Improved isolation of bioactive components of bovine colostrum using cross-flow microfiltration

A Comprehensive Review of Bovine Colostrum Components and Selected Aspects Regarding Their Impact on Neonatal Calf Physiology

Colostrum contains macro- and micronutrients necessary to meet the nutritional and energy requirements of the neonatal calf, bioactive components that intervene in several physiological aspects, and cells and microorganisms that modulate the calf's immune system and gut microbiome. Colostrum is sometimes mistaken as transition milk, which, although more nutritive than whole milk, has a distinct biochemical composition. Furthermore, most research about colostrum quality and colostrum management focuses on the transfer of maternal IgG to the newborn calf. The remaining components of colostrum and transition milk have not received the same attention, despite their importance to the newborn animal. In this narrative review, a large body of literature on the components of bovine colostrum was reviewed. The variability of these components was summarized, emphasizing specific components that warrant deeper exploration. In addition, the effects of each component present in colostrum and transition milk on several key physiological aspects of the newborn calf are discussed.

Concentration of Immunoglobulins in Microfiltration Permeates of Skim Milk: Impact of Transmembrane Pressure and Temperature on the IgG Transmission Using Different Ceramic Membrane Types and Pore Sizes

The use of bioactive bovine milk immunoglobulins (Ig) has been found to be an alternative treatment for certain human gastrointestinal diseases. Some methodologies have been developed with bovine colostrum. These are considered in laboratory scale and are bound to high cost and limited availability of the raw material. The main challenge remains in obtaining high amounts of active IgG from an available source as mature cow milk by the means of industrial processes. Microfiltration (MF) was chosen as a process variant, which enables a gentle and effective concentration of the Ig fractions (ca. 0.06% in raw milk) while reducing casein and lactose at the same time. Different microfiltration membranes (ceramic standard and gradient), pore sizes (0.14–0.8 µm), transmembrane pressures (0.5–2.5 bar), and temperatures (10, 50 °C) were investigated. The transmission of immunoglobulin G (IgG) and casein during the filtration of raw skim milk (<0.1% fat) was evaluated during batch filtration using a single channel pilot plant. The transmission levels of IgG (~160 kDa) were measured to be at the same level as the reference major whey protein β-Lg (~18 kDa) at all evaluated pore sizes and process parameters despite the large difference in molecular mass of both fractions. Ceramic gradient membranes with a pore sizes of 0.14 µm showed IgG-transmission rates between 45% to 65% while reducing the casein fraction below 1% in the permeates. Contrary to the expectations, a lower pore size of 0.14 µm yielded fluxes up to 35% higher than 0.2 µm MF membranes. It was found that low transmembrane pressures benefit the Ig transmission. Upscaling the presented results to a continuous MF membrane process offers new possibilities for the production of immunoglobulin enriched supplements with well-known processing equipment for large scale milk protein fractionation.

Donkey milk as a supplement in infant formula: Benefits and technological challenges

The aim of this review paper is to assess the applicability of donkey's milk to infants suffering from Cow Milk Protein Allergy (CMPA) compared to human and other available milk types. The bioactive and immune-supportive character which could be beneficial as a fortifier to the formula-fed infants is described while limitations of this type of milk are also discussed. Studies showed that human and donkey's milk have similar, overall, chemical composition as well as protein homogeneity and antigenic similarities. Several in vitro and in vivo studies showed that donkey's milk has nutraceutical and functional properties that can support immunity, alter metabolism and beneficially modify gut microbiota. Clinical studies illustrated that donkeys' milk is well tolerated (82.6%-88%) by infants. Finally, the effect that processing (i.e. thermal, non-thermal treatments, drying methods) has on donkey milk components is also discussed pointing out the need for minimally processing this type of milk.

Effect of different feed ingredients and additives on IPEC-J2 cells challenged with an enterotoxigenic Escherichia coli strain

The intestinal porcine epithelial cell line IPEC-J2 was used as an in vitro model to assess effects of additives on the adhesion and cell toxic effects of a F4-positive (ETEC) and a F4-negative Escherichia coli (DSM 2840) strain. Bacterial adhesion was examined using flow cytometry in IPEC-J2 cells infected with bacteria stained with 5,6-carboxymethyl fluorescein diacetate succinimidyl ester. Measurement of transepithelial electrical resistance (TEER) was performed to characterize the impact on IPEC-J2 monolayer integrity. The feed additives were prepared as aqueous extract and tested in different dilutions and incubation times. The F4-positive ETEC strain had a high adhesion to IPEC-J2 cells and reduced TEER shortly after the in vitro infection. The nonpathogenic E. coli strain DSM 2840 showed only low adhesion capacity and no TEER impairment. Infection with ETEC with added test extracts showed a reduction of bacterial adhesion to IPEC-J2 cells by an autolyzed yeast product (p < 0.05). Bovine colostrum, an additive containing thyme extract and an organic acid mix did not interfere with the ETEC adherence. The TEER decrease of the IPEC-J2 monolayer after ETEC infection was not affected by the added substances. In conclusion, interference with epithelial adhesion might be a protective mechanism of the tested yeast extract, indicating that the cell culture model might be suitable as screening tool to complement in vivo challenge trials with piglets.