Effect Of Corns At Different Storage Periods On Growth Performance, Digestive Tract Development And Nutrient Utilization Of Broilers

The aim of this study was to explore the changes of nutrients in stored maize and effect of new maize on growth performance, visceral organs growth, nutrient utilization and digestive tract development of broilers. The objective was to determine the evaluation of new corn forage nutrient and provide scientific theoretical basis in new corn as feed resources.In experiment 1:The experiment was to Study the changes of nutrients in 4 new maize samples from Shandong, Hebei and Shanxi which stored at room temperature and low temperature for 1 months. The results showed as follows:(1) Based on the sampling, The moisture content, crude protein and gross energy in new corn in Shandong, Hebei and Shanxi are close to each other. Normal temperature storage and low temperature storage had little effect on conventional nutrient components of maize. (2) There was no significant difference in crude protein between the predicted value by near-infrared spectroscopy and the measured value. The content of crude protein in the new corn in low temperature storage of maize was higher than that in normal temperature storage. The content of total phosphorus in low temperature storage of maize was higher than that in normal temperature storage. (3) The contents of amino acids in low temperature storage of maize of Shandong and Shanxi were all higher than those in the normal temperature storage. The amino acid in the standard ileum in low temperature storage of maize Shandong and Shanxi was higher than that in normal temperature storage. Summary:The nutrient composition of maize was significantly influenced by different storage temperature. The respiration intensity of low temperature storage was very weak, and the loss of nutrients was significantly reduced, and the amino acid consumption was low.In experiment 2:The experiment was to study the effect of new maize on growth performance, visceral organs growth, nutrient utilization and intestinal morphology of broilers. A total of 3841-day-old Ross 308 broilers were randomly divided into 4 groups with 6 replicates and 16 broilers per replicate. The 4 treatment groups were 1,2,3 and 4, respectively. The corn in group 1 was old corn, the corn in group 2 was 2/3 old corn and 1/3 new corn, the corn in group 3 was 1/3 old corn and 2/3 new corn, the corn in group 4 was new corn. At 21 days of age and 42 days of age 2 broilers were randomly selected from each pen. Determine the pH and length of each part of the digestive tract and the thickness of the front and back ends of the duodenum as well as the widest part of the duodenum. Mensurate the related enzyme activities in different parts of digestive tract. At 39-42 days to carry out metabolic experiment to determine the nutrient utilization of broilers. (1) The results showed that:The feed conversion ratio in group 1 was the highest, was significantly higher than that of group 2 and the group 3 (P< 0.05). The average daily gain in group 1 was the lowest. The feed intake of the old maize group was the highest. (2) The index of jejunum of 42 days of broilers in old maize group was significantly higher than that of new maize group and 2/3 new maize group (P< 0.05). The result showed that the new maize may have a bad effect on the growth of jejunum. (3) The gland stomach lipase and protease activity of 21 days of broilers in new maize group and 2/3 new maize group was significantly higher than that of other groups (P< 0.05). The lipas activity in proventriculus of 42 days of broilers in new maize group was significantly lower than that of other groups (P< 0.05). The lipase activity in gizzard of 42 days of broilers in new maize group was significantly higher than that of 2/3 old maize group and 2/3 new maize group (P< 0.05). (4) The calcium utilization rate of broilers was significantly lower than that of other groups (P< 0.05). The P utilization rate of broilers was significantly lower than that of other groups (P< 0.05). According to the above analysis, the nutrient composition of maize was significantly influenced by different storage temperature. The new maize influenced broiler feed conversion rate, the ameliorating effect of old maize was most apparent.