A Modified Device for Collecting Milk from Guinea Pigs1
W. N. McKENZIE, JR., and R. R. ANDERSON Department of Dairy Husbandry University of Missouri Columbia 65211
ABSTRACT
DESCRIPTION
A modified device for milking small animals is discussed. The advantage of these modifications are 1 ) quiet operation, 2) ease of operation in animal room, and 3) quick change to allow the same device to be used on different animals. This device can be tailored to the teat size as well as milk volume expected. Construction is simple, and materials are inexpensive.
The main advantage of this milking device over others is no need for a mechanical source of vacuum. The operator is the vacuum source and can pulse the vacuum to meet the needs of the animal. The guinea pig is placed gently on its back in the operator's right or left hand and arm. Restraint is necessary only the first few times the animal is milked, especially if she has been separated from her young and her mammary glands are full. Oxytocin also may be necessary for the first few times. Restraint should not be necessary and only serves to excite the animal. With the animal relaxed in the supine position, the operator can place the mouthpiece in his mouth and with the free hand hold the milking apparatus at about a 60 ° angle to facilitate milk collection. This apparatus particularly is suited to guinea pigs and other small mammals in that
INTRODUCTION The guinea pig is an excellent animal to study milk production, milk composition, mastitis, and other dairy related subjects. Guinea pigs, as well as mice, rats, and other small mammals, must be hand milked or milked with a suitable milking apparatus. There have been many such apparatus described (1 to 7). Vacuum source was a mechanical pump controlled by mechanical pulsators. In most cases an oxytocin derivative had to be administered i.p. to induce milk ejection. Guinea pigs are naturally excitable, and unless handled daily are not content enough to milk without oxytocin. Stress of unusual mechanical noises and strange environments further decreases milk output. Gupta et al. (1) described a device for milking guinea pigs that although simple to construct and operate still required a mechanical pump. Our modified device (Figure 1) uses the basic design of Gupta et al. but does not need a mechanical vacuum pump and can be used in the animal maintenance area without a mechanical pump system. This allows the female to be milked in the presence of her young and others of her species.
-'"~,/~ Nipple ~ /.Fibrotip Leaveair channel betweenglass ~ vial and tip of fibrotip
~
6 ml disposable syringe
m O0 Rubberstopper ~'~-'-(hole for fibr0tip)
--ll 'v~lmlReaction vial (forcollectingmilk)
~
~Filter
~1
22 mmx7mm
40 cm long
~ ~ o u t h Received April 20, 1979. a Contribution from Missouri Agr. Exp. Sta., Journal Series No. 8344. Approved by the Director. 1979 J Dairy Science 62:1469--1470
1469
Figure 1. Small animal milking apparatus.
piece
1470
McKENZIE AND ANDERSON
the Fibro-tip® can be cut to m a t c h the teat diameters of the animal. The tip of the Fibrotip must be far enough inside the sample bottle and have enough clearance around the inside neck o f t h e sample b o t t l e to allow air to escape w i t h o u t drawing milk with it. The size o f the syringe and sample bottle can be varied to match the v o l u m e of milk e x p e c t e d . The 40-cm long rubber tube, normally for drawing blood, has a thicker wall t h a n m o s t tubing its size. In our e x p e r i m e n t o n l y .5 ml of milk was needed and the 1-ml reaction vial was suitable. If m o r e milk is needed t h e filter can be cut to facilitate a longer collection vial. MATE R IA LS
1. Fibro tip TM disposable pipette tips f r o m BBL, Division of Becton, Dickinson and Co., Cokeysville, MD 21031. (Catalogue # 7 0 3 1 4 ) . 2. Glass reaction vials (1 ml) f r o m Supelco, Inc., Supelco Park, Bellefonte, PA 16823. (Catalogue #3-3123 ). 3. 6 cc m o n o j e c t syringe disposable, Sherw o o d Medical Industries, Inc., Deland, FL 32720. 4. R u b b e r stopper (00) cut to length of 15 m m (use large end).
Journal of Dairy Science Vol. 62, No. 9, 1979
5. Filter 22 m m x 7 ram, f r o m Rainin Instrument Co., Inc., 94 Lincoln St., Brighton, MA 02135. (used with Pipetman Microliter Pipettes). ACKNOWLEDGMENT
for
The authors wish to t h a n k Charles Jorgenson his drawing of the milking apparatus. REFERENCES
1 Cox, W. M. Jr., and A. J. Mueller. 1937. The composition of milk from stock rats and an apparatus for milking small laboratory animals. J. Nutr. 12:249. 2 Gupta, B. N., G. H. Conner, and R. F. Longham. 1970. A device for collecting milk from guinea pigs. Amer. J. Vet. Res. 31:557. 3 Kahler, H. 1942. Apparatus for milking mice. J. Nat. Cancer Inst. 2:457. 4 McBurnery, J. J., H. Meier, and W. G. Hoag. 1964. Device for milking mice. J. Lab and Clin. Med. 64:485. 5 Nelson, W. L., A. Kaye, M. Moore, H. H. Williams, and B. L. Herrington. 1951. Milking techniques and the composition of guinea pig milk. J. Nutr. 44: 585. 6 Personal communication from A. Kirksey, Dept. Nutr. and Home Econ. Purdue University. 7 Temple, P. L., and S. K. Kon. 1937. A simple apparatus for milking small laboratory animals. Biochem. J. 31:2197.
