Effects of Plant Extracts Replacing Anticoccidial Drugs on Broiler Performance and Fecal Coccidia Count

[Objective]The paper was to investigate the impact of plant extracts replacing anticoccidial drugs on growth performance and fecal coccidia count in broilers.[Method]A total of 234 one-day-old healthy yellow-feathered broilers were selected and randomly divided into 3 groups,with 6 replicates in each group and 13 broilers in each replicate.The test lasted for a total of 55 d,The control group was fed the basic diet,the anticoccidial group was fed the basic diet+500 g/t dinitolmide,and the plant extract group was fed the basic diet+500 g/t plant extract.[Result]The daily gain of the plant extract group from 1 to 21 days of age was significantly higher than that of the anticoccidial drug group(P<0.05),and the feed/gain ratio was significantly lower than that of the anticoccidial drug group(P<0.05).There was no significant difference in daily gain and feed intake between the plant extract group and the anticoccidial drug group from 1 to 55 days of age(P>0.05),and the feed/gain ratio was reduced by 6.30%and the mortality and culling rate was reduced by 10.26%.The number of fecal coccidia at 33 days of age in the plant extract group was found to be significantly lower than that observed in the anticoccidial group and the control group(P<0.05).In conclusion,the administration of plant extracts resulted in a notable enhancement in the growth performance of chicks aged 1-21 days,when compared with the use of anticoccidial drugs.No significant difference was observed in growth performance between the plant extract and the anticoccidial drugs from 1 to 55 days of age.The administration of plant extracts resulted in a notable reduction in the fecal coccidia count.[Conclusion]Plant extracts may serve as viable alternatives to anticoccidial drugs and show promise for application in animal husbandry.

Effects of Fresh Cupressus sempervirens Leaves Infusion on Growth Performance, Intestinal Microbiota and Haemato-Biochemical Parameters in Broilers

The accumulation of growth-promoting antibiotic residues in animal products and the resistance developed by bacteria in poultry farms has led to a search for natural compounds derived from plants. This study was designed to promote the production performance of broiler chickens using fresh Cupressus sempervirens leaves infusion. Fresh Cupressus sempervirens leaves were harvested, washed, chopped and ground to a paste using a blender and fermented for three days in a closed container at a rate of 500 g/L of water. The solution obtained was filtered and added at the rate of 2, 4, 6, 8 and 10 ml/L of drinking water. The chickens fed on the graded level of the solution were compared to a control ration without an additive and positive control group supplemented with 1 g antibiotic/kg feed. At the finisher phase and throughout the study period, water intake increased significantly (P < 0.05) with increasing levels of infusion. Feed intake decreased significantly (P < 0.05) with 2 and 4 ml of infusion/L drinking water. Live weight and weight gain were significantly (P < 0.05) higher with 6 ml/L, while feed conversion significantly (P < 0.05) decreased with the same treatment compared with the control treatment without additives (T0). Carcass characteristics were not significantly (P > 0.05) affected by the inclusion of Cupressus sempervirens infusion. Haematological parameters significantly (P < 0.05) increase independently of the rate of incorporation of the infusion into the drinking water, with the exception of RBCs, MCHT and PCT. Serum content in total protein, globulins, LDL cholesterol and triglycerides were significantly (P < 0.05) high with 8 and 10 ml Cupressus sempervirens infusion/litre drinking water as compared to all other treatments. AST, ALT, urea, creatine, albumin, total cholesterol and HDL-cholesterol were not significantly affected. The lactic acid bacteria load increased significantly (P E. coli and salmonella counts decreased significantly (P < 0.05) with infusion compared to the control without additive. In conclusion, 6 ml of Cupressus sempervirens infusion can be used as an alternative to antibiotic feed additives to promote growth performance in broilers.

