IMPORTANCE OF PHYTASE SUPPLEMENTS IN PIG NUTRITION
Pigs are monogastric has gastrointestinal tract relatively simple with three main compartments, the stomach, small and large intestine. The small intestine of the adult pigs is approximately 18 meters long.
Phytase enzyme is an important enzyme with nutrient content for monogastric livestock feed. It breaks down the phospho-monoester linkages present in phytate, a derivative of phytic acid that is the most abundant form of phosphorus (P) in plant cells. Monogastric agricultural animals like poultry and pigs, on the other hand, generate little or no phytase enzyme in their gut. Plant proteins are extensively utilized in chicken diets, and their phytate P is difficult to digest.
Furthermore, by chelating some minerals into the molecule, phytate P lowers their bioavailability. Phytic acid is a naturally occurring anti-nutritional agent, and the smaller the myo-inositol phosphates create complexes with divalent metallic materials. As a result, incorporating phytase enzyme in a mono-gastric feed increases nutritional bioavailability while reducing significant P buildup in manure, which creates environmental difficulties such as water contamination, algae growth, fish mortality, and changes in plant and animal life.
The small and large intestine grow and completely develop and becomes functional only after 6-8 weeks of birth so why the weaning is required for piglet to digest fibrous and coarse feeds in better way.
The energy and protein are required in right proportion in the diet of pigs for proper utilization and further development of organs and productive performances. Energy and amino acids imbalance results in improper growth, poorer feed efficiency and low protein and fat deposition. Therefore, pigs are fed on balance diet in respect of protein together with appropriate amount of energy, minerals and vitamins to achieve best results (Table 1).
It is well-established facts that feed accounts for 70-75% of total cost of production. A common conventional diet of pig contains 60-80% cereal grains and its by-products, 20-40% vegetable protein supplements.
It is also fact that a good numbers of pig farrowed die before they reach market due to bad feeding and nutritional deficiency and it can only be achieved through balanced and nutritious feed.
Mechanism Of Action
The phytase enzyme is a protein that catalyzes the conversion of phytate (phytic acid) to inositol and phosphoric acid. The phytase enzyme catalyzes the conversion of the phosphate groups present in the phytic acid one by one to create precursors IP5, IP4, IP3, and IP, with inositol and phosphoric acid as the end products. Various sources of phytase enzymes have various catalytic processes. When 3-phytase works on phytic acid, first it hydrolyzes the ester bond at the 3rd carbon site to liberate inorganic phosphorus, subsequently releasing phosphorus from additional carbon sites one at a time, eventually esterifying the overall phytic acid. The catalytic reaction of this enzyme needs the presence of divalent magnesium ions (Mg2+).
Microorganisms are used to make the new feeding phytase, which is scaled up utilizing bioengineering and recombinant DNA technology. Fungi are commonly used to make phytase. Various microbial fermentation processes, such as submerged, semi-solid state, and solid-state fermentation, are used to create microbial phytases. The method is widely utilized in the fermentation sector, notably for the manufacture of enzymes.
Application of Phytase Enzyme
Phytic acid is an excellent source of carbon, nitrogen, and sulfur that may be converted into a range of chemicals in the natural world. Phytase enzymes have a wide range of industrial, agricultural, and biotechnological uses due to their ability to break down keratins.
Feed Supplements
Phytase enzymes are of excellent importance in biotechnological applications in animal and human nutrition processing and manufacturing because they have the ability to increase phosphorus efficiency and minimize phytate concentration in food and livestock feed.
Monogastric animals, like pigs, poultry, and fish, have no or low amounts of gastrointestinal phytases, preventing them from using the phytate, phosphorus found in food and livestock feed. As a result, they require inorganic phosphate supplementation to satisfy their dietary and growth requirements, which raises feed costs and phosphorus pollution levels. Phytase enzyme is significant in the livestock feed sector because it improves the phosphorus digestive process.
