Feed & Additive Magazine Issue 4 May 2021

SPECIAL STORY FEED & ADDITIVE MAGAZINE May 2021 43 production animals. Its verdict is unfavorable, that is, the environmental risk exceeds the pharmacolog- ical benefit, and there are also no effective measures to manage or eliminate the environmental accumu- lation of Zn. In addition to the environmental risk, there was the risk of co-selection of antimicrobial re- sistance, although it was not quantifiable. Despite finding a multitude of formulations already approved on the market, the revocation of the mar- keting licenses of all of them is recommended (up to 80 marketing licenses coexisted in 2015 throughout Europe). Resolution, on June 26th 2017, set June 26th 2022 as the deadline for the use of prophylactic ZnO, while valid alternatives to the use of ZnO were found and the appropriate measures were taken to cushion the transition. Despite the above, its use as a nutritional ingredient is still authorized, since Zn is a mineral necessary for the correct functioning of enzymatic processes, immune system, contributes to the stability of cell membranes, and even intervenes in the transcription of polynucleotides. In the absence of just over a year for the implemen- tation of the ban, and in conjunction with the global framework of disuse and responsible consumption of antibiotics, several alternatives are postulated as ideal substitutes for ZnO. THE ERA OF FUNCTIONAL INGREDIENTS The appearance of post-weaning diarrhea is a mul- tifactorial process, which can be approached from several fronts. It appears due to stress processes, which occur with inflammation and oxidative le- sions. The alteration of the intestinal flora is also a key factor, so in addition to reducing stress at this stage, we must adjust the nutrients (protein, fiber, sugars, fats, ...) and their digestibility so that the ex- cess or lack of them do not generate dysbiosis. Some antinutritive factors and toxins can damage the mu- cosa, making it easier for opportunistic microorgan- isms to attack. And we cannot forget the presence of pathogenic bacteria, such as E. Coli, which can cause severe damage to the intestinal mucosa and trigger inflammatory processes that will decrease the growth and animal welfare. All these needs make one type of product stand out from all the others. Functional products capable of providing not only nutrients in a balanced way, but also bioactive molecules capable of, for example, neutralizing pathogenic microorganisms or accelerat- ing the maturation of the intestine of young animals. In this line, we find both plasma and egg powder, whose effectiveness has been demonstrated on many occasions, mainly in early weaned animals and with special effectiveness in unhygienic environments and with highly challenging conditions. These beneficial effects are the result of many factors, highlighting its high content in IgG in the case of plasma, and IgY in the case of eggs, since both types of immunoglobu- lins decrease the binding of pathogens and toxins to the intestinal mucosa. Plasma and egg also provide bioactive molecules such as growth factors and cyto- kines, with the ability to accelerate the maturation of the intestine in recently weaned animals. Another benefit is the lack of antinutritional factors. FAMILIAR PRODUCTS, NEW ALTERNATIVES There are multiple studies that have demonstrated the efficacy and high value of plasma and egg powder as a functional ingredient, as evidenced by the me- ta-analysis carried out by Remus et al in 2013, or the study carried out by Harmon et al. published in 2000.