Gastrointestinal helminths in calves and cows in an organic milk production system

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Isolation and identification of mycobacteria from livestock specimens and milk obtained in Brazil

The prevalence of Mycobacterium bovis and other mycobacterial species in livestock specimens and milk was evaluated. An emphasis was placed upon the distribution of these organisms in milk that is readily available to the public that was either untreated, pasteurized, or treated using ultra high temperature. Twenty-two pathologic specimens from livestock (bovine, swine and bubaline) in five Brazilian states and 128 bovine milk samples from retail markets in the State of São Paulo were examined for mycobacteria. Identification was made by classical biochemical tests, thin layer chromatography of mycolic acids and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Mycobacteria were isolated from 15 (68.2%) caseous lesions and from 23 (18%) milk samples. Eleven isolates were identified as M. bovis, and the remaining 27 nontuberculous mycobacterial isolates were represented by five species and six unidentified rapidly growing mycobacterial strains. The data demonstrate that animal products in Brazil are frequent reservoirs of mycobacteria and may pose a risk to the public.

Occurrence of toxigenic Escherichia coli in raw milk cheese in Brazil

Pesquisou-se a ocorrência de Escherichia coli toxigênica, em queijo produzido com leite não pasteurizado, na Região Centro Oeste do Brazil. Foram utilizados 50 queijos adquiridos em diferentes supermercados. As amostras isoladas foram classificadas por sorogrupo, avaliadas em relação à sensibilidade para 13 agentes antimicrobianos e submetidas à reação em cadeia da polimerase para a presença de genes característicos de E. coli verotoxigênica (VTEC) e enterotoxigênica (ETEC). E. coli foi recuperada em 48(96,0%) dos queijos. Foram identificados os sorogrupos O125 (6,0%), O111 (4,0%), O55 (2,0%) e O119 (2,0%). Três (6,0%) amostras de E. coli foram classificadas como VTEC e uma (2,0%) como ETEC. Os maiores índices de resistência foram verificados para: cefalotina (60,0%), ácido nalidíxico (40,0%), doxiciclina (33,0%), tetraciclina (31,0%) e ampicilina (29,0%).

Water adsorption isotherms and isosteric sorption heat of spray-dried and freeze-dried dehydrated passion fruit pulp with additives and skimmed milk

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Isolation of Mycobacterium spp. in milk from cows suspected or positive to tuberculosis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of age at first calving, gestation length and dry period on milk yield in a Gyr herd

Relationships of several reproductve traits and milk yield were studied in 716 Gyr cows at Sant'Ana da Serra farm, Mococa, State of São Paulo, a humid tropical climate region. Mean age at first calving was 49.8 +/- 0.4 months, with a coeficient of cariation (C. V.) of 20.8%. Only year of parturition significantly affected age at first calving (P < 0.01). Heritability, estimated from paternal half-sib correlations, was 0.91 +/- 0.20, a value considered unrealistically high. Overall mean gestation length was 287.7 +/- 0.5 days (C. V. = 3.3%) for 419 observations, with month and year of parturition having significant effects. Heritability estimate was 0.30 +/- 0.14. Overall mean dry period for 1.276 observations was 238 +/- 3 days (C. V. = 48%); repeatability estimate was 0.19 +/- 0.06. Estimated annual genetic trend for dry period was -0.6 days, phenotypic trend was 11.5 days, and environmental trend, 12.1 days. Month and year of parturition and cow age had no significant effect on dry period. Highest milk yield was obtained at fourth lactation. The gross correlation between milk yield and gestation period was 0.11, and between previous dry period and subsequent milk yield, 0.16. Normal gestations of 285 to 290 days were associated with higher milk yields. Milk yield increased as dry period advanced from 30 to 390 days, and declined as dry period continued beyond 390 days. Delays in first mating and a more extensive dry period decreased reproductive efficiency in the herd studied.

ORGANOCHLORINE PESTICIDE-RESIDUES IN HUMAN-MILK IN THE RIBEIRAO-PRETO REGION, STATE OF SAO-PAULO, BRAZIL

Thirty-seven samples of human milk (colostrum) from donors living in the Ribeirao Preto region were analyzed to determine the levels of organochlorine pesticide residues. Donors were classified into two groups, i.e., occupationally exposed and non-exposed to pesticides. Other factors such as age, previous lactations, race, smoking habit, occupation, family income and educational level were also considered. Analysis was performed by preliminary lipid extraction followed by fractional partition on a column and finally by gas chromatography with an electron capture detector. Lindane was found in 32% of the samples in amounts of less than 0.001 mg/kg; heptachlor was found in 65% of the samples at mean levels of 0.001 mg/kg, i.e., a level five-fold lower than that established by FAO/WHO (1970) for cow's milk. Aldrin and endrin were not detected in any of the samples. Dieldrin was detected in only one sample at a level of 0.038 mg/kg, which is considered high. DDT and DDE amounts are reported as total DDT and at least one of these compounds was present in every sample. Amounts detected in donors occupationally exposed to pesticides ranged from 0.008 to 0.455 mg/kg (mean, 0.149 mg/kg), i.e., three times the limit established by FAO/WHO (1970), while values for donors who had not been exposed ranged from 0.002 to 0.072 mg/kg (mean, 0.025 mg/kg), i.e., half the limit. Considering the level of acceptable daily intake proposed by FAO/WHO (1973), lactents ingested 1% of the acceptable intake of lindane (all donors), 30% of the acceptable intake of heptachlor (all donors), 60% of the acceptable intake of DDT (non-exposed donors), and 3.7 times the acceptable intake of DDT (exposed donors). Comparing the present results with those obtained 10 years ago, the total DDT level in human milk is decreasing in this part of the country. The mean amount of organochlorine residues in non-exposed women's milk was one of the lowest levels among those recorded in the literature. DDT levels of occupationally exposed women's milk were comparable with those reported for developed countries and lower than those detected in Latin American countries. When the results of this survey are considered in relation to the advantages of breast-feeding, the risk-benefit balance is still favorable to breast-feeding. However, given the lack of long-term epidemiological studies, undesirable or harmful long-lasting effects cannot be excluded.