Food Additives
Phytic acid is highly abundant in the grain and wholewheat flour of many types of bread and dough, hence phytases are utilized as a food additive in fermentation processes and in a variety of applications in the production of bread, also feeding additives. The phytase enzyme of A. ficuum, for instance, has been employed in the dephosphorylation of legumes. Up to 78% of phytate was eliminated after combining and incubating soybean meal with fungal phytase for 15 hours.
Plant Growth Promotional Applications
Phosphorus (P) is a key and essential component of cells, and it plays a role in energy metabolism, acid production, and cell membrane biosynthesis. This is also a key macronutrient for plant growth and developmental processes. Soil phosphorus shortage is a big issue for agricultural farmers all over the world. The majority of soils contain considerable levels of total soil P, which may be found in both organic and inorganic forms. Phytic acid is a primary source of biological phosphorus in the soil, accounting for 10 to 50% of available organic phosphorus content. So, the phytase enzyme is essential to digest it.
Therapeutic Applications
Humans use plant-based food items as their primary source of raw component nutrition in many regions of the globe. Plant-based foods are rich in nutrients (carbohydrates, protein, fibre, and vitamins), as well as non-nutrients. Phytate is the most important phosphorus storage molecule in seeds and grains, accounting for up to 90% of overall seed phosphorus. It creates a mineral shortage in humans by forming a complex with dietary elements such as zinc, iron, calcium, magnesium, manganese, and copper.
Other Commercial Phytase Enzyme Products
Phytases are enzymes that are advantageous to animal feeding. They had the major revenue share in the whole industry, accounting for 83.6%. Phytases are added to around 70% of the monogastric animal diet. A. niger provided the very first industrial phytase, which was categorized as a 3-phytase. Peniophora lycii was later used to create an industrial product that was a 6-phytase. For years, a few fungal phytase products are created and commercialized by different firms. Phytase Enzyme is produced on a commercial basis utilizing either phytate-producing fungus or recombinant DNA technologies.
The Chemistry behind Phytate:
Phytic acid is a six-fold dihydrogen phosphate ester of inositol, also called inositol hexakisphosphate or inositol polyphosphate. It can form complexes with metals or proteins and therefore reduce their bioavailability in the gastrointestinal tract. Phytate or phytic acid is the principal storage form of phosphorus in many plant tissues, especially bran and seeds.
The basic principle of phytic acid is to protect the seeds from sprouting in unfavourable environments. It is usually found right next to or in the peel. In favourable environmental conditions, specially in the presence of water phytate breaks and releases phosphorus required for sprouting of seeds.
Enzymatic break down of phytate in feed results in improving availability and absorption of essential minerals like phosphorus and other trace minerals.
Negative Effect
The effect of the phytate inside our body are mostly negative, as it chelates minerals. It binds strongly to nutrients such as calcium, magnesium, zinc, iron, vitamin B3 and does not allow the body to use these. Phytate also affects efficacy of digestive enzymes. In tests outside of the body it has been seen that it strongly diminishes the ability of amylase to do its job and break down starch. It also seems to affect pepsin and trypsin, enzymes that our body uses to break down proteins.
Positive Effect
Phytate is also able to bind radioactive substances and heavy metals. By doing so it can help us eliminate them through bowel movements. However, there are other, healthier ways of eliminating heavy metals.
Phytate can also act as a type of antioxidant and thereby eliminate some free radicals. Phytate contains phosphorus. The enzymatic breaking of phytate releases phosphorus and decreases cost of feed by reducing the inclusion of phosphorus rich ingredients like di-calcium phosphate etc.
How can we reduce the amount of phytate and can get positive benefits?
Enzyme phytase breaks complex phytate molecule and makes the phosphorus and other nutrients available for animals to use. Phytase is already present in the seeds, but to be activated it needs water. It works best at temperatures that are a little higher than the body temperature (41°C) and pH-ranges around 5, which is a slightly acidic environment.
Phytase becomes inactive at temperatures higher than 55ºC (131ºF). It can even be destroyed if the seed (grain) is grounded so that the temperature in the grinding process rises above 55ºC (131ºF).
