What “crop” insurance is needed for this fall?

Management

The fall season is another good time to assess body condition score (BCS) in cows nursing calves. Scheduling pregnancy checks for cows nursing calves provides a good opportunity to identify cows for market and to prewean vaccinated calves.

Pregnancy checking heifers provides the opportunity to market open females directly off-pasture.

Bulls need evaluation in the fall as well. They should be evaluated physically to assess feet, legs, penile injuries and BCS. Mature bulls should have minimal weight loss during the breeding season, while yearling bulls will lose some weight during the breeding season and would benefit from improved nutrition when removed from the breeding herd.

Product and protocol

This aspect of “crop insurance” must be done in consultation with your veterinarian because it involves an assessment of the risk of certain diseases and the efficacy and safety of specific products (vaccines).

The preweaning vaccination protocol provides an ideal opportunity to follow up on springtime vaccinations and enhance the immune response to respiratory pathogens. The primary risk to weaned calves:

• Respiratory disease – Bovine respiratory disease complex (BRDC) is associated with the stress of weaning, a change of diet, transportation or movement to new surroundings, and often the commingling of different pasture groups on the same ranch. By enhancing immunity to specific potential pathogens, the risk of BRDC is decreased.

In addition, the process of sorting and vaccinating calves while still nursing their dams reduces the stress of the processing event. Depending on the risk to individual herds assessed by your veterinarian, calves may receive booster doses at weaning or simply may be separated from their dams without additional vaccinations.

The infection risk is related to viral pathogens such as IBR, BVDV (type 1 and 2), BRSV, PI3 and bacterial pathogens Mannheimia haemolytica, Histophilus somni, Pasteurella multocida and Mycoplasma bovis. Modified live virus (MLV) vaccines, often called five-way viral vaccines, labeled for use on nursing calves can provide excellent protection when properly handled and administered according to label instructions.

Mannheimia haemolytica infections often are isolated and implicated in pre- and postweaning respiratory disease cases, so vaccines against this pathogen commonly will be included, very often in combination with the MLV vaccines.

In specific herds, other bacterial vaccines may be used, depending on herd history and risk. What is important to remember is that killed/inactivated vaccines usually will require a booster dose to achieve an adequate level of protection.

Consult your veterinarian about specific products related to viral and bacterial vaccines.

• Reproductive vaccines can be administered to breeding herd females at this time. Be very aware of label recommendations regarding the timing and use of vaccines in pregnant cows. Make sure your veterinarian has provided recommendations regarding their use.
  
  
• The clostridial diseases, commonly called “blackleg” – The risk of this infection is difficult to assess; however, this organism resides in the soil and can cause severe illness and death in susceptible animals. A second dose administered at this time will enhance protection against this family of pathogens.
  
  
• Cattle on grass will have internal parasites. In calves, the economic impact is due to reduced feed/forage intake, resulting in reduced weaning weights. In addition, the presence of internal parasites can have a negative impact on calves’ ability to respond to vaccination.

If dewormer products are used at preweaning, calves should be moved to clean pastures to avoid re-infection. Rotational grazing can increase parasite loads, especially if the cattle are left too long on rotation units or if some units are utilized several times during the grazing season.

Conversely, rotational grazing can decrease internal parasite load when cattle are moved appropriately (one month or less) to clean grazing units. Consult with your veterinarian about the choice of products to use.

• External parasites will be very evident at this time of year. Horn and face flies have survived and can be bothersome to adults and calves. Topical treatment at preweaning for cows, bulls and calves is advisable, depending on the fly population.
  
  Treatment for biting and sucking lice is not recommended at this time. The feeding activity of lice will increase with colder weather, so hold off on systemic treatments until signs of lice appear.

An important aspect of the protocol portion of herd management is to record inventory and assess breeding females for pregnancy, and to sort out market animals. Take inventory of bulls, assess the physical status and make decisions regarding the marketing of extra animals.

Preweaning vaccination events, while stressful, can minimize pathogen stress that normally is associated with commingling of different pastures, separation from the dam and changes in diet that occur with weaning. Work to ensure that all animal handling events are conducted in a calm, low-stress manner to the extent possible.

The concept of “crop insurance” for cattle is not a commonly discussed topic. Crop insurance in cow-calf operations is a matter of management and product. Consult with your veterinarian on this important topic for advice on management and product insurance choices.

Carl Dahlen is an extension beef cattle specialist with North Dakota State University.

—Excerpts from North Dakota State University Extension Service newsletter The Ranch Hand, September 2015

• Gerald Stokka

• Extension Livestock Stewardship
• North Dakota State University
• Email Gerald Stokka