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Sick Animals Cost You Money - That's Not News. But Merial Has a New Approach to Dairy Herd Health. That IS News!
Health Issues in Dairy Herds
Although the threats to dairy animal health vary depending on the stage of a given animal's life, there are a number of health issues common to your dairy operation, including:
Parasites
Internal and external parasites, such as stomach worms and lice, are organisms that feed on a host animal’s tissue, blood, and tissue fluids and can interfere with productivity and performance.
- Internal parasites can cause appetite suppression, reduced feed digestibility and nutrient absorption, blood loss, and anemia, which in turn can lead to decreased weight gain and milk production, weakened immune system, and tissue and organ damage
Liver fluke (Fasciola hepatia) can cause loss of appetite, weakness, and weight loss, which can lead to decreased weight gain, reduced overall performance, lower weaning weights, liver condemnation, and death
Cooperia spp (small intestinal worm, cooperids, cattle bankrupt worm)
Dictyocaulus viviparus (cattle lungworm)
Haemonchus placei (large stomach worm)
Nematodirus helvetianus (thick-necked intestinal worm, thread-necked strongyle)
Oesophagostomum radiatum (nodular worm)
Ostertagia ostertagi (brown stomach worm)
Strongyloides papillosus (intestinal threadworm)
Toxocara vitulorum (large roundworm)
Trichostrongylus axei (stomach hair worm)
Trichuris discolor (whipworm)
- External parasites can cause sores and scabbing, blood loss and anemia, and skin irritation, and act as a disease vector. The effects of external parasites on production can include decreased weight gain and milk production, hide damage, and damage to facilities and fences from rubbing and scratching
Chorioptes bovis (chorioptic mange)
Damalinia bovis (red louse, biting louse)
Haematopinus eurysternus (short-nosed cattle louse)
Hypoderma bovis (ox warbles, cattle grub, heel fly, bomb fly)
Linognathus vituli (long-nosed cattle louse, blue cattle louse)
Sarcoptes scabiei (mange mite)
Haematobia irritans (horn fly)
Pasteurella
The most significant Pasteurella spp in cattle are P. haemolytica (Mannheimia) and P. multocida, which are major contributors to bovine respiratory disease complex (BRD), aka “shipping fever.” Haemophilus somnus can also play a role and viruses may or may not contribute. A number of environmental, host, and pathogenic factors contribute to BRD. Weaning, transport, commingling, and crowding exert stress on cattle, compromising the animals’ immune and nonimmune defenses. These conditions also favor transmission of infection among animals. Shipping fever generally appears in feeder calves a week to 10 days after arrival in the feedlot. Morbidity is ~35%; mortality is 5-10%.1
Clostridial Disease
Clostridial disease is the result of a bacterial infection of the muscle that causes swollen muscles or sudden death. The disease typically strikes animals younger than two years old – calves that appear to be doing well. Although signs of clostridial disease can include lameness and depression, often the only “symptom” is a dead calf.
Coccidiosis
Coccidiosis typically affects groups of growing cattle that are between 1 month and 1 year of age. Subclinical coccidiosis is characterized by calves that seem unthrifty and have soiled rear quarters. In light infections, feed efficiency may be compromised. In more serious infections, cattle develop thin, bloody diarrhea with mucus and pieces of epithelium. Additional signs include fever, depressions, dehydration, weight loss, and secondary complications such as pneumonia. Cattle that survive acute coccidiosis may not compensate for the weight lost during the illness.
Cystic Ovary Disease
Cystic ovary disease, also known as "bulling," can occur in individual animals or a herd. The signs of cystic ovary disease can vary - they can include unusual behavior such as frequent estrus and "bull-like" behavior, including mounting, pawing on the ground, and bellowing. The disease is primarily a disease of dairy cattle and is more common among certain family lines. While it appears that cystic ovary disease is associated with high production, it may be that higher producing cows are more likely to be examined and the disease discovered. When cystic ovary disease is suspected in a herd, the cysts should be confirmed to be cysts and not some other structure, and the herd's incidence of postparturient complications and stress should be assessed. Producers should also make sure they're checking their cows at regular intervals.
Pinkeye
Pinkeye is an acute, contagious condition caused by Moraxella bovis and, to a lesser degree, infectious bovine rhinotracheitis (IBR) and Mycoplasma. Affected cattle are teary eyed - as the condition progresses, mucous may develop in the eyes. Both eyes can be affected. Dry and dusty conditions, stress due to shipping, and irritants such as pollen, grass, and flies can predispose cattle to pinkeye or make the condition worse. The course of the disease ranges from a few days to several weeks.
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