Supranutrition of microalgal docosahexaenoic acid and calcidiol improved growth performance,tissue lipid profiles,and tibia characteristics of broiler chickens

Background Docosahexaenoic acid(DHA)and calcidiol could be enriched in chicken for improving public nutrition and health.It remains unclear if supranutritional levels of DHA and calcidiol impair growth performance or metabolism of broiler chickens.This study was to determine singular and combined effects of high levels of supplemental DHA-rich microalgal biomass or oil and calcidiol on growth performance,concentrations of triglycerides,cholesterol,and nonesterfied fatty acids in plasma,liver,breast,and thigh,and biophysical properties of tibia.Methods In Exp.1,144 day-old Cornish chicks were divided into 4 groups(6 cages/treatment,6 birds/cage),and were fed a corn-soybean meal basal diet(BD),BD+10,000 IU calcidiol/kg(BD+Cal),BD HA),and BD+1%DHA-rich Aurantiochytrium(1.2 g DHA/kg;BD+D+Cal+DHA for 6 weeks.In Exp.2,180 day-old chicks were divided into5 groups,and were fed:BD,BD+DHA(0.33%to 0.66%oil,1.5 to 3.0 g DHA/kg),BD EPA/kg),BD+DHA+EPA(1.9%to 3.8%eicosapentaenoic acid-rich Nannochloropsis sp.CO18,0.3 to 0.6 g BD+DHA+calcidiol(6000 to 12,000 IU/kg diet),and+DHA+EPA+Cal for 6 weeks.Results Birds fed BD+Cal diet in Exp.1 and BD lower(P+DHA<0.05)+EPA diet in Exp.2 had higher(P<0.05)body weight gain(10%-11%)and gain:feed ratio(7%),and total cholesterol and triglyceride concentrations in plasma(18%-54%),liver(8%-26%),breast(19%-26%),and thigh(10%-19%),respectively,over the controls.The two diets also improved(P<0.05)tibial breaking strength(8%-24%),total bone volume(2%-13%),and(or)bone mineral density(3%-19%)of chickens.Conclusion Supranutrition of dietary calcidiol and DHA alone or together did not produce adverse effects,but led to moderate improvements of growth performance,lipid profiles of plasma and muscle,and bone properties of broiler chickens.

Feeding broiler chickens with arginine above recommended levels:effects on growth performance,metabolism,and intestinal microbiota

Background Arginine is an essential amino acid for chickens and feeding diets with arginine beyond the recommended levels has been shown to influence the growth performance of broiler chickens in a positive way.Nonetheless,further research is required to understand how arginine supplementation above the widely adopted dosages affects metabolism and intestinal health of broilers.Therefore,this study was designed to assess the effects of arginine supplementation(i.e.,total arginine to total lysine ratio of 1.20 instead of 1.06-1.08 recommended by the breeding company) on growth performance of broiler chickens and to explore its impacts on the hepatic and blood metabolic profiles,as well as on the intestinal microbiota.For this purpose,630 one-day-old male Ross 308 broiler chicks were assigned to 2 treatments(7 replicates each) fed a control diet or a crystalline L-arginine-supplemented diet for 49 d.Results Compared to control birds,those supplemented with arginine performed significantly better exhibiting greater final body weight at D49(3778 vs.3937 g;P < 0.001),higher growth rate(76.15 vs.79.46 g of body weight gained daily;P < 0.001),and lower cumulative feed conversion ratio(1.808 vs.1.732;P < 0.05).Plasma concentrations of arginine,betaine,histidine,and creatine were greater in supplemented birds than in their control counterparts,as were those of creatine,leucine and other essential amino acids at the hepatic level.In contrast,leucine concentration was lower in the caecal content of supplemented birds.Reduced alpha diversity and relative abundance of Firmicutes and Proteobacteria(specifically Escherichia coli),as well as increased abundance of Bacteroidetes and Lactobacillus salivarius were found in the caecal content of supplemented birds.Conclusions The improvement in growth performance corroborates the advantages of supplementing arginine in broiler nutrition.It can be hypothesized that the performance enhancement found in this study is associated with the increased availability of arginine,betaine,histidine,and creatine in plasma and the liver,as well as to the ability of extra dietary arginine to potentially ameliorate intestinal conditions and microbiota of supplemented birds.However,the latter promising property,along with other research questions raised by this study,deserve further investigations.

