**4.6 Use of nano-minerals**

*Advances in Poultry Nutrition Research*

enzyme supplementation [35–37].

phosphorus in manure into the environment [34].

well secrete enzymes which aid digestion of feed.

and thereby exclude them [44].

Isoleucine, Valine and Arginine [45–48].

ins associated with cereal grains [50, 51].

been reviewed which have demonstrated improvements in feed utilisation with

Additional beneficial effects of feed enzymes, particularly phytase, in cereal and oilseed- based diets include the following: release of digestible phosphorus to reduce the use of expensive supplemental inorganic phosphorus (e.g. dicalcium phosphate); release of minerals such as calcium, magnesium, zinc and potassium which are complexed with the phytate molecule; and prevent excessive excretion of

The bird's gut microbial ecology has implications for feed digestion and disease control. This has to do with maintenance of natural balance of beneficial and pathogenic microorganism populations in the gut. Thus, the use of antibiotics previously as feed additive tended to cause imbalance between these two groups of microbes by eliminating largely the beneficial microbes as well as cause meat contamination and resistance problems in humans [38, 39]. Hence, the introduction of probiotics/ prebiotics/synbiotics (combination of pro-prebiotic) as replacement for antibiotics. Probiotics are a culture of live microorganisms. The probiotic product may contain microbes such as *Aspergillus oryzae, Lactobacillus acidophilus, L. bulgaricus, L. planetarium, Bifidobacterium bifidium, Streptococcus lactis and Saccharomyces cerevisiae*. Some of the commercially available probiotics for poultry are Bactocell®,

BioPlus 2B®, Cylactin®, Lactobacillus acidophilus D2/CSL®, Microfern®, Oralin®, Protexin® and Thepax®. These products promote growth of beneficial microbes which competitively exclude the pathogenic microbes [40] and may as

The use of prebiotics in animal nutrition post- dated probiotics with favourable effects on poultry health and meat quality [41, 42]. It has been defined recently as "a non-digestible compound that, through its metabolization by microorganisms in the gut, modulates composition and/or activity of the gut microbiota, thus conferring a beneficial physiological effect on the host' [43]. Commonly used prebiotics are mannanoligosaccharides (MOS), fructooligosaccharides and inulin. Generally, prebiotic products are resistant to attack by endogenous enzymes and therefore reach the site for proliferation of gut microorganisms, where they interfere with colonisation of the pathogenic microbes

Inclusion of synthetic essential amino acids in poultry has been on the rise as a result of improving efficiency of protein utilisation. This is in line with current trend of formulating diets based on digestible amino acids in order to reduce amount of dietary protein [45]. These are DL-Methionine, L-lysine HCl, L-Threonine and L-Tryptophan. Initially, the idea was to meet first-limiting amino acids (Lysine and Methionine) requirements for poultry; however, with the need to further reduce dietary protein requirements as well as reduction in nitrogen excretion, this calls for increased use of second and third limiting amino acids such as L-Threonine and L-Tryptophan as well as the next limiting amino acids including

Advances in dietary supplementation with vitamins (water/fat soluble) and trace minerals (Zn, Cu, Mn, Se, Co, Fe) continue to be made and have brought about improvements in feed utilisation, growth performance and welfare of birds [49]. Vitamins and trace mineral supplements are vital feed additives aimed at supplying sufficient amounts that meets the needs of the biochemical systems of the cells of birds culminating in varied benefits. These benefits include enhanced mineral uptake, improved immune system, proper tissue and bone development,

The use of toxin binders in poultry feeds has counteracted problems of mycotox-

cellular growth as well as amelioration of oxidative stress in birds [49].

**10**

The use of nano-minerals in poultry nutrition is a recent concept that is gaining grounds as a result of varied application of nanotechnology in animal production systems. This has to do with alteration of particle size to few nano meters (1–100 nm) and studies reviewed so far have proved that feeding of nanoparticle improved digestive efficiency, immunity, growth rate, performance, resistance to pathogens, quality of meat and eggs in birds [52, 53].
