November 2018 Punch PDF

ARTICLE
3. Welfare issues
● Pododermatitis (foot pad lesions) and hock burn. ● Other leg problems ● Breast blisters.
● Soiled feathering. ● Secondary disease, especially respiratory.
Causes of loss of intestinal integrity
The major reasons revolve around the following aspects:
1. What you are doing - Producers may be influencing the situation, e.g. lack of control of disease, poor biosecurity
or poor environmental control through inadequate or inappropriate ventilation or poor drinker management.
2. What others are doing - This may relate to unwanted challenges from poor regional biosecurity or nutritional effects
due to inappropriate diets, errors in specification, unwanted interaction, etc.
3. What we are forced to do - The restriction towards continuous use of antimicrobial agents due to legislation is bound
to have an effect on intestinal integrity and the ability of the intestine to recover from disease and other toxic challenges.
4. Factors outside our control - Ambient temperature and climatic conditions can affect the producer’s ability to
manage a wet litter problem, especially in very cold/hot weather where there may be difficulties in maintaining suitable
minimum ventilation or where relative humidity is excessive.
These reasons are important in the ability to cope with wet litter problems, but the actual precipitating causes can be
even more numerous and varied. There are a number of ways of categorizing these causes, but they can be broadly divided
into external or internal effects.
External causes include:
1. Feed
● Interruptions, physical quality, ingredients ● Minerals/electrolytes (e.g. potassium, sodium, chloride)
● Protein – quality and quantity or digestibility ● Fats – carbohydrate source (e.g. wheat versus maize)
● Mycotoxins ● Other anti-nutritive factors
2. Drugs
● Anticoccidial choice ● Feed interactions ● Feed errors
3. Environmental
● Ventilation (especially minimum ventilation). ● Structural insulation ● Water and water systems
● Drinker management ● Litter type ● Ambient temperature
Internal causes include:
1. Nutrition
● Physical quality ● Effects of digestibility and viscosity of intestinal contents
● Presence/absence of antimicrobial digestive enhancers
2. Disease: ● Coccidiosis ● Other parasites
3. Viruses
● Coronaviruses ● Rotaviruses ● Enteroviruses ● Adenoviruses ● Reoviruses ● Parvoviruses
● Caliciviruses ● Picornaviruses
4. Intrinsic effects
● Malabsorption syndrome ● Immunosuppression ● Bacteria and dysbacteriosis
Feed and various feed ingredients are commonly blamed as triggers for wet litter/scouring episodes. This is frequently
prompted by a temporal relationship with observed clinical problems. However, on most commercial sites, feed deliveries
are such a frequent occurrence that it would be surprising if an episode of scouring did not occur close to the time of delivery.
In the case of broilers, feed interruption, sudden changes in physical quality and changes in raw material matrix are known
to precipitate conditions such as necrotic enteritis.
Changes in other factors such as mineral/electrolyte composition, protein quality, quantity and digestibility and
carbohydrate source (wheat versus maize) have also been linked to problems with intestinal stability. Bacteria in the intestines
gain their energy for growth from components of the diet. Different bacteria have different preferences for substrates, such
that the chemical composition of the digesta can have a potent effect on the composition of the microbial community of the
intestines.
The physical presentation of feed, pellet versus mash, grist size, whole wheat feeding and other digestibility factors
which can have potent effects on viscosity and time of feed passage are all areas requiring further research.
96 November, 2018