703. Cineradiographic observations on machine milking

Abstract

Milk is obtained from the teat during machine milking by the creation of a partial vacuum; the rate of flow is influenced by many factors including changes in the vacuum, the pulsation rate or ratio, alterations in the design or construction of the teat cup liner. Recent research relating to these problems has been reviewed by Dodd & Clough(i).The rate of milk flow or machine milking rate is usually expressed as the mean rate of flow from one or more teats over a specified period of milking. In this way it is possible to show whether a change in the milking machine affects milk flow but not how the change is brought about; for example, it is possible to demonstrate that an increase in pulsation rate and teat liner tension causes much faster milking but the reason remains obscure. In order to discover why such changes in milking rate occur it is necessary to measure the proportion of time during which milk flows in each pulsation cycle and the rate of flow of milk during the flow period. In this investigation we have studied some aspects of this problem with the aid of a portable X-ray cine-camera (2). METHODThree cows accustomed to machine milking were milked in a two-level stall designed so that the movement of the cow could be restricted. The left front teat of each cow was turned up against the udder and held in that position with adhesive tape to allow an unrestricted view of the right front teat. The right front quarter was then milked until most of the milk was removed. The teat cup assembly was then removed from the teat and a warm (100° F.) sterile suspension of barium sulphate (Micropaque: Messrs Damancy) was infused into the udder through the teat orifice with an enema syringe. The aim was to achieve a 25 % suspension of barium sulphate in the udder contents so that there was sufficient opacity for the cineradiography.The teat cup assembly consisted of a normal extruded teat cup liner (Alfa Laval 20003 B) fitted into a glass teat cup of standard size. When a liner is caused to pulsate the collapse is always in the same plane: in this experiment the liner was applied to the teat so that the plane of the collapse was parallel to the X-ray beam. The milking machine vacuum under different conditions was measured with a mercury manometer, the pulsation ratios had been previously determined by a cine-camera technique (3), and changes in liner tensions were measured with a spring balance (4). The X-ray camera was operated at 50 frames/sec.: the exposure time for each frame was T^5 sec.

An automated in-line clinical mastitis detection system using measurement of conductivity from foremilk of individual udder quarters

“…Milk fl ows from the teat when the liner is open. Milk fl ow is stopped when the closing liner applies suffi cient pressure to the distal end of the teat to occlude the teat canal (Ardran et al 1958;Mein 1992). Stopping the liner in its closed position, i.e.…”

A comparison of the milking characteristics of transparent and conventional teatcup liners

“…Radiography (Pier, Schalm & Hage, 1956) and cine radiography (Ardran, Kemp, Clough & Dodd, 1958) have been used very effectively to study the action of the teatcup liner and its effect on the teat. Now that transparent liners are more readily available, a simpler alternative for some studies may be cine photography using transparent shells and liners.…”

Effect of hydraulic milking on milking performance, teat condition and lipolysis

“…Conventional milking studies using cineradiography (Ardran et al 1958) and cinephotography using transparent liners and shells (Mein et al 1974) showed that in each pulsation cycle milk flow through the teat orifice starts when the liner is about half open and ceases when the liner is about half closed. During conventional milking the liner readily opens when the pulsation chamber is evacuated, owing to milk and air returning to the expanding liners.…”