The transition period is a difficult time for both cows and producers. Cows are in a state of negative energy balance which makes them susceptible to diseases, and producers suffer the consequences with treatment bills and lost milk production. A new study conducted at the University of British Columbia Dairy Education and Research Centre in Canada has produced some evidence that incomplete milking for the first five days after calving could be beneficial for the immune health of transition cows (Carbonneau, de Passille et al. 2012). The researchers hypothesized that reducing the milk harvested till five days postpartum while still stimulating milk production the same amount of times would make the animals energy balance more positive thus decreasing disease susceptibility, while not affecting total milk production for the lactation. In this study, researchers used 47 cows in three treatment groups, two of which will be discussed. The first group included 15 cows which were milked out completely twice a day for the duration of the 61d experimental period (control, CON). The second group consisted of 16 cows which were incompletely milked twice a day, 6 liters(L) on d1 was taken from the animals, 8L on d2, 10L on d3, 12L on d4, and 14L on d5. The cows were milked out completely twice a day after five days postpartum for the rest of the experimental period (Incomplete, INC).
During the experimental period, feed intake, water intake, and milk production were recorded daily. Milk composition including fat, protein, lactose, and SCC were evaluated weekly. Blood samples were taken on day 21 prepartum and day 2, 3, 4, 5, 14, 21, 28, and 61 postpartum. From these samples, BHBA, plasma NEFA, glucose concentration, phosphorus concentration and many other parameters were evaluated. Researchers measured that milk taken from INC cows through d5 was 35% of the amount of milk taken from CON but there was no effect of incomplete milking on overall milk production for the lactation which averaged 47.8 ± 0.72 and 45.7 ± 0.83 kg/d between wk 2 and 9 for CON and INC, respectively. Blood glucose concentration was greater for INC cows than CON cows until 21 DIM. The concentration of NEFA and BHBA was greater for CON than INC cows until 21 DIM. Phosphorus concentration was greater for INC cows until day 5 and then was similar in both treatments during the remaining time in the experimental period. Based on BHBA concentration, 47% (7/15) of cows in the CON treatment and 6% (1/16) in the INC treatment met the criteria for clinical ketosis and 13% (2/15) in CON and 6% (1/16) in INC met the criteria for subclinical ketosis.
From these results, incomplete milking was shown to be beneficial by lowering the amount of NEFA and BHBA in the blood which is a good indicator of the degree of negative energy balance of the cow. Along with lower NEFA and BHBA levels, the glucose concentration was greater in INC cows than CON which would indicate these cows would be at a lower risk of ketosis. This was found to be true by the amount of clinical and subclinical ketosis cases in each treatment. In addition to reducing the number of ketosis cases, a higher phosphorus concentration in the blood for INC cows could indicate that incomplete milking would also lower the amount of calcium and phosphorus mobilized from the body for milk synthesis. If this is true, incomplete milking could lower the incidence of milk fever in transition cows. Furthermore, incomplete milking within five days postpartum had no effect on overall milk production for the lactation. More research will be needed as blood calcium concentration was not tested in the current experiment due to the cows receiving a subcutaneous injection of calcium to prevent milk fever. With more research, incomplete milking with an equal amount of milking stimulation (twice daily or more) could become a tool to improve herd health and increase farm profits.
Carbonneau, E., et al. (2012). "The effect of incomplete milking or nursing on milk production, blood metabolites, and immune functions of dairy cows." J Dairy Sci.
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Issued in furtherance of Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, and the U.S. Department of Agriculture cooperating. Edwin J. Jones, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg; Jewel E. Hairston, Administrator, 1890 Extension Program, Virginia State, Petersburg.
February 28, 2013