One hundred and forty-four Avin broilers (1 d of age) were randomly divided into six groups, with three replicates of eight birds each to study on the effects of different oligosaccharides on performance and availabil...One hundred and forty-four Avin broilers (1 d of age) were randomly divided into six groups, with three replicates of eight birds each to study on the effects of different oligosaccharides on performance and availability of nutrients in broilers. The control group(Group I)was fed with corn-soybean meal as basal diet, and the trial groups (Group II, III, IV,V and VI) were fed with basal diet plus 0.1% Manoligosaccharides(MOS), 0.3% Soybean-Oligosaccharides(SBOS), 0.3% Fructo-oligosaccharides(FOS), 0.3% α-Glucooligosaccharides(α-GOS) and 50 mg·L-1 Chlortetracycline(CTC), respectively. The results showed that the supplementation of oligosaccharides slightly improved daily gain and feed intake. SBOS supplementation improved, but MOS and α-GOS significantly decreased availability of energy. Oligosaccharides supplementation improved availability of energy, phosphorus, calcium, magnesium and iron, and significantly increased cholesterol content of fecal, and did not affect on availability of protein and cholesterol contents in serum and muscle. Availability of phosphorus of broilers fed with FOS was much higher than that with α-GOS. SBOS supplementation remarkably increased availability of iron.展开更多
The antioxidant effects of quercetin were studied in vitro and in vivo.In vitro,vitamin C was used as a positive control to evaluate the antioxidant capacity of quercetin in three aspects:scavenging free radicals,prot...The antioxidant effects of quercetin were studied in vitro and in vivo.In vitro,vitamin C was used as a positive control to evaluate the antioxidant capacity of quercetin in three aspects:scavenging free radicals,protecting biological macromolecules and the total reducing power.In vivo,a total of 240 AA broilers(1-day age)with similar body weight were randomly divided into four groups with six replicates in each group,and 10 broilers in each replicate.The four groups were fed with corn-soybean basal diet supplemented with 0.00%,0.02%,0.04%and 0.06%quercetin to study its effects on antioxidant indexes of AA broilers,and to explore the optimal dose of quercetin as a dietary additive.The results showed that quercetin scavenged superoxide anion,hydroxyl radical and 1,1-diphenyl-2-picrylhydrazyl(DPPH)in vitro,the scavenging effects of quercetin on O_(2)-and•OH first increased and then decreased with the increase of the concentrations(P<0.01),and its maximum scavenging effect was observed at concentrations of 40 and 300 mg·L^(-1).The scavenging effects of quercetin on DPPH was increased constantly with increasing concentrations.The scavenging effect of quercetin on three free radicals was DPPH>•OH>O_(2)-.The inhibition of vitelline lipoprotein peroxidation by quercetin was increased with increasing concentrations(P<0.01)and the inhibitory effect was higher than that of vitamin C.The inhibition of red blood cell hemolysis by quercetin was increased with increasing concentrations at 0.05-1.25 mg·L^(-1)(P<0.01);however,the inhibition tended to decrease when the concentration was too high(31.25 mg·L^(-1)),and the inhibitory effect was higher than that of vitamin C.The inhibition of mitochondrial expansion by quercetin was increased with increasing concentrations,according to the degree of mitochondrial expansion at 60 min,the integrity of mitochondria in the experimental groups was significantly higher than that in the model group(P<0.01).The total reducing power of quercetin was increased with increasing concentrations(P<0.01);however,the total reducing power was less than that of vitamin C.In vivo,malondialdehyde(MDA)and nitric oxide(NO)were significantly decreased with increasing quercetin(P<0.01).Quercetin supplementation had no effect on the content of lipid peroxidation(LPO)in livers(P>0.05);however,superoxide dismutase(SOD)activity was significantly increased,whereas glutathione peroxidase(GSH-Px)and catalase(CAT)activities were significantly decreased in livers with increasing quercetin(P<0.05).These results suggested that quercetin exhibited strong antioxidant effects in vitro and in vivo.展开更多
AA female broilers were used to examine the effect of high temperature and β-agonist Clenbuterol (CL) on performance, carcass composition, efficiency of the deposition of energy and protein in diet, carcass character...AA female broilers were used to examine the effect of high temperature and β-agonist Clenbuterol (CL) on performance, carcass composition, efficiency of the deposition of energy and protein in diet, carcass characteristics and meat quality. The trial was 2×2 factorial design with four replicates. Experimental period was last for 24 days from 29 to 52 days after birth. There were four groups in the trial: normal temperature with no CL, nomal temperature with CL, high temperature with no CL and high temperature with CL. The normal terperature was 22±1℃, high temperature was 32±1℃. The lever of CL was administred at 3mg·kg -1 feed. There were three days withdrawal of CL before the end of the trial. The results showed that: (1) High temperature had a significantly negative influence on performance. Where feed intake, daily weight gain and feed efficiency were significantly reduced so that daily feed intake and daily weight gain reduced by 12.6% (P<0.01) and 14.4% (P<0.01), respectively. Feed/gain ratio increased by 1.9% (P<0.05). (2) At high temperature, body protein and water content decreased by 9.4% (P<0.05) and by 2.0% (P<0.05), respectively. Body fat content increased 12.4% (P<0.01). (3) Abdorminal fat significantly increased (P<0.01) at high temperature, compared with that at the normal temperature, where carcass fat ratio and abdominal fat ratio increase 5.8% and 26.4%, respectively. (4) In this trial, CL reduced feed intake significantly (P<0.01) by 6.6% and 5.1% at the normal and high temperature during the whole test period, respectively. CL had no significant influence on daily weight gain (P>0.05), but reduced feed/gain ratio by 5.0% and 5.3% at normal and high temperature, respectively. (5) Carcass analysis indicated that the CL-fed birds had a significantly higher carcass protein content (P<0.01) and lower carcass fat content (P<0.01), where body protein content increased 4.4% and 12.7% and body fat content reduced 16.0% and 17.1% for the normal and high temperature, respectively. (6) Carcass characteristics indicated that CL reduced skin fat ratio by 7.6% (P<0.01) and abdominal fat ratio 8.5% (P<0.01) at the normal temperature; at high temperature, reduced by 14% and 24%, respectively. CL increased breast musle ratio by 14.1% and 3.2%, and increased leg muscle ratio 5.2% and 3.2% at the normal and high temperature, respectively. (7) CL had no negative influence on meat quality. (8) High temperature did not change the function of CL to increase protein deposition and reduce fat deposition.展开更多