Phytase also becomes inactive if it is frozen or stored during prolonged periods. Though it is not practically possible in animal feed manufacturing, this method could be used wherever suitable, in high value frozen food.
A better understanding of the phytate molecule in recent years has lead to the realization that novel phytases have benefits beyond phosphorus release. Phytases have been shown to reduce the anti-nutrient effects of phytate in animal diets by degrading it, thereby, increasing the availability of energy and amino acids. This provides the potential for phytases to further reduce the cost of feed, particularly when the price of energy and protein/amino acids in diets is high.
Apart from using phytase, several other methods could be explored as combined strategies along with regular usage of phytase in feed.
Organic acid:
Adding organic acid in diet may reduce the pH of the feed. It helps in activating phytase to break phytate molecules.
Probiotics:
It has been seen that probiotics, especially lactobacillus, tends to produce phytase. Adding probiotic in feed is an increasing trend which releases several enzymes including phytase in gut. Phytase produced by probiotic complements phytase enzymes and augments enzymatic break down of phytate to release phosphorus.
Fermentation:
By further fermenting our food we can often greatly reduce or even eliminate the phytic acid.
Formulating feed considering phytate content in feed ingredient is another way to reduce the presence of phytate in feed. High phytate exhibits negative impacts on intestine and reduces the performance. On the other hand, using phytase along with probiotic and acidifier would be a combined strategy to explore bound nutrients, especially phosphorus and other trace minerals.
Table 1: Important nutrient requirement for different categories of pig
| Nutrient | Creep Ration (5-10 kg) | Grower Ration | Finisher Ration | Adult Boar / Breeding Gilt | Lactating Gilt | |||
| 10-20 kg | 20-30 kg | 30-40 kg | 40-60 kg | 60-90 kg | ||||
| Protein (%) | 20 | 16 | 16 | 14 | 14 | 14 | 12 | 13 |
| Lysine (%) | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| Methionine (%) | 0.30 | 0.30 | 0.30 | 0.30 | 0.30 | 0.30 | 0.30 | 0.30 |
| Tryptophane (%) | 0.18 | 0.18 | 0.19 | 0.19 | 0.19 | 0.20 | 0.18 | 0.18 |
| Digestible Energy
(Kcal/kg) |
3400 | 3000 | 3000 | 3000 | 3000 | 3000 | 3400 | 3400 |
| Calcium (%) | 0.80 | 0.60 | 0.60 | 0.60 | 0.50 | 0.50 | 0.75 | 0.75 |
| Phosphorus (%) | 0.60 | 0.50 | 0.50 | 0.50 | 0.40 | 0.40 | 0.60 | 0.50 |
| Common Salt (%) | 0.60 | 0.50 | 0.50 | 0.50 | 0.50 | 0.50 | 0.50 | 0.50 |
Swine rations are prepared as per the categories at different stages of growth and production as mentioned in table1. The creep ration is fed from suckling period to weaning age of high protein and energy.
The requirement of iron is more in piglets due to faster growth and sow milk alone cannot fulfill the requirement. In emergency cases, piglets can be fed cow’s milk by bottle-feeding otherwise skimmed milk fortified with minerals and vitamins are best sources of protein for the piglets.
The weaned piglets are switched over to grower ration when attained body weight of 10 kg and feed offered @ 1 kg/head/day during initial period and goes up to 1.5 kg/head/day during latter stages.
The cheaper feed resources should be taken to formulate economic ration. The pigs attained the body weight of 40 kg they are switched over to finisher ration. The pigs can eat 2 kg/head/day concentrate feed during early stages of these groups and it goes up to 2.5 kg/head/day at latter stages of body weight.
Swine Feeding system on locally available feedstuffs:
The eastern region of India is having in totality almost 50 percent of country’s pig population. These pigs are fed on locally available feedstuffs only. No special feed is offered even during various important physiological stages and thus it results in poor productive performance.
