Importance of chicken pigmentation in Mexico

Chicken skin pigmentation is of great importance in countries such as Mexico, China, the Philippines, Peru and some regions of Spain. Consumers in Mexico are among the most demanding when it comes to chicken skin coloration, since they associate yellow and bright tones as a sign of freshness, quality and wholesomeness.

In countries where pigmentation is highly valued, it is important to maintain intestinal welfare since the absorption of pigments and skin coloration depend on it. The challenges and imbalances of the intestinal tract will be evidenced in the alteration of the coloration.

The pigments used will vary depending on the skin tone to be achieved and will depend on the preferences of each country and can increase the costs of the diet between 8-10%.

Among the most important factors that affect the absorption of pigments, deficiency of intestinal conditioner pronutrients and coccidiosis stand out, since they decrease the absorption of pigments at the intestinal level.

This article describes the natural solutions available to improve intestinal welfare and, consequently, skin pigmentation.

Types of pigments and factors that affect pigmentation

There are natural and synthetic pigments. Natural compounds derived from carotenoids such as yellow xanthophylls (lutein and zeaxanthin) are used for chicken skin. In certain regions, red xanthophylls (capsanthin and/or canthaxanthin) are used, which, in combination with those that provide yellow color, achieve golden tones. Among the synthetics, the apo-ester is used to give a yellow-orange color, but its use is limited because its cost is high.

The accumulation of pigments in the skin requires an average of 2 to 3 weeks and this process many factors that affect welfare or intestinal integrity can interfer with it and, therefore, nutrient absorption. The most important factors are:

Infectious:

• Coccidiosis
• Bacterial enteritis

Diet-dependent:

• Deficiency of intestinal conditioner pronutrients
• Concentration, type and combination of pigments
• Concentration of natural pigments present in the diet
• Presence of mycotoxins

Animal dependent:

• Sex (females are more easily pigmented than males)
• Genetic line (there are genetic lines that do not fix carotenoids in the skin)

Natural tools to improve intestinal welfare and skin pigmentation

Intestinal welfare should be considered as a broad concept, which embraces several factors that will have an impact on the skin pigmentation.

Biovet S.A I+D department has developed different technologies that focus on improving intestinal welfare to respond to the most important problems: intestinal optimizer pronutrients and intestinal conditioner pronutrients.

Intestinal optimizer pronutrients

When skin coloration problems appear, the strategies used to control coccidiosis should be reviewed, since it is a very prevalent disease in Mexico and is considered one of the main factors that affect chicken coloration.

In fact, coccidiosis is the parasitic disease with the greatest economic impact in the Mexican poultry industry. The economic losses are represented by the decrease in production efficiency and anticoccidial treatments. The resistance generated by these protozoa to the traditionally used coccidiostats is becoming more and more frequent, which is why it is necessary to develop other solutions, such as intestinal optimizer pronutrients.

The etiological agent is classified within the genus Eimeria, a group of protozoa that multiply in the intestinal tract, causing tissue damage, poor absorption of nutrients and pigments, diarrhea, dehydration, bleeding, and mortality. The subclinical form does not have obvious signs, but it generates alteration of the productive parameters and pigmentation problems.

The new strategies developed by Biovet’s I+D department for the control of coccidia seek to strengthen the local immunity of the intestine by increasing resistance to infestations by this parasite. They are strategies based on intestinal optimizer pronutrients, complex molecules of natural origin that improve the immunity of the intestine through a metagenetic mechanism of action. These molecules activate specific genes that lead to increased interleukin production by local immune cells in the intestine, such as polymorphonuclear cells (PMNs). Interleukins are chemical mediators involved in the recruitment of defense cells (macrophages, lymphocytes, etc.) essential in anti-Eimeria reactions. This way, these pronutrients stimulate local immunity, which breaks the asexual cycle of coccidia, preventing its replication in epithelial cells. Pronutrients are a patented solution that does not generate resistances, since they do not act directly on the parasite, and they do not leave residues, so they do not have a withdrawal period.

In addition, it is a very versatile tool, since it can be used as a single solution, or in combination with coccidiostats (on top or in shuttle programs) to delay the development of resistance and together with vaccination against coccidiosis, to increase its effectiveness.

Intestinal conditioner pronutrients

Industrial conditions generate situations of constant stress in animals and require the use of highly concentrated diets. This, without a doubt, has an impact on different aspects, such as intestinal integrity, nutrient absorption and balance of the microbiota, which compromises intestinal welfare and, consequently, skin coloration.

To achieve a correct use of the pigments present in the ingredients of the diet and the ones in the additives the intestine must express its maximum absorption potential. This can be achieved using intestinal conditioner pronutrients.

Biovet S.A.’s R&D department has studied and patented a natural tool based on these pronutrients. They are complex molecules of plant origin that improve intestinal physiology based on a metagenetic mechanism of action, by which they stimulate specific DNA genes that improve the physiology of enterocytes. They act as an external stimulus that increases the synthesis of functional proteins in enterocytes, which is reflected in a greater regeneration and activity of the cells of the intestinal mucosa, increasing the absorption of nutrients and pigments (see chart 3). This increase in absorption at the digestive level is correlated with the increase in pigmentation (see chart 2).

Increased expression of genes (CD1E, RIMBP2, among others) due to the metagenetic stimulation of intestinal conditioner pronutrients has been identified in enterocytes. These genes are related to specific functions: cell adhesion (tight junctions, key to maintaining intestinal integrity and welfare) and proliferation, nutrient absorption, immune system, and metabolism.

Conclusions

Chicken skin pigmentation is a feature that is very important in Mexico, where consumers demand chickens with bright yellow skin. Natural solutions (pronutrients) focused on improving intestinal welfare are an excellent strategy to improve pigmentation and productive parameters, since a greater absorption of pigments at the digestive level means that there is a greater amount of these substances available to be deposited in the skin.

Coccidiosis is a problem that directly affects pigmentation. Improving local gut immunity with the use of gut optimizer pronutrients is an effective tool. The use of these pronutrients together with anticoccidial vaccines showed good efficacy in controlling the excretion of Eimeria oocysts, achieving a reduction of 84% compared to the control and almost 20% less than the batch that received only the vaccine.

For a correct use of the pigments, enterocytes must express their full absorption potential. In this sense, the different tests with intestinal conditioner pronutrients showed evident improvements in the use of pigments: it was possible to increase the absorption of lutein by 42% and an evaluation by reflectance colorimetry confirmed their good performance as enhancers of chicken coloration.

The intestinal optimizer pronutrients are produced and marketed by Biovet S.A under the name Alquernat Zycox.

Intestinal conditioner pronutrients are produced and marketed by Biovet S. A. under the name of Alquernat Nebsui, also available in combination with xanthophylls, Alquernat Pigmentante L Premium.

Bibliographic references:

• Borrell, J. (2005). Use of pronutrients of natural origin in veterinary medicine. RACVE (Royal Academy of Veterinary Sciences of Spain).
• Alquernat Zycox trial combined with a coccidiosis vaccine in Eimeria challenged broilers, Southern Poultry Research Group (SPRG), USA, 2020.
• Trial of the use of Alquernat Nebsui in broilers against BMD and halquinol, Universidad Nacional de Colombia, 2020.
• Ekaitz Maguregui (2020), The color of the egg yolk and pigments, veterinariadigital.com.