The objective of this study is to determine the effect of different protein levels on the growth performance and metabolic rate of nutrition in broilers. Total 360 healthy and weight closed local broilers of 3 weeks w...The objective of this study is to determine the effect of different protein levels on the growth performance and metabolic rate of nutrition in broilers. Total 360 healthy and weight closed local broilers of 3 weeks were chosen and then divided into three groups randomly by one factor. Each group contains three handlings, each handling consists of 40 broilers. The period of experiment was 7 weeks. The metabolic experiment was performed at the 7th week. Three different protein levels were used in broilers＇ diet. The levels of protein were 19%, 17.5% and 16%. The results showed that the different levels of protein in crude dietary had significant difference between 19% group and the other two groups. The average daily weight gain and daily efficiency were significantly higher than that of the other two groups （P〈0.05）. Compared to protein levels of 19% and 16%, there was no significant difference in the metabolism of calcium （P〉0.05）, and the metabolic rate of the impact of phosphorus was significantly different （P〈0.05）. The result showed that when protein level was 19%, the growth of the local broiler was the best.展开更多
480 healthy 1-day-old male yellow-feathered chickens were selected and assigned randomly into groups A and B,each having 6 pens with 40 birds per pen.The birds in group A were fed with wheatbased diet and group B with...480 healthy 1-day-old male yellow-feathered chickens were selected and assigned randomly into groups A and B,each having 6 pens with 40 birds per pen.The birds in group A were fed with wheatbased diet and group B with wheat-based diet supplemented with xylanase(1.2×l0~4 U/kg diet).On day 16,two birds per replication with average live weight were selected and sacrificed.Tissue samples of jejunum and ileum were collected to detect mRNA expression of cationic amino acid transporters using RT-PCR.The results showed that xylanase significantly increased the abundance of mRNA for rBAT and CAT4 in the intestines of broilers fed with wheat-based diets(P<0.05)and had a tendency to increase the mRNA expression of y^+LAT2 and CAT1 in jejunum(P>0.05),y^+LAT2,CAT1 and CAT4 in ileum(P>0.05).The treatment had no effect on the expression of rBAT mRNA in ileum(P>0.05).展开更多
A total of 120-day-old broilers were divided into four groups. In group-A, broilers were left without supplementation of minerals and vitamins(control), while the broilers in groups B, C and D were given mineral and v...A total of 120-day-old broilers were divided into four groups. In group-A, broilers were left without supplementation of minerals and vitamins(control), while the broilers in groups B, C and D were given mineral and vitamin supplementation 1-6, 1-4 and 5-6 weeks, respectively. The results showed that the feed consumption of broilers in groups A, B, C and D was 4 234.61, 4 028.38, 4 169.32 and 4 181.87 g · b-1; water intake was 9 668.88, 9 295.55, 9 882.11 and 9 402.86 L · b-1; live body weight was 2 068.90, 2 360.90, 2 255.30 and 2 157.40 g · b-1, respectively. The feed conversion ratio of broilers in groups A, B, C, D was 2.05, 1.71, 1.85 and 1.94 g · b-1, carcass weight(wt) was 1 550, 1 656, 1 552 and 1 528.8 g · b-1, and average dressing percentage was 61.24, 63.02, 62.60 and 60.51 respectively. Weight of heart in groups A, B, C and D was 15.13, 13.16, 11.72 and 11.50 g · b-1, weight of gizzard was 32.98, 37.48, 37.62 and 33.35 g · b-1, weight of liver was 51.94, 48.70, 51.94 and 48.70 g · b-1 and spleen weight was 3.48, 3.28, 3.06 and 2.82 g · b-1, respectively. Average mortality of broilers in groups A, B, C and D was 6, 2, 4 and 5 resulting 20.00%, 8.00%, 13.00% and 16.00% mortality rate, respectively. The haemoglobin level in blood of broilers in groups A, B, C and D was 9.20, 12.23, 10.87 and 7.60 g · dL-1,white blood cell level 77.47, 89.83, 81.63 and 78.13(×106 μL); red blood cell level 1.85, 2.58, 2.45 and 1.40(×106 μL), respectively. It was concluded that broilers given mineral and vitamin supplementation(Aquavit Electrolyte) for 6 weeks were proven to be most effective regime to result the lowest feed intake, the highest live body weight, better feed conversion ratio, higher carcass weight, better dressing percentage, higher net profit, relatively improved haemoglobin level in blood, increased counts of red blood cells and white blood cells. In all the above parameters, the broilers received mineral and vitamin supplementation for the first 4 weeks and the last 2 weeks showed relatively inferior performance, it is suggested that mineral and vitamin supplementation through water for partial period was not much effective in broiler productivity. Broilers may be supplemented with commercially available minerals and vitamins in drinking water over full rearing period, for achieving higher live body weight and efficient feed conversion ratio.展开更多
An experiment was conducted to determine the effects of dietary fructooligosaccharides(FOS),compared with direct-fed microbial bacteria(DFM),and zinc bacitracin,on cecal microbial populations and performance of broile...An experiment was conducted to determine the effects of dietary fructooligosaccharides(FOS),compared with direct-fed microbial bacteria(DFM),and zinc bacitracin,on cecal microbial populations and performance of broiler Chickens.One hundred and ninety-two broilers(Avian) were randomly assigned to four groups,with four replicates of 12 birds each.The control group was fed with the basal diet,without any drug additive.FOS,DFM and zine bacitracin was respectively added to the basal diet at the level of 1.5%,800 mg·kg -1 and 300 mg·kg -1 to form the experimental diets.Body weight,feed intake and feed efficiency were measured weekly.The feeding trial started at 1 d and ended at 21 d.At day 14 and day 21,four broilers per group were killed and cecum was taken to determined microflors and pH.The results showed that dietary FOS increased bifidobactrial concentration by 1.75-fold(P<0.05) at 14 d of age and 1.45-fold(P<0.05) at 21 d of age compared with control.FOS had no effect on concnetrations of E.coli and pH.There were no dietary effects of FOS,DFM,and zinc bacitracin on weight gain,feed intake,feed conversion(P>0.05).展开更多
The study was conducted to investigate the effect and mechanism of dietary quercetin supplementation on protein utilization of Arbor Acres(AA)broilers.A total of 2401-day-old AA broilers were randomly allocated to fou...The study was conducted to investigate the effect and mechanism of dietary quercetin supplementation on protein utilization of Arbor Acres(AA)broilers.A total of 2401-day-old AA broilers were randomly allocated to four treatments with six replicates,comprising 10 broilers each replicate(60 broilers per treatment).Birds were fed either a corn-soybean meal basal diet without quercetin(control)or a basal diet supplemented with 0.2,0.4 or 0.6 g of quercetin per kg feed,and the trial lasted 42 days.Dietary quercetin supplementation tended to increase the apparent metabolic rate of protein(p=0.076)and the content of serum albumin(p=0.062)in AA broilers.Compared with the control,dietary quercetin supplementation increased the contents of protein in breast muscle(p<0.05)and in thigh muscle(p=0.053).In addition,quercetin up-regulated mRNA expression of insulin-like growth factor 1(IGF-1),phosphatidylinositol 3-kinase(PI3K),target of rapamycin(TOR),ribosomal protein S6 kinase 1(S6K1),eukaryotic translation initiation factor 4E(eIF4E),eukaryotic translation initiation factor 4G(eIF4G),eukaryotic elongation factor 2(eEF2)and eukaryotic translation initiation factor 4B(eIF4B)genes and down-regulated mRNA expression of eukaryotic elongation factor 2 kinase(eEF2K)and eukaryotic initiation factor 4E binding protein1(4E-BP1)genes in breast muscle,thigh muscle and liver of AA broilers(p<0.05).The present results suggested that dietary quercetin supplementation enhanced protein utilization in broilers by activating TOR signaling pathway.展开更多
