Eggshell factors influencing eggshell penetration and whole egg contamination by different bacteria, including Salmonella enteritidis.

Trans-shell infection routes and whole egg contamination of 7 selected bacterial strains; Staphylococcus warneri, Acinetobacter baumannii, Alcaligenes sp., Serratia marcescens, Carnobacterium sp., Pseudomonas sp.

Eggshell characteristics and penetration by Salmonella enterica serovar Enteritidis through the production period of a layer flock.

1. Egg weight, shell thickness, number of pores, cuticle deposition and ability of Salmonella enterica serovar Enteritidis (SE) to penetrate the shell were determined for eggs from one layer flock through the entire production period. 2.

Incidence of residues of nine anticoccidials in eggs.

A survey of the presence of residues of anticoccidials was performed. Three hundred and twenty egg samples, purchased in eight different European countries, were analysed for the presence of nine different compounds: dimetridazole, diclazuril, halofuginone, robenidine, nicarbazin, narasin, salinomycin, lasalocid and monensin. Analyses were performed by LC-MS/MS.

Deposition and depletion of five anticoccidials in eggs.

Anticoccidials are compounds that are widely used as feed additives to prevent and treat coccidiosis. They are licensed for use in a prescribed concentration and during a certain time interval for broilers and pullets but not for laying hens. It was shown in the past that carry-over at the feeding mill is found to be the main reason for the presence of residues in eggs.

Growth of Salmonella in egg white.

Six non-S. Enteritidis strains and eleven S. Enteritidis strains of which 8 were isolated from eggs, were tested on their growth behaviour in fresh eggs and in eggs of 2 and 3 weeks old hold at 20 degrees C.

Liquid chromatographic tandem mass spectrometric determination of five coccidiostats in poultry eggs and feed.

A method is described which permits the quantitative detection of the chemical coccidiostats halofuginone, robenidine, diclazuril, nicarbazin and dimetridazole and its main metabolite 2-hydroxydimetridazole in poultry eggs and feed. Sample preparations were kept very simple and are based upon extraction with an organic solvent. Sample extracts were injected into the liquid chromatography tandem mass spectrometry (LC-MS/MS) system on a C18 column and a gradient elution was performed.

Detection of residues of the coccidiostat diclazuril in poultry tissues by liquid chromatography-tandem mass spectrometry after withdrawal of medicated feed.

A liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the quantitative determination of diclazuril in poultry tissues and feed is presented. A simple clean up with an organic solvent was carried out. A reversed-phase C(18) column was used for the high-performance liquid chromatography (HPLC) to separate the analyte with a gradient of acetonitrile and water as mobile phase.

Determination of the ionophoric coccidiostats narasin, monensin, lasalocid and salinomycin in eggs by liquid chromatography/tandem mass spectrometry.

A sensitive and selective liquid chromatographic tandem mass spectrometric method (LC/MS/MS) for the simultaneous detection of the ionophoric coccidiostats narasin, monensin, lasalocid and salinomycin in whole eggs has been developed. A very simple sample preparation consisting of an extraction with an organic solvent was carried out. Sample extracts were injected into the LC/MS/MS system on a C18 column and an isocratic elution was performed.

Prevalence and typing of Listeria monocytogenes in ready-to-eat food products on the Belgian market.

Listeria monocytogenes is a major concern to producers of ready-to-eat foods because of the high mortality rate associated with listeriosis and the widespread nature of the organism. To investigate the prevalence of this pathogen in different ready-to-eat food products on the Belgian market, a variety of 252 ready-to-eat food products, mainly fish and meat products, were analyzed. Overall, L.

Distribution and depletion of flubendazole and its metabolites in edible tissues of guinea fowl.

1. We measured the distribution and depletion of residues of flubendazole and its major metabolites in breast muscle, thigh muscle and liver of guinea fowls during and after oral administration of the veterinary medicine Flubenol 5% at two doses. 2.

The effect of physical structure in maize silage-based diets for beef bulls.

To investigate the influence of physical structure on zootechnical performances, four feeding regimens were evaluated with 52 Belgian Blue double-muscled bulls starting from 327 kg until slaughter (646 kg). All diets were fed ad libitum and consisted of concentrates and maize silage in different ratios. The structural value (SV), currently used in Belgium as an evaluator of physical structure in the diet for dairy cows, amounted to 0.

Determination of halofuginone in eggs by liquid chromatography/tandem mass spectrometry after cleanup with immunoaffinity chromatography.

A sensitive and very selective high-performance liquid chromatography/tandem mass spectrometric (LC/MS/MS) method for the detection of halofuginone in whole egg has been developed. After deproteinisation with acetonitrile and evaporation of the organic solvent, halofuginone was further isolated by applying immunoaffinity chromatography. The concentrated eluent was injected into the LC/MS/MS system on a C18 column.

Development of an indirect competitive ELISA for flumequine residues in raw milk using chicken egg yolk antibodies.

To detect flumequine in raw milk, an indirect competitive enzyme-linked immunosorbent assay (ELISA) was developed. By carbodiimide conjugation, flumequine was conjugated to cationized bovine serum albumin (cBSA-flumequine) and to cationized ovalbumin (cOVA-flumequine). For the immunization of chickens, cBSA-flumequine was used, which allowed the isolation of specific chicken egg yolk immunoglobulins (IgY) for flumequine.

Carcass and meat quality in double-muscled Belgian Blue bulls and cows.

