Study On Effect Of Nutritional Regulation On Pig Production Performance And Discharge Of Nitrogen And Phosphorus

In recent years, the rapid expansion of pig industry has met the people's demand of pork and developed the local economy, while the problem of environment pollution has become more and more serious. The main pollutant in pig industry is the mass of nitrogen and phosphorus in pig manure and urine. Among numerous methods of reducing nitrogen and phosphorus, nutrition regulation is the most feasible one.Effect of dietary protein, phosphorus and phytase on discharge of nitrogen and phosphorus from pigs was studied with experimental period of 60 d in this study. Fifty healthy pigs (Duroc×Landrace×Pietrain) were divided into five groups (Control, Treat 1, Treat 2, Treat 3, Treat 4), 10 pigs for each group. Each group was fed respectively with diets such as 17.50% protein+0.60% phosphorus+13.87 MJ/kg digestive energy (DE), 17.5% protein+0.44% phosphorus+ 0.1% phytase, 17.5% protein+0.72% phosphorus, 15.10% protein +0.44%phosphorus+0.1% phytase+amino acids (Lys 0.15%;Phe 0.02%;Thr 0.08%), 15.10% protein +0.44% phosphorus+0.1% phytase+13.09 MJ/kg DE+ amino acid(Lys 0.15%;Phe 0.02%;Thr 0.08%). The results were as following.(1) Discharge rates of nitrogen and phosphrous in treatment 3 were reduced by 20.62% and 27.85% with nutritional regulation, compared with the control (P<0.05).(2) Pig performance was significantly improved by reducing dietary protein and phosphorus with adding phytase and amino acid. ADG was increased by 2.67% (P<0.05), F/G was reduced by 2.67% and calcium digestibility was increased by 21.23% (P<0.05). Calcium digetibility was increased by 24.03% by reducing dietary phophorus with adding phytase (P<0.05). Performance was not increased by simply decreasing or increasing the phosphorus content in feed. It was a negative impact on pig performance by reducing content of protein and phosphorus as well as DE. Digestive rate of energy was not significantly influenced by adding phytase and reducing phosphorus content, while calcium utilization was significantly increased.(3) AKP contents in small intestine and rib were respectively decreased by 16.27% and 12.78% by adding phytase and reducing phosphorus content (P<0.05), while phosphorus utilization was not increased by simply adding phosphrous. (4) Protease activities of treat 1 and treat 3 was respectively increased by 52.40% and 84.87% (P<0.05). Amylase activity of treat 3 was increased by 15.34 (P<0.05). The counts of lactobacillus was increased by 5.11% (P<0.05). And the pH value in pig feces was reduced in treat 3.