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Health 1

To be successful with a coccidiosis vaccination,  we must maintain the litter humidity at about 25-30%.
I even tried spraying water on the litter, but 2 hours later, the moisture in the litter dropped to only 10%.
How do I overcome this challenge?

Indeed, litter humidity is one of the main factors for a successful vaccination.
In your case, I am assuming that you are using rice hulls which have low moisture absorption and high moisture release. So, even if you spray the litter, the moisture is not retained in the litter, especially during the first days of life. Subsequently, the droppings will increase the humidity of litter. (If it is not enough, spray 3 to 5 times a day with a small amount of water).
To improve the conditions during the first days of life, and to allow the first sporulation (around 5 to 9 days post vaccination), I will advise using wood shavings or wood shavings mixed with rice hulls, because wood shavings will be able to capture humidity.

Is it advisable to keep broiler breeders on a 5/2 or 6/1 feeding program during a coccidiosis outbreak?

In a coccidiosis outbreak, the birds will not eat properly. Then, thanks to the chemical treatment, they will recover quickly, but the body weight of the birds will not be uniform.
The goal will be to increase the uniformity as soon as possible, so I encourage you to stick with your usual feeding program (5/2 or 6/1). Indeed, a daily distribution will enhance the growth of the healthiest birds, and the weakest ones will not eat enough.

Many housing systems use slatted floors.
What will be the challenge facing with a coccidiosis vaccine?

On slat, the main issue will be the recycling of the oocysts. The birds must stay permanently and for a long time (at least 1 month) to peck the vaccinal oocysts contained in the droppings.
Usually, adding paper will help. The quality of paper is the key to absorbing water efficiently and not to releasing it too quickly. (ideally 250gr/m²).

Health 2

What could be the cause of the feces-eating behavior in young chicks?

Pecking is a natural behavior. Early in their life, they peck to determine what they can eat and drink.
Wild birds are foraging and scratching to look for food sources, and coprophagia helps them to find extra-food (undigested grains, insect eggs and larvae, worms, etc.).
Our commercial birds have not lost this habit, which also leads to health problems such as coccidiosis, salmonella, etc.

What is the best organ to sample for PCR in IBH (FAdV)?

Cloacal samples, as well as affected organs (liver, pancreas, caecal tonsils), are perfect for carrying out FAdV analyses. But the PCR will detect the presence of FAdV easily without indicating the virulence of the virus. So, I do not recommend PCR for diagnosis but for monitoring existing FAdV strains if the flock is healthy.
In the event of an outbreak, I recommend diagnosing the disease first by histopathology and taking samples from the liver, spleen and caecal tonsils for PCR or virus isolation. (This should be done a few days after the onset of mortality).

Is ELISA a good tool for monitoring FAdV? If so, what level of titers indicates protective titers or active infection? Do we have a threshold to interpret ELISA result?

The short answer is: ELISA is not a good tool to monitor FAdV infection.
Interpretation of FAdV ELISA is not easy unless the results are negative (this can happen but rarely), meaning that the flock has not been infected.
ELISA analyses are not specific to one serotype, so, a positive result (>6000) may show contamination by a pathogenic or an apathogenic virus.
However, to assess the vaccination, ELISA might be useful and the titres expected are higher than 10,000.

Health 3

How can we improve the development of the villi?

Physiologically, upon hatching, the intestinal crypts which contain stem enterocyte cells start to multiply. The new enterocytes will migrate from the crypts to the villi. This process needs nutrients to build and multiply these cells.
Early feeding and water intake, as well as, highly digestible nutrients in the diet, will ensure optimal development of the villi.
Many factors can interfere with feed intake or intestinal health and affect the villi's development. This includes: Mycotoxins, low or high body temperature, poor ventilation, poor water quality, poor biosecurity (higher risk of immunosuppressive diseases).

What is the normal population level of Clostridium Perfringens in poultry gut?

The normal population of C. Perfringens is up to 105cfu/g in the intestine. However, not all C. Perfringens are highly virulent, some of them are part of the commensal bacteria population.
Furthermore, necrotic enteritis is a multifactorial disease. Outbreaks occur due to a high number of pathogenic C. Perfringens combined with predisposing factors.

