By Maria Jose Fuenzalida and Tina Kohlman
The current dairy market situation and the need to reduce milk supply to processing plants have farmers seeking strategies to reduce milk production while still being able to support their herd for subsequent lactations and ensure good cow health and welfare.
Current university, industry, and National Mastitis Council recommendations are to provide a 45 to 60 day dry period for cows in order to prepare her udder for the next lactation. Drying cows off earlier and providing a longer dry period is one of a few strategies to reduce milk production on-farm. In terms of cellular turnover within the mammary gland, a longer dry period should not affect the next lactation, as long as attention is paid to nutrition and health management (L. Hernandez, UW-Madison).
How much milk can be reduced through early dry off?
Extending the dry period from 45 to 55, 60, or even 70 days may be a strategy to reduce milk production. UW-Madison Extension Dairy Management Specialist Victor Cabrera calculated one can anticipate an estimated 500 pounds less milk from the lactation (assuming a 25,000 pound lactation) for every 10 days increase to the dry period. This would equate to approximately $60 less Income Over Feed Cost (IOFC) for every 10 days, when milk price is $0.15 per pound and feed cost is $0.10 per pound of dry matter (DM).
To calculate one’s own milk reduction based on herd production and extended dry period, please visit http://dairymgt.info -> Tools -> Milk Curve Fitter -> (tab) Exploring Pregnancy Timing.
Which cows are candidates for early dry off?
- Low producers, or those cows who are not producing enough milk to cover their own expenses.
- Cows with subclinical mastitis infections can have a longer dry period. An extended dry period would provide an opportunity for the immune system of the cow to get rid of an intramammary infection given an appropriate environmental, nutritional, and animal health management.
- First lactation cows should be considered over second lactation cows due to the amount of milk they produce and the income they generate. Second lactation cows produce approximately 15 percent more milk than first lactation cows.
What are management considerations for early dry off?
The risk of new intramammary infections during the dry period is 10 times greater than during lactation. Because of this risk, an early dry off program will need to address two very important areas during the dry period: maximize the cow’s immune system and minimize exposure of environmental pathogens at the teat end.
- Maximize and supplement the cow’s immune response through the proper use of antimicrobial dry cow therapy and internal and external teat sealants. The length of effective protection of an approved intramammary dry cow therapy product varies depending on type and use of product. When deciding on an extended dry period, consult with your herd veterinarian for the best option available. Closure of the teat canal is key for preventing new intramammary infections. The teat canal produces a natural keratin plug, however this process takes several weeks after dry off. Teat sealants are used to reduce bacterial contamination and leaking due to failure of keratin plug formation.
- Reduce environmental exposure: Cows should be housed in clean, dry, and physically and thermally comfortable facilities. Close-up dry cow pens should be stocked at 80 percent of bunk capacity or less, or about 30 inches of bunk per cow. Freestalls should be sized for the average cow in the group and be based on Midwest Plan Service recommendations. Bedded packs should provide 150 square feet per cow.
It is suggested not to extend the dry period to more than 70 days, as this may cause metabolic issues at freshening. Cows may gain excess body condition during the extended dry period if nutrition is not managed properly. Metabolic disorders that may occur to excess body condition include such as ketosis, milk fever, displaced abomasums (DA), retained placentas, and metritis. What do these metabolic issues mean for the cow’s next lactation?
- Decreased dry matter intake and going off feed
- Decreased milk production
- Immunosuppression
- Possible infertility issues
All of these issues that could affect the cow will affect the bottom line of the farm. How can you cope with the metabolic risks and help prevent or reduce losses for your bottom line?
- Feed a balanced dry cow ration that provides the appropriate nutrients and energy levels to the cow for maintenance and fetal development without weight gain. Far off dry cow rations should be adjusted for lower percent crude protein (CP) as compared to close up dry cows. Consult with your nutrition for dry cow feed management which fits your management.
- Body condition score (BCS) cows at the start of and midway through the extended dry period to determine if cows are maintaining or gaining weight. There are several ways to assess body condition. PAACO Animal Welfare Auditor Training provides two scoring systems commonly used in the dairy industry. Select a system that fits your interests and test your repeatability.
- Feed research-proven products that will aid in the reduction of metabolic problems during the transition period three weeks pre- and post-calving.
- Update the farm’s fresh cow protocols and have supplies ready to address an early dry-off plan.
To maintain high levels of animal welfare, it is necessary to minimize social, environmental, and metabolic stress, especially for cows close to calving. When cows are abruptly dried off, stress hormones increase, especially for previously high-producing cows. This could be due to several factors, including hunger from reduced dry matter intake and fewer nutrients, along with pain or discomfort from a full udder. Therefore, working with your nutritionist to adjust to a dry cow diet while maintaining satisfaction may help to reduce stress during the cow’s acclimation to the dry period. Studies have suggested a step-down in milking (similar to weaning, but from the cow’s, instead of the calf’s, perspective) may help reduce discomfort related to udder engorgement. In automated milking systems (AMS), many cows voluntarily reduce their own milking frequency. In conventional milking systems, such as parlors or traditional milking barns, it may be beneficial for cow welfare to step down from 3x milkings per day to one time per day for one week before total dry off (J. Van Os, UW-Madison).
When determining if extended, or early, dry off is a strategy on your farm, management strategies need to be focused on getting cows as healthy as possible through the early udder involution stage and close to freshening while minimizing stress to the cow. In general, we need to make sure cows are not producing high yields of milk when dried off along with providing proper environmental and nutritional management, appropriate dry cow therapy, and teat sealant. Cows need to remain healthy and well cared for during this transition period, keeping in mind not every cow might be a candidate for an early, or extended dry period.
Source : wisc.edu