Reproductive diseases in dairy cattle - Cooks Community

Reproductive diseases in dairy cattle

Description

Animals affected

Common names

Causes

Contributing factors

Clinical signs

Disease management: prevention

Disease management: treatment

Economic impacts

Description

Reproductive diseases can have devastating economic consequences to a dairy. Abortions, stillbirths, weak or persistently infected calves, strung-out breeding cycles and open cows all diminish the profitability that comes from reaching the goal of maximizing the lactation period. While some reproductive diseases have highly visible consequences, such as late-term abortions, many do their work silently, with the results unseen for weeks or months.

Bovine virus diarrhea (BVD) virus is easily spread from acutely or persistently infected cattle. In pregnant cows, BVD virus crosses the placenta and infects the fetus.

If a non-immune cow is exposed to BVD in her first trimester, abortion can result or she may give birth to a stillborn or persistently infected (PI) calf. If BVD infection occurs before the calf's immune system has fully developed (in utero), the calf learns to recognize the virus as part of itself. This results in either a healthy calf that constantly sheds (spreads) the virus or weak, stunted calves.

The IBR virus can become latent in the animal following exposure and then be reactivated by stress. This can lead to shedding that triggers disease outbreaks in herds where there is no visible source of infection.

Leptospirosis is a highly contagious disease that can be transmitted from cattle to humans. The bacteria are quite hardy and can survive in standing water for up to 10 days; chronic carrier animals can shed the bacteria for years. Leptospires are harbored in the kidneys and shed in urine, easily contaminating pastures, drinking water and feed. Infected animals may have bloody, wine-colored urine and a marked decrease in milk production.

Campylobacteriosis (vibriosis) and trichomoniasis are both spread by infected bulls. Abortion and other outward signs of infection are rare; temporary infertility and strung-out breeding seasons are the most common effects.

Neosporosis is a parasitic disease of growing concern around the world, especially in dairies. Infected cows abort at 5-6 months gestation, or give birth to persistently infected calves that maintain the infection in the herd.

Brucellosis is a reproductive disease that affects both bulls and cows, causing late term abortion and infection of the male accessory glands. The disease, which is associated with undulant fever in humans, has been nearly wiped out in the United States.

Animals affected

First-calf heifers, bulls and mature cows are all susceptible to reproductive diseases. Cows exposed to BVD virus in the first trimester of pregnancy are at high risk of delivering persistently infected calves. Health library: Persistent BVD Infection and Mucosal Disease.

IBR, leptosporosis and neosporosis can also cause abortions in the second half of gestation. Cows that are artificially inseminated are at lower risk of infection than those using natural service are. Heifers are more susceptible to vibriosis than mature cows.

Common names:

IBR, BVD, lepto, leptospirosis, neosporosis, vibrio, vibriosis, brucellosis, Bang's disease, trichomoniasis, trich, mycotic infection, open cow diseases, infectious pustular vulvovaginitis (IPV)

Causes

?Viruses: Bovine herpesvirus (infectious bovine rhinotracheitis, infectious pustular vulvovaginitis), Bovine virus diarrhea virus (BVD)

?Bacteria: Campylobacter fetus (vibriosis), Leptospira spp., (leptospirosis) Brucella abortus,(brucellosis) Haemophilus somnus (somnus)

?Protozoa: Neospora caninum (neosporosis), Tritrichomonas foetus (Trichomoniasis or trich)

Contributing factors

?Natural service vs. AI

?Heat stress

?Poor nutrition

?Contact with contaminated tissues (aborted fetuses)

?Transmission via other species and vermin (farm dogs may play a role in neosporosis, for example)

?Contaminated feed and pastures

Clinical signs

?Early term abortion (IBR, BVD, vibriosis, trichomoniasis)

?Late term abortion: (IBR, lepto, neosporosis)

?Retained placenta (Brucellosis)

?Extended breeding season (vibrio)

?Low calving rates (vibrio)

?Temporary infertility (IBR, BVD)

?Decreased libido (IPV)

?Decline in quantity and quality of milk (lepto)

?Early embryonic death (BVD, vibriosis, neosporosis)

?Immune suppression (BVD, IBR)

?Neurological damage (BVD, neosporosis)

?Weak, stunted or deformed calves (BVD, neosporosis, lepto)

?Persistent infection (BVD, neosporosis)

?Bloody, port-wine colored urine (lepto)

?Rough, dry hair coat (lepto)

?IBR and BVD also cause respiratory diseases

Disease management: prevention

The key to preventing reproductive disease is vaccination and management. Management tips:

?Isolate or cull infected cows to reduce herd contamination

?Test infected animals to determine specific cause of disease and to diagnose persistent infection

?Test and vaccinate replacement stock and breeding bulls for disease prior to introduction into the herd

?Use artificial insemination to reduce risk of natural infection

?Handle and store feedstuffs properly to reduce risk of contamination

?Avoid contact between dogs and cattle to prevent spread of neosporosis and leptospirosis

?Rodent control can help control neosporosis and leptospirosis

Your reproductive vaccination program should include protection against:

?IBR, BVD

?Leptospirosis

?Vibriosis

?See Health programs for specific vaccination suggestions for cows and calves

Pfizer reproductive vaccines : Bovi-Shiel d? 4+L5, CattleMaster? 4+L5, Leptoferm? 5, Vibrin?

Disease management: treatment

Most reproductive diseases do not respond well to antibiotics. In the case of viral disease, antibiotics are not effective, but they may help treat secondary infections of bacterial origin. Your veterinarian plays a valuable role in accurately diagnosing disease and suggesting the best therapeutic and management options.

Economic impacts

Losses to reproductive disease include:

?Fewer calves to be sold for beef or to be raised as replacements

?Feed costs for open cows

?Health care, diagnostic, treatment and veterinary costs

?Time and money spent on re-breeding (estrus synchronization, semen, embryo transfer)

?Lost milk production

Increased production costs

Each open cow costs an estimated $2.50 per animal per day for feed, lost milk production and lost calf.21

Increased reproduction costs

The cost of rebreeding can vary greatly, depending on the type of synchronization, heat detection, insemination method used and cost of bull semen (if using artificial insemination). The repeat breeding rate in US dairies is estimated at approximately 50-60 percent, due to a variety of causes ranging from physiological abnormalities to viral and bacterial diseases. Repeat breeding means reduced milk production, fewer calves to sell, cull costs and replacement costs.

With some diseases, reinfection or persistent-infection may extend into the next breeding season. If that happens, the loss multiplies. In addition to the expense of feeding an open cow for another year, rebreeding her and expending management time, the cow may have a reproductive disease that prevents her from conceiving, or she may produce persistently infected calves. It is important to identify the cause of abortions and reproductive losses and, with that information, determine if the open female should be culled.

Decreased milk production

Peak milk production is reached shortly after calving, with a gradual decline in production until the cow is dried off, usually 45-60 days before her next calving. Cows that do not breed back quickly after calving have an extended dry period and may not produce enough milk late in lactation to remain profitable.

Some reproductive diseases including IBR and leptospirosis cause a drop in milk production. Mastitis, which is characterized by reduced milk production, is occasionally caused by leptospirosis.

References

? 2000, 2001, 2002 Pfizer Inc. All rights reserved.

The product information provided in this site is intended only for residents of the United States. The product discussed herein may have different product labeling in other countries.

The health information contained herein is provided for educational purposes only and is not intended to replace discussions with a health care provider. All decisions regarding patient care must be made with a healthcare provider, considering the unique characteristics of the patient.

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