Effects Of Multiple-enzyme Complex On Laying Performance, Bone Mineralization And Nutriments Availability Of Laying Hen

Two experiments were conducted with laying hens (Lohmann pink-shell) in an individual cage system to evaluate the efficiency of different dose multiple-enzyme with low-phosphorus, calcium and low protein and metabolism energy diets on performance of laying hens.Trial 1 studied the effects of nutrient levels and multiple-enzyme on performance and bone mineralization of laying hens. A total of 2,160 30-wk-old Lohmann pink-shell hens were randomly assigned to 6 treatments with 10 replicates of 36 hens as follows:A positive control (PC) with Crude protein (CP) 16.54%, Metabolizable Energy (ME) 11.53MJ/kg, Calcium 3.55% and Non-phytic phosphorus (NPP) 0.36%; The negative control 1(NCl) diet was formulated on the basis of PC diet with ME and CP levels decreased to 11.32 MJ/kg and 16.39%. The negative control 2(NC2) diet was formulated on the basis of PC diet with Ca and NPP levels decreased to 3.45% and 0.24%(1-5wk) or 3.38% and 0.19%(6-10wk) respectively; The negative control 3(NC3) diet was formulated on the basis of PC diet with ME, CP, Ca and NPP decreased to the levels same as NCl and NC2. The other two diets were supplemented with 2 dosages of multi-enzyme (60g and 100g/ton). Results showed that feed intake, bone ash were significantly depressed (P<0.05) and cracken and broken egg ratio was increased (P<0.05) in NC2 diet from 6-10 week, no significant difference was observed in egg production, egg weight, feed conversion, body weight, egg shell quality and tibia ash compared to PC diet(P>0.05). In NCl diet, there was trendy to improved feed intake, no significant difference was observed in other index (P>0.05). No significant difference was observed in laying performance and tibia in NC3 diet with or without multi-enzyme compared to PC diet (P>0.05). In conclusion, reducing Ca, P level decreased feed intake significantly in NC2; reducing ME, CP had trendy to increase feed intake in NCI; the high feed intake met Ca, P requirements to maintain normal production in laying hens in NC3, multi-enzyme supplementation had no trendy to improve the performance and bone mineralization of laying hens, and no difference was observed in NC3 diet with 2 dosages of multi-enzyme.Trial 2 was conducted to effects of the same multiple-enzyme complex (in trial 1) on the laying performance, bone mineralization, egg quality, Ca, P in serum and nutriments availability of laying hens fed reduced nutrient corn-soybean-based diets. A total 540 commercial laying hens of 56-week-old with laying rate around 88% were randomly assigned to 5 treatments with 6 replicates of 18 birds per replicate for 20 weeks. The treatments were including:a positive diet with ME 11.09 MJ/kg, CP 15.5%, Ca 3.40%, and nonphytate P (NPP) 0.26%; a negative control (NC) diet was formulated on the basis of PC diet with CP, ME, Ca, and AP decrease to 15.27%,10.88 MJ/kg,3.30%, and 0.14% respectively without any inorganic phosphorus; three dose addition diets of.RovabioTM Max AP (50,75,100 g/t) in NC diet. Laying rate, feed intake, live weight at start and end, and mortality, egg weight, rate of broken and dirty eggs, egg shell thickness and strength, (2 eggs per replicate at week 20) were measured on he basis of replicate. At the end of the trial,1 hen per replicate was sacrificed to collect their left tibia for bone ash determination. With the addition of RovabioTM Max AP, housed-hen laying rate (P<.0.05), and feed intake (P< 0.05), hen body weight (P< 0.05) were improved to levels equal or better than the PC diet, while the hen mortality rate were decreased significantly(P< 0.05). There was tread to improve the feed conversion ratio (P> 0.05), tibia Ca and P content with the addition of enzyme, while there were no significant influence on the egg weight, cracked and broken egg rate, dirty egg rate, tibia ash content, egg shell strength and thickness. There were also no significantly difference on utrients utilization except for total energy(GE) utilization of laying hens fed NC diet(P< 0.05). N and P utilization were improved in NC diet with multi-enzyme, and significantly enhanced the nitrogen(P<0.05), phosphorus(P<0.05)utilization in NC2 diet by phytse inclusion.Trial 1 and 2 indicate that:feed intake, nutrition levels of diet, age of laying hen are the key factors of complex enzyme used in diets of low nutritional levels; laying performance are excellent in all dosages treatments, but considering the economic benefit, dose of 50g/ton is better.