Effects Of Coated Acidifier And Small Peptide Chelate Iron On Performance, Egg Yolk Fe Content And Serum Biochemical Indices Of Laying Hens

This experiment was conducted to study the effects of coated acidifier and s-mall peptide chelate iron on performance, egg quality, the contents of mineral elem-ents in egg yolk and serum biochemical parameters of Lohmann pink-shell laying hens in the peak of egg production, and to discuss the deposition of small peptide chelate iron in the egg yolk and the interaction of small peptide chelate iron and coated acidifier.576 plume and 38 week-old healthy Lohmann pink-shell hens we-re selected and randomly divided into 8 dietary treatment groups with six replicates of twelve hens in each for a 42-day feeding trial in a completely randomized de-sin involving a 2 � 4 factorial arrangement of treatments with two levels of added coated acidifier (0, or 300 mg/kg of acidifier) and four concentrations of added s-mall peptide chelate iron(0,60,120, or 180 mg of Fe/kg). The adjustment period lasted for 7 days and the experimental period lasted for 42 days. Production index-es of the trial period were recorded, Eggs samples and blood samples were collect-ed respectively for egg quality and serum antioxidation and other biochemical indic-ators determination in the 21st and 42nd of the trial period. The experimental resul-ts showed that:(1) Dietary supplemented with coated acidifier significantly increased the average daily feed intake in the 2nd and 5th week (P<0.05). Dietary supplemented with small peptide chelate iron had significant effects on the average daily feed intake in the 4th and 5th week (P<0.05), adding 120 mg/kg iron of small petide chelate iron group significantly increased the average daily feed intake, compared to adding 180 mg/kg iron of small petide chelate iron. Dietary supplemented with the combination of coated acidifier and small peptide chelate iron significantly had significant effects on the average daily feed intake in the 4th and 5th week (P<0.05), adding 300 mg/kg coated acidifier and 120 mg/kg iron of small peptide chelate iron significantly increased the average daily feed intake from 3rd to 6th week (P<0.05). Dietary supplemented with coated acidifier and small peptide chelate iron had no significant effects on laying rate, the feed/egg ratio and average egg weight (P >0.05), however, compared to adding 0 mg/kg small petide chelate iron, adding 60 mg/kg iron of small petide chelate iron significantly decreased feed/egg ratio in the 5th week (P< 0.05), and significantly increased laying rate in the 5th and 6th week (P<0.05).(2) In the 21st of the trial period, dietary supplemented with coated acidifier significantly increased egg weight and egg shell thickness (P<0.05), dietary supplemented with small peptide chelate iron had no significant effect on egg quality (P>0.05), adding the combination of coated acidifier and small peptide chelate iron had no significant effect on egg quality (P>0.05), but dietary supplemented with the combination of 300 mg/kg coated acidifier and 0 or 60 mg/kg iron of small peptide chelate iron significantly increased egg shell thickness (P<0.05), dietary supplemented with the combination of 300 mg/kg coated acidifier and 120 mg/kg iron of small peptide chelate iron significantly increased yolk index compared to adding the combination of 0 mg/kg coated acidifier and 120 mg/kg iron of small peptide chelate iron (P<0.05). Dietary supplemented with the combination of 300 mg/kg coated acidifier and small peptide chelate iron significantly decreased yolk color (P<0.05). Dietary supplemented with the combination of 0 mg/kg coated acidifier and 60 mg/kg iron of small peptide chelate iron significantly decreased yolk color (P< 0.05). In the 42nd of the trial period, dietary supplemented with coated acidifier significantly increased yolk index and haugh unit (P<0.05). Dietary supplemented with small peptide chelate iron had significant effects on yolk index (P<0.05), adding 60 mg/kg iron of small petide chelate iron significantly increased yolk index, compared to adding 0 mg/kg small petide chelate iron (P<0.05). Dietary supplemented with the combination of coated acidifier and small peptide chelate iron significantly increased yolk index (P<0.01) and haugh unit (P<0.05). The egg shell thickness and yolk index of adding 300 mg/kg coated acidifier and 60 mg/kg iron of small peptide chelate iron were the most (P<0.05).