Blood samples were taken from birds,from a commercial line of broiler chicken,being in a fully fed state and in fasting state for 2,4,6 hours respectively at 49 d of age and plasma very low density lipoprotein(VLDL) c...Blood samples were taken from birds,from a commercial line of broiler chicken,being in a fully fed state and in fasting state for 2,4,6 hours respectively at 49 d of age and plasma very low density lipoprotein(VLDL) concentration was measured with turbidimetric assay.The experiment results showed that the variation coefficients of plasma VLDL concentration mersured at four different times were 58.11%,74.39%,69.70%,47.83%,respectively for male broilers,and 41.82%,60.87%.59.26%,50.0%for female broilers respectively.Plasma VLDL concentration decreased with the fasting time.There was a significant positive phenotypic correlation between abdominal fat weight,percentage of abdominal fat and plasma VLDL concentration for the birds being in fully feeding state,and the correlation decreased or no longer existed for the bired being in fasting state.The conclusion was that for practically application of plasma VLDL content selected in broiler chicken breeding,blood samples should be collected from birds being in feeding state.展开更多
The aim of this study was to determine the effects of supplementing organic forms of zinc(zinc acetate,ZnA)and inorganic zinc(zinc sulfate,Zn S)on performance,the gain to feed ratio(G:F)and skeletal characters in broi...The aim of this study was to determine the effects of supplementing organic forms of zinc(zinc acetate,ZnA)and inorganic zinc(zinc sulfate,Zn S)on performance,the gain to feed ratio(G:F)and skeletal characters in broilers from the first day to the 42th day.A total of 240-day-old broilers(Arbor Acres)were randomly distributed in four groups.A corn-soybean meal-based control diet containing recommended concentrations of inorganic trace minerals and other nutrients was prepared.On the basal diets,the control goup(CG)was supplemented with Zn S and the treatment group(TG)feeding diets were with different ZnA supplemental levels(80,100 and 150 mg·kg^-1)of ZnA.Each group was allotted randomly to five replicates and 12 broilers in each replicate and fed ad libitum from the first day to the 42th day.The results showed that supplementation of ZnA significantly increased(p<0.05)energy and phosphorus(P)compared to that fed Zn S on the 21th day.Calcium(Ca),tibia weight,ash weight,tibia Ca and tibia P in TG(80 mg·kg^-1 of ZnA)were the highest(p<0.05).The pancreas Zn content of TG was higher than that in CG and increased with the supplementation of ZnA.On the 42th day,the content of energy,crude protein(CP),Ca and tibia Ca in TG(80 mg·kg^-1 of ZnA)were the highest(p<0.05),the change of pancreas Zn was the same as the results on the 21th day,but enter extract(EE),tibia weight,tibia length,tibia width and ash weight were not affected(p>0.05)by ZnA.The results of this study showed that ZnA was better than Zn S in improving the early growth performance,nutrient utilization rate in broilers,the length and weight of broiler tibia,it promoted the calcium,phosphorus deposition and normal growth of tibia,and the optimum dietary ZnA level to feed was 80 mg·kg^-1.ZnA affected body Zn stores and the apparent metabolic rate of nutrients.展开更多
The present experiment was performed with the objective of examining the effects of copper sources and levels on hydrogen peroxide(H_2O_2) generation by mitochondria from broiler hepatocytes. Treatments were applied t...The present experiment was performed with the objective of examining the effects of copper sources and levels on hydrogen peroxide(H_2O_2) generation by mitochondria from broiler hepatocytes. Treatments were applied to compare sources of copper(CuSO_4 versus Cu-Met) and 4 levels of dietary Cu (11,110,220 and 330 mg/kg).Day-old broilers(Cobb 500,Gallus domesticus,n=288) were randomly divided into 8 groups of 36 each and fed diets as follows:Controls(Cu 11 mg/kg) and high copper(Cu 110, 220,and 330 mg/kg),for 60 days under normal conditions.Sample collections were made at 12,36 and 60 days of age to investigate the changes in H_2O_2 generation by mitochondria from hepatocytes.Compared with those of the control diets,H_2O_2 generation by mitochondria in the high copper groups(110 to 330 mg/kg) of the two copper sources were increased(P<0.05 or P<0.01);At days 36 and 60,H_2O_2 generation by hepatic mitochondria from Cu-Met supplementation exceeded that from birds supplemented with CuSO_4 (P<0.05 or P<0.01).In addition,H_2O_2 generation by mitochondria from broilers fed with high dietary copper appeared to be associated with altered function of mitochondrial complexⅣ.The results indicated that dietary supplementation with copper induced oxidative stress damage in liver.At each level of copper supplementation,the organic Cu-Met led to more rapid H_2O_2 generation than did inorganic CuSO_4.The results also suggest that mitochondrial complexⅣmay be targeted under conditions of high dietary copper supplementation.展开更多
Raw,heat treated soybean meal and diets made from soybeans extruded at varying temperature were compared to examine dietary threshold levels of the major soybean antinutritional factors(ANF)for broilers.Whole full fa...Raw,heat treated soybean meal and diets made from soybeans extruded at varying temperature were compared to examine dietary threshold levels of the major soybean antinutritional factors(ANF)for broilers.Whole full fat soybeans were extruded at 90,100,110,120,130,or 140 ℃.An in vivo nutritional evaluation of the extruded soybean meals was carried out using 224 Arbor Acres broilers allotted to seven treatments with four replicates of eight birds per pen.As extrusion cooking temperature increased,the urease activity,TI activity,lectin content and PDI decreased.Extruding at 120 ℃ reduced the urease actvity to 0 11 units,the TI activity to 7 20 mg·g -1 ,and lectin content to zero.Raw soybean meal significantly depressed the growth rate of broiler chickens.Remaining ANF obviously reduced feed intake and dietary nitrogen metabolism.The performance of broilers was improved as extrusion temperature increased.Extruding at 110 ℃ produced an effect equal to that of conventional soybean meal.The weight of the pancreas of the birds fed the raw soybean or 90℃ extruded soybean were significantly higher than those in heated soybean meal group and in the higher temperature extruded soyean groups.The same tendency was found from 3 to 7 wk of age.The weights of duodenum and ileum of the broilers fed the raw soybean were significantly higher than those in heated soybean meal group.Extending the feeding of raw soybean or low temperature extruded soybean to 7 wk old broilers significantly increased the fresh weights of proventriculus,jejunum and ileum and dry weights of jejunum and ileum.The villi of birds fed raw soybean meal and low temperature extruded soybean meals were shor tened and damaged.Broilers grew well on the diets containing soybean trypsin inhitory activity as high as 3 74 mg·g -1 without showing any negative effect on the weights of organs and alimentary tracts.展开更多