AN IMPROVED ELECTROPHORETIC METHOD FOR THE DETERMINATION OF SERUM MILK PROTEIN VARIANTS IN GYR-HOLSTEIN COWS

Milk serum proteins such as alpha-lactalbumin (ALA) and beta-lactoglobulin (BLG) present biochemical polymorphism which is under the control of codominant autosomal alleles. In the present report, we propose modifications of traditional electrophoretic techniques such as increasing the running gel concentration from 5 to 10% and the addition of 5 M urea to the stacking gel, which permitted the detection of two variants (A and B) at the ALA and BLG loci. About 8 mul of milk serum (6 mg/ml protein) and 10 pl of total fresh milk were applied. Bovine serum albumin (BSA) and immunolactoglobulins (ILG) could also be discriminated. Total fresh milk was as useful as the purified serum milk proteins for the discrimination of ALA and BLG serum milk protein polymorphism by alkaline vertical slab polyacrylamide gel electrophoresis. However, BSA and ILG ran with caseins, which prevented their characterization in this system.

Study of the dielectric and ferroelectric properties of chemically processed BaxSr1-xTiO3 thin films

Polycrystalline BaxSr1-xTiO3 (x = 0.4 and 0.8) thin films with a perovskite structure were prepared by the polymeric precursor method on a platinum-coated silicon substrate. High-quality thin films with uniform composition and thickness were successfully produced by dip-coating and spin-coating techniques. The resulting thin films prepared by dip and spin-coating showed a well-developed dense polycrystalline structure with uniform grain size distribution. The metal-BST-metal structure of the thin films displays good dielectric and ferroelectric properties. The ferroelectric nature to BaxSr1-xTiO3 (x = 0.8) thin film, indicated by butterfly-shaped C-V curves and confirmed by the hysteresis curve, showed 2P(r) = 5.0 muC/cm(2) and E-c = 20 kV/cm. The capacitance-frequency curve reveals that the dielectric constant may reach a value of up to 794 at 1 kHz. on the other hand, the BaxSr1-xTiO3 (x = 0.4) thin films had paraelectric nature and dielectric constant and the dissipation factor at a frequency of 100 kHz were 680 and 0.01, respectively, for film annealed at 700 degreesC. In addition, an examination of the film's I-V curve at room temperature revealed the presence of two conduction regions in the BaxSr1-xTiO3 (x = 0.4 and 0.8) thin films, showing ohmic-like behavior at low voltage and a Schottky-emission or Poole-Frenkel mechanism at high voltage. (C) 2001 Elsevier B.V. B.V. All rights reserved.

Analysis of organochlorine pesticides in plain milk using direct injection on an ISRP column, with column switching

A simple and rapid procedure for extraction and separation from aldrin, DDT, endrin, heptachloro- and methoxychloro-organochlorine pesticides in raw milk has been developed by direct injection into an HPLC system without pretreatment of the samples, using an ISRP column.

Isolation of Candida spp. from mastitic bovine milk in Brazil

The purpose of this study was to isolate yeast (Candida) from the quarter milk of cow udders from 37 dairy farms in Brazil and to identify the different species involved in mastitis. The samples were collected between October 2002 and February 2003. Two-hundred-and-sixty milk samples from cows with clinical and subclinical mastitis were examined. Milk samples were plated onto Blood agar, Mac Conkey agar and Sabouraud dextrose agar. Forty-five (17.3%) samples were positive for the genus Candida. The Candida species isolated were C. krusei (44.5%), C. rugosa (24.5%), C. albicans (8.9%), C. guilliermondii (8.9%), and others (13.2%). We also isolated Escherichia coli (26.5%), coagulase-positive Staphylococcus (25.0%), Streptococcus spp. (8.1%), Enterobacter spp. (8.1%), and other fungi (8.1%), among others.

On-line extraction and determination of carbofuran in raw milk by direct HPLC injection on an ISRP column

A method has been developed for extraction and determination of carbofuran in milk. The method involved direct injection of raw milk on to a human serum albumin dimethyloctyl-silica gel (HSA-Cs) column and the use of 80:20 (v/v) 0.01 M phosphate buffer pH 5.5 - acetonitrile as mobile phase. UV spectrophotometric detection was performed at 220 nm. Identification was based on retention time. Quantification was performed by automatic peak-area determination and was calibrated by use of an external standard.