Some of the farmers are very unaware of the balance feeding benefit, some cannot afford due to cost and some due to unavailability. The regions also having an acute shortage of concentrate animal feed. Apart from this, pig is direct competitor of human beings in respect of food. Under such situation the available nutrients is inevitably bound to formulate ration for domestic non-ruminants involving minimum uses of cereal grain and maximum uses of agro-industrial by-products and other potential feedstuffs.
On the other hand, region roughly produces 3.84 million tonne rice milling by products which is almost 62.54% of total concentrate feed available in the region that sufficient to meet energy need of entire pig population.
Cereal by-products are important feed ingredients in Asia as a whole, but their efficient use in monogastric diets is hindered by the presence of high levels of non- starch polysaccharides and phytate.
Phytate is the major form of phosphorus (P) in cereal grains and oil seed meals and approximately 70% of the P is organically bound in the form of phytate which is a negatively charged ion that is able to bind cations and proteins and reduces its bioavailability due to lack of endogenous phytase enzyme in non-ruminants.
This low availability of phytate P poses two problems for pig and poultry farmers i.e. need to add inorganic phosphorus supplements to diet and excretion of large amount of phosphorus in the manure.
However, to improve the nutritive value of different available rice milling by-products with supplementation of phytase enzyme will be essential before their inclusion in swine and poultry ration for economical production and better results.
The studies revealed that crossbred pigs performed better even on maize or rice polish based balanced ration after fortification with vegetable protein and minerals (Table 2).
Similarly, the average daily gain was improved by 17% on addition of active phytase unit at 1.0 lac FTU/100kg diet in the ration of pigs at grower stage of growth with significant improvement in feed conversion ratio and nutrients digestibility (Table 3).
Table 2: Performance of crossbred pigs fed on maize and rice polish based ration
| Ration composition (kg/100kg) | Corn-rice polish-Soy Ration | Corn-Soy Ration |
| Maize | 30 | 80 |
| Rice polish | 50 | — |
| Soy meal | 17 | 17 |
| Minerals and salt | 3 | 3 |
| Post weaning stage | ||
| Growth rate (g/day) | 175 | 189 |
| Dry matter intake (g/day) | 464 | 456 |
| Feed conversion ratio | 2.66 | 2.42 |
| Grower stage | ||
| Growth rate (g/day) | 372 | 406 |
| Dry matter intake (g/day) | 1365 | 1336 |
| Feed conversion ratio | 3.71 | 3.33 |
Table 3: Growth performance and nutrient digestibility in pigs fed on rice polish based ration supplemented with phytase enzyme
| Particulars | Diet-1
(without phytase at grower stage) |
Diet-2
(with 1 lac unit phytase at grower stage) |
| Ingredient composition (kg/100kg) | ||
| Rice polish | 50.00 | 50.00 |
| Maize | 30.40 | 30.38 |
| Protein feeds | 17.00 | 17.00 |
| Lime | 1.50 | 1.50 |
| Common salt | 1.00 | 1.00 |
| Growth performance | ||
| Initial body weight (kg) | 8.87 | 9.00 |
| Av. Daily gain (g/d) | 387 | 453 |
| Av. Feed intake (g/d) | 1305 | 1305 |
| Feed conversion ratio | 3.37 | 2.88 |
| Nutrient digestibility (%) | ||
| Dry matter | 72.81 | 76.51 |
| Crude protein | 69.59 | 73.12 |
| Phosphorus | 37.61 | 52.25 |
Therefore, farmers are advisable to feed their pigs a balance ration made from available resources for better growth performance and economic return.
More importantly, the rations computed must be balanced in respect of energy and protein for profitable piggery as well as it is also recommended that diets containing rice polish at 50 percent level, phytase may be used at 1.0 lac FTU/100kg for better growth performance and nutrient digestibility.
Compiled & Shared by- Team, LITD (Livestock Institute of Training & Development)
Image-Courtesy-Google
Reference-On Request.
