**3. Sources of minerals**

*Advances in Poultry Nutrition Research*

conventional mineral sources.

Mineral nutrition is an indispensible part of animal feeding system which ensures optimum health, production, and reproduction in animals and birds. Even though, required in small quantities as compared to other nutrients such as energy and protein, their deficiency and imbalances are promptly reflected in the changes of animal wellbeing and their production. Sometimes, this may also cost the animals with their lives. They are essential for maintaining the normal health and productions; whereas in some cases additional supplementation could yield better growth and egg production. The significance of mineral nutrition is well documented and still new projects are undertaken to understand, explore better aspects and validate newer postulates associated in the field of mineral

Conventionally, minerals are used in the diets through their inorganic salts, but low bioavailability of inorganic mineral salts necessitates using at higher doses in order to meet the animal requirements, which indirectly creates more pollution with minerals [1]. Recently, nano-sized minerals are considered to have greater bioavailability in animals and birds due to increased surface area, which tend to produce better desirable responses [2]. This chapter discusses synthesis of different nano-minerals, their mechanism of action, poultry performance, tissue retention, immunity, antioxidant activity and antimicrobial actions compared with their

**2. Importance of mineral nutrition in biological system**

Minerals are vital for all biochemical functions in the body along with providing structural supports, electrolyte balance and homeostasis. The requirements of calcium (Ca) and phosphorus (P) in animals and poultry are comparatively greater than other minerals. They are mainly needed for bone development [3]. Zinc (Zn) is essential for several physiological and biochemical processes such as normal growth, reproduction, wound healing, ossification, DNA synthesis, cell division and gene expression, photochemical processes of vision, and augmenting the immune system of the body through lymphocyte replication and antibody production [1–4]. Selenium (Se) is essential for

optimum animal production, fertility, and disease prevention [3]. However, role of Se in intra- and extra-cellular antioxidant systems is vividly recognized [5], which, as a component of glutathione peroxidase (GPx) neutralizes hydrogen and lipid hydroperoxide and thus maintains membrane integrity and guards from oxidative damage of lipid membranes [1]. Copper (Cu) is essential for normal growth, bone development, immune response, foetal development, nerve functioning, and in antioxidant system as a part or a cofactor of several enzymes [1]. Manganese (Mn) is an essential trace mineral necessary for optimum antioxidant, immune system as well as a component on several important enzymes [2]. Likewise, iron (Fe) is needed for synthesis of hemoglobin, which transports oxygen in the body and myoglobin, and is also associated with enzymes, e.g., peroxidases, hydroxylases, and catalase. Chromium (Cr) is a component of glucose tolerance factor and is essential for maintaining immune and antioxidant function and metabolism of lipids and proteins [6]. Combining all the effects together, minerals are associated with all the physiological functions in the body either involved directly or indirectly. Hence, a diet balanced in all the minerals is always a matter to maximize the productivity and health of

**1. Introduction**

nutrition.

**62**

the animals.

The minerals are present in all the food and feed sources as an integral part, but the amount required to support the productivity is not met through the feed resources. Added to this, the mineral component from plants are less absorbed and retained in the body as they form complex compounds with other components. For an instance, plant ingredients in the diets contain large amounts of unavailable P as phytates, which accounts almost 60–80% of total P and are not absorbed by the birds due to insufficiency of phytase enzyme [7]. Again, the bioavailability of minerals from traditional inorganic sources is relatively less for many minerals, while the requirements for high producing animals and birds are very high [8]. This necessitates the addition of minerals in the diets from extraneous sources [1, 9, 10], which gives the concepts of minerals as feed supplements in animal and poultry rearing. Minerals are generally supplemented in higher concentrations than their actual needs at cellular levels when inorganic supplements are added due to their poor bioavailability [11] along with chemical antagonism and interactions with other nutrients [12]. Conventionally, minerals are supplemented in the diets in their inorganic salts — oxides, sulphates, or carbonates — for instance, Zn oxide, Zn sulphate, sodium selenite, Ca carbonate, and dicalcium phosphate (DCP). The low bioavailable inorganic mineral salts supplemented at higher doses in order to meet the animal requirements, indirectly creates more pollution with minerals [1, 9, 10]. This issues needs to be addressed and better bioavailable mineral sources are a thrust of mineral studies for many decades. Many organic chelated minerals have been tried to fill the gap and reports indicated mixed responses considering their bioavailability, cost effectiveness and biological responses. Organic minerals as proteinate supplemented retained better in poultry signified better bioavailability as compared to their inorganic counterparts [13, 14]. Organic mineral supplementation has shown varied type of response in layers. For example, Rajendran et al. [15] reported improvement in laying percentage of birds, whereas Soni et al. [16] did not observed any effect on egg production by feeding organic minerals. In spite of better bioavailability of organic minerals over their inorganic counterparts, these sources are less used due to their higher cost [17]. This necessitates the urgent requirement for better bioavailable sources to be used particularly in poultry production to save guard the environment without affecting the animal or bird productivity at a cost effective manner.