To investigate the antibacterial activity of commercial organic acid Activate WD （WD）, the minimal inhibitory concentration （MIC） and minimal bactericidal concentration （MBC） of WD against Staphylococcus aureus,...To investigate the antibacterial activity of commercial organic acid Activate WD （WD）, the minimal inhibitory concentration （MIC） and minimal bactericidal concentration （MBC） of WD against Staphylococcus aureus, Escherichia coli, Salmonella pullorum, and Campylobacter jejuni were determined by double broth dilution method. Bacteria were added in a mixture of water and commercial broiler feed adjusted by WD into pH 3.0, 4.0, and 5.0; the survival of bacteria was determined by a direct plate count method at 0, 0.5, 1, 4, 8, and 24 h after being mixed to test the bactericidal potential of WD. The results showed that the MIC of WD against four bacteria was 0.3125%, and the MBC was 0.625%. At pH 3.0, bacteria could not survive. Campylobacter jejuni died after 4 h of incubation at pH 4.0, 5.0, whereas for other three bacteria, the bacterium numbers were below detection limits until 8 h of incubation. In conclusion, WD had significant antibacterial activity, and could be used on farms to prevent cross-infection via rearing water.展开更多
An experiment was conducted to study the response of broiler to diet dilution during the finishing period. Sixty 29-day-old commercial Avian male broiler chicks were assigned to two groups randomly, with 30 broilers e...An experiment was conducted to study the response of broiler to diet dilution during the finishing period. Sixty 29-day-old commercial Avian male broiler chicks were assigned to two groups randomly, with 30 broilers each. Birds were offered a conventional finishing diet or with 10% dilution diet with ground rice hulls from 29 to 49 days of age. The result showed that there were no significant differences between the effects of diet dilution and the control on final body weight, growth rate and feed conversion efficiency. Diet dilution led to a reduction in abdominal fat weight, whereas carcass and breast muscle weight were not affected.展开更多
An experiment was conducted to study the influence of eady quantitative feed restriction on the performance and carcass characteristics of broiler chickens. Two hundred 8-day-old commercial Avian male broiler chicks w...An experiment was conducted to study the influence of eady quantitative feed restriction on the performance and carcass characteristics of broiler chickens. Two hundred 8-day-old commercial Avian male broiler chicks were assigned to four groups randomly, with 50 broilers each. At the age of 8 days the broilers were restricted to 90%, 80% or 70% of the ad libitum intake for 7 days. When the restricion was finished, all birds received feed ad libitum again. The results showed that diet restriction resulted in a reduction in body weight and daily gain during the restriction period （P 〈0.05）. The birds restricted to 90% of the ad libitum intake showed the occurring of growth compensation in the 3rd week. The birds restricted to 80% and 70% of the ad libitum intake had growth compensation in the 4th week. No significant differences between the effects of the restriction and the control on final body weight, growth rate, feed conversion efficiency and carcass characteristics （P 〈0.05）.展开更多
The study was carried out to investigate the effects of maternal dietary energy restriction on growth performance, serum indices and fat deposition of offspring. A total of 400 female Arbor Acres （AA） broiler breede...The study was carried out to investigate the effects of maternal dietary energy restriction on growth performance, serum indices and fat deposition of offspring. A total of 400 female Arbor Acres （AA） broiler breeders were studied. These female birds involved three experimental treatments and a control group with normal dietary energy diets （ND, 11.7 MJ of ME. kgt during the laying）. In treatments 2, 3 and 4, the energies of diets were 20%, 30% and 50% （LD20, LD30 and LD50） lower than those of the control, respectively. The study commenced at the beginning of the laying period when the total egg production reached 5% of the flock. All the broiler offspring were fed the same diets. The results showed that in low energy diets, offspring showed decreased 1-day-old weight, but 49-day-old weight was higher in LD20 diet （P〈0.05）. For offspring during days 1-49, the average daily gain （ADG） in LD20 group and the feed conversion ratio in LD50 group were improved as compared with those of the control （P〈0.05）. Compared with the control, abdominal fat percentage increased in 49-day-old offspring from LD30 diet （P〈0.05）; the fat content of breast muscle in offspring increased in broilers fed low energy diets （P〈0.05）. In 28-day-old offspring from breeders given LD20 and LD50 diets, liver fat percentages were higher compared with ND （P〈0.05）. The subcutaneous fat thickness in 28-day-old offspring from LD50 group and 49-day-old offspring from LD30 group was higher （P〈0.05）. On day 49, the serum cholesterol （CHO） of offspring from breeders fed LD20 diet and serum high-density lipoprotein （HDL） of offspring from breeders fed LD50 diet reduced compared with those of the control （P〈0.05）. In addition, a higher triiodothyronine （T3） content in serum was found in offspring from broiler breeders given LD20 and LD30 diets （P〈0.05）. Serum thyroxine （T4） in offspring significantly decreased with the decrease of diet energy （P〈0.05）. In conclusion, to a certain extent, dietary energy restriction in breeders could improve growth performance and promote lipid metabolism of offspring.展开更多
After 1500 male and female broiler chickens from a pure line were selected on the basis of plasma very low density lipoprotein (VLDL) concentration at 8 weeks of age,abdominal fat(AF),liver fat,body weight,meat traits...After 1500 male and female broiler chickens from a pure line were selected on the basis of plasma very low density lipoprotein (VLDL) concentration at 8 weeks of age,abdominal fat(AF),liver fat,body weight,meat traits and plasma lipids were determined,and effects of interaction between genotype and nutrition on AF and its correlated traits were studied.1) It was efficient to select against AF on the basis of plasma VLDL concentration.The indirect response of gizzard fat was the greatest,and that of liver fat was the second.AF was decreased,whereas liver fat was increased,feed conversion efficiency during growing period were improved, body weight and meat traits were both not influenced by selecting for low plasma VLDL concentration.2) Nutrition had significant effect on fat deposition and growth performance.Interaction between line and diet had evident effect on AF and its correlated traits.In general,diet had greater effect on H-VLDL line than L-VLDL line,namely chickens of L-VLDL line were less sensitive to diet than those of H-VLDL line.3) Due to high coefficients of variation of plasma VLDL and AF in H-VLDL and L-VLDL lines in the first generation.It will be possible that plasma VLDL is to be selected continuously to breed low fat line of broiler chickens of which the feed conversion efficiency is much better.Moreover,family combined with individual selection should be adopted during future generation selection and breeding because of significant family difference in plasma VLDL concentration.展开更多
