Research On Energy And Protein Requirement For 28-39 Week Jinghong Layers

Experiment were conducted to investigate the effect of different dietary metabolizable energy(ME) and crud protein(CP) levels on laying performance in 28³9 week Jinghong layers,also conculde the ME and CP requirement for maintenance and the ratio of them in diet,by rearing,comparative slaughter and metabolism experiments.Experiment 1 Study on the laying performance of 28³9 week Jinghong layers in the different dietary ME and CP leversA 2×3factorial experiment was conducted with 1152 28 week Jinghong layers to investigate the requirement of ME and CP ,which took ME and CP as the two factors,to determine the influence of dietary ME and CP levels on the laying performance.The diet was based on corn-soybean meal,the 1152Jinghong hens were randomly divided into 6 treatment groups(4 replicates of 48 hens per treatment),six diet treatments were formulated based on metabolizable energy(ME) content of 11.13MJ/kg and 11.55MJ/kg and crud protein(CP) content of 15.5%,16.5%,and 17.5%.The results showed that:the laying rate in treatmentⅡ(ME:11.13 MJ/kg ;CP:16.5%)was the highest of all treatment groups and was increased by 2.63%( P>0.05), 0.85%( P>0.05), 4.14%( P<0.05), 1.44%( P>0.05) and 0.56%( P>0.05), compared with other experiment groups;The treatmentⅡwas significantly higher than treatmentⅠa ndⅤ(P<0.05)in average egg weight ,there were no significant difference with the other treatment groups(P>0.05). The treatmentⅡwas significantly higher than treatmentⅤ(P<0.05)in average daily increased body weight and day produces amount of egg, there were no significant difference with the other treatment groups(P>0.05). The treatmentⅡwas significantly lower than treatmentⅤ(P<0.05)in feed-egg rate, there were no significant difference with the other treatment groups(P>0.05).There were no significant amoung the mortality and grow egg past muster rate(P>0.5).The treatmentⅥwas the highest in feed cost ,well,the treastmentⅡwas of the highest laying rate and a lower feed cost.At comprehensive consideration of laying performance and economic benefit,11.13MJ/kg and 16.5% were respectively recommended as ME and CP leves in 28³9 week Jinghong layers. Experiment 2 Research on Energy Requirement for 28³9 week Jinghong layersThis experiment was conducted to investigate the ME and CP deposition, and the ME requirement.At beginning of the test (28 week),3 hens were slaughtered as the contrast.And at the end of the test(39 week),3 hens ,selected from the treatmentⅡgroup in the rearing test according to the BW,were also slaughtered to compare the contrast. At last three-day of the test(39 week),96 hens ,selected from 6 groups(in each replicates 4 hens) according to the BW,were used in nitrogen(N) balance test.The conclusion: ME requirement for maintence was 607.8 KJ/BW^0.75and ME requirement in dietary for 28³9 week Jinghong layers was 11.41MJ/kg.Experiment 3 Research on Protein Requirement for 28³9 week Jinghong layersThis experiment was conducted to determine the CP requirement for maintenance and ratio of CP in diet, by rearing and metabolism experiments. At last three-day of the test(39 week),96 hens ,selected from 6 groups(in each replicates 4 hens) according to the BW,were used in nitrogen(N) balance test.At end of the test(39 week),4 hens ,selected from the treatmentⅡgroup according to the BW,were used in nitrogen(N) balance test with an N-free diet.The result showed that:The dietary with different CP levels has signification effects on nitrogen ingestion , nitrogen excretion, nitrogen retention and the efficiency of nitrogen retention(P<0.05). The dietary with different energy levels han signification effects on nitrogen ingestion and day nitrogen balance (P<0.05).The treatmentⅡw as be superior to other groups in nitrogen retention, day nitrogen balanceand the efficiency of nitrogen retention,and significant higher than the treatmentⅠandⅣ(P<0.05).the energy and protein had significant on nitrogen ingestion and nitrogen excretion(P<0.05).CP requirement for maintence was4.14g/kgBW^0.75and CP requirement in dietary for 28³9 week Jinghong layers was 16.67%In summary The ME and CP requirement formulas for 28³9 week Jinghong layers were: ME=607.8BW^0.75+13E+13.7△w ;CP=4.14BW^0.75+10.7E+0.38△w . ME and CP requirement for maintenance were 607.8 KJ/BW^0.75 and 4.14g/kgBW^0.75.