Bacteriophage cocktail supplementation improves growth performance,gut microbiome and production traits in broiler chickens

Background:Effective antibiotic alternatives are urgently needed in the poultry industry to control disease outbreaks.Phage therapy mainly utilizes lytic phages to kill their respective bacterial hosts and can be an attractive solution to combating the emergence of antibiotic resistance in livestock.Methods:Five hundred and four,one-day-old broilers(Ross 308)were allotted to 1 of 4 treatment groups in a completely randomized design.Treatments consisted of CON(basal diet),PC(CON+0.025%Avilamax®),BP 0.05(CON+0.05%bacteriophage),and BP 0.10(CON+0.10%bacteriophage).Results:A significant linear effect on body weight gain(BWG)was observed during days 1–7,days 22–35,and cumulatively in bacteriophage(BP)supplemented groups.The BWG tended to be higher(P=0.08)and the feed intake(FI)was increased(P=0.017)in the PC group over CON group.A greater(P=0.016)BWG and trends in increased FI(P=0.06)were observed in the experiment in birds fed PC than CON diet.At the genus level,the relative abundance of Lactobacillus was decreased in PC(65.28%),while it was similar in BP 0.05 and BP 0.10(90.65%,86.72%)compared to CON(90.19%).At the species level,the relative abundance of Lactobacillus salivarus was higher in BP 0.05(40.15%)and BP 0.10(38.58%)compared to the CON(20.04%)and PC(18.05%).A linear reduction in the weight of bursa of Fabricius(P=0.022)and spleen(P=0.052)was observed in birds fed graded level of BP and an increase(P=0.059)in the weight of gizzard was observed in birds fed PC over BP diets.Linear and quadratic responses were observed in redness of breast muscle color in birds fed graded level of BP.Conclusions:The inclusion of the 0.05%and 0.1%BP cocktail linearly improved broiler weight during the first 7 days,22–35 days and cumulatively,whereas 0.05%BP addition was sufficient for supporting immune organs,bursa and spleen as well as enhancing gut microbiome,indicating the efficacy of 0.05%BP as a substitute antibiotic growth promoter in broiler diets.

Effects of Replacing Maize with Dioscarea bulbifera Flour on Growth Performance of Broiler Chickens

The present study was designed to evaluate Dioscarea bulbifera flour as potential feed ingredient in broilers diets. For this purpose, 256-day-old Cobb 500 broiler chicks, were divided into 4 groups replicated 4 times in a completely randomized design. A control ration (R0) containing maize as the main energy source was compared to three other rations in which 50%, 75% and 100% maize were substituted with Dioscarea bulbifera flour. The main results showed that, the increasing rate of Dioscarea bulbifera flour had no significant (p > 0.05) effect on the digestibility of feed components. Feed intake was higher with 50% and 75% Dioscarea bulbifera flour inclusion levels. As compared to the control ration, a significant (p < 0.05) drop in live weight and weight gain was recorded with 50% substitution while feed conversion ratio increased significantly with increasing level of Dioscarea bulbifera flour in the ration. Dioscarea bulbifera flour induced a linear and significant (p < 0.05) increase in the relative weight of the gizzard, liver and production cost. It was concluded that, substituting 50% maize with Dioscarea bulbifera flour could be a sustainable solution to palliate the growing inflation of maize as animal feed ingredient. However, the incorporation level of Dioscarea bulbifera as feed ingredient in substitution of maize must not exceed 50% at the risk of depreciating growth performance of broilers.

Growth performance,nutrient digestibility,intestinal morphology,cecal mucosal cytokines and serum antioxidant responses of broiler chickens to dietary enzymatically treated yeast and coccidia challenge

