Fractionized milk composition in dairy cows with subclinical mastitis

Abstract

ABSTRACT:Mastitis is the inflammatory reaction of the udder to invading pathogens. One of the most apparent reactions is the increased influx of immunoreactive cells from blood into milk inducing a dramatic increase of milk somatic cell counts (SCC). We have investigated (i) the relationship between log SCC/ml in infected quarters being >6 (n = 8, group I) or varying between 5.4 and 6 (n = 8, group II) and concentration of dry ma�er (DM), fat, protein, lactose, insulin-like growth factor (IGF)-1, insulin, prolactin, tumor necrosis factor (TNF)-α, sodium, potassium, chloride, electrical conductivity and osmolarity as compared with the contralateral (healthy) quarter (log SCC/ml <5.2); and (ii) composition of fractionized milk [cisternal milk, quartiles of alveolar milk and residual milk (a�er i.v. injection of 10 u.i. oxytocin)] during machine milking of infected and healthy quarters. SCC were higher (P < 0.05) in infected than in healthy quarters. Concentrations of fat, sodium, chloride, and IGF-1 were higher (P < 0.05), while that of lactose was lower (P < 0.05) in infected than in healthy quarters (group I). Concentrations of fat and chloride in both groups, of DM (in group II), and electrical conductivity and sodium (in group I) increased from the cisternal to alveolar (100%) fractions in infected quarters, while fat and DM concentrations similarly increased in healthy quarters. In conclusion, several but not all milk traits changed in a different manner during the course of milking in infected and non-infected quarters.

Short communication: Fractional milking distribution of immunoglobulin G and other constituents in colostrum

“…This increase has been reported in many studies (Ontsouka et al, 2003;Bruckmaier et al, 2004;Sarikaya et al, 2005;Tan in et al, 2007). It is likely that the fat droplets, which are delimited by lipoprotein membranes, are held back by capillary forces in the alveoli and through adhesive forces on the udder epithelium during the process of milking.…”

“…Other studies found a similar lactose and protein content (Ontsouka et al, 2003;Bruckmaier et al, 2004, Sarikaya et al, 2005. The reasons for the decrease over the course of milking of both protein and lactose are unclear, but it is conceivable that contents of water-soluble milk constituents decrease when fat content rises towards the end of milking.…”

“…Hostetler et al (2003) showed that a hand-stripped post-milking-machine sample of colostrum exhibited lower IgG concentration (P < 0.05) than a hand premilking sample (10 mL) as well as the remaining milking machine fraction. Studies of colostrum fractionation from d 2 (Ontsouka et al, 2003) and of mature milk (Ontsouka et al, 2003;Bruckmaier et al, 2004;Sarikaya et al, 2005;Tan in et al, 2007) found that milk composition changes during the course of milking, which corresponds to a continuous character of milk ejection during milk removal (Bruckmaier et al, 1994;Bruckmaier and Blum, 1998). Thus, the concept that colostrum composition could also be different during the first milking remained unclear.…”

“…Cell types are reported to vary in their proportion in different milk fractions; macrophages represent the predominant cell fraction in cisternal milk, whereas PMNL make up the predominant cell fraction in alveolar milk (Sarikaya et al, 2005). Bruckmaier et al (2004) proposed that milk immune cells, because of their polar membrane, are subject to the same adhesive forces as are fat cells or that they are partially attached to the milk fat fraction.…”

Application of osmometry in quality analysis of milk

“…In previous studies by Bruckmaier et al (2004) the osmolality of raw milk was found to lie between 284 and 295 mOsmoles . In similar investigations, the osmolality of pasteurized milk was found to be in the range 274-281.5 (mean of 277.8 mOsmoles kg…”