| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Animal Sciences and
2 College of Veterinary Medicine, University of Illinois, Urbana 61801
3 Lueking Dairy Farm, Centralia, IL 62250
Corresponding author: G. Dahl; E-mail: gdahl{at}uiuc.edu.
 |
ABSTRACT |
|---|
 TOP ABSTRACT REFERENCES |
|---|
Key Words: early lactation • frequent milking • somatic cell score
Abbreviation key: 3x = milking 3 times/d, 6x = milking 6 times/d, PRL = prolactin
Increasing the frequency of milk removal increases milk production in cattle as it does in many species (Stelwagen, 2001). Indeed, this is a common management approach to maximize production per cow and to fully optimize capital investment in machinery and facilities. One obvious drawback is the increase in variable costs, mainly labor, required to reap the higher milk yield. Traditionally, this technique has been employed throughout lactation, but recent evidence suggests that frequent milking, appropriately timed within the lactation cycle, can have persistent effects, eliminating some of the higher costs while maintaining higher yields. Bar-Peled et al. (1995) observed higher production in cows milked 6 times/d (6x) relative to 3 times/d (3x) during the initial 42 d of lactation. More importantly, the production response was strikingly persistent following a return to 3x from 6x at d 42. That is, cows milked 6x continued to yield more milk even after milking frequency was reduced to 3x. A preliminary report by Henshaw et al. (2000) confirmed, under field conditions, that milking cows 6x in early lactation produces persistent improvements in milk yield even after cows returned to 3x. For the first 42 d of lactation, cows were milked 3x at 8-h intervals or 6x at approximately 4- to 5-h intervals. After d 42, all cows were milked 3x for the rest of the study, which lasted through 38 wk of lactation. Relative to those milked 3x, multiparous cows milked 6x produced more milk throughout the study.
Milk yield, however, may not be the only benefit of increased milking frequency in early lactation. Frequent milk removal is associated with reductions in somatic cells (Kelly et al., 1998; Smith et al., 2002), a general indicator of mammary gland health. Yet no previous studies have reported the effect of frequent milking in early lactation on any aspect of udder health. Further, the lower limit of number of days that cows need to be milked at higher frequency to observe a persistency response, particularly under management conditions observed in the field, has not been identified. The objective of the present study was to evaluate the effect of milking 6x vs. 3x for the initial 21 d of lactation on milk yield and udder health as indicated by SCS.
During Spring and Fall 2001, 9 cows were assigned at calving to 6x milking for 21 d after parturition. All remaining multiparous cows in the herd (n = 17) that calved within 2 mo of the 6x cows were used as controls to test for main effects of 6x milking on milk and milk component yield and udder health. All work was completed at Lueking Dairy, a commercial farm located in Centralia, Illinois. Milking times were 0600, 1400, and 2200 h for all cows, and 6x cows were milked an additional 3 times at 0800, 1600, and 2400 h. Cows were housed together and managed according to common commercial techniques, including ad libitum TMR feeding (31.1% corn silage, 31.1% ground corn, 16.6% alfalfa hay, 10.4% corn gluten, 8.3% cottonseed, 1.5% urea, and 1% vitamin-mineral premix), bST according to label directions, and DHIA testing of fluid milk and component production. Fresh feed was offered 3 times/d after milking.
Data was collected from Dairy Herd Improvement for test day and lactation totals. Lactation totals included DHI variables of summit milk, peak milk, days in milk at peak, 305-d milk yield, mature equivalent 305-d milk yield, actual corrected 305-d milk, and lactation average SCS. Because cows were assigned to treatments in groups based on sequence of freshening, covariates were included in the model for PTA for milk and inbreeding (Young et al., 1969). Therefore, model for lactation totals included main effect of treatment (i.e., 3x vs. 6x for 21 d) and covariates for PTA milk and inbreeding. Least squares means for 3x and 6x milking were adjusted for differences in PTA and inbreeding of the cows in the study. Some caution must be used in interpreting the results of the lactation totals because variables were not independent. Test day data included milk per day and SCS on test day for 10 test d per cow. As a part of a repeated measures analysis, each test day was analyzed separately with a model that included main effect of treatment (3x vs. 6x for 21 d) and covariates for PTA milk and inbreeding. All cows were milked an equal number of times per day during the 2nd through 10th test days. Cows milked 3x averaged 103 ± 125 for PTA milk with a range of -811 to 974. Cows milked 6x averaged 185 ± 178 for PTA milk with a range of -674 to 983. Inbreeding of cows milked 3x averaged 4.5 ± 0.4% with a range of 2 to 8%, whereas 6x cows averaged 4.1 ± 0.6% with a range of 2 to 9%.
