Proper nutrition for animal welfare

Recent studies using continuous behavior monitoring systems show that productive animals retain an instinct that allows them to detect nutritional deficiencies and select diets or ingredients that best meet their needs and compensate for the deficiency (Manteca et al. 2008).

This instinct or food intelligence developed in evolutionary process for survival variety in the natural environment and identify foods that contain all the essential nutrients they need and avoid ingredients that are toxic or harmful to their body.

In conditions intensive and extensive production With low diversity of resourcesanimals do not have access to natural food diversity.

Under these conditions, we must offer them complete food containing all the necessary nutrients, depending on their species, race, age, physiological state, sexual type, productive, sanitary, social conditions, etc.

The task is not easy, but every day we have more and more information and technologies to effectively solve it.

An animal welfare problem that can be linked to nutritional deficiencies or imbalances is tail-eating by fattening pigs.

Tail eating is a complex and multifactorial problem related to environment, ethology, density, pig keeping, etc., as well as nutritional issues.

A prime example of the importance of nutrition to animal welfare is the consequences that an unbalanced or nutrient-deficient diet causes in food-producing animals.

Cases of tail eating may worsen and lead to cannibalism being one of major welfare concerns for pig fattening systems.

It has been known for many years that one of the main factors that can cause this problem is nutrient deficiency or imbalance.

• was associated with diets deficient in salt, iron and amino acids (Frazer, 1987). Thus, the level of salts, macro- and microelements, the amount and balance of digestible amino acids in the diet are key points that need to be reconsidered when faced with this problem.
• In this sense use of ideal protein profiles that favor the production brain serotoninwith adequate levels of tryptophan and restriction of long chain branched chain amino acids, may be useful in reducing aggressive behavior in pigs (LeFloch et al., 2007).

On the other side, nutritional and functional use of fiber in the diets of pregnant sows It has a satiating effect by mobilizing the digestive system, using energy and improving the gut microbiota, with important implications for animal performance, health and welfare (Cerisuelo, 2018).

At the broiler nutritional deficiency and imbalance They can cause pecking problems and coprophagia due to excessive litter consumption, with the subsequent welfare, health, and productivity problems they cause.

• It is a problem associated with certain vitamin deficiencies that alters the birds’ behavior in seeking out faeces and caecal excretions.

Another important factor related to animal nutrition and welfare is the general inflammatory state of the animals.

In conditions intensive production animals are exposed multiple antigenic stimuli from microorganisms, environmental pathogens, etc.

This overstimulation the immune system may have consequences productive harmful when they provoke situations chronic inflammation, subclinical, but with alteration intestinal mucosa and subsequent increase risk of infections, changes in permeability, trend to diarrhea and malabsorption nutrients. is also pain-related factor and situations of allergy and hyperalgesia affecting animal welfare (Pluske et al., 2018).

A balanced diet has numerous plant proteins with antigenic capacitysome of which are identified as anti-nutritional factors and many others are not, which may promote immune stimulation in the gut and induce a pro-inflammatory state (Cano, JL, 2018).

This is especially important for young animals in weaning periodConsidering immature digestive and immune systems. It is during this phase that a massive intake of dietary antigens can induce states of immune hyperreactivity that are harmful to the intestinal mucosa (Modina et al., 2019).

Lipid nutrition also plays a role in this aspect, as the use of high amounts of Ω3/Ω6 polyunsaturated fatty acids has been shown to have a natural anti-inflammatory and immunomodulatory effect by increasing the synthesis of less active prostaglandins and less pro-inflammatory cytokines, with subsequent beneficial effects on intestinal health, animal performance and welfare (Calder PC, 2017).

Another factor that has a significant impact on animal welfare is the gut microbiome.

Recent studies in human and experimental animal medicine point to a link between the microbiome and behavior, modulating anxiety and depression by acting on the sympathetic and parasympathetic nervous systems through bacterial peptides, volatile fatty acids, cytokines, and other compounds.

Information in this regard is still scarce in animal husbandry, but it appears to be another way for the microbiome to interact with the host in a symbiotic relationship (Foster JA, 2016).

Despite all these advances, new knowledge and tools in the field of nutrition, which contribute to the improvement of the nutrition of our animals, there are problems that we must face and solve.

• active recipe systemsvery effective when it comes to optimizing costs and productivity, They leave aside important questions that are not part of optimization inequalities affecting animal welfare.
• Development of diets for large populations of animals with their internal variability does balanced diet is not properly adapted to certain subpopulations far from the average due to physiological, health, environmental, pathological, etc.
• The use of a limited amount of balanced feed in feeding programs also causes a mismatch between the needs of the animals and the nutrients available in the feed, especially when changing from one feed to another.

This is where nutritionists must apply the latest scientific and technological advances and the best criteria to improve formulas and meet these new challenges.