Background There is a growing search for natural feed additives to alleviate the deleterious effects of coccidia infection in poultry production.This study aimed to investigate the effect of enzymatically treated yeast(ETY) on the growth performance,nutrient digestibility,intestinal morphology,antioxidative status,and cecal mucosa cytokines of coccidia-challenged broiler chickens.Methods From d 1 to 14 post hatching,480 broiler chickens were allocated to 3 corn-soybean meal-based experimental diets with increasing concentrations of ETY(0,1,or 2 g/kg).The experiment was designed as a randomized complete block design with body weight(BW) used as a blocking factor.On d 14 post hatching,the birds were re-randomized within each of the 3 experimental diets.Each of the 3 diet groups was split into a challenge or no-challenge group.This resulted in a 3 × 2 factorial arrangement of treatments.The coccidia challenge was administered on d 15 by an oral gavage.Results Dietary ETY improved(P < 0.05) the G:F of birds on d 21 regardless of the challenge state and linearly increased(P < 0.01) the apparent ileal digestibility of dry matter(DM),nitrogen,and gross energy(GE).The coccidia challenge decreased(P < 0.05) BW gain and feed intake of broiler chickens and reduced(P < 0.01) the total tract retention of DM,GE,and nitrogen.The coccidia challenge increased(P < 0.01) the mRNA gene expression of TNFα,IL-1β,IL-10,and IL-6 in the cecal mucosa.There was a tendency(P ne = 0.08) for ETY to linearly reduce IL-1β expression.Additionally,ETY supplementation increased(P < 0.05) the geexpression of OCLN.Serum catalase increased(P < 0.05) with dietary ETY in broiler chickens on d 21.Dietary ETY linearly increased(P < 0.05) the ileal villus height to crypt depth ratio,and ileal goblet cell density in broiler chickens.The ileal and excreta oocyst counts decreased(P < 0.01) with increasing supplementation of dietary ETY in coccidia-challenged broiler chickens on d 21.Conclusions Dietary ETY enhanced nutrient utilization and augmented intestinal development in broiler chickens.However,dietary ETY did not completely attenuate the adverse effects of a coccidia challenge in broiler chickens.

Encapsulated peracetic acid as a valid broad‑spectrum antimicrobial alternative,leading to beneficial microbiota compositional changes and enhanced performance in broiler chickens

Background Antimicrobial alternatives are urgently needed,including for poultry production systems.In this study,we tested the potential broad-range antimicrobial alternative peracetic acid,delivered in feed via the hydrolysis of encapsulated precursors through a 28-day study using 375 Ross 308 broiler chickens.We tested two peracetic acid concentrations,30 and 80 mg/kg on birds housed on re-used litter,and we evaluated the impact of both levels on gut microbial communities,bacterial concentration,antimicrobial resistance genes relative abundance and growth performance when compared to control birds housed on either clean or re-used litter.Results Body weight gain and feed conversion ratio improved in peracetic acid fed birds.At d 28,birds given 30 mg/kg of peracetic acid had a decreased Firmicutes and an increased Proteobacteria abundance in the jejunum,accompanied by an increase in Bacillus,Flavonifractor and Rombustia in the caeca,and a decreased abundance of tetracycline resistance genes.Chicken given 80 mg/kg of peracetic acid had greater caecal abundance of macrolides lincosamides and streptogramins resistance genes.Growth performance on clean litter was reduced compared to reused litter,which concurred with increased caecal abundance of Blautia,decreased caecal abundance of Escherichia/Shigella,Anaerostipes and Jeotgalicoccus,and greater gene abundance of vancomycin,tetracycline,and macrolides resistance genes.Conclusions Peracetic acid could be used as a safe broad-spectrum antimicrobial alternative in broilers.Encapsulated precursors were able to reduce the bacterial concentration in the jejunum whilst promoting the proliferation of probiotic genera in the caeca,especially at the low peracetic acid concentrations tested,and improve growth performance.Moreover,our findings offer further insights on potential benefits of rearing birds on re-used litter,suggesting that the latter could be associated with better performance and reduced antimicrobial resistance risk compared to clean litter rearing.

