Dairy Producers Banquet is Thursday, December 11 starting at 9 AM. Speakers are Dr. Kirby Krogstad, our new OSU extension educator presenting Monitoring Nutrition, Old Classics and New Technology" and "Controlling Mastitis at the Feed Bunk". I’ve heard him speak 4 times and every time was very well presented. Dr. Brittney Davidson is a recent Ph. D graduate from the University of Wisconsin presenting: Consequences of Heat Stress in Dry Pregnant Cows, Growing Heifers, and post weaning dairy calves. We’ve known about this science for 5 years, now it is time to get it done and capitalize on the opportunities.

Dr. Hardesty attends Tri-State Nutrition Conference in Fort Wayne. Preconference Topics included Feedworks Aiming for Success in the Calf Raising Program, Kemin Improving Performance Amongst the Challenges Through Transition Cow Management, Impacts of Changes in Milk Component Pricing, Benefits of High Oleic Soybeans. The conference kicked off with The Cows’ Perspective of Two Decades of Management Changes at Minner Institute, Genetic Contributions to Mitigating Methane Emissions, Nutrient Interventions Can Improve the Immune Status of Dairy Calves and Feeding Management of Heifers.

Elanco showcased their Carbon mitigating feed additive, Bovare. Other topics included Impacts of Skeletal Muscle Depletion and Accretion, Improving Diet Digestibility, Impacts of Heat Stress on the Dry Cow and Her Fetus, Feed Inventory Maximization, Dairy Cow Personality Traits, and What We Have Learned with Feeding Automatic Milking Systems.

Vaccinating for Flies - House cattle face two types of fly infestations. House flies live on building surfaces and on cattle and reproduce in decaying material. Premise sprays and cleaning up are effective at controlling these populations.

The other nuisance is horn flies that spend their lifetime on cattle and are very irritating causing cows to bunch. Premise sprays have almost no effect on horn flies and we commonly use topical sprays.

We can now vaccinate cows for horn flies that spend their lifetime on the cattle and are irritating enough to cause them to bunch making heat stress worse. Insecticides have been successful in the past, but horn flies has a high potential to develop resistance. The ability to develop resistance is due to the constant contact with the host feeding up to 38 times a day and a short life cycle or 9 to 12 days resulting in up to 14 generations per year.

The genomically developed vaccine offers a long term, sustainable solution. It targets the host’s immune system to produce antibodies impacting the fly’s ability to take a blood meal. Horn flies use a protein called thrombosassin as an anticoagulant when they feed causing the host animal’s blood not to clot. Vaccinated animals produce antibodies that interfere with thrombosastasin protein. The blood clots so the fly takes smaller meals and it’s reproductive cycle is effected causing fewer eggs to be produced. This results in significantly smaller fly populations.

We envision 2 doses of the fly vaccine in the spring and premise sprays as recommended being a complete program.

Calcium Supplementation – Cows Have Changed

Production has increased by 10% in ten years from 21,700 to 24,000 pounds per year from 2012 to 2021. We now have cows giving 100 pound of milk at a week fresh. Their calcium needs therefore changed, too. We could once do some good with oral calcium to every cow at freshening. We now know more and we can do better. Dr. Jess McArt of Cornell has been the third wave of studying calcium metabolism in fresh cows. She presented her findings at the North East Dairy Production Medicine Symposium.

McArt studied lactation two and greater cows and found that they fell into four groups. Blood levels of calcium were measured on days one and four postpartum. Normocentric (N) cows were 40% of cows measured and they did not drop in calcium levels postpartum. Transient (T) cows were low on day 1 but normal on 4. They were the 20% of the cows and the highest producers. It is thought that they needed the low drop early to signal calcium mobilization needed for high production. Persistently (P) low calcium cows were low at both day 1 and day 4. They struggled the most with immune function and intakes and took 7 to 10 days to get to normal blood calcium. They benefit greatly from two doses of oral calcium at 24 and 48 hours in milk. The delayed (D) calcium cows were high at day 1 but low at day 4.

Lactation and calcium dynamics are shown to be similar to L2+ but they are seldom studied because there may be more variation between herds. There may be a genetic component and we’ll breed our way out of these situations, but we can manage the cows we have. Rumenation monitoring can be an indicator of dyscalcemic cows.

The best medicine for fresh cows is feed. Maximize access to feed and water. Optimize cow comfort and feed quality. Prefresh is not the place to dump refusals. Sand beds for prefresh make sense even in mattress dairies. Cooling is mandatory for pre and postpartum. Calcium supplementation has a place, probably not at freshening when it is convenient. Days 2 and 3 are the most optimal to reduce the persistent and delayed calcemic cows. Testing would be ideal, but you need to test twice and the cost of testing is the same or greater than the supplementation.

Type of supplementation is important. IV calcium to a standing cow will make them subclinical calcemic for several days. Don’t do it. SubQ is OK, but who has that amount of time? Oral is most common. There is wide variation in cost and composition. Generally, you get what you pay for. Bovicalc is the most common in research. It has no added features and a high price. We like Quadrical for its lower cost, additional probiotics and 4 different all absorbable calcium salts. Vital is the most fortified and also the highest cost. Our trials showed significantly more milk with Vital over Quadrical. Many products are cheap but are high in Calcium Carbonate, which is very slowly absorbed. Our opinion; Vital or Quadrical on Days 2 and 3.