What are the root causes of greenish droppings?

Greenish droppings mean that the bile has not been reabsorbed into the duodenum. This is usually due to rapid transit by enteritis for example.
An investigation should rule out infectious diseases such as Newcastle disease, Avian Influenza or worms, and all the causes that can lead to bacterial dysbiosis (feed and water quality).
Regulation of transit and proper feed intake will help birds to recover.

Health 4

How does an aggressive feed increment during lay cause an increase in the percentage of hen mortality?

The most critical moment will be around the onset of lay. Indeed, at that period, the feed intake will be used for metabolism, growth and egg production.
If the feed increment is higher than the need of the female, the sexual maturity will accelerate and result in over-stimulation of follicle development from onset of lay to around 35 weeks old.
You can observe:
- Prolapse.
The excessive energy will be stored in fat and lead to prolapse. This is because the elasticity of the vent muscles will not contract enough to replace the distal part of the oviduct into the cloaca. On top of that, egg size due to double yolk eggs will also facilitate prolapse with the above.
- Prolapse, Double yolk, egg peritonitis, internal laying.
The ovary will be overstimulated, an excessive number of follicles larger than 1 cm will be developed (meaning that they are large enough to enter in the laying process). As a result, 2 follicles can enter in the infundibulum and trigger double yolk eggs, internal laying, egg yolk peritonitis and prolapse.
- Calcium tetany: aggressive feed increment can lead to excessive egg production and a tremendous demand for Calcium. Indeed, calcium intake will not be high enough to cover the needs of eggshell production.
On top of that, the tetany leads to fatigue, as the hens lay down, they can be the victim of aggressive males attracted by the “mating” position.
-Sudden Death Syndrome due to re-feeding syndrome (Phosphorus/Potassium imbalance).

What will happen if we give more calcium to hens before laying starts?

Higher calcium intake (>1.2%) before egg production may exacerbate Calcium tetany.
If we provide high calcium before egg production, then broiler breeder pullets will remove the excessive calcium, this mechanism should be ended when hens start to lay egg.
Some hens still maintain the excretion mechanism after laying, which will cause blood calcium level to drop significantly and develop muscle contraction failure with paralysis and blood circulation disturbances.

If the flocks are already overstimulated, how can we overcome this?

If hens are already overstimulated, it means that you experience higher hen mortality because overstimulated flocks usually have higher mortality. So, you may need to slow down the allocation of feed by 3-5 days from your actual target.  Higher mortality will be inevitable, but you may mitigate it.

Health 5

 How often can the water line be flushed with Hydrogen Peroxide (H2O2) during production? What is the safest dose and duration of flushing?

Flushing the lines with hydrogen peroxide during production is an excellent practice if done correctly.

  1.  If the water lines have not been thoroughly cleaned during the downtime, it may be risky to start it during the production period. Indeed, the biofilm will be released in abundance in the water pipes and will deteriorate the water quality. Nipples may clog by the buildup of dirt.

  2. Suppose effective cleaning and disinfection is implemented during the downtime (flushing with high pressure, oxygen peroxide to remove biofilm, acids to remove minerals).

In this case, a regular shock with hydrogen peroxide can be performed with 2% solution for 4-6 hours for example (every week will be perfect).
If you want to give a shock treatment, the birds will not be able to drink the water due to the high level of peroxide (follow the recommendations on the leaflet). To prevent mistakes, you must treat at night and lift the lines during the process. The next day, make sure that the entire water line is flushed before providing water to the birds.

   3. Target 25-50ppm for safe residue in drinking water.

What are the effects of high levels of iron (2.5 mg/L) in water on the gut health in broiler breeders?

The maximum acceptable level is around 0.3 mg/L. In high concentrations, iron accumulates in water lines and reduces their diameter and clogs the nipples. These rough surfaces allow the development of biofilms (and multiplication of bacteria), leading to poor water quality and consequently bacterial dysbiosis.
Birds are tolerant of iron metallic taste but high iron causes leaking drinkers and promotes the growth of E. coli and Pseudomonas, and could lead subsequent disturbance in normal gut flora.

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