Bovine Respiratory Complex (BRC)

• Preventive health for cattle considers breeding, immune system management, nutrition, and general management.
• A herd health program combines sound management, housing, nutrition, biosecurity, and vaccinations.

Bovine Respiratory Complex BRC

• Diseases under BRC include Bovine Viral Diarrhea (BVD), Infectious Bovine Rhinotracheitis (IBR), Bovine Respiratory Syncytial Virus (BRSV), and Parainfluenza-3 (PI3).
• BVD is caused by a Pestivirus of the Flaviviridae family.
• Acute BVD signs: nasal discharge, coughing, depression, anorexia, and profuse diarrhea.
• With Mucosal BVD, severe persistent BVD results from in utero infection followed by infection with a cytopathic strain of BVD virus after maternal antibodies wane, and it's lethal.
• Peracute BVD affects calves and adult cattle, resulting in high mortality rates, bleeding from injection sites, hemorrhages, oral ulcers, bloody diarrhea, depression, anorexia, and rapid death.
• IBR is caused by bovine herpesvirus 1 and is associated with respiratory and reproductive diseases, as well as abortion.
• BRSV is caused by a pneumovirus of the Paramyxovirus family and causes lower respiratory infections and secondary bacterial pneumonia.
• BRSV leads to labored breathing, interstitial pneumonia, edema, and emphysema with clinical signs that may vary to include death.
• PI3 is caused by a paramyxovirus which is associated with secondary bacterial pneumonia, coughing, and clear ocular and nasal discharge.
• Mannheimia haemolytica plays a role in Bovine Respiratory Complex (BRC) and is related to shipping fever, feedlot cattle, crowding, and shipping.
• Cattle have the smallest internal lung surface area per body weight of all mammals which limits their ability to compensate for lung infections.

Further Vaccines

• Include Clostridial diseases (perfringens, chauvoei, novyi, septicum, sordelli).
• Also include Escherichia Coli, Bovine rotavirus & coronavirus (calf scours), Leptospirosis, Mycobacterium Bovis, Pasteurellosis, and Haemophilus Somnus.
• Clostridial diseases have many contributing factors.
• Calves show weakness and diarrhea if less then one month old.
• Enterotoxemia and sudden death may occur
• Clostridial Diseases are Infectious but not contagious.
• Clostridial chauvoei, or Blackleg, involves ingestion of bacterial spores while grazing which leads to bloodstream and then skeletal muscle infection.

Colibaccillosis, Rotavirus, and Coronavirus

• Colibaccillosis from Escherichia coli causes severe watery diarrhea, weakness, and death.
• Rotavirus causes scours within 24 hours of birth, watery diarrhea, depression, and green or yellow scours.
• Coronavirus affects older calves (over 5 days old) and is not as depressing as rotavirus.

Haemophilus Somnus

• A gram-negative bacteria that causes bronchopneumonia, fever, head pressing, incoordination, pleuritis, and polyarthritis.
• It affects musculoskeletal and circulatory systems.

Leptospirosis

• There are 6 serovars in total.
• Cattle are the maintenance host for serovar hardjo bovis.
• Infected water source is most common.
• The organism localizes in the kidney, uterus, and udder.
• Infection is inapparent, with reproductive consequences and it is zoonotic.

Mycobacterium bovis

• Causes tuberculosis and is a chronic, slow-progressing disease with vague or no clinical signs which often results in culling.
• It is zoonotic and requires close contact with infectious animals.

Typical Vaccination Schedule: Calves (0-6 Months)

• At 0-6 hours, passive protection from colostrum is provided.
• At 6 weeks, administer IBR-PI3-BVD-BRSV (MLV) and Clostridium spp. (Bacterin/toxoid-7-way).
• At 4-6 months, vaccinate for Brucellosis (Strain 19 or RB51).
• At 6 months, administer IBR-PI3-BVD-BRSV (MLV), Clostridium spp. (Bacterin/toxoid-7-way), and Leptospirosis (5-way bacterin).

Typical Vaccination Schedule: Replacement Heifers

• Pre-breeding (10-12 months): IBR-PI3-BVD-BRSV (MLV), Clostridium spp. (Bacterin/toxoid-7-way), Leptospirosis (5-way bacterin), and Vibriosis (Bacterin).
• 40-60 days before calving; optional IBR-PI3-BVD-BRSVb (Killed virus), Leptospirosisb (5-way bacterin), and Rota and Corona (Killed Bacterin/toxoid) with E. Coli+Clostridium perfringens type C & D.
• 3 weeks before calving: Rota and Corona (killed Bacterin/toxoid) useE. Coli+Clostridium perfringens type C & D.

Milk Fever (Hypocalcemia)

• Shortly before calving, calcium is utilized for colostrum production.
• Calcium in colostrum can be 8-10x greater than in the blood supply.
• Rapid calcium drop and decreased calcium absorption can predispose animals to milk fever.
• Milk fever, which is also known as hypocalcemia, has three stages:
• Stage 1 symptoms (<1 hour): loss of appetite, excitability, nervousness, hypersensitivity, weakness, weight shifting, and shuffling hind feet.
• Stage 2 symptoms (1-12 hours): turning head into flank, dullness, cold ears, incoordination, muscle trembling, and inactive digestive tract where body temp 35.6 – 37.8 °C and heart rate > 100 bpm.
• Stage 3: Inability to stand, progressive loss of consciousness, inaudible heart sounds, heart rate > 120 bpm, and will die within hours.
• Symptoms can include muscular weakness, increased heart rate, subnormal temperature, sternal recumbency, and loss of consciousness.