Udder

Milk consists of 85—89% water and 11—15% total soflds (Table 1) the latter comprises soflds-not-fat (SNF) and fat. Milk having a higher fat content also has higher SNF, with an increase of 0.4% SNF for each 1% fat increase. The principal components of SNF are protein, lactose, and minerals (ash). The fat content and other constituents of the milk vary with the animal species, and the composition of milk varies with feed, stage of lactation, health of the animal, location of withdrawal from the udder, and seasonal and environmental conditions. The nonfat soflds, fat soflds, and moisture relationships are well estabhshed and can be used as a basis for detecting adulteration with water (qv). Physical properties of milk are given in Table 2. 

Milk may be a carrier of diseases from animals or from other sources to humans. To avoid contamination before pasteurization, healthy animals should be separated from sick animals or those with infected udders. The animals should be clean, kept in clean housing with clean air, and handled by workers and equipment under strictly sanitary conditions. Post-pasteurization contamination can occur as a result of improper handling, due to exposure to contaminated air, improperly sanitized equipment, or an infected worker. 

Euter, n. udder, ev., abbrev. of eventuell. evakuieren, v.t. evacuate, empty, exhaust. Evakuienmgskessel, m. vacuum boiler, vacuum pan. 

The infection process and disease development process can be related to a range of factors that affect various udder tissues (localisations). There are also a range of interactions between the udder tissues and mastitis pathogens. These were recently reviewed by Hamann 2001 (see also Table 11.1). 

Table 11.1 Localisation and stages of germ-udder interaction depending on different factors (Hamann, 2001 modified)...

Teat skin, teat canal Contamination Environment, udder anatomy, milking machine... 

Both clinical and sub-clinical mastitis are usually accompanied by an increase in the somatic cell count (SCC a measure of white blood cells (95%) such as macrophages, segmented neutrophil granulocytes or lymphocytes) in milk. SCCs above a certain level are an indication of immune-system activation and are used as an indicator of sub-clinical , latent or chronic udder infections/mastitis (Concha, 1986 Ostensson et al., 1988), which were shown to affect milk quality, composition and shelf life. Dairy companies therefore impose SCC thresholds or reduce payments to farmers if certain thresholds are exceeded (Hamann, 2001 Urech et al., 1999). 

The objective of mastitis treatments is to cure the infected udders from the infection, but cure is defined in very different ways. For example, in economic terms, the farmer needs to achieve a level of udder health that allows expected milk yields and quality parameters specified by processors/ national regulations to be achieved. On the other hand, cure with respect to antibiotic treatments, is often defined in terms of absence of bacterial pathogens in milk (bacterial cure), with the proportion of cows without detectable pathogen presence following treatment being defined as the bacterial cure rate (BCR). The main problem with using BCR as the main indicator of cure is that it was frequently shown to include a proportion of cows with drastically elevated SCC values (indicative of sub-clinical mastitis) after treatment, but without clinical (sensory) symptoms. 

The objective of antibiotic treatments is to reduce the density of microbial pathogen in infected udder tissues and thereby improve the capacity of the animal s immune system to deal with the infection. The effect of a successful antibiotic treatment is therefore self-cure of mastitis (Hamann and Kromker, 1999). However, some antibiotics (e.g. tetracycline and gentamycine) may also have negative side effects on the animal s immune response to udder infection, as they have been shown to inhibit/reduce phagocytosis of the animal s own defence cells (Nickerson et al 1986). 

Faye, B., Lescourret, F., Dorr, N., Tillard, E., MacDermott, B. and McDermott, J., (1997a), Interrelationships between herd management practices and udder health status using canonical correspondence analysis . Preventive Veterinary Medicine, 32, 171-192. 

Matzke, P., Holzer, A. and Deneke, J. (1992), (The effect of environmental factors on the occurrence of udder diseases). Tierarztliche Praxis, 20, 21-32. 

Signs and Symptoms Initial symptoms include fever, watery eyes, increased nasal secretions, drooling (ptyalism), diarrhea, loss of appetite, reduced milk production, depression, and reluctance to move. This is followed by the eruption of various sized skin nodules that may cover the whole body. They can be found on any part of the body but are most numerous on the head and neck, perineum, genitalia and udder, and the limbs. The nodules are painful and involve all layers of the skin. Skin lesions may show scab formation. Regional lymph nodes are enlarged and full of fluid. Secondary bacterial infection can complicate healing and recovery. Final resolution of lesions may take 2-6 months, and nodules can remain visible 1-2 years. 

If this is to be avoided and several fractions are expected, it is preferable to use an apparatus which permits various receivers to be brought successively under the mouth of the delivery tube. The form shown in Fig. 16 may be used, for example. According to its shape it is known in laboratory slang as a spider , frog , pigling , or cow s udder . 

Further specimens in use are the perfused cow udder, the porcine forelimb, and the isolated perfused porcine skin flap (IPPSF) [55-57], While the first two require the sacrifice of the animal, the last one can be isolated surgically from the abdomen of the pigs, which afterwards can be returned to their prior disposition [49],... 

M. Kietzmann, W. Loscher, D. Arens, P. Maass, and D. Lubach. The isolated perfused bovine udder as an in vitro model of percutaneous drug absorption of dexamethasone, benzoyl peroxide, and etofenamate. J. Pharm. Toxicol. Meth. 30 75-84 (1993). 

A. M. Ehinger and M. Kietzmann. Studying the tissue distribution of antibiotics in the udder—Comparison of the situation in vivo with the isolated perfused bovine udder. Deutsche Tierarztliche Wochenschrift 108 195-200 (2001). 

W. F. Pittermann and M. Kietzmann. Bovine udder skin (BUS) Testing of skin compatibility and skin protection. ALTEX 23 65-71 (2006). 

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