Relative to a 3x milking frequency, cows milked at 6x produced more milk from the first DHIA test day, and greater milk yields persisted through the 6th test day (Figure 1
). Overall, 6x cows produced 1,118 kg more milk over the 305-d lactation than did cows milked 3x (Table 1). Similar increases were observed for mature equivalent milk and milk production corrected for components in the 6x cows relative to those milked 3x (Table 1). Compared with 3x cows, 6x cows had higher summit and peak milk yield and achieved peak at fewer days in milk (Table 1).
|
|
In addition to the production responses, 6x cows also had lower SCS relative to 3x cows. This reduction in SCS was most apparent during the 21 d when milking frequency was increased, but a tendency (P = 0.138) for this decrease in SCS persisted for the entire lactation (Table 1
). Examination by Chi-square analysis using a 200,000-cell/mL cutoff provided further evidence of improved udder health with more frequent milking (Table 2). Previous reports indicate that milking frequency is inversely related to indices of udder health such as SCS (Kelly et al., 1998; Smith et al., 2002); however, those studies examined SCS while the cows were milked at higher frequency and did not note effects after milking frequency was reduced. Our data support the concept of an inverse relationship between milking frequency and SCS while cows are milked more frequently, but also suggest that there may be a persistent effect of early lactation milking frequency on SCS.
|
Received for publication July 18, 2003. Accepted for publication December 19, 2003.
|
REFERENCES |
|---|
|
TOPABSTRACTREFERENCES |
|---|
This article has been cited by other articles:
|
|
 |
|
  E. H. Wall and T. B. McFadden Use it or lose it: Enhancing milk production efficiency by frequent milking of dairy cows J Anim Sci, March 1, 2008; 86(13_suppl): 27 - 36. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. O'Dowd, J. C. Kent, J. M. Moseley, and M. E. Wlodek Effects of uteroplacental insufficiency and reducing litter size on maternal mammary function and postnatal offspring growth Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2008; 294(2): R539 - R548. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. H. Wall and T. B. McFadden Optimal Timing and Duration of Unilateral Frequent Milking During Early Lactation of Dairy Cows J Dairy Sci, November 1, 2007; 90(11): 5042 - 5048. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. R. Rastani, N. S. Del Rio, T. F. Gressley, G. E. Dahl, and R. R. Grummer Effects of Increasing Milking Frequency During the Last 28 Days of Gestation on Milk Production, Dry Matter Intake, and Energy Balance in Dairy Cows J Dairy Sci, April 1, 2007; 90(4): 1729 - 1739. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. H. Wall and T. B. McFadden The Milk Yield Response to Frequent Milking in Early Lactation of Dairy Cows Is Locally Regulated J Dairy Sci, February 1, 2007; 90(2): 716 - 720. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. Ouweltjes, B. Beerda, J. J. Windig, M. P. L. Calus, and R. F. Veerkamp Effects of Management and Genetics on Udder Health and Milk Composition in Dairy Cows J Dairy Sci, January 1, 2007; 90(1): 229 - 238. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. H. Wall, H. M. Crawford, S. E. Ellis, G. E. Dahl, and T. B. McFadden Mammary Response to Exogenous Prolactin or Frequent Milking During Early Lactation in Dairy Cows J Dairy Sci, December 1, 2006; 89(12): 4640 - 4648. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. J. VanBaale, D. R. Ledwith, J. M. Thompson, R. Burgos, R. J. Collier, and L. H. Baumgard Effect of Increased Milking Frequency in Early Lactation With or Without Recombinant Bovine Somatotropin J Dairy Sci, November 1, 2005; 88(11): 3905 - 3912. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
; n = 9) for the initial 21 d of lactation or milked 3 times/d (3x; 
; n = 17) for the initial 21 d of lactation. All cows were milked 3x for the remainder of lactation. Standard error of the mean ranged from 2.04 to 3.11 kg/d. Test day average milk yields past test day 5 were not significantly different between 3x and 6x treatments.
2 and continuity adjusted