1 The production of high quality milk depends upon clean, healthy goats, properly fed and cared for, and milked in a clean efficient manner.
2 Dairy goats may be milked equally well by hand or by machine. In either case, care must be taken to produce a clean, wholesome product and to prevent injury and/or infection of the udder.
3 Vacuum
The milking unit removes milk from the teat of the animal by the application of a partial vacuum. Vacuum is measured in inches of mercury. The recommended range of vacuum level on the milking system is between 10.0 and 14.0 inches of mercury. The primary effect of the different vacuum levels is milking rate. As vacuum level increases, milking rate increases. Within these vacuum level ranges, no difference in udder infection rates will be noted.
4 The Milking Unit The operation of the milking unit is shown in Figure 1. The pulsator causes the machine to switch from the milking phase to the rest phase. As the pulsator operates, it causes the chamber between the shell and the inflation to alternate regularly from vacuum to air source.
5 During the milking phase, the space between the inflation and shell becomes a vacuum. Equal pressure inside and outside of the inflation causes it to open and the milk to flow.
6 During the rest phase, air at normal pressure enters between the shell and inflation. Due to the vacuum in the stem the inflation collapses around the teat. The pressure of the collapsed inflation on the teat prevents congestion of blood and body fluids in the teat skin and tissues.
7 The rate at which the inflation is closed and opened, called the pulsation rate, varies from 40 to 80 pulsations per minute depending upon the manufacturer. The optimum pulsation rate is yet to be determined. The manufacturer's recommendations for a particular pulsator should be followed.
8 Pulsator Ratio
The pulsator ratio is the length of time the pulsator is in milking position compared to the time it is in rest position. It is expressed as a simple ratio or as percentage of time open to time closed. The ratio should range between 50:50 and 60:40 milk to rest ratio.
9 Inflations or Teat-cup Liners
Many types of teat-cup shell and inflation combinations are available. Teat size governs the choice of inflation size. In general, large teated animals can utilize larger inflations without discomfort, while the smaller teats are best milked with smaller inflations.
10 Claw units should be equipped to admit a small amount of air in order to prevent milk from building up in the claw and creating ''milk block''. An air bleed is necessary on most types of pipeline units.
11 The Vacuum Pump
The most important consideration with regard to the vacuum pump is that it possess ADEQUATE CFM CAPACITY AT THE OPERATIONAL VACUUM LEVEL. Manufacturers can provide CFM ratings for various vacuum pumps or the CFM delivery can be determined by the use of a flow rate meter.
12 The size of pump needed for milking machine operation depends upon a number of factors. Among these are:
1. Number of units
2. Size and length of pulsating lines
3. Type of pulsator
4. Type of system (bucket or pipeline)
5. Requirements of other vacuum-operated equipment
13 The recommended capacity of the vacuum pump(s) used in bucket milking systems is shown in Table 1. Table 2 indicates suggested capacities for pipeline systems.
14 ++++MISSING DATA++++
15 Make sure that your system has adequte CFM capacity. Check with your manufacturer for the vacuum pump ratings.
16 The vacuum pump and the power unit should be installed as close as possible and practical to the center of the milking area. Such locations as a feed room or near a haymow chute should be avoided. The exhaust from the pump should be piped to the outside of the building through a pipe whose diameter is at least as great as that of the pump's discharge port.
17 Since oil is present in most exhausts, the exhaust should be directed downward and away from the side of the building, which prevents rain water from entering the pump, and also prevents accumulation of oil and dirt on the side of the building.
18 Servicing the pump should be performed as directed in the service manual. Maintaining the oil level in the sump or supply cup and checking the belt for proper alignment and tension are the two most important maintenance procedures, and should be done every two weeks. Recommended annual or semi-annual service checks will vary with the pump and the manufacturer's specifications.
19 Vacuum regulators admit air into the milking system to prevent the vacuum level from going too ++++MISSING DATA++++
20 Regulator performance is affected by basic design. Servodiaphram regulators are the most effective, while weighted level types are the least desirable.
21 Pipe Sizes
The milking units are operated by a piping system(s) which must be large enough to permit the units to function properly. Restricted vacuum and milk line sizes may result in ma ++++MISSING DATA++++
22 Install low lines where possible. The hoses to the milking units should not exceed six (6) feet in length. Adequate pipeline slope and size are essential to prevent flooding of the system. Flooding causes erratic vacuum changes in the system, which may result in increased udder irritation and a possible increase in the incidence of new infections.
23 The size of sanitary milk pipe is shown in Table 3. Sanitary Milk Pipe Size (inches) Pipe Size Maximum Number of Units per Slope 1 1/2 4 2 8 These sizes apply to conditions where the animal is milked directly into the milk pipeline. Pipes for weigh jar systems operated primarily as milk transfer and wash lines must be of adequate size for washing.
24 Number of Units
The number of units you should have varies widely, depending upon the type of system, the nature of the goats (fast or slow milking), and the operator. The following table may serve as a guide for the number of units to use. Table 4. Maximum Number of Milking Units per Operator Type of System Maximum Number of Units
Milking area only 2
Elevated single stall 2
Elevated platform 3
Herringbone parlor 6
(units both sides of parlor)
25 Milking Practices
Good milking practices are essential to keep goats healthy and to achieve good labor efficiency.
26 During milking, there are two critical periods when udder damage is most likely to occur: at the beginning and the end.
27 Make sure the animal is properly stimulated for ''let-down'' prior to attaching the machine. The stimulation should be accomplished in the same manner at each milking. The interval between stimulation and machine application should be short and constant. Ideally, the stimulation to machine-on time should be about one minute. The ''let-down'' hormone effect lasts about 7 minutes. It is important that the goat be milked out rapidly and the machine removed as soon as the goat is milked out.
28 Preparation
Washing the udder to remove dirt and at the same time stimuate the goat for ''let-down'' is u ++++MISSING DATA++++
29 Checks and Maintenance
A regular thorough checking and maintenance schedule is essential to keep equipment in top working condition. The manufacturer of your equipment has specified many items. Follow those instructions carefully.
30 Several items apply to all systems. The most important are as follows:

1. Check vaccuum level.
2. Make sure pulsators are operating properly.
3. Check rubber parts for breaks, tears, and cleanliness.
4. Check vacuum pump oil supply and belt tension.
5. Install clean filters.
6. Make sure air inlets to claw assemblies are open.

1. Check and clean vacuum regulator.
2. Inspect and rotate inflations.
3. Check couplings and stall cocks for leaks and electrical connections.

1. Disassemble pulsator and check for wear. Clean all air passages and screens.
2. Check condition of vacuum pump oil.
3. Check CIP (clean-in-place) system for proper cycling and water temperature.
4. Check pulsator performance with portable test gauge.

1. Check operation of the vacuum pump. Use a flow rate meter to determine if it is pumping at its rated capacity.
2. Connect the system and obtain an air flow reading with the system in operation. A loss of more than 10 percent of the vacuum pump capacity indicates excessive leaks in the system.
3. Check all pipeline gaskets for leaks and condition. Replace as needed.
4. Check electrical connections and the pulsation control. A voltage meter is suggested to check the electrical pulsation system.
5. Make all service checks as specified by the manufacturer.