文摘One hundred and forty-four Avin broilers (1 d of age) were randomly divided into six groups, with three replicates of eight birds each to study on the effects of different oligosaccharides on performance and availability of nutrients in broilers. The control group(Group I)was fed with corn-soybean meal as basal diet, and the trial groups (Group II, III, IV,V and VI) were fed with basal diet plus 0.1% Manoligosaccharides(MOS), 0.3% Soybean-Oligosaccharides(SBOS), 0.3% Fructo-oligosaccharides(FOS), 0.3% α-Glucooligosaccharides(α-GOS) and 50 mg·L-1 Chlortetracycline(CTC), respectively. The results showed that the supplementation of oligosaccharides slightly improved daily gain and feed intake. SBOS supplementation improved, but MOS and α-GOS significantly decreased availability of energy. Oligosaccharides supplementation improved availability of energy, phosphorus, calcium, magnesium and iron, and significantly increased cholesterol content of fecal, and did not affect on availability of protein and cholesterol contents in serum and muscle. Availability of phosphorus of broilers fed with FOS was much higher than that with α-GOS. SBOS supplementation remarkably increased availability of iron.
基金Supposed by the National Natural Science Foundation of China(32072749)。
文摘The antioxidant effects of quercetin were studied in vitro and in vivo.In vitro,vitamin C was used as a positive control to evaluate the antioxidant capacity of quercetin in three aspects:scavenging free radicals,protecting biological macromolecules and the total reducing power.In vivo,a total of 240 AA broilers(1-day age)with similar body weight were randomly divided into four groups with six replicates in each group,and 10 broilers in each replicate.The four groups were fed with corn-soybean basal diet supplemented with 0.00%,0.02%,0.04%and 0.06%quercetin to study its effects on antioxidant indexes of AA broilers,and to explore the optimal dose of quercetin as a dietary additive.The results showed that quercetin scavenged superoxide anion,hydroxyl radical and 1,1-diphenyl-2-picrylhydrazyl(DPPH)in vitro,the scavenging effects of quercetin on O_(2)-and•OH first increased and then decreased with the increase of the concentrations(P<0.01),and its maximum scavenging effect was observed at concentrations of 40 and 300 mg·L^(-1).The scavenging effects of quercetin on DPPH was increased constantly with increasing concentrations.The scavenging effect of quercetin on three free radicals was DPPH>•OH>O_(2)-.The inhibition of vitelline lipoprotein peroxidation by quercetin was increased with increasing concentrations(P<0.01)and the inhibitory effect was higher than that of vitamin C.The inhibition of red blood cell hemolysis by quercetin was increased with increasing concentrations at 0.05-1.25 mg·L^(-1)(P<0.01);however,the inhibition tended to decrease when the concentration was too high(31.25 mg·L^(-1)),and the inhibitory effect was higher than that of vitamin C.The inhibition of mitochondrial expansion by quercetin was increased with increasing concentrations,according to the degree of mitochondrial expansion at 60 min,the integrity of mitochondria in the experimental groups was significantly higher than that in the model group(P<0.01).The total reducing power of quercetin was increased with increasing concentrations(P<0.01);however,the total reducing power was less than that of vitamin C.In vivo,malondialdehyde(MDA)and nitric oxide(NO)were significantly decreased with increasing quercetin(P<0.01).Quercetin supplementation had no effect on the content of lipid peroxidation(LPO)in livers(P>0.05);however,superoxide dismutase(SOD)activity was significantly increased,whereas glutathione peroxidase(GSH-Px)and catalase(CAT)activities were significantly decreased in livers with increasing quercetin(P<0.05).These results suggested that quercetin exhibited strong antioxidant effects in vitro and in vivo.
文摘AA female broilers were used to examine the effect of high temperature and β-agonist Clenbuterol (CL) on performance, carcass composition, efficiency of the deposition of energy and protein in diet, carcass characteristics and meat quality. The trial was 2×2 factorial design with four replicates. Experimental period was last for 24 days from 29 to 52 days after birth. There were four groups in the trial: normal temperature with no CL, nomal temperature with CL, high temperature with no CL and high temperature with CL. The normal terperature was 22±1℃, high temperature was 32±1℃. The lever of CL was administred at 3mg·kg -1 feed. There were three days withdrawal of CL before the end of the trial. The results showed that: (1) High temperature had a significantly negative influence on performance. Where feed intake, daily weight gain and feed efficiency were significantly reduced so that daily feed intake and daily weight gain reduced by 12.6% (P<0.01) and 14.4% (P<0.01), respectively. Feed/gain ratio increased by 1.9% (P<0.05). (2) At high temperature, body protein and water content decreased by 9.4% (P<0.05) and by 2.0% (P<0.05), respectively. Body fat content increased 12.4% (P<0.01). (3) Abdorminal fat significantly increased (P<0.01) at high temperature, compared with that at the normal temperature, where carcass fat ratio and abdominal fat ratio increase 5.8% and 26.4%, respectively. (4) In this trial, CL reduced feed intake significantly (P<0.01) by 6.6% and 5.1% at the normal and high temperature during the whole test period, respectively. CL had no significant influence on daily weight gain (P>0.05), but reduced feed/gain ratio by 5.0% and 5.3% at normal and high temperature, respectively. (5) Carcass analysis indicated that the CL-fed birds had a significantly higher carcass protein content (P<0.01) and lower carcass fat content (P<0.01), where body protein content increased 4.4% and 12.7% and body fat content reduced 16.0% and 17.1% for the normal and high temperature, respectively. (6) Carcass characteristics indicated that CL reduced skin fat ratio by 7.6% (P<0.01) and abdominal fat ratio 8.5% (P<0.01) at the normal temperature; at high temperature, reduced by 14% and 24%, respectively. CL increased breast musle ratio by 14.1% and 3.2%, and increased leg muscle ratio 5.2% and 3.2% at the normal and high temperature, respectively. (7) CL had no negative influence on meat quality. (8) High temperature did not change the function of CL to increase protein deposition and reduce fat deposition.
