Many additives have become an indispensable part of both animal and human nutrition. However, as consumers become more conscious and aware, dozens of questions appeared in their minds. Over time, the significance of using these additives will be more clearly understood in order to obtain an optimum quantity and more economical as well as healthy, quality and safe products.

Dr. Bahadır SOYUDAL Doctor of Veterinary Medicine Yem-Vit Devenish

The increasing world population brings food and water issues together with it. The problem has become even bigger when combined with environmental pollution and the deteriorating ecosystem. For this reason, the quantity of animal products to be obtained from one unit of feed is as important as the quantity of crops obtained from one unit of feed for obtaining herbal products. They need high nutrition in order to ensure high efficiency while maintaining healthy lives.

A basic nutritional formula that meets only the protein and energy needs is not enough for all the activities in the metabolism of high-performance animals. Therefore, when preparing the feed formula, feed additives such as vitamins, minerals and amino acids sufficient to meet high physiological activity should be added to the feed ration, as well as the basic raw materials that will create protein and energy.

What is a feed additive? What should the features be? According to the European Commission, feed additives are defined as substances used in animal feeding in order to improve the quality of feed or animal products or to improve the health and performance of animals by increasing the digestibility of feed materials.

First of all, the effect of a material defined as a feed additive should be demonstrable through scientific methods. However, they must be detectable in both feed and animal products. Only in this way can its effects on both human and animal health and the environment be monitored.

What are feed additives? How did the need for feed additives come out? Feeds in today's commercial animal breeding are expected to be safe, healthy and economical. At the same time, it is necessary to ensure the same quality every time. In addition to the desired nutritional value, taste, texture and shelf life, it is necessary to use certain special substances in order to provide the highest benefit. Feed additives have been classified in accordance with the properties of the compounds needed by the animal and expectations from the feed.

We can list and explain them by examples;

TECHNOLOGICAL ADDITIVES Technological additives do not directly affect the nutritional value of the feed but change the hygienic properties or processability of the feed. Thus, it increases the consumability and availability of feed.

For example; bacterial contamination, mold growth and the formation of mycotoxins in parallel with it all of which may occur in feed raw materials or the presence of anti-nutritional factors in feed raw materials can negatively affect feed digestibility, pelletizability and even animal health. In such cases, feed additives to help eliminate these factors are in the category of technological additives. Examples of this group are preservatives, antioxidants, emulsifiers, acidity regulators and silage additives.

NUTRITIONAL ADDITIVES Nutritional additives consist of specific nutrients that are essential for optimum growth and optimum yields, such as amino acids, vitamins, and trace elements.

Yield levels achieved in today's livestock have emerged as a result of intense genetic selection (not genetic manipulation or gene engineering) that has been achieved over many years. Selection studies based on yield characteristics have increased the genetic structure and thus the physiological potential of animals to a high level in order to enable high yield. Therefore, in order to support the high yield provided by high genetic potential, using only feedstuff is not sufficient, this should be supported with feed additives with different structures.

SENSORY ADDITIVES Sensory additives are feed additive groups that help to improve the appetite and feed consumption by affecting the properties of feed such as taste, texture, and smell. Ruminants, horses and pet animals, like humans, do not want to consume feed raw materials or feeds prepared using these raw materials of which taste, smell or texture they do not like. In addition, a process implemented on feed raw materials or a feed additive used for another purpose may change one of these impacts in the feed. In such cases, substances that will help improve the sensory properties of the feed - especially flavor enhancers such as vanilla and orange - are used to encourage animals to consume feed and prevent spoilage of feed consumption.

ZOOTECHNICAL ADDITIVES Zootechnical Additives is a feed additive group that does not contain any nutrients but affects the amount of nutrients to be obtained from the feed as a result of the digestion. These additives improve digestive system health, nutrient digestion, and nutrient absorption. In addition, the additives in this group not only increase animal health and feed utilization but also have a positive effect on the amount and character of waste material littered to nature.

The nutritional and environmental conditions that young animals are exposed to during their growth period affect the yield performance during the entire adulthood stage. For this reason, the development of the digestive system is very important, especially in the growth period. The functions and capacities of the digestive systems are not fully developed when both poultry and ruminants are born. In this period, digestive systems are not physically sufficient, and not all enzymes necessary for effective digestion can be secreted in sufficient quantity. Since the immune system, which is another important factor besides digestive function, is not sufficiently developed, particularly digestive systems are open to all kinds of microorganism settlements.

The digestive system is sterile in newborn animals, but as soon as they get into contact with the environment, microorganisms begin to colonize the digestive system. Although E. coli is the first microorganism to colonize the digestive system, it is expected that Lactobacillus and Streptococcus species replace them in a short time and form the majority in the intestinal tract. However, in some cases which may lead to impaired immunity or intestinal health pathogen microorganism colonization can exceed the Lactobacillus spp. level. This is a frequent situation in young animals and may cause animal health and economic damages. Digestive enhancers and probiotics, especially enzymes, are the most important examples of this group.

How can we assess the future of feed additives? Many additives have become an indispensable part of both animal and human nutrition. However, as consumers become more conscious and aware, dozens of questions appeared in their minds. Over time, the significance of using these additives will be more clearly understood in order to obtain an optimum quantity and more economical as well as healthy, quality and safe products.

Besides, with the developing technology, new feed additives from various sources will continue to be defined in the future. The important point during the identification of these new substances is that they should be analyzed very well scientifically, with the positive effect they provide and the negative effects that they may cause in different doses or their interactions with other substances. Studies in this field will continue intensely in the future as in the past.