Application of phytase in laying hen feed
60% to 80% of phosphorus in plant-based feeds is in the form of phytate phosphorus. Phytic acid not only affects the digestion and utilization of minerals, but also combines with proteins and amino acids to form indigestible complexes, which reduces the digestibility. At the same time, phytic acid also inactivates the amylase, protease, and lipase derived from animals.
Phytase is a new type of monogastric animal feed enzyme preparation that can hydrolyze phytic acid in feed into inorganic phosphorus and inositol. Natural phytase exists in many plant seeds. Under certain conditions, phytic acid can be decomposed to release phosphorus and other elements for seed germination and growth. The rumen microorganisms of herbivorous animals have the ability to synthesize phytase, while poultry animals, because the digestive tract does not contain phytase, cannot or cannot make good use of phytate phosphorus in plant feeds, so phytic acid has always been regarded as a Ingredients that are harmful to poultry. In production practice, only inorganic phosphorus feed can be added to the feed to meet the phosphorus requirement of animals.
In 1995, my country's Guangdong and Beijing first began to test the utilization of phytase, and achieved great success. Later, more than a dozen provinces and cities such as Tianjin, Hebei, Henan, Shandong, Heilongjiang, and Jiangsu have also begun large-scale trials. At present, the use of phytase in our region is almost entirely used for laying hens, and the amount is far from the potential demand.
1 The role of phytase
1.1 Directly replace the inorganic phosphorus source feed in the feed. As long as the total phosphorus level in the laying hen's feed is maintained above 0.4%, adding 60g /t enzyme and supplementing 5000G (phytase) to the feed can completely replace calcium hydrogen phosphate or bone meal.
1.2 Reduce the consumption of phosphorus for feed and greatly reduce the production cost of feed.
1.3 Improve the production performance of laying hens and reduce the egg breaking rate.
1.4 Significantly improve the utilization of calcium, phosphorus, magnesium, zinc, protein, starch and other nutrients.
1.5 Improve the utilization value of plant-based feed, and increase the adjustment space for raw materials of feed formula by 0.5 to 0.9 percentage points.
1.6 Reduce the phosphorus content in livestock and poultry manure by 40% to 75%, which can reduce phosphorus pollution in the environment such as rivers and soil.
1.7 The problem of fluorosis and other heavy metal poisoning caused by calcium hydrogen phosphate can be significantly alleviated and completely eliminated.
2 The use of phytase and the amount of phytase added in the feed of laying hens
2.1 It can be directly added to the full-price feed, or it can be diluted with 5000G of the enzyme at a ratio of 1:10 before use.
2.2 First add it to 4%~6% premix, and then prepare full-price feed according to the proportion of premix. 2.3 First add it to 20%~40% concentrated feed, and then formulate it into full-price feed according to the usage ratio of the concentrated feed.
2.4 When the feed moisture is higher than 14%, the storage period is more than 8 weeks, and the external temperature is continuously higher than 30 ℃, the addition amount should be appropriately increased.
3 Principles of feed formulation design and adjustment using phytase
Using phytase, the amount of phosphorus source feed was greatly reduced, and the total calcium level was also reduced by 0.1% to 0.3%. It adds valuable space for formula design, improves the digestibility of protein, and the feed can reduce 3g/kg protein. Therefore, it is of great significance to reduce the cost of feed, reduce pollution, and to solve the problems of low energy concentration and high price of protein feed in domestic laying hen feed. The principle of using enzyme supplement 5000G to adjust the original feed formula is:
3.1 Reduce the total phosphorus content of the diet by 0.42% to 0.45%, and determine the amount of substitute feed and the amount of supplemented calcium source feed according to the calcium and phosphorus content of the phosphorus source feed.
3.2 If the nutrient level of the original diet is maintained unchanged, the proportion of raw materials can be adjusted. Such as increasing the amount of rapeseed meal, sunflower meal, or using other fillers, use the remaining space of about 0.5% to 0.9%.
3.3 Use the remaining space that appears to improve the nutritional balance of the diet. For example, increasing the amount of corn to alleviate the current low energy problem of laying hens.
3.4 According to the quality characteristics and requirements of the original feed, as well as the supply of raw materials, the remaining space can be freely used.
Here are two examples. In a laying hen feed, 14kg/t of calcium hydrogen phosphate with a phosphorus content of 16% was used, so that the total phosphorus content in the diet reached 0.61%, and the calcium content reached 3.5%. Now the enzyme supplemented with 5000G phytase is used, and 60g of /t enzyme supplemented with 5000G and 8kg of stone powder with a calcium content of 39% are added to the feed, which can completely replace the calcium hydrogen phosphate in the feed. 36kg of remaining space is also provided. In another laying hen feed, 22kg/t of bone meal with a phosphorus content of 11% was used, so that the total phosphorus content in the diet reached 0.61% and the calcium content reached 3.5%. Now the enzyme supplemented with 5000G phytase is used, and 60g of /t enzyme supplemented with 5000G and 11kg of stone powder with a calcium content of 39% are added to the feed, which can completely replace the bone meal in the feed. It also provides 8kg of remaining space.