基金Supported by Youth Funded Projects of Heilongjiang Academy of Agricultural Sciences (2007AA6CN033)
文摘The objective of this study is to determine the effect of different protein levels on the growth performance and metabolic rate of nutrition in broilers. Total 360 healthy and weight closed local broilers of 3 weeks were chosen and then divided into three groups randomly by one factor. Each group contains three handlings, each handling consists of 40 broilers. The period of experiment was 7 weeks. The metabolic experiment was performed at the 7th week. Three different protein levels were used in broilers＇ diet. The levels of protein were 19%, 17.5% and 16%. The results showed that the different levels of protein in crude dietary had significant difference between 19% group and the other two groups. The average daily weight gain and daily efficiency were significantly higher than that of the other two groups （P〈0.05）. Compared to protein levels of 19% and 16%, there was no significant difference in the metabolism of calcium （P〉0.05）, and the metabolic rate of the impact of phosphorus was significantly different （P〈0.05）. The result showed that when protein level was 19%, the growth of the local broiler was the best.
基金supported by National Key Basic Research Development Program 973 of China(No.2004CB117501)National Natural Science Foundation of China(No.30671519)Guangdong Province Scientific Technology Research Project(No.2005B20201016)
文摘480 healthy 1-day-old male yellow-feathered chickens were selected and assigned randomly into groups A and B,each having 6 pens with 40 birds per pen.The birds in group A were fed with wheatbased diet and group B with wheat-based diet supplemented with xylanase(1.2×l0~4 U/kg diet).On day 16,two birds per replication with average live weight were selected and sacrificed.Tissue samples of jejunum and ileum were collected to detect mRNA expression of cationic amino acid transporters using RT-PCR.The results showed that xylanase significantly increased the abundance of mRNA for rBAT and CAT4 in the intestines of broilers fed with wheat-based diets(P<0.05)and had a tendency to increase the mRNA expression of y^+LAT2 and CAT1 in jejunum(P>0.05),y^+LAT2,CAT1 and CAT4 in ileum(P>0.05).The treatment had no effect on the expression of rBAT mRNA in ileum(P>0.05).
文摘A total of 120-day-old broilers were divided into four groups. In group-A, broilers were left without supplementation of minerals and vitamins(control), while the broilers in groups B, C and D were given mineral and vitamin supplementation 1-6, 1-4 and 5-6 weeks, respectively. The results showed that the feed consumption of broilers in groups A, B, C and D was 4 234.61, 4 028.38, 4 169.32 and 4 181.87 g · b-1; water intake was 9 668.88, 9 295.55, 9 882.11 and 9 402.86 L · b-1; live body weight was 2 068.90, 2 360.90, 2 255.30 and 2 157.40 g · b-1, respectively. The feed conversion ratio of broilers in groups A, B, C, D was 2.05, 1.71, 1.85 and 1.94 g · b-1, carcass weight(wt) was 1 550, 1 656, 1 552 and 1 528.8 g · b-1, and average dressing percentage was 61.24, 63.02, 62.60 and 60.51 respectively. Weight of heart in groups A, B, C and D was 15.13, 13.16, 11.72 and 11.50 g · b-1, weight of gizzard was 32.98, 37.48, 37.62 and 33.35 g · b-1, weight of liver was 51.94, 48.70, 51.94 and 48.70 g · b-1 and spleen weight was 3.48, 3.28, 3.06 and 2.82 g · b-1, respectively. Average mortality of broilers in groups A, B, C and D was 6, 2, 4 and 5 resulting 20.00%, 8.00%, 13.00% and 16.00% mortality rate, respectively. The haemoglobin level in blood of broilers in groups A, B, C and D was 9.20, 12.23, 10.87 and 7.60 g · dL-1,white blood cell level 77.47, 89.83, 81.63 and 78.13(×106 μL); red blood cell level 1.85, 2.58, 2.45 and 1.40(×106 μL), respectively. It was concluded that broilers given mineral and vitamin supplementation(Aquavit Electrolyte) for 6 weeks were proven to be most effective regime to result the lowest feed intake, the highest live body weight, better feed conversion ratio, higher carcass weight, better dressing percentage, higher net profit, relatively improved haemoglobin level in blood, increased counts of red blood cells and white blood cells. In all the above parameters, the broilers received mineral and vitamin supplementation for the first 4 weeks and the last 2 weeks showed relatively inferior performance, it is suggested that mineral and vitamin supplementation through water for partial period was not much effective in broiler productivity. Broilers may be supplemented with commercially available minerals and vitamins in drinking water over full rearing period, for achieving higher live body weight and efficient feed conversion ratio.
文摘An experiment was conducted to determine the effects of dietary fructooligosaccharides(FOS),compared with direct-fed microbial bacteria(DFM),and zinc bacitracin,on cecal microbial populations and performance of broiler Chickens.One hundred and ninety-two broilers(Avian) were randomly assigned to four groups,with four replicates of 12 birds each.The control group was fed with the basal diet,without any drug additive.FOS,DFM and zine bacitracin was respectively added to the basal diet at the level of 1.5%,800 mg·kg -1 and 300 mg·kg -1 to form the experimental diets.Body weight,feed intake and feed efficiency were measured weekly.The feeding trial started at 1 d and ended at 21 d.At day 14 and day 21,four broilers per group were killed and cecum was taken to determined microflors and pH.The results showed that dietary FOS increased bifidobactrial concentration by 1.75-fold(P<0.05) at 14 d of age and 1.45-fold(P<0.05) at 21 d of age compared with control.FOS had no effect on concnetrations of E.coli and pH.There were no dietary effects of FOS,DFM,and zinc bacitracin on weight gain,feed intake,feed conversion(P>0.05).
