Heat and ultraviolet light treatment of colostrum and hospital milk: effects on colostrum and hospital milk characteristics and calf health and growth parameters.

The aim of this study was to evaluate the effects of different physical treatments of bovine colostrum and hospital milk on milk bacteriology, immunoglobulin G (IgG) and lactoferrin concentrations, calf serum IgG concentrations and calf health, growth and survivability. Pooled colostrum samples (n=297) were heat treated (HTC; 63°C for 60 min), exposed to ultraviolet light (UVC; 45 J/cm(2)) or untreated ('raw', RC). Hospital milk (n=712) was subjected to high temperature short time pasteurization (HTST; 72°C for 15s), ultraviolet light irradiation (UVH; 45 J/cm(2)) or was untreated. Neonatal Holstein heifer calves (n=875) were randomly enrolled (309 HTC, 285 UVC, 281 RC) and block randomized (by colostrum treatment) into hospital milk treatments HTST (n=449) or UVH (n=426). HTC was more effective than UVC and HTST was more effective than UVH in reducing bacterial counts. IgG and lactoferrin concentrations were significantly lower in HTC and UVC than in RC. Lactoferrin concentrations were significantly lower in HTST than in UVH or untreated hospital milk. There were no significant differences in serum IgG concentrations among calves fed HTC, UVC or RC. Colostrum and hospital milk treatments did not have any significant effect on calf body weight gain, survivability, or frequency of diarrhea or pneumonia.

Effect of microwave radiation, pasteurization and lyophilization on the ability of human milk to inhibit Escherichia coli adherence to HEp-2 cells.

The effect of different physical treatments on the ability of colostrum and human milk to inhibit the adherence of enteropathogenic Escherichia coli (EPEC) to human epithelial cells was studied. Pools of colostrum and milk were submitted to microwave radiation, pasteurization or lyophilization, and then tested for the ability to inhibit the adherence of EPEC O111:H- to HEp-2 cells. The inhibitory effect of untreated colostrum and human milk on localized adherence was not significantly modified after exposure to any treatment. The total protein values of colostrum and milk were maintained, but IgA concentration and colostral anti-EPEC IgA were reduced after pasteurization. Nevertheless, the remaining IgA was sufficient to be effective in adhesion inhibition assay. Western blotting assays carried out with EPEC antigens showed that the treated and untreated pools recognize a 94-kDa outer-membrane protein which molecular weight is compatible with intimin, an EPEC adhesin related to bacterial attachment to epithelial cells. These results suggest that the protection of colostrum and milk to infantile diarrhoea due to EPEC remains unalterable after the physical treatments studied.

Factors that influence passive transfer of immunoglobulins in foals.

Effects of farm management, breed, mare age, gestation duration, and climatologic factors on colostral specific gravity, colostral IgG concentration, and foal serum IgG concentration were evaluated. Climatologic variables measured were daily maximal, minimal, and mean air temperature, precipitation, average relative humidity, and total solar radiation. Presuckle, postpartum colostrum samples were collected from 140 Standardbred, 94 Thoroughbred, and 59 Arabian mares from January through June during 1985 and 1986. Thoroughbred (farm A, n = 61; farm B, n = 33) and Arabian (farm C, n = 45; farm D, n = 14) mares were located in Ocala, Fla; Standardbred mares (farm E) were in Montgomery, NY. Mares from farms A, B, D, and E foaled in box stalls, and mares from farm C foaled in sand paddocks. Mares with premature lactation greater than 12 hours were not included in the study. Foals were clinically normal at birth and suckled colostrum without assistance within 2 hours of parturition. Specific gravity of presuckle colostrum samples was measured by use of an equine colostrometer. Blood samples were collected 18 hours after parturition from 253 of the 293 foals (n = 45, 25, 32, 13, 138 on farms A through E, respectively) to determine serum concentration of IgG. The IgG concentrations in colostrum and serum were measured by single radial immunodiffusion. Data were analyzed by multiple regression or chi 2 analysis. The most important determinants of foal serum IgG concentration were the IgG content and specific gravity of presuckle colostrum samples (P less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Production and preparation of hyperimmune bovine colostrum for passive immunotherapy of cryptosporidiosis.

Pregnant cows were immunized to produce hyperimmune bovine colostrum (HBC) by intramuscular injection or intramammary infusion (TI) followed by 3 successive TI boosters with Cryptosporidium parvum (Cp) oocyst antigen mixed with Freund's (F) or Ribi (R) adjuvant. Control cows received no Cp. Colostrum from all cows was skimmed of butterfat and tested for specific anti-Cp immunoglobulin isotypes by ELISA. The HBC from Cp-F and Cp-R immunized cows had IgG1 titers exceeding 1:400,000 and 1:800,000, respectively. Some HBC from Cp-F immunized cows was freeze-dried to facilitate storage and some were irradiated at 42.5 kGy to kill potentially contaminating pathogens. Freeze-drying, but not irradiation, reduced IgG1 titers by only one dilution. Neither treatment affected Western blot banding patterns.

Characteristics of frozen colostrum thawed in a microwave oven.

Use of a microwave oven to thaw frozen colostrum was evaluated. Colostrum was collected from nine cows, four of which were immunized to produce specific colostral antibodies. Colostrum from each cow was frozen, subsequently thawed, and pooled. One-liter aliquots of the pooled colostrum were frozen and assigned randomly to three thawing treatments. Colostrum was thawed using one of three regimens: 10 min in a microwave oven at full power (650 W), 17 min in a microwave oven at half power (325 W), and 25 min in 45 degrees C water. Colostrum thawed in the microwave oven was slightly coagulated and had lower volume and total protein content than colostrum thawed in water. Casein and pH were not different among treatments. Both concentration and total content of immunoglobulin A were higher in the control than in microwave treatments. Neither amount nor concentration of immunoglobulin G and immunoglobulin M were different among treatments. Immunological activity, measured by a hemolytic test, was lower for microwave treatments than the control but did not differ between microwave treatments. Frozen colostrum thawed in a microwave oven should provide a reasonable source of colostrum when fresh high quality colostrum is not available.

Effects of irradiated sow colostrum on some biochemical and haematological measurements in newborn piglets.

Some biochemical and haematological variables were measured in piglets during the first 48 hours after birth. The piglets were reared either by the sow, or bottle-fed with colostrum (either natural or sterilised by irradiation), or a commercial milk replacer. Mean haemoglobin concentrations, packed cell volumes and erythrocyte counts decreased by approximately 45 per cent in all the groups between birth and 48 hours, but leucocyte counts increased more markedly in the colostrum-fed groups. All the colostrum-fed groups showed rapid increases in serum total protein concentrations which were almost entirely due to increases in gamma globulin concentrations. There was no difference in this respect between natural colostrum and colostrum sterilised by irradiation with 500 Krad of gamma rays. Colostrum sterilised by irradiation can protect piglets against infectious agents and simplify the rearing of piglets under specific pathogen free conditions.