Producer’s Banquet Thank You The banquet was well attended, speakers enlightening, sponsors said they got good questions, and the food was enjoyed. Thank you to all who attended. We have distributed notes to some producer’s that were unable to attend.  If we missed you, please let us know.

Adult Cow Pneumonia It has started and it looks like its here to stay.  Last year, starting January 15, we had 8 herds that experienced sudden adult cow deaths due to Pasteurella Multocida and Mannheimia Haemolytica.  Prevention is whole herd vaccination with Once PMH or Nuplura.  We have already had two herds this year and vaccination stopped the losses.  Herds that have been through this will tell you they never again want to lose 5-10% of their herd in a week.  Do you gamble and wait or get vaccinated and stay secure? We commonly have enough vaccine on hand for smaller herds, but larger herds may take a few days.

Peer Group Meetings are scheduled for the winter months at Speedway Lanes 455 N Herman St., New Bremen, OH.   Pizza is ready at 11:30, talks  begin at noon.  If there is a theme to this year’s topics, it’s “Old Topics with New information”. Jan 29^th:  Dr Trent Westfall of Elanco “A New Look at Colostrum – More Magic.”  Feb 19^th: Dr. Dave Erf of Zoetis “Genomics – Are you part of or watching the change,” & Dr. Joel Franks of Zoetis, “Quality Milk, How Good Can it Get?”

Consequences of Heat Stress in Dry-Pregnant Cows, Growing Heifers, and Post-natal Dairy Calves.  Dr. Brittany Davidson’s talk was the most commented on and very enlightening.  This is what we can do to improve the quality of our herds.  Epiogenetics are the effects, usually of heat stress on the DNA of in utero calves that results in reduced performance carrying through generations. The US averages 100 days of heat stress, 90 in New York, 270 in Florida. Direct effects on Lactating cows are decreased DMI, fertility, milk production, milk proteins and fats, and immunity. Increased metabolic disease, body temperatures, and respiratory rates.  Non-lactating animals are often overlooked.  Heat stress in the dry period also results in decreased calf birth weights and decreased calf performance.

There are three generations effected by heat stress in the pregnant dry cow. Herself, the calf she is carrying, and the granddaughter due to decreased development of the daughter’s follicles.  Impacts of in utero heat stress are on the gastrointestinal tract, ovaries, skin and mammary gland.  Heifers exposed to in utero heat stress have decreased body weights and stature.  They also consumed less grain and had lower average daily gain.  Gastrointestinal function was decreased with in utero heat stress calves due to increased break down of intestinal villi, crypts and fewer cells proliferating.  

In utero heat stressed calves have altered ovarian function and size.  Slowed primordial follicle activation and increased follicular atresia.  Altered downstream signaling pathways lead to delays in follicle development and advancement through the follicle stages.  In utero heat stress calves had smaller ovaries at day 63 with a correlating decrease in follicle counts.

The skin of in utero heat stressed heifers have more but smaller sebaceous glands and smaller and fewer sweat glands.  They have shorter undercoat and longer topcoat trapping more heat.  They have smaller udders, smaller fat pad and parychyma, less proliferating cells and underdeveloped ductal epithelial structures.

Late gestation heifers are still growing with 80% of fetal and mammary growth in this time.  Cooling leads to increased milk production and fat and protein yield. In utero heat stressed heifers born to heifers experienced reduced gestation length and impaired absorption capacity for IGg.

Early life exposure to heat stress decreases milk grain and water intake and activity.

The summary is to cool dry cows and springers just like lactating cows and consider what you can do for calves.  Hutches need to be thermal opaque and have air flow.  Addition of shades and fans helps.  Group housed calves have emphasized air exchanges per hour for ventilation, but not cooling.  We need to emphasize cooling.  Fans should be similar to our adult housing, coming on at higher temperatures.  Less focus on sprinklers.  Cross vent and tunnel buildings have become more popular for these animals.

Bovine leptospirosis is a serious disease in cattle. It is a zoonotic disease which is caused by various serovars of Leptospira which can cause disease that typically manifests as reproductive issues in cattle. There are several serovars that are known to be pathogenic to cattle. One is Leptospira borgpetersenii serovar hardjo-bovis. This is a host adapted serovar in which cattle act as the primary reservoir by maintaining the pathogen in their kidneys and genital tracts. These host adapted serovars typically cause reproductive failures such as early embryonic death and late term abortions.  Other serovars such as Pomona, Grippotyphosa, Canicola and Icterohaemorrhagiae are maintained in wildlife but can still be transmitted to cattle and

cause disease.  These other serovars can cause clinical disease which manifest as fever, anemia or jaundice.

Infection of cattle typically occurs through contaminated water that enters the mucous membranes of the mouth, nose and eyes.   The usual contamination is urine of infected cattle.  In heavily infected herds, it is important to vaccinate before the cattle go on concrete floors as the urine splashes into their eyes. Leptospires migrate to the kidney, specifically to the proximal renal tubules of the kidney, where they can avoid detection by the host’s immune system.  The ability to reside in the kidneys makes detection of Leptospira difficult because there can be low circulating anti-bodies with a current infection. Urine samples can be used as a screening test to detect Leptospira DNA through PCR which identifies cows shedding the pathogen. Serology can then be used to identify the infecting serovar. 

Prevention of Leptospira infection is primarily through vaccination.

Vaccination does not eliminate current infections, but it prevents new Leptospira infections.  Oxytetracycline at dry off is the best available treatment for infected cattle.  There are several commercially available 5-way serovar combination whole cell killed vaccines.  Heifers are vaccinated at 1 to 6 months of age and boostered in a month, then every 6 months.  Pregnant heifers are then re-vaccinated 4 to 10 weeks pre-fresh.  Cows are vaccinated twice a year to provide adequate protection against Leptospira infection.  Vaccine selection is important as many 5 ways list hardjo bovis on their label, but they do not actually have the right strain for protection.  

Dr. Matt Hertlein