基金Supported by the National Natural Science Foundation of China(31872377)。
文摘The study was conducted to investigate the effect and mechanism of dietary quercetin supplementation on protein utilization of Arbor Acres(AA)broilers.A total of 2401-day-old AA broilers were randomly allocated to four treatments with six replicates,comprising 10 broilers each replicate(60 broilers per treatment).Birds were fed either a corn-soybean meal basal diet without quercetin(control)or a basal diet supplemented with 0.2,0.4 or 0.6 g of quercetin per kg feed,and the trial lasted 42 days.Dietary quercetin supplementation tended to increase the apparent metabolic rate of protein(p=0.076)and the content of serum albumin(p=0.062)in AA broilers.Compared with the control,dietary quercetin supplementation increased the contents of protein in breast muscle(p<0.05)and in thigh muscle(p=0.053).In addition,quercetin up-regulated mRNA expression of insulin-like growth factor 1(IGF-1),phosphatidylinositol 3-kinase(PI3K),target of rapamycin(TOR),ribosomal protein S6 kinase 1(S6K1),eukaryotic translation initiation factor 4E(eIF4E),eukaryotic translation initiation factor 4G(eIF4G),eukaryotic elongation factor 2(eEF2)and eukaryotic translation initiation factor 4B(eIF4B)genes and down-regulated mRNA expression of eukaryotic elongation factor 2 kinase(eEF2K)and eukaryotic initiation factor 4E binding protein1(4E-BP1)genes in breast muscle,thigh muscle and liver of AA broilers(p<0.05).The present results suggested that dietary quercetin supplementation enhanced protein utilization in broilers by activating TOR signaling pathway.
文摘Blood samples were taken from birds,from a commercial line of broiler chicken,being in a fully fed state and in fasting state for 2,4,6 hours respectively at 49 d of age and plasma very low density lipoprotein(VLDL) concentration was measured with turbidimetric assay.The experiment results showed that the variation coefficients of plasma VLDL concentration mersured at four different times were 58.11%,74.39%,69.70%,47.83%,respectively for male broilers,and 41.82%,60.87%.59.26%,50.0%for female broilers respectively.Plasma VLDL concentration decreased with the fasting time.There was a significant positive phenotypic correlation between abdominal fat weight,percentage of abdominal fat and plasma VLDL concentration for the birds being in fully feeding state,and the correlation decreased or no longer existed for the bired being in fasting state.The conclusion was that for practically application of plasma VLDL content selected in broiler chicken breeding,blood samples should be collected from birds being in feeding state.
文摘The aim of this study was to determine the effects of supplementing organic forms of zinc(zinc acetate,ZnA)and inorganic zinc(zinc sulfate,Zn S)on performance,the gain to feed ratio(G:F)and skeletal characters in broilers from the first day to the 42th day.A total of 240-day-old broilers(Arbor Acres)were randomly distributed in four groups.A corn-soybean meal-based control diet containing recommended concentrations of inorganic trace minerals and other nutrients was prepared.On the basal diets,the control goup(CG)was supplemented with Zn S and the treatment group(TG)feeding diets were with different ZnA supplemental levels(80,100 and 150 mg·kg^-1)of ZnA.Each group was allotted randomly to five replicates and 12 broilers in each replicate and fed ad libitum from the first day to the 42th day.The results showed that supplementation of ZnA significantly increased(p<0.05)energy and phosphorus(P)compared to that fed Zn S on the 21th day.Calcium(Ca),tibia weight,ash weight,tibia Ca and tibia P in TG(80 mg·kg^-1 of ZnA)were the highest(p<0.05).The pancreas Zn content of TG was higher than that in CG and increased with the supplementation of ZnA.On the 42th day,the content of energy,crude protein(CP),Ca and tibia Ca in TG(80 mg·kg^-1 of ZnA)were the highest(p<0.05),the change of pancreas Zn was the same as the results on the 21th day,but enter extract(EE),tibia weight,tibia length,tibia width and ash weight were not affected(p>0.05)by ZnA.The results of this study showed that ZnA was better than Zn S in improving the early growth performance,nutrient utilization rate in broilers,the length and weight of broiler tibia,it promoted the calcium,phosphorus deposition and normal growth of tibia,and the optimum dietary ZnA level to feed was 80 mg·kg^-1.ZnA affected body Zn stores and the apparent metabolic rate of nutrients.
基金supported by the National Natural Science Foundation of China(NSFC) awarded to Tang Zhao-xin(grant number:30671550)
文摘The present experiment was performed with the objective of examining the effects of copper sources and levels on hydrogen peroxide(H_2O_2) generation by mitochondria from broiler hepatocytes. Treatments were applied to compare sources of copper(CuSO_4 versus Cu-Met) and 4 levels of dietary Cu (11,110,220 and 330 mg/kg).Day-old broilers(Cobb 500,Gallus domesticus,n=288) were randomly divided into 8 groups of 36 each and fed diets as follows:Controls(Cu 11 mg/kg) and high copper(Cu 110, 220,and 330 mg/kg),for 60 days under normal conditions.Sample collections were made at 12,36 and 60 days of age to investigate the changes in H_2O_2 generation by mitochondria from hepatocytes.Compared with those of the control diets,H_2O_2 generation by mitochondria in the high copper groups(110 to 330 mg/kg) of the two copper sources were increased(P<0.05 or P<0.01);At days 36 and 60,H_2O_2 generation by hepatic mitochondria from Cu-Met supplementation exceeded that from birds supplemented with CuSO_4 (P<0.05 or P<0.01).In addition,H_2O_2 generation by mitochondria from broilers fed with high dietary copper appeared to be associated with altered function of mitochondrial complexⅣ.The results indicated that dietary supplementation with copper induced oxidative stress damage in liver.At each level of copper supplementation,the organic Cu-Met led to more rapid H_2O_2 generation than did inorganic CuSO_4.The results also suggest that mitochondrial complexⅣmay be targeted under conditions of high dietary copper supplementation.
文摘Raw,heat treated soybean meal and diets made from soybeans extruded at varying temperature were compared to examine dietary threshold levels of the major soybean antinutritional factors(ANF)for broilers.Whole full fat soybeans were extruded at 90,100,110,120,130,or 140 ℃.An in vivo nutritional evaluation of the extruded soybean meals was carried out using 224 Arbor Acres broilers allotted to seven treatments with four replicates of eight birds per pen.As extrusion cooking temperature increased,the urease activity,TI activity,lectin content and PDI decreased.Extruding at 120 ℃ reduced the urease actvity to 0 11 units,the TI activity to 7 20 mg·g -1 ,and lectin content to zero.Raw soybean meal significantly depressed the growth rate of broiler chickens.Remaining ANF obviously reduced feed intake and dietary nitrogen metabolism.The performance of broilers was improved as extrusion temperature increased.Extruding at 110 ℃ produced an effect equal to that of conventional soybean meal.The weight of the pancreas of the birds fed the raw soybean or 90℃ extruded soybean were significantly higher than those in heated soybean meal group and in the higher temperature extruded soyean groups.The same tendency was found from 3 to 7 wk of age.The weights of duodenum and ileum of the broilers fed the raw soybean were significantly higher than those in heated soybean meal group.Extending the feeding of raw soybean or low temperature extruded soybean to 7 wk old broilers significantly increased the fresh weights of proventriculus,jejunum and ileum and dry weights of jejunum and ileum.The villi of birds fed raw soybean meal and low temperature extruded soybean meals were shor tened and damaged.Broilers grew well on the diets containing soybean trypsin inhitory activity as high as 3 74 mg·g -1 without showing any negative effect on the weights of organs and alimentary tracts.
