rK99-476, which is specific and effective in blocking the receptors on the host cells, may be able to competitively inhibit K99+ ETEC infections in cattle.