drying cows off
There was an interesting article in the July 2013 edition of “Milk Producer” on this topic. For years, we have been told that the best method was abrupt dry-off of all cows. There can be some significant challenges drying off cows which are still milking quite heavily when they are due to be dried.The National Mastitis Council (NMC) has for several years recommended drying off cows when milk production drops below 15 kilograms daily. A study in Quebec showed that 62% of cows were producing more than 15 kgs on their last DHI test day. What should we be doing with these cows?
After the last milking at dry-off, the mammary gland continues to produce milk for a period of time. The udder will become congested, and if severe, milk will leak from the teats. A study in British Columbia showed that 75% of cows with abrupt dry-off leaked milk, while 27% of intermittent dry-off cows leaked milk. Leaking provides an ideal environment for bacteria to gain entry into the udder and cause infection. When leaking, much if not all the Dry Cow Mastitis medications administered will come out. Internal teat sealants (Orbeseal) help reduce leaking, but are not enough. Research has shown that for each 5 kg of extra milk production over 12 kg at dry-off, the intra-mammary infection risk at calving increases by 80%.
At present, we have 2 strategies at our disposal to reduce milk production before dry-off: intermittent milking and decreased caloric intake.
Intermittent milking involves milking cows less frequently for a number of days before dry-off. If presently milked two or three times a day, they would be milked once daily for 5-7 days and then dried off. It appears that intermittent milking at dry-off speeds up the involution of the mammary gland, which increases its protection against infections.
Decreased caloric intake typically involves removing the grain and concentrate from the cows ration for 5-14 days before dry-off. On some farms, these cows are simply put on a hay only diet for that period. The caloric reduction will result in a negative energy balance causing the cow to mobilize some of her body fat reserves. If severe, this will increase the risk of developing metabolic problems (ketosis, fatty liver), and will compromise her immune system, making her more susceptible to infections. It is important that water, minerals, and salt are not restricted, and that the cow(s) are housed in dry, comfortable surroundings during the “drying-off” process to minimize the degree and duration of the negative energy balance.
Both strategies will reliably reduce milk production in pre-drying-off period. In free-stall herds (excluding robotic milking herds where much of the grain is fed at the robot) it is often impractical to restrict energy intake prior to dry-off unless they have a “dry-off” pen or a tie-stall area to put these soon-to-dry cows. Tie-stall herds can easily implement both strategies simultaneously.
1. Cows Milking >15 kg Daily:
-7 days before dry-off date, remove all grains and concentrates from the diet
-keep the minerals and water readily available
-start intermittent milking 5 days before dry-off date
-if possible, move these cows to an area where they cannot see milking activities
-if milking >22 kg daily:
-consider a shorter dry period (longer lactation) to allow more time for milk production to drop before dry-off
2. Cows Milking < 15 kg Daily:
-practice abrupt dry-off at 60 days before calving