Q&A With PAC

How soon should calves consume colostrum after being born?

A calf should receive colostrum as soon as possible after birth to avoid gut closure to immunoglobulin absorption. For many years, gut closure was believed to occur at 24 to 48 hours of age. However, new research shows that the earlier a calf consumes colostrum the better for absorption of the immunoglobulins across the gut wall. At 6 hours post-birth, 70% of the immunoglobulins are absorbed by the calf, while at 12 and 24 hours post-birth only 47% and 12% of the immunoglobulins are absorbed across the gut wall, respectively. In a study conducted at Kansas State University, calves that lacked appropriate levels of circulating immunoglobulin in their blood 6 hours after birth never reached the appropriate immunoglobulin levels suitable for protection from disease. Therefore, producers should prioritize administering colostrum or colostrum supplement to the calf as soon as possible after birth.

When should I get the

Breeding Soundness

exam done on my bulls?

A producer should schedule a veterinarian to conduct a BSE on their bulls at least 30 to 60 days prior to the breeding season. The reason we select 30 to 60 days prior to the breeding season is that if a bull fails the BSE test, a veterinarian can retest that bull again prior to the breeding season to see if the bull’s fertility has improved. Also, if the bull is found to be non-fertile, this gives the producer ample time to find a replacement bull if it is needed. Breeding soundness examinations can be conducted on the farm or at the veterinarian’s facilities. If you want to have the procedure done on your farm, make sure you have adequate facilities to handle and restrain the bulls so a veterinarian can examine the bull and collect the semen sample safely.

How do calves become persistently infected with Bovine Viral Diarrhea Virus (BVD)?

There are two types of infections in which cattle can succumb to BVD virus. Transient infections (TI) are infections that calves or cows get which they fight off, recover and rid the virus from their body. Persistent infections (PI) are infections in which the animal never rids the body of the virus and constantly sheds the organism in the environment. The TI cattle shed BVD virus in the environment but only for about 14 to 21 days until they clear the viral infection. How do cattle become TI or PI animals? Cattle that are transiently infected do so through nose to nose contact or contact with body secretions from a BVD infected animal. A PI calf however must be infected as a fetus in utero prior to the fetal immune system being activated which occurs around 120 days gestation. The fetal immune system takes an inventory of cells and proteins when it is activated for the first time. If a fetal calf has BVD virus in its body at the time the immune system takes inventory, the immune system thinks that BVD virus is actually a part of the calf’s body similar to heart cells, hair follicles, etc. Therefore, the calf never forms an immune reaction against BVD virus because it recognizes BVD as self. A persistently infected calf will have BVD virus in every cell in its body for the entirety of its life.