Recently, nano-sized minerals are considered as a potential alternate to fill the gap and they have been tried and tested in many ways to validate their better bioavailability in diversified animals and birds. Nanotechnology confers the materials with particle size in nanometer (nm) range (<100 nm) at least in one direction, and by virtue of the nano-sized particle (NP), their structures exhibit significantly novel physical, chemical, and biological properties and functionality [18]. Due to their small size, the surface area increases many folds and thus they tend to produce many desirable responses [2]. The altered chemical and physical properties of NP could potentially modify the biological responses compared to its bulk materials [2, 19]. Studies have been carried out across the globe to unveil more beneficial effects as a feed additive in animals and birds, but still nanotechnology is in its infancy in the animal husbandry sector. In this chapter, we have tried to compile the various effects of the nano-minerals and other nano-materials in poultry.

### **4. Nano-minerals: synthesis**

Nanotechnology deals with research and development related to nano-sized materials, and are specifically focused at understanding of measurement and

#### **Figure 1.**

*Different methods of nano-minerals synthesis.*

manipulation of matters at the nanoscales. Use of NP is gaining importance in diversified disciplines starting from medicine, environment, food, electronics, pharmaceutical applications, biotechnology, agriculture, and animal science [2]. Nano-minerals are specially synthesized mineral particles with its particle size ranging from 1 to 100 nm [20]. Like NP, nano-minerals possess higher physical activity and chemical neutrality, which may be a reason for efficient absorption in the animal system [21] and are reported to be stable under high temperature and pressure [22] as well. Nano-minerals as feed supplement can increase the feed efficiency, diminishing feed cost by reducing the supplemental doses, and simultaneously intensifying the yield and value of animal products by virtue of their superior bioavailability [1, 23, 24]. For example, nanominerals, due to their smaller size, were reported to be easily taken up by the gastrointestinal tract and efficiently utilized in vivo, and hence were more effective than the larger sized zinc oxide (ZnO) at lower doses [20]. Moreover, nanominerals exhibit lesser adverse effects as compared to their conventional counterparts. For instance, Reddy et al. [25] reported that nano-ZnO had less adverse effect on human cells. Nanominerals can cross the small intestine and further distribute into the blood, brain, and other different organs [26]. The functional properties of nanominerals, such as chemical, catalytic or biological effects, are highly influenced by their particle size, shape, composition, crystalline structure, surface ions, and morphology [27–29]. Nano minerals can be synthesized by physical, chemical or biological methods (**Figure 1**) [1, 19]. In physical method, physical forces are used to break down the larger sized materials to nanoscale, whereas in chemical method, reducing agents are used to reduce the particle size. Nanomaterials produced from physical method have wide range of particle size, but chemical method produce tentatively uniform particle size [19]. In biological method, also called green synthesis, different plant products or cultures are used for reducing the size of the intended materials. This method is free from use of corrosive chemicals which is the main constraint in chemical synthesis of NP. However, maintaining the culture needs technical expertise and is considered as a limitation in this method. Considering all points and methods, for use in livestock and poultry feeding, chemical method seems preferred as they are cheap, easy to produce and do not require any special instrument and expertise [19].

#### **5. Mechanism of action of nanominerals**

Nanoparticles are quite different in physical properties from bulk materials, contributing to wide range of new applications. Due to the much-reduced particle size they exhibit novel and improved physical, chemical, and biological activity that do not necessarily resemble the bulk mineral counterpart, and thus numerous modes

**65**

*Essential Nanominerals and Other Nanomaterials in Poultry Nutrition and Production*

to establish or abolish any mechanism of action postulated till date.

of action are postulated by different workers. We have tried to compile the available resources keeping poultry nutrition in view. As such, further studies are warranted