文摘To investigate the antibacterial activity of commercial organic acid Activate WD （WD）, the minimal inhibitory concentration （MIC） and minimal bactericidal concentration （MBC） of WD against Staphylococcus aureus, Escherichia coli, Salmonella pullorum, and Campylobacter jejuni were determined by double broth dilution method. Bacteria were added in a mixture of water and commercial broiler feed adjusted by WD into pH 3.0, 4.0, and 5.0; the survival of bacteria was determined by a direct plate count method at 0, 0.5, 1, 4, 8, and 24 h after being mixed to test the bactericidal potential of WD. The results showed that the MIC of WD against four bacteria was 0.3125%, and the MBC was 0.625%. At pH 3.0, bacteria could not survive. Campylobacter jejuni died after 4 h of incubation at pH 4.0, 5.0, whereas for other three bacteria, the bacterium numbers were below detection limits until 8 h of incubation. In conclusion, WD had significant antibacterial activity, and could be used on farms to prevent cross-infection via rearing water.
基金National Basic Research Program of China (2004CB11750-5)
文摘An experiment was conducted to study the response of broiler to diet dilution during the finishing period. Sixty 29-day-old commercial Avian male broiler chicks were assigned to two groups randomly, with 30 broilers each. Birds were offered a conventional finishing diet or with 10% dilution diet with ground rice hulls from 29 to 49 days of age. The result showed that there were no significant differences between the effects of diet dilution and the control on final body weight, growth rate and feed conversion efficiency. Diet dilution led to a reduction in abdominal fat weight, whereas carcass and breast muscle weight were not affected.
基金National Basic Research Programof China (2004|CB11750-5)
文摘An experiment was conducted to study the influence of eady quantitative feed restriction on the performance and carcass characteristics of broiler chickens. Two hundred 8-day-old commercial Avian male broiler chicks were assigned to four groups randomly, with 50 broilers each. At the age of 8 days the broilers were restricted to 90%, 80% or 70% of the ad libitum intake for 7 days. When the restricion was finished, all birds received feed ad libitum again. The results showed that diet restriction resulted in a reduction in body weight and daily gain during the restriction period （P 〈0.05）. The birds restricted to 90% of the ad libitum intake showed the occurring of growth compensation in the 3rd week. The birds restricted to 80% and 70% of the ad libitum intake had growth compensation in the 4th week. No significant differences between the effects of the restriction and the control on final body weight, growth rate, feed conversion efficiency and carcass characteristics （P 〈0.05）.
基金Supported by the Education Department Research Program of Heilongjiang Province(12531036)Doctor Science Foundation of Northeast Agricultural University(2009RC28)
文摘The study was carried out to investigate the effects of maternal dietary energy restriction on growth performance, serum indices and fat deposition of offspring. A total of 400 female Arbor Acres （AA） broiler breeders were studied. These female birds involved three experimental treatments and a control group with normal dietary energy diets （ND, 11.7 MJ of ME. kgt during the laying）. In treatments 2, 3 and 4, the energies of diets were 20%, 30% and 50% （LD20, LD30 and LD50） lower than those of the control, respectively. The study commenced at the beginning of the laying period when the total egg production reached 5% of the flock. All the broiler offspring were fed the same diets. The results showed that in low energy diets, offspring showed decreased 1-day-old weight, but 49-day-old weight was higher in LD20 diet （P〈0.05）. For offspring during days 1-49, the average daily gain （ADG） in LD20 group and the feed conversion ratio in LD50 group were improved as compared with those of the control （P〈0.05）. Compared with the control, abdominal fat percentage increased in 49-day-old offspring from LD30 diet （P〈0.05）; the fat content of breast muscle in offspring increased in broilers fed low energy diets （P〈0.05）. In 28-day-old offspring from breeders given LD20 and LD50 diets, liver fat percentages were higher compared with ND （P〈0.05）. The subcutaneous fat thickness in 28-day-old offspring from LD50 group and 49-day-old offspring from LD30 group was higher （P〈0.05）. On day 49, the serum cholesterol （CHO） of offspring from breeders fed LD20 diet and serum high-density lipoprotein （HDL） of offspring from breeders fed LD50 diet reduced compared with those of the control （P〈0.05）. In addition, a higher triiodothyronine （T3） content in serum was found in offspring from broiler breeders given LD20 and LD30 diets （P〈0.05）. Serum thyroxine （T4） in offspring significantly decreased with the decrease of diet energy （P〈0.05）. In conclusion, to a certain extent, dietary energy restriction in breeders could improve growth performance and promote lipid metabolism of offspring.
文摘After 1500 male and female broiler chickens from a pure line were selected on the basis of plasma very low density lipoprotein (VLDL) concentration at 8 weeks of age,abdominal fat(AF),liver fat,body weight,meat traits and plasma lipids were determined,and effects of interaction between genotype and nutrition on AF and its correlated traits were studied.1) It was efficient to select against AF on the basis of plasma VLDL concentration.The indirect response of gizzard fat was the greatest,and that of liver fat was the second.AF was decreased,whereas liver fat was increased,feed conversion efficiency during growing period were improved, body weight and meat traits were both not influenced by selecting for low plasma VLDL concentration.2) Nutrition had significant effect on fat deposition and growth performance.Interaction between line and diet had evident effect on AF and its correlated traits.In general,diet had greater effect on H-VLDL line than L-VLDL line,namely chickens of L-VLDL line were less sensitive to diet than those of H-VLDL line.3) Due to high coefficients of variation of plasma VLDL and AF in H-VLDL and L-VLDL lines in the first generation.It will be possible that plasma VLDL is to be selected continuously to breed low fat line of broiler chickens of which the feed conversion efficiency is much better.Moreover,family combined with individual selection should be adopted during future generation selection and breeding because of significant family difference in plasma VLDL concentration.
