Getting cows and heifers off to a good start at the beginning of lactation is critical for the profitability of the dairy. Even with all the advances in nutrition and veterinary care, freshening and the onset of lactation are very stressful for dairy cows. Fresh cows are susceptible to a number of infections and metabolic disorders due to stress, low immunity and reduced dry matter intake. Two of the most common metabolic disorders in fresh cows are milk fever and ketosis.
Milk fever
The calcium requirements for a dry cow are minimal compared to a lactating cow. With calving and sudden onset of lactation, massive amounts of calcium are moved from blood to mammary glands and into colostrum. This leads to low calcium levels in the blood of fresh cows.
Calcium in the blood is replenished from both the bones and the cowâs diet, but the mechanism to move calcium reserves from the bone to blood is not very efficient during the first 24 to 48 hours post-freshening, and this leads to milk fever. Depending on the severity of calcium deficiency, a cow can be diagnosed with clinical milk fever or subclinical milk fever.
In the more severe of the two â clinical milk fever â the cow is down and unable to get up, extremities are cold and the cow has flaccid paralysis. If the deficiency is not severe, the cow can have subclinical milk fever. In this condition, cows are not down but have poor appetite and performance and are prone to other metabolic disorders.
So, it is critical to prevent fresh cows from becoming hypocalcaemic and getting milk fever. Dry cow nutritional management is the key to prevention. Talk to your nutritionist and work on the dry cow ration, which will help maintain calcium balance in blood at freshening.
Another easy way to help fresh cows maintain mineral balance is by giving oral calcium supplements. There are wide choices of oral calcium supplements in the market today like calcium gels/pastes, drenches, boluses and capsules.
Products are available as just plain calcium or in combination with other minerals like phosphorus, magnesium, potassium, etc., with and without vitamins. Producers can proactively feed these oral calcium supplements to fresh cows, especially to animals at or beyond their third lactation, as they are more prone to milk fever.
If a cow is already down with milk fever, it is not advisable to feed oral calcium supplements. Cows in this condition should be given intravenous calcium therapy. In the majority of cases, she will respond immediately.
It is advisable to give an oral calcium supplement as a follow-up to intravenous calcium therapy to prevent relapse. Make sure the cow is up and has a strong swallowing reflex before you give oral supplements.
Ketosis
Ketosis is a disturbance of energy metabolism. When energy demand for milk production exceeds energy supplied by feed, the cow starts to mobilize body fat stores at a faster rate than normal. Affected cows have low blood glucose, high blood ketone levels and low dry matter intake. These factors reduce production, and increase susceptibility to other problems.
Again, as in milk fever, prevention is the key. Make sure cows have the right body condition when they calve, that they maintain dry matter intake and try to reduce stress as much as possible. In addition, feeding glucose precursors like propylene glycol at freshening will help the cow maintain sufficient energy levels.
Today, energy supplements containing propylene glycol are available with niacin and other vitamins in ready-to-use forms like drenches, gels/pastes, etc. Additionally, a variety of direct-fed microbial supplements are available which provide beneficial bacteria, yeast, vitamins, etc., to help the cow in recovery. When given as directed, these supplements help maintain appetite and dry matter intake.
Milk fever and ketosis not only reduce the performance of your cows, but also increase the possibility of other postpartum complications like retained placenta, mastitis, metritis and displaced abomasums. So, preventing milk fever and ketosis are keys to profitability. PD
Vijay Sasi
R&D Director
Vets Plus, Inc.
vsasi@vets-plus.com