Carcass and meat quality of 37 bulls and 91 cows of the Belgian Blue breed (double-muscled type) were compared. Age at slaughter averaged 648±73 and 1820±689 days, respectively. Both groups of cattle were finished on maize silage supplemented with concentrate, and were slaughtered at about 750 kg live weight.

Variation of the sensory quality within the m. longissimus thoracis et lumborum of PSE and normal pork.

This study evaluated the variation in instrumental and sensory meat quality within the m. longissimus thoracis et lumborum of carcasses with normal and PSE meat. Out of 80 slaughtered pigs, respectively, 9 and 7 carcasses were selected with a pH30 value > or=5.

The efficiency of nitrogen retention during compensatory growth of food-restricted broilers.

1. Two experiments were conducted to investigate the influence of compensatory growth, induced by early quantitative food restrictions, on the efficiency of nitrogen-retention in two lines of Ross broilers. 2.

Development and validation of a liquid chromatographic-electrospray tandem mass spectrometric multiresidue method for anthelmintics in milk.

A liquid chromatographic-tandem mass spectrometric multiresidue method for the simultaneous quantitative determination of the tetrahydroimidazole, levamisole and the benzimidazoles thiabendazole, oxfendazole, oxibendazole, albendazole, fenbendazole, febantel and triclabendazole in milk has been developed and validated. The anthelmintic residues were extracted with ethyl acetate. The liquid chromatographic separation was performed on a reversed-phase C18 column with gradient elution.

Decreasing the roughage:concentrate ratio of a diet to determine the critical roughage part for beef cattle.

The critical roughage part (CRP) of 2 diet types was determined in a cross-over design with 6 double-muscled and 6 normally conformed Belgian Blue bulls fitted with rumen cannulae. The roughage:concentrate ratio was lowered weekly until signs of a lack of physical structure were observed. For diet 1, consisting of maize silage and concentrates, the initial proportion of maize silage was 25% of DM but it decreased weekly with 5% units of DM.

Development and validation of a liquid chromatography-electrospray tandem mass spectrometry method for mebendazole and its metabolites hydroxymebendazole and aminomebendazole in sheep liver.

A quantitative liquid chromatography-electrospray tandem mass spectrometry method for the determination of mebendazole and its hydrolysed and reduced metabolites in sheep liver has been developed and validated. The benzimidazole substances were extracted with ethyl acetate after the sample mixture had been made alkaline. The HPLC separation was performed on a reversed-phase C18 column with gradient elution using a mobile phase consisting of water containing 0.

Trace metals in cut trough shell (Spisula subtruncata) from Belgian coastal waters.

In the period 1985-1996 concentrations of mercury, cadmium, lead, copper, zinc and chromium in cut trough shell (Spisula subtruncata) sampled on 11 stations on the Belgian Continental Shelf were determined. On the whole, contents of trace metals showed a tendency to decrease. No significant differences in concentrations were found between the stations, except on one site for lead and chromium.

The preference of the consumer for pork from homozygous or heterozygous halothane negative animals.

To evaluate the taste preference of the consumer for meat from homozygous (NN) halothane negative pigs or heterozygous (Nn) halothane negative pigs, a consumer test was conducted at the "Agriflora" exhibition, concerning Flemish agriculture and horticulture, held from 8 to 10 January 1999 in Ghent, Belgium. The carcass quality of both tested genotypes was similar, while acidity, colour and drip loss were inferior and cooking loss and Warner-Bratzler shear force superior for the Nn pigs compared with the NN pigs. One hundred and seventy-one visitors completed the test correctly.

Determination of flubendazole and its metabolites in eggs and poultry muscle with liquid chromatography-tandem mass spectrometry.

The optimization of a quantitative and sensitive LC-MS/MS method to determine flubendazole and its hydrolyzed and reduced metabolites in eggs and poultry muscle is described. The benzimidazole components were extracted from the two matrices with ethyl acetate after the sample mixtures had been made alkaline. The HPLC separation was performed on an RP C-18 column with gradient elution, using ammonium acetate and acetonitrile as mobile phase.

Relationship between fat depots in carcasses of beef bulls and effect on meat colour and tenderness.

Four hundred and thirty-three double-muscled and two hundred and two non-double-muscled Belgian Blue bulls, with mean cold carcass weights of 470±27 and 414±33 kg, respectively, were studied to investigate the relationships between the SEUROP fat grade, the anatomical fat content in the carcass (adipose tissue) and the chemical fat content in the Longissimus thoracis. The relationships between the shear force value and the lightness of the meat and fat characteristics were also studied. A moderate correlation was found between the fat characteristics within each data set with correlation coefficients, ranging from 0.

Confirmatory assay for the simultaneous detection of penicillins and cephalosporins in milk using liquid chromatography/tandem mass spectrometry.

A high-performance liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the detection of residues of penicillins and cephalosporins in milk has been developed. After a simple extraction with acetonitrile, the extract was directly injected into the LC/MS/MS system on a C(18) column. A gradient consisting of acetonitrile and water, each containing 0.

Pork tenderness estimation by taste panel, Warner-Bratzler shear force and on-line methods.

The extent to which modification of Warner-Bratzler shear force (WBSF) determinations, relating to storage and preparation of the meat, aperture of the V-shaped cutting blade and shearing velocity, improve the relationship with sensory tenderness perception of pork was studied. Additionally four on-line methods: pH1, FOP1 (light scattering), PQM1 (conductivity) and DDLT (Double Density Light Transmission), were evaluated for their ability to predict tenderness. Sensory tenderness evaluation was conducted on 120 frozen (at -18°C for several months) samples of m.