REPORT OF TECHNICAL INQUIRIES RECEIVED
Review period: 26/12/2022 to 31/12/2022

POULTRY

• The relationship between Vitamin D3 dosage and egg laying drop.

Vitamin D3 regulates the intestinal absorption of calcium, phosphorus, and magnesium, as well as their metabolism and homeostasis. It is also involved in bone mineralization and eggshell formation. Furthermore, it plays an important role in immune function, with immunomodulatory, antioxidant, anti-inflammatory, antibacterial and antiviral properties.

Several causes can generate an egg laying drop, both infectious and non-infectious.

Whether due to illness, age, heat stress or lack of light, the addition of a high dose of Vitamin D3 increases the absorption of calcium from the diet. Moreover, it enhances the ability to promote the mobilization of calcium stores from the bones, thus increasing the availability of calcium for the eggshell formation and decreasing the laying drop.

• Causes of the increase of Sinusitis-Tracheitis-Synovitis Syndrome in Turkeys

Sinusitis-tracheitis-synovitis syndrome consists of a triad of symptoms in birds, beginning with infection and inflammation of the infra-orbital sinuses (sinusitis), known as swollen head.

The pus that forms in the sinuses, due to sinusitis, travels through the neck (tracheitis), subcutaneously, continues through the breast until it reaches the heel of the animal’s leg, where it accumulates in the tendon pocket causing synovitis.

The inflammation of the sinuses occurs in animals from 25 to 26 days of age, with the shortening of the age at slaughter, the other two symptoms are no longer observed in conventional farms.

However, with the emergence of organic production and the increasing age of the animals for slaughter, the other two symptoms, especially lameness due to synovitis are beginning to be observed.

A good characterization of the microorganisms causing sinusitis would allow its treatment with specific antibiotics before the infection spreads and leads to complications in older animals.

SWINE

• Causes of the increase of Atrophic Rhinitis

Atrophic Rhinitis => swine infectious disease characterized by serous or mucopurulent nasal discharge, shortening or deformity of the face, atrophy of the nasal turbinates and reduced productivity.

Environmental and management factors may contribute to the severity and incidence of this disease.

The possible causes of an increase in the disease can be: inefficient ventilation, overcrowding of animals, temperature fluctuations, humidity in farrowing pens, weaning and fattening, non-vaccination of breeders, or not following the all-in, all-out procedure, from weaning to slaughter, that allows a good sanitary emptying

AQUACULTURE

• Inclusion of fungi in salmon feed

The composition of salmon feed is changing, it has gone from being based on fish oil and fishmeal to containing an increasing percentage of plant-based ingredients, such as soybean meal or rapeseed oil.

In recent years, alternative ingredients have also been included, such as insect meal, single cell proteins, fermented products, and microalgae.

Mushrooms are also an option, as they are a source of high biological value proteins, polysaccharides, vitamins, minerals, various antioxidant and phenolic compounds, nucleotides, and polyunsaturated fatty acids.

There are different fungal products that are in the study phase or are already being used in fish feed: such as mushrooms (fruiting body of fungi), filamentous biomass from fungiculture, yeasts, fermentation products or mycoproteins.

CUNICULTURE

• Relationship of cecotrophy with the microbiota

Cecotrophy is a digestive strategy of the rabbit that allows it to take advantage of the nutrients resulting from the cecal fermentation of small fibrous particles.

The strategy is based on the consumption of a type of soft feces (cecotrophs) that are formed in the cecum by fermentation of the dietary short fiber.

In this way, they take advantage of the nutrients produced by the microbiota of the cecum, especially the microbial protein rich in essential amino acids, water-soluble vitamins (B complex) and volatile fatty acids, an energy source for bacteria and for the rabbit.

This digestive strategy allows them to use fiber as the basis of their diet, without the need to store large amounts of food, unlike other herbivores such as horses or cows.

They must have a healthy and diverse microbiota for this strategy (cecotrophy) to provide them with the nutrients that they cannot obtain directly from their diet.

FEEDS

• Relationship of calcium, phosphorus, and magnesium levels in feed for layers of different ages

In layers, calcium (Ca), phosphorus (P) and magnesium (Mg) are essential minerals for growth (bone formation) and egg production (shell formation).

The metabolism of all 3, especially P and Ca, is closely related, so that a deficiency or excess in the diet of one can interfere with the utilization of the other and have negative effects on the bird growth and the egg quality.

Therefore, the amount of each of the minerals is as important as the relationship between them. In layers, throughout their growth and productive life, this rate changes according to their productive needs.

The ratio between Ca and P, during the first weeks of life of the pullets (0-15 weeks) is around 2:1, two of Ca for one P. This proportion starts to increase with pre-laying feeds (5:1), laying feeds (7:1) and end-laying feeds that can reach up to 12:1, depending on the productive life of the animal.

The relationships of Mg with the other two minerals are not so well studied, but it is known that an excess of Mg interferes with the availability of both Ca and P, and its needs are more similar to those of P than to those of Ca.

Bibliography:

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• https://www.veterinariadigital.com/post_blog/sindrome-sinusitis-traqueitis-tendinitis/
• https://www.woah.org/fileadmin/Home/esp/Health_standards/tahm/3.08.02_Rinitis_atr%C3%B3fica_porcina.pdf
• https://www.thepigsite.com/disease-guide/atrophic-rhinitis-ar-progressive-atrophic-rhinitis-par
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