Bovine colostrum whey: Postpartum changes of particle size distribution and immunoglobulin G concentration at different filtration pore sizes.

Bovine colostrum, as vital as it is for calves, is also a valuable source of functional components with rich health benefits for humans. Bovine colostrum whey consists of a large number of bioactive proteins and peptides. The most abundant of these is IgG. Particle size distribution (PSD) is an important feature of many of the processes in the dairy food industries. Despite this, scientific literature on PSD of colostrum whey is scarce. The goal of this research was to describe bovine colostrum whey PSD with an emphasis on postpartum milking time, filtration (pore size 450, 100, and 20 nm), IgG concentration, and lactation number. For this purpose, 4 postpartum milking colostrum samples were sequentially milked from 46 Holstein cows at 12 ± 1 h intervals. Colostrum whey was prepared by renneting and diluted (1:200) for PSD analyses by a Malvern Zetasizer Nano ZS (Malvern Instruments Ltd., Malvern, UK). Immunoglobulin G concentration of these diluted colostrum whey samples were analyzed by an Octet K2 (Molecular Devices LLC, San Jose, CA) system. Linear mixed model analysis revealed significant effects of filter pore size, postpartum milking, and lactation on colostrum whey IgG concentrations. The percentage of particles in the size interval 5 to 15 nm (the hydrodynamic diameter of IgG is around 10 nm) had an intermediate positive correlation (r = 0.50) with IgG concentration. Furthermore, we showed that PSD was associated with IgG concentration, postpartum milking time, and lactation number. The PSD measurement results showed the mean hydrodynamic diameter of 100 nm pore size filtered colostrum whey to be around 10 nm. This, with the IgG concentration results, suggests that even though the size of IgG is around 10 nm, a 100 nm pore size is adequate for membrane-involved IgG separations. In terms of energy efficiency of the filtration process, the use of a larger filter pore size can make a remarkable difference, for example, in pressurizing and cooling costs. Our work contributes to the development of sustainable and widely available colostrum-derived food and feed supplements.

Method for determination of fatty acids in bovine colostrum using GC-FID.

Bovine colostrum is potentially valuable source of essential fatty acids (FAs), but so far only few studies have made the effort to estimate FA composition of this potential resource. The aim of current research was to fill this gap with selecting and validating an accurate procedure for the analysis of the composition of the FAs in bovine colostrum. We used colostrum samples of Holstein-Friesian cattle from Märja experimental farm as a test material. The validated method includes derivatization, in which FAs are sent through esterification with the acidic catalyst boron trifluoride. Formed methyl esters of fatty acids (FAMEs) were analysed using GC-FID. The obtained LOD and the LOQ of FAMEs were 0.11-0.68 and 0.37-2.27ppm, respectively. The analysis of fortified samples showed very good and similar recoveries, indicating that the method proposed here can be routinely used for determination and investigation of the fatty acids in dairy products.

Contactless measurement of cow behavior in a milking robot.

We have worked on automatically measuring the behavior of dairy cows during automatic milking. A milking robot offers a unique possibility for a dynamic measurement of physical data. Four strain gauge scales were installed into a milking robot in order to measure the weight of each leg separately, and a laser distance sensor was placed next to the robot in order to measure the radial movement of the cow's body surface. The data were collected into a PC. Three video cameras were installed to observe the system, and the data were recorded digitally. From the data, the dynamic weight or load of each leg and the respiration rate of a cow could be measured. Different stages of milking were observed, and the changes in behavior during milking were analyzed. The acquired information could be used to judge a cow's restlessness and welfare--for example, leg health and stress.

Incidence of multifactorial diseases in Estonian dairy herds--a survey.

An important precondition of a well-functioning dairy production is knowledge about the incidence of environmentally evoked non-infectious diseases in a particular herd, in the region and in the country as a whole. The aim of this study was to determine the incidence rate of environmentally evoked multifactorial diseases in Estonian dairy herds, and to compare the disease incidence in small (< or = 100 cows) and large herds (101-300 cows). The disease incidence was recorded by local veterinarians in twelve production units with a total of 33 cowsheds and about 5000 dairy cows. Fourteen disease groups were formed. In order to describe the range of disease incidence, the relative frequency of each group of diseases was determined, as well as the incidence rate. The 95 % confidence interval was applied in order to assess the reliability of the incidence rates. The most common disorders of Estonian dairy cows are udder diseases, followed by uterine infection, metabolic diseases and retained placenta. The disease incidence in Estonian dairy herds is similar to that of other European countries. Most of the diseases occur more often in small herds than in large herds.