Fixed Responses to Multiple Milking Frequencies

Dr. Allen Young
USU Extension Dairy Specialist
Fixed Response

    Most dairy cows are milked twice daily (2X): however, the practice of milking cows three (3X) or more times per day has become more prevalent. There are many reasons why producers are milking more times per day: better utilization of existing facilities, more milk production per animal, and better udder health being just a few.

    The observed response to increased milking frequency ranges from 5 to 20%. Such a wide variability in response makes it difficult for a person to make the decision to go from 2X to 3X milking because economic budgeting becomes more risky.

    Research has shed some light on this dilemma, and I think it should help make some of those decisions easier. Researchers from the University of Maryland analyzed published reports from 19 different studies which looked at the milk response due to the effects of multiple milking frequencies (1). They determined that milk production and composition increased by a fixed amount when milking frequency increased from 2X to 3X or 2X to 4X, regardless of milk yield for 2X. Table 1 lists those changes in quantity and composition.

Table 1. Changes in milk quantity and composition due to increased milking frequency.

Frequency	Milk Increase (lbs)	Milk Fat (MF)Increase (lbs)	MF Change (%)	Protein Increase (lbs)	Protein Change (%)
2X to 3X	7.7 (95% confidence range of 6.8 to 8.6)	0.2 (95% confidence range of 0.15 to 0.26)	-0.14%	0.18	-0.06%
2X to 4X	10.8	0.25	-0.18%	0.25	-0.04%

    Previously, increased milk production has been defined as a percentage (%) increase above 2X production. A fixed response would explain some of the variability which one finds when comparing the literature or herd responses. For example, a response of 8 lbs for a cow producing 100 lbs milk would give an 8% increase, whereas the same 8 lbs would represent a 16% increase for a cow which was producing 50 lbs.

    Was there a difference in response between primiparous and mature animals? Although less data were available, primiparous animals seemed to have a fixed response of about 0.5 lb milk per day less (7.3 lb) than multiparous cows.

What do we do with this information?

    How would you use this information to decide whether 3X or even 4X milking is for you? Consider the following questions:

1. Is it economically feasible for you to go to 3X milking given an average response of 8 lb milk/cow/day? Sample economic worksheets can be found in copies of references 2 and 3.
   
   
2. Do I have enough available, trained, and good labor to add another milking shift? Labor is a very big factor in determining if it is feasible to go to multiple milkings. Don't forget to consider your increased management effort, too.
   
   
3. Are my milking facilities able to handle the increased milking time?
   
   
4. Am I willing or financially able to stay with it for a minimum of 6 months or, preferably, a complete lactation? Research indicates that it may take that long to fully realize the response.
   
   
5. Am I a good 2X manager, and likely to be a good 3X manager? Even though udder health seems to be improved with 3X+ milking, problems can also be magnified due to the increased intensity of production. Close monitoring of body condition scores is strongly recommended. Feed intake does not go up at the same rate as milk production, and therefore it is very critical to monitor changes in animal body weight.
   
   
6. Do I have a way of monitoring whether I am getting a response and its magnitude? Many factors go into how much milk a cow produces at a given time such as nutrition, stage of lactation, age, seasonal variation, management, etc. Being able to determine how much of the response, or lack of a response, is due to 3X milking or some other management aspect is extremely vital. Two examples of ways of monitoring production would be to use 150 DIM corrected milk value or bulk milk values corrected for the number of animals being milked. The critical item is that you need to be on some type of records system.

    What if it isn't feasible to go to 3X+ milking, but I still need to utilize facilities more fully? Many producers have found that it is economical in those situations to add more animals to the herd. Again, many of the considerations listed above should be taken into account before making the transition.

    Multiple milkings per day can work to your advantage if you have the resources and management skills necessary to take on the additional work.

References

1. Erdman, R.A. and M. Varner. 1995. Fixed yield responses to increased milking frequency. J. Dairy Sci. 78(5):1199-1203.
   
   
2. Merrill, W.G., W.A. Knoblauch, and L.E. Chase. 1984. Possibilities, problems and profits of milking three times a day. Animal Science Mimeograph Series, No. 77 (A.E. Ext. 84-1).
   
   
3. Armstrong, D.V., D.L. Bath, and R. Selley. 1992. Three times a day milking. National Dairy Database CD-ROM.