THE FIGHT AGAINST MILK FEVER Having our Milk and Drinking it Too (Part 1) “Having our milk and drinking it too”… this is my play on a popular proverb, the meaning of which is that we can’t have the best of both worlds. Modern agriculture strives to produce more with less – we breed, feed, and manage cows to produce more meat and milk to feed an ever-expanding hungry world. This is a good thing. One of the unintended consequences when pushing cows to the limit is that unforeseen conditions could develop (termed as “production diseases”) that make it harder for us to “Have our milk and drink it too”. I see the mission of the modern farmer, veterinarian, nutritionist, and other farm advisors, as striving to prove this proverb wrong. One of the most important production diseases in modern dairy, especially for those milking Jersey cows, is milk fever (aka parturient paresis and post-parturient hypocalcemia). The condition was first described in 1793, corresponding with a focus on breeding and feeding for higher production in cows. I have scoured the literature to understand where the term milk fever originated, as the condition is NOT associated with a fever, in fact cows tend to have LOWER temperatures. So far I have come up empty handed, but I have found a variety of interesting treatments that have been attempted over the years: • sweating with hot packs and blanketing; • blood letting; • concoction of alum, nitre, cream of tartar, treacle, ale and beer.
muscles and this pressure causes damage - a snowballing effect - where being down results in damage that keeps cows down.
Treating milk fever
By Dan Shock, DVM, PhD Upper Grand Veterinary Services & Associate Consultant, ACER Consulting Cell: 226-971-3490 Twitter: @DanShock1 dan.shock.dvm@gmail.com dshock@acerconsult.ca
Most farmers that milk Jersey cows are well able to treat clinical cases of milk fever. There are, however, a few things to keep in mind prior to treatment. I always do a full physical exam prior to administering calcium intravenously (IV). Some of the things I’m looking for include: • Toxic mastitis – cows with toxic mastitis can also go down. In addition, cows with toxic mastitis are at a higher risk of death with IV calcium treatments. • Vaginal exam – I have seen more than a few cases of an undiagnosed twin being present that could be compounding the issue for the cow. Also, tears in the vagina and uterus are possible and would affect the prognosis for that cow. • Evidence of injury – I look at hip mobility and physical evidence of back/leg trauma that could affect the cow’s ability to rise. Uncomplicated cases where a cow is unable to rise require So, what is milk fever and why does it occur? intravenous therapy with an approved calcium product. This Calcium is an essential mineral responsible for a variety of func- needs to be administered slowly over 20-30 minutes, as too tions in the body. Whenever any muscle contracts, calcium is rapid a rise in blood calcium could cause heart arrhythmias there. Whenever a nerve cell and possibly cardiac arrest. It is fires, calcium is there. Need always a good idea to collect a strong bones, fully functioning pre-treatment sample of blood enzymes, and proper blood clot in the event that the cow does formation in your cow? Well then, not respond to the initial calcium she needs calcium. It comes as 1. Cows are unable to rise. IV bolus. This sample should be no surprise then that through a refrigerated and sent to your 2. Skin and extremities become cool. complex interplay between manveterinarian for analysis in case aging stores in bone, intestinal 3. Rectal temperature could be low (<38°C). the cow does not get up. After IV absorption of dietary calcium, calcium is administered, I typically 4. The gastrointestinal tract stops contracting. and excretion rates of calcium in recommend running a bottle of 5. Breathing becomes shallow and rapid. the kidney, the cow absolutely calcium borogluconate under the needs to precisely regulate sys6. Cows become dull and depressed. skin to ensure sustained calcium temic calcium to within a precise is released over the following 12 7. Labour could be delayed. range. Around calving, modern hours. dairy cows that are being bred to All calving areas should have exproduce far more milk than what cellent traction, meaning lots of their calves would require, need to deal with a massive and sudclean, deep, soft bedding for adequate footing. If the down cow den shift in calcium from their blood to their udders. Cows that needs to be moved (i.e. she did not respond to initial therapy and cannot adequately compensate for this change develop clinical milk fever (although it is true that most cows will develop at least is in an area without adequate bedding), then a stone boat should some level of subclinical or “silent” hypocalcemia prior to calving). be used. If this is not possible, gently rolling the down cow into Jerseys, having fewer vitamin D receptors, are less able to re- a stationary loader bucket (filled with straw) is also an acceptable spond to periods of rapid calcium needs, as seen around calving. method for moving down cows. Vitamin D is required for calcium absorption from the intestines, Up next: Prevention as well as triggering calcium release from bone storage sites. Now that we’ve gone over some important aspects of what hyIf left untreated, cows will die. If a cow survives but, for what- pocalcemia is and how it is treated, our next article in the Deever reason stays down for prolonged periods of time despite cember issue of the Canadian Jersey Breeder will outline some intravenous calcium therapy, her life is still in jeopardy. There steps that you can take to prevent milk fever on your farm. Stay is a tremendous amount of weight placed on vital nerves and tuned! •
The Clinical Signs of Milk Fever
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September 2018 Canadian Jersey Breeder
