Studies On Requirement Levels Of Methionine And Lysine In Wheat-based Meal Diets Adding Non-starch Polysaccharides Enzyme For Laying Hens

This experiment was conducted to study the effects of different levels of methionine and lysine in wheat-based meal diets adding non-starch polysaccharides enzyme on the egg laying performance of laying hens and determined the appropriate level of methionine and lysine in wheat-based meal diets. The 1 024 Lsa-Ting(40-wk-old)were randomly divided into 16 treatment groups (4 replicates of 16 hens per treatment). Laying hens were fed with the diets containing four levels of methionine(0.28%, 0.34%, 0.40% and 0.46%) and four levels of lysine(0.68%, 0.75%, 0.82% and 0.89%) in a 4×4 factorial arrangement.The dies were supplemented with NSPE 0.01% in each group. The adjustment period was 7d, the trial period was 60d.The results were showed as follows:(1)There was significant effects of increasing dietary methionine level on egg weight(P<0.05).There are significan effect on egg weight with 0.34% methionine(P<0.05). The dietary lysine levels had significant effects on the average laying rate、egg weight and Feed/egg ratio(P<0.05). There were no significant effects of on feed intake. The laying rate increased significantly(P<0.05), the Feed/egg ratio decreased significantly(P<0.01)while dietary lysine was 0.82%.The egg weight was the best in the treatment which contained 0.75% lysine in the diet (P<0.05). The different methionine and lysine levels had no significant interaction effect on feed intake、laying rate、egg weight and Feed/egg ratio.(2)There was significant effects of increasing dietary methionine level on egg shape index(P<0.05). There are significan effect on egg shape index with 0.40% methionine(P<0.05). The different methionine levels was no significant effect on the haugh unit、yolk index and yolk color(P>0.05). The haugh unit and yolk index was the biggest in the treatment which contained 0.34% methionine in the diet (P<0.05). The yolk color was positive correlation with methionine level(P>0.05). There were significant effects (P<0.05) of increasing dietary lysine level on the haugh unit、yolk index and yolk color(P<0.05).The haugh unit was reduced while lysine 0.82%(P<0.05). The yolk color was reduced while lysine 0.75% or 0.89%(P<0.05). The different methionine and lysine levels had no significant interaction effect on egg shape index、haugh unit、yolk index and yolk color(P>0.05).(3)There were significant effects of different methionine and lysine levels on nitrogen digestibilities(P<0.01). The nitrogen digestibilities was the highest in the treatment which contained 0.34% methionine in the diet (P<0.05), which was higher 4.79%(P<0.01) than0.28%,higher 1.76%(P<0.05) than 0.40%,higher 1.09%(P<0.05) than 0.46%,0.82% and 0.75% lysine levels was higher 5.37%(P<0.01) and 4.47%(P<0.01) than 0.68%.The different methionine and lysine levels had no significant interaction effect on nitrogen digestibilities(P>0.05). (4)There were significant effects of different methionine level on ileal digestibility of methionine and alanine(P<0.05). The ileal methionine digestibility was the highest in the treatment which contained 0.34% methionine in the diet (P<0.05), which was higher 2.17%(P<0.05) than 0.28%,higher 1.62%(P<0.05) than 0.40%,higher 1.79%(P<0.05) than 0.46%. The ileal alanine digestibility was the highest in the treatment which contained 0.28% methionine in the diet , higher than 0.34% and 0.46%(P<0.05). There were significant effects of different lysine level on ileal digestibility of methionine and lysine (P<0.05). The ileal lysine digestibility was the highest in the treatment which contained 0.89% lysine in the diet (P<0.05), which was higher 0.48%(P<0.05) than 0.82%,higher 4.1%(P<0.05) than 0.75%,higher 3.64%(P<0.05) than 0.68%.0.89% and 0.82% lysine levels was higher 1.49%(P<0.05) and 1.42%(P<0.05) than 0.68%.The different methionine and lysine levels was significant interaction effect on ileal digestibility of lysine、methionine and histidine(P<0.05), The interaction effect was the highest on ileal digestibility of lysine(P<0.01).(5)There was significant effect of different methionine level on serum concentration of leucine (P<0.05).The serum concentration of leucine was higher than 0.28% in the treatment which contained 0.40% and 0.46% methionine in the diet (P<0.05). There were significant effects of different lysine level on the ileal serum concentration of alanine、leucine and phenylalanine(P<0.05),and the serum concentration was the highest in the treatment which contained 0.82% lysine in the diet as well. The different methionine and lysine level had no significant interaction effect on the amino acid serum concentration (P>0.05).(6)There was significant effect of different methionine level on spleen index(P<0.05).0.40% methionine level group was higher 0.05 than 0.28%(P<0.05), the spleen index was higher than 0.28% in the treatment which contained 0.34% and 0.46% methionine in the diet (P<0.05).There were significant effect of different lysine level on spleen index and thymus index(P<0.05). They coincide well of 0.75% and 0.80% lysine level on spleen index,were higher than 0.68% lysine level(P<0.05). The thymus index was the highest in the treatment which contained 0.75% lysine in the diet (P<0.05),0.82% and 0.89% lysine level group has to take second place,higher 0.06、0.05 and 0.03(P<0.05) than 0.68%,respectively. The different methionine and lysine levels was no significant interaction effect on spleen index and thymus index(P>0.05).There was significant effect of different methionine level on Newcastle antibody titer(P<0.05).The Newcastle antibody titer was increased in 0.40% methionine level group(P<0.05),higher 1.13 and 1.00 than 0.34% and 0.28%. The different methionine and lysine levels had no significant interaction effect on Newcastle antibody titers.(7)There were no significant effects of different methionine and lysine levels on Cecal Microbe (P>0.05). There was significant effect of different lysine level on Colibacillus (P<0.05),0.82% and 0.89% lysine level groups had lower than 0.68% and 0.75%(P<0.05). There were no significant effects of different lysine level on Lactobacillus and Bifidobacteria (P>0.05).The Lactobacillus and Bifidobacteria were highest,the Colibacillus was lowest of 0.82% lysine level group. The different methionine and lysine levels had no significant interaction effect on Cecal Microbe (P>0.05).(8) There was significant effect of different methionine level on serum UA(P<0.05). The serum UA was the highest and lowest in the treatment which contained 0.28% and 0.40% methionine in the diet, respectively (P<0.05),0.34% methionine level compared with 0.46%,the serum UA was no significant effect(P>0.05). There were significant effects of different lysine level on serum UA and total amino acid(P<0.05). the serum UA was the lowest in the treatment which contained 0.82% lysine in the diet,lower 7.34 and 8.00 than 0.68% and 0.89%(P<0.05). The serum UA of 0.75% lysine level was lower 5.48 than 0.89%(P<0.05).There is significantly negative correlation between lysine level and total amino acid(P<0.05). The different methionine and lysine levels had significant interaction effect on serum total amino acid (P>0.05).