W. N. McKENZIE, JR., and R. R. ANDERSON Department of Dairy Husbandry University of Missouri Columbia 65211
ABSTRACT
DESCRIPTION
A modified device for milking small animals is discussed. The advantage of these modifications are 1 ) quiet operation, 2) ease of operation in animal room, and 3) quick change to allow the same device to be used on different animals. This device can be tailored to the teat size as well as milk volume expected. Construction is simple, and materials are inexpensive.
The main advantage of this milking device over others is no need for a mechanical source of vacuum. The operator is the vacuum source and can pulse the vacuum to meet the needs of the animal. The guinea pig is placed gently on its back in the operator's right or left hand and arm. Restraint is necessary only the first few times the animal is milked, especially if she has been separated from her young and her mammary glands are full. Oxytocin also may be necessary for the first few times. Restraint should not be necessary and only serves to excite the animal. With the animal relaxed in the supine position, the operator can place the mouthpiece in his mouth and with the free hand hold the milking apparatus at about a 60 ° angle to facilitate milk collection. This apparatus particularly is suited to guinea pigs and other small mammals in that
INTRODUCTION The guinea pig is an excellent animal to study milk production, milk composition, mastitis, and other dairy related subjects. Guinea pigs, as well as mice, rats, and other small mammals, must be hand milked or milked with a suitable milking apparatus. There have been many such apparatus described (1 to 7). Vacuum source was a mechanical pump controlled by mechanical pulsators. In most cases an oxytocin derivative had to be administered i.p. to induce milk ejection. Guinea pigs are naturally excitable, and unless handled daily are not content enough to milk without oxytocin. Stress of unusual mechanical noises and strange environments further decreases milk output. Gupta et al. (1) described a device for milking guinea pigs that although simple to construct and operate still required a mechanical pump. Our modified device (Figure 1) uses the basic design of Gupta et al. but does not need a mechanical vacuum pump and can be used in the animal maintenance area without a mechanical pump system. This allows the female to be milked in the presence of her young and others of her species.
-'"~,/~ Nipple ~ /.Fibrotip Leaveair channel betweenglass ~ vial and tip of fibrotip
~
6 ml disposable syringe
m O0 Rubberstopper ~'~-'-(hole for fibr0tip)
--ll 'v~lmlReaction vial (forcollectingmilk)
~
~Filter
~1
22 mmx7mm
40 cm long
~ ~ o u t h Received April 20, 1979. a Contribution from Missouri Agr. Exp. Sta., Journal Series No. 8344. Approved by the Director. 1979 J Dairy Science 62:1469--1470
1469
Figure 1. Small animal milking apparatus.
piece
1470
McKENZIE AND ANDERSON
the Fibro-tip® can be cut to m a t c h the teat diameters of the animal. The tip of the Fibrotip must be far enough inside the sample bottle and have enough clearance around the inside neck o f t h e sample b o t t l e to allow air to escape w i t h o u t drawing milk with it. The size o f the syringe and sample bottle can be varied to match the v o l u m e of milk e x p e c t e d . The 40-cm long rubber tube, normally for drawing blood, has a thicker wall t h a n m o s t tubing its size. In our e x p e r i m e n t o n l y .5 ml of milk was needed and the 1-ml reaction vial was suitable. If m o r e milk is needed t h e filter can be cut to facilitate a longer collection vial. MATE R IA LS
1. Fibro tip TM disposable pipette tips f r o m BBL, Division of Becton, Dickinson and Co., Cokeysville, MD 21031. (Catalogue # 7 0 3 1 4 ) . 2. Glass reaction vials (1 ml) f r o m Supelco, Inc., Supelco Park, Bellefonte, PA 16823. (Catalogue #3-3123 ). 3. 6 cc m o n o j e c t syringe disposable, Sherw o o d Medical Industries, Inc., Deland, FL 32720. 4. R u b b e r stopper (00) cut to length of 15 m m (use large end).
Journal of Dairy Science Vol. 62, No. 9, 1979
5. Filter 22 m m x 7 ram, f r o m Rainin Instrument Co., Inc., 94 Lincoln St., Brighton, MA 02135. (used with Pipetman Microliter Pipettes). ACKNOWLEDGMENT
for
The authors wish to t h a n k Charles Jorgenson his drawing of the milking apparatus. REFERENCES
1 Cox, W. M. Jr., and A. J. Mueller. 1937. The composition of milk from stock rats and an apparatus for milking small laboratory animals. J. Nutr. 12:249. 2 Gupta, B. N., G. H. Conner, and R. F. Longham. 1970. A device for collecting milk from guinea pigs. Amer. J. Vet. Res. 31:557. 3 Kahler, H. 1942. Apparatus for milking mice. J. Nat. Cancer Inst. 2:457. 4 McBurnery, J. J., H. Meier, and W. G. Hoag. 1964. Device for milking mice. J. Lab and Clin. Med. 64:485. 5 Nelson, W. L., A. Kaye, M. Moore, H. H. Williams, and B. L. Herrington. 1951. Milking techniques and the composition of guinea pig milk. J. Nutr. 44: 585. 6 Personal communication from A. Kirksey, Dept. Nutr. and Home Econ. Purdue University. 7 Temple, P. L., and S. K. Kon. 1937. A simple apparatus for milking small laboratory animals. Biochem. J. 31:2197.