(3) In the 21st and 42nd of the trial period, dietary supplemented with coated acidifier had no significant effect on iron, zinc, copper and manganese contents in egg yolk (P>0.05), but had an increasing trend in yolk iron content. Dietary supp-lemented with small peptide chelate iron significantly increased yolk Fe content (P <0.01). In the 21st of the trial period, the yolk iron content increased linearly with the increasing of small peptide chelate iron (P<0.05). In the 42nd of the trial period, the yolk iron content had no significant increasing with the increase of s- mall peptide chelate iron (P>0.05). In the 21st and 42nd of the trial period, dieta-ry supplemented with the combination of coated acidifier and small peptide chelate iron significantly increased yolk Fe content (P<0.01). In the 21st of the trial perio-d, the yolk iron content of adding the combination of 300 mg/kg coated acidifier and 180 mg/kg iron of small peptide chelate iron was most. In the 42nd of the tri-al period, through curve fitting, adding the combination of 0 mg/kg coated compou-nd acidifier and 128.9 mg/kg iron of small peptide chelate iron deposited largest Fe in egg yolk, and adding the combination of 300mg/kg coated compound acidifier and 141.2 mg/kg iron of small peptide chelate iron were more beneficial to depos-it Fe in egg yolk.(4) In the 21st of the trial period, dietary supplemented with coated acidifier si-gnificantly decreased serum glutathione peroxidase (GSH-PX) activity and significan-tly increased serum total superoxide dismutase (T-SOD) activity (P<0.05). In the 42nd of the trial period, dietary supplemented with coated acidifier significantly inc-reased serum total superoxide dismutase (T-SOD) activity (P<0.01), and significant-ly decreased malonadldehyde (MDA) content (P<0.05). Dietary supplemented with small peptide chelate iron had significant effects on serum antioxidant index (P>0. 05), but with the increasing adding level of small peptide iron, the activity of seru-m total superoxide dismutase (T-SOD) increased gradually, and adding 180 mg/kg small peptide iron significantly increased serum total superoxide dismutase (T-SOD) activity (P<0.01). In the 21st of the trial period, dietary supplemented with coate-d acidifier and small peptide chelate iron had no significant effect on serum antiox-idant index (P>0.05), but adding the combination of 300 mg/kg coated acidifier a-nd 180 mg/kg iron of small peptide chelate iron significantly decreased serum glut-athione peroxidase (GSH-PX) activity and significantly increased serum total antioxi-dant capacity (T-AOC, P<0.05), adding the combination of 300 mg/kg coated acid-ifier and 120 mg/kg iron of small peptide chelate iron significantly increased total superoxide dismutase (T-SOD) activity (P<0.05). In the 42nd of the trial period, dietary supplemented with coated acidifier and small peptide chelate iron significant-ly increased serum total superoxide dismutase (T-SOD) activity (P<0.05) and had a decreasing trend in serum malonadldehyde (MDA) content (P>0.05), adding the combination of 300 mg/kg coated acidifier and 60,120,180 mg/kg iron of small peptide chelate iron reduced serum malonadldehyde (MDA) content by 21.74%(P> 0.05),62.80%(P>0.05),56.04%(P>0.05) respectively.(5) Dietary supplemented with coated acidifier or small peptide chelate iron or their interaction had no significant effect on serum immunogobulin G (IgG), immu-nogobulin A (IgA) and immunogobulin M (IgM, P>0.05), but adding the combina-tion of 0 mg/kg coated acidifier and 120 mg/kg iron of small peptide chelate iron significantly increased immunogobulin M (IgM, P<0.05).(6) Dietary supplemented with coated acidifier had no significant effect on seru-m biochemical indexes (P>0.05). Dietary supplemented with small peptide chelate iron had significant effects on serum calcium (Ca, (P<0.05)), phospgorus (P, (P< 0.05)) and iron (Fe, (P<0.05). Compared to adding 0 mg/kg small peptide chelate iron, adding 60,120 mg/kg iron of small peptide chelate iron significantly increased serum calcium and phospgorus (P<0.05), adding 120 mg/kg iron of small peptide chelate iron significantly increased serum iron (P<0.05), adding 60 mg/kg iron of small peptide chelate iron significantly increased serum triglyceride (P<0.05). Die-tary supplemented with the combination of coated acidifier and small peptide chelat-e iron had significant effects on serum calcium and phospgorus (P<0.05).It is concluded that diet supplemented with the combination of coated acidifier and 60-120 mg/kg small peptide chelate iron effectively improved its production performance and health. In the trial period of 21 days, diet supplemented with 180 mg/kg iron of small peptide chelate iron was most beneficial to the enrichment of iron in egg yolk. In the trial period of 42 days, the predicted optimum adding le-vel of 128.9-141.2 mg/kg iron of small peptide chelate iron effectively increased e-gg yolk iron content.