SALMONELLA can affect cattle during every stage of production, including when pregnant and on feed. It's a particular issue for young calves in high density environments.
Treatment of infected cattle is challenging, made more difficult because the control of an outbreak can't be achieved using antibiotics. There is also no vaccination program.
Control requires an understanding of how the disease occurs and the aggressive implementation of appropriate control strategies.
There are three forms of disease caused by salmonella: enteric, systemic and inapparent.
It's the enteric form that is characterised by foul-smelling, brownish, watery diarrhea with shreds of mucous, fibrin and fresh blood that's the most obvious. Infected cattle are usually affected suddenly, quiet, and off their feed.
The most likely sources of disease are usually rats and mice and/or contaminated feed and water.
Salmonella is transmitted primarily by the fecal-oral route. This means that fecal contamination can occur with anything that goes in an animal's mouth e.g. water, feed, hay, and even oral medication equipment.
It's also important to recognise salmonella carriers are more likely to shed the bacteria when they are stressed, particularly in hospital and receiving pens. These should be focal areas for control and prevention.
Salmonella carriers are more likely to shed the bacteria when they are stressed, particularly in hospital and receiving pens.
- Toby Doak, Alltech Lienert Australia
The source of infection can be difficult to determine, although carrier animals introduced to a herd are considered the most common source.
Diagnosis can only be confirmed with the culturing of the bacteria from manure or tissue. Affected feedlot animals are commonly in poor condition or die suddenly.
Many cases in feedlots have an unusual form of chronic broncho-pneumonia with abscesses present in esophagus. It is these animals that are often wrongly diagnosed as having BRD.
Hay should be fed in racks or bunks, not on the ground where it will become contaminated with faeces.
It is also important to scrape feedlot pens regularly to remove organic matter, promote drying and expose bacteria to UV sunlight.
Plus, avoid using the same loader bucket to clean pens and move feed. Also don't walk in the bunks when entering and leaving pens.
Actigen reduces morbidity
In conjunction with a clean feedlot environment, preconditioning animals prior to feedlot entry and during the starter ration period will improve immunity levels.
A nutritional supplement like Actigen will reduce the incidence of morbidity by helping overcome the stresses associated with transport and social adjustment.
Research shows establishing a good immune response can reduce morbidity by 6pc and mortality by 0.7pc.
Actigen is a complex carbohydrate that binds pathogens including salmonella in the intestinal tract, lowering the pathogen load and increasing nutrient absorption.
Actigen is fed at 10 grams/head/day and costs about 16c/head/day.
- Toby Doak is a livestock nutrition advisor with Alltech Lienert Australia.
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