Characterization of detergent-soluble proteins of Corynebacterium pseudotuberculosis.

Whole cells and culture supernatant of isolates of Corynebacterium pseudotuberculosis were studied by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting (immunoblotting). SDS-PAGE analysis of detergent-solubilized whole cells revealed more than 20 bands in silver-stained gels. However, the SDS-soluble proteins that are present in all the isolates of the bacterium can be separated into four groups, as follows, (i) high molecular mass proteins that are greater than 119 kDa, (ii) a set of three proteins with molecular mass of 84, 64 and 58 kDa, (iii) a doublet consisting of proteins of molecular mass 33 to 30 kDa, and (iv) low molecular mass proteins of 25 to 20 kDa. SDS-PAGE analysis of ammonium sulphate concentrated culture supernatant demonstrated more than seven bands in silver-stained gels ranging in molecular mass from 64-14 kDa. Sera from goats with C. pseudotuberculosis-induced disease were used to probe immunoblots of electrophoresed SDS-soluble proteins. Ten or more SDS-soluble proteins from whole cells, ranging in molecular mass from 119-20 kDa were recognized by antibodies in sera of naturally infected goats. These sera also recognized up to five molecules ranging from 64-30 kDa, on immunoblots of ammonium sulfate concentrated culture supernatant.

Low molecular weight branched-chain and n-chain fatty acids in caprine and bovine colostrum.

Colostrum from French-Alpine and Anglo-Nubian goats and Holstein cows was collected and analyzed for both total and FFA of 12 and fewer carbon atoms. Short-chain VFA were separated from long-chain fatty acids using simultaneous distillation extraction. The n-butyl esters of fatty acids were quantified by gas chromatography, and their identity was confirmed by gas chromatography-mass spectrometry. The concentration of decanoic acid was 33 and 83% less in Holstein colostrum than in colostrum from Alpine and Nubian goats, respectively. Colostrum from Nubian goats had twice as much decanoic acid as colostrum from Alpine goats. The FFA in colostrum that differed between species but not between goat breeds were octanoic and decanoic acids. These respective fatty acids were approximately two and three times greater in colostrum from goats than in colostrum from Holsteins. The quantity of decanoic acid was different between goat breeds and between animal species. The ratio of total fatty acid concentration to free-state concentration for hexanoic acid appeared to be useful for differentiating between Nubian and Alpine goat colostrum as well as between Nubian and Holstein colostrums.

Toxicological evaluation of aflatoxin and cyclopiazonic acid in broiler chickens.

The individual and combined effects of aflatoxin (AF) and cyclopiazonic acid (CPA) were evaluated in day-old Petersen x Hubbard broiler chickens to 3 wk of age. Treatments were arranged in a 2 x 2 factorial with levels of 0 and 3.5 mg AF/kg of feed, and 0 and 50 mg CPA/kg of feed. Production performance, serum biochemistry, and gross pathological observations were evaluated. Body weight gain was significantly (P less than .05) reduced by AF, CPA, and the AF-CPA combination at the end of 3 wk. Aflatoxin significantly increased the relative weight of the kidney and serum concentration of blood urea nitrogen and decreased serum concentrations of protein, albumin, cholesterol, phosphorus, and the activity of lactate dehydrogenase. The toxicity of CPA was expressed through increased relative weights of the liver, kidney, and proventriculus, increased levels of uric acid and cholesterol, and decreased serum phosphorus. The activity of AF-CPA combination was characterized by increased relative weight of the liver, kidney, pancreas, and proventriculus, decreased concentrations of serum albumin and phosphorus, increased concentrations of serum glutamic oxalacetic transaminase and blood urea nitrogen, and decreases in the relative weight of the bursa of Fabricius. Post-mortem examination revealed that the chickens fed CPA and the AF-CPA combination had thickened mucosa and dilated proventricular lumens, hard fibrotic spleen, and atrophy of the gizzard. The data from the present study demonstrate that both AF and CPA alone and the AF-CPA combination can limit broiler performance and adversely affect broiler health. In most cases the effects of AF and CPA were additive.

Magnesium sulfate effects on coliform bacteria reduction in the intestines, ceca, and carcasses of broiler chickens.

The objective of the study was to evaluate the effects of MgSO4 on intestinal and cecal content reduction with subsequent effects on carcass weight loss and coliform bacterial counts in the intestine and ceca, and on the processed carcass. Four hundred and eighty broiler chicks, 49 days of age, were fed MgSO4 at levels of 0, 2.5, 4.0, 5.5, 7.0, and 8.5 g/L via drinking water 24 h before processing. Samples from the intestinal and cecal contents and swabs from the processed carcass surface were plated for coliform bacteria colonization. The results indicated that carcass weight loss was not affected significantly by MgSO4, irrespective of the levels fed. The mean dressing percentage of the treated chicks was 64.9% compared with 65.2% for the controls. Although the reduction in the intestinal contents was not significant, the coliform bacterial counts declined from 1.4 x 10(6) to 1.4 x 10(4), a reduction of 2 logs when the MgSO4 was administered at 5.5 g/L. However, both the cecal contents and coliform bacteria were reduced significantly when the birds were given 5.5 g/L of MgSO4. The reduction of the coliform bacteria in the ceca was significant when compared with the control, an approximate reduction of 3 logs. Also, the bacterial counts on the carcass surface were nonsignificantly reduced from 2.2 x 10(4) to 2 x 10(3), a 1-log reduction. Correlation coefficients showed that as the contents of the intestine decreased, the coliform bacterial counts in the ceca and on the carcass surface decreased.(ABSTRACT TRUNCATED AT 250 WORDS)

Single and combination effects of administering salinomycin and aflatoxin to broiler chicks.

A factorial design (2 by 3) was used to evaluate the interaction between aflatoxin (0, 2.5, and 5 mg per kg) and salinomycin [0, 60 g per ton (909 kg)]. There were four replicates of 10 chicks per treatment. The chicks were maintained in batteries from 0 to 3 wk of age, with feed and water available for ad libitum intake. Aflatoxin at both levels (2.5 and 5 mg per kg) with and without salinomycin decreased body weight. The efficiency of feed utilization was affected only at the 5 mg per kg level of aflatoxin. Feeding 5 mg per kg of aflatoxin alone decreased the hemoglobin level. The inclusion of salinomycin (60 g per ton) in the diet with 2.5 or 5 mg per kg of aflatoxin initiated no significant change in body weight or feed efficiency. No significant interaction was observed between aflatoxin and salinomycin on any of the parameters measured.