Possibly the increased surface area of NP facilitates better interaction in biological interface and their increased retention time in the gut, reduced influence of intestinal clearance mechanisms and effective delivery of functional compounds to target sites result in better bioavailability and functionality [30]. By virtue of their small size, uptake by the gastrointestinal epithelium is much easier [20]. Uptake of NP through mucosal layer is dependent upon the charge on their surface and pH of adjacent environment. Changes in pH alter the surface charge and thus lead to agglomeration and change in size [31, 32]. For example, cationic NP was reported to be trapped within the glycosylated areas of mucin, whereas the diffusion of carboxylated anionic microparticles through the epithelial surface was better [33]. Nanoparticles are either absorbed through epithelial villi into the circulation and are subsequently transported to the liver and spleen [20, 34] or through M-cells in the Peyer's patches crossing the enterocytes and pass into the hepatic circulation [35]. Due to the smaller pore size (0.6 to 5 nm) of tight junctions, paracellular transport of NP is usually limited under normal physiological conditions [36]. Trace element NP may decrease mineral antagonisms in the intestine leading to enhanced absorption and utilization, thereby lowering their excretion into the environment. They are chiefly transported by transcellular mechanism. After absorption, their dispersion, breakdown, and discharge are related to their dissolvability, charge, and size. Nano-minerals have the potential to enter the blood, brain, lung, heart, kidney, spleen, liver, intestine and stomach after crossing the small intestine [26]. But their uptake rate in intestinal epithelia and other body tissues substantially differs [37]. The particle sizes less than 300 nm can reach to the blood circulation, whereas particles smaller than 100 nm can penetrate various tissues and organs [38].

The amount of mineral absorbed and retained is termed as bio-availability, and this can be reflected by improved performance of animals or birds. Better bioavailability is indicated by more amount of mineral deposits in the organ, serum, and also better biological responses, and is affected by factors that influence absorption such as concentration, chemical forms, transport pathway, nutrient-nutrient interactions and excretory losses. Reports suggest that the bioavailability of inorganic salts is less, which results in high excretion of minerals into the environment through urine and feces [39]. Considering the other potential replacement of inorganic salts, organic and nano-minerals have provided encouraging biological effects when fed to animals and birds [1, 8, 21, 40, 41] with certain limitations. Of the different mechanisms of transportation through intestinal epithelium,

paracellular transport involves passage of substances across the epithelium

through the intercellular spaces whereas transcellular transport involves passage of substances through the cells [42, 43]. Paracellular transport does not include any transporter or energy expenditure for transport and the absorption occurs along the concentration gradient, thus is not very efficient [42]. Tight junctions act as gatekeeper of paracellular transport and they exclude entry of macromolecules [42, 43]. Transcellular absorption involves either diffusion across concentration gradient or active carrier mediated transportation utilizing energy or through endocytosis [42]. Intestinal absorption can be improved by altering paracellular and transcellular transport. Compared with CuSO4 and CuO microparticles, CuO NP are believed to be rapidly transported into cells, and subsequently interact with the Cu transport

*DOI: http://dx.doi.org/10.5772/intechopen.96013*

**6. Mineral absorption and metabolism**

#### *Essential Nanominerals and Other Nanomaterials in Poultry Nutrition and Production DOI: http://dx.doi.org/10.5772/intechopen.96013*

of action are postulated by different workers. We have tried to compile the available resources keeping poultry nutrition in view. As such, further studies are warranted to establish or abolish any mechanism of action postulated till date.

Possibly the increased surface area of NP facilitates better interaction in biological interface and their increased retention time in the gut, reduced influence of intestinal clearance mechanisms and effective delivery of functional compounds to target sites result in better bioavailability and functionality [30]. By virtue of their small size, uptake by the gastrointestinal epithelium is much easier [20]. Uptake of NP through mucosal layer is dependent upon the charge on their surface and pH of adjacent environment. Changes in pH alter the surface charge and thus lead to agglomeration and change in size [31, 32]. For example, cationic NP was reported to be trapped within the glycosylated areas of mucin, whereas the diffusion of carboxylated anionic microparticles through the epithelial surface was better [33]. Nanoparticles are either absorbed through epithelial villi into the circulation and are subsequently transported to the liver and spleen [20, 34] or through M-cells in the Peyer's patches crossing the enterocytes and pass into the hepatic circulation [35]. Due to the smaller pore size (0.6 to 5 nm) of tight junctions, paracellular transport of NP is usually limited under normal physiological conditions [36]. Trace element NP may decrease mineral antagonisms in the intestine leading to enhanced absorption and utilization, thereby lowering their excretion into the environment. They are chiefly transported by transcellular mechanism. After absorption, their dispersion, breakdown, and discharge are related to their dissolvability, charge, and size. Nano-minerals have the potential to enter the blood, brain, lung, heart, kidney, spleen, liver, intestine and stomach after crossing the small intestine [26]. But their uptake rate in intestinal epithelia and other body tissues substantially differs [37]. The particle sizes less than 300 nm can reach to the blood circulation, whereas particles smaller than 100 nm can penetrate various tissues and organs [38].