Effect of relative humidity at chronic temperature on growth performance, glucose consumption, and mitochondrial ATP production of broilers

An experiment was conducted to investigate the effect of relative humidity(RH)at chronic temperature on growth performance,glucose consumption,and mitochondrial adenosine triphosphate(ATP)production of broilers.A total of 180 28-day-old Arbor Acres broilers(half males and half females)were randomly allocated to three treatments,each containing six replicates of 10 birds per treatment,using a completely randomized design.Birds were reared at 35,60 or 85%RH at 32℃for 15 days(temperature increased by 3℃every 3 days from 20 to 32℃within 15 days:20–23–26–29–32℃).RH affected(P<0.05)average daily feed intake(ADFI),average daily gain(ADG),average daily water consumption(ADWC),blood glucose concentrations,muscle glycogen levels,avian uncoupling protein(av UCP)mRNA expression,and cytochrome c oxidase(CCO)activity in liver of broilers at 42 days of age.The 85%RH decreased(P<0.05)ADFI,ADG and ADWC;35%RH decreased(P<0.02)ADG.Both 85 and 35%RH increased(P<0.01)blood glucose and decreased(P<0.05)muscle glycogen.Both 85 and 35%RH increased(P<0.05)av UCP mRNA expression.35%RH decreased(P<0.05)CCO activity.In conclusion,both high and low RH inceased glucose consumption and reduced mitochondrial ATP poduction,leading to a decline in growth rate.

Production Performance of Broiler Chickens Fed with Silkworm Pupa （Bombyx mon~

The production performance of broilers fed with silkworm pupa （Bombyx mori） was studied by focusing on growth, feed utilization, carcass composition and meat quality. There were two difference sources of silkworm pupa： （1） silkworm pupa from spun silk industry （SSP） and （2） silkworm pupa from silk yam reeling industry （RSP） were mixed into five isonitrogenous （20% CP） and isocaloric （ME = 3,150 kcal/kg feed） diet. The 195 chickens at three weeks old were equally distributed to 15 pens in the closed housing. The experiment was divided into five dietary treatments （three replications each）： treatment 1 （10% fishmeal, FM and 0% silkworm pupae） （control））, treatment 2 （0% FM and 10% SSP）, treatment 3 （0% FM and 20% SSP）, treatment 4 （0% FM and 5% SSP ＋ 5% RSP）, and treatment 5 （0% FM and 10% SSP ＋ 10% RSP）. Daily weight gain was 0.069, 0.060, 0.051, 0.065 and 0.061 kg/chick in treatments 1, 2, 3, 4 and 5, respectively. It is indicated that replacing fishmeal with silkworm pupa （5%SSP ＋ 5%RSP） performed the same daily weight gain as control but exhibited the higher feed conversion ratio （1.87） than control （1.68）. Carcass muscle of control treatment 1 （58.26%） was the highest （P 〈 0.05） and closed to treatment 4 and 5 （57.62% and 57.83%, respectively）. Sensory evaluation was not significantly differences （P 〉 0.05）. Therefore, treatment 4 （5%SSP ＋ 5%RSP） could be substituted FM with little adverse effect on broiler growth but without any adverse effect on percentage of muscle and sensory test. However, further supplemental silkworm pupa performed reduction in dietary utilization and carcass muscle.

Hybrid data-driven framework for shale gas production performance analysis via game theory, machine learning, and optimization approaches

A comprehensive and precise analysis of shale gas production performance is crucial for evaluating resource potential,designing a field development plan,and making investment decisions.However,quantitative analysis can be challenging because production performance is dominated by the complex interaction among a series of geological and engineering factors.In fact,each factor can be viewed as a player who makes cooperative contributions to the production payoff within the constraints of physical laws and models.Inspired by the idea,we propose a hybrid data-driven analysis framework in this study,where the contributions of dominant factors are quantitatively evaluated,the productions are precisely forecasted,and the development optimization suggestions are comprehensively generated.More specifically,game theory and machine learning models are coupled to determine the dominating geological and engineering factors.The Shapley value with definite physical meaning is employed to quantitatively measure the effects of individual factors.A multi-model-fused stacked model is trained for production forecast,which provides the basis for derivative-free optimization algorithms to optimize the development plan.The complete workflow is validated with actual production data collected from the Fuling shale gas field,Sichuan Basin,China.The validation results show that the proposed procedure can draw rigorous conclusions with quantified evidence and thereby provide specific and reliable suggestions for development plan optimization.Comparing with traditional and experience-based approaches,the hybrid data-driven procedure is advanced in terms of both efficiency and accuracy.

Effects of the Compatibility of Chinese Medical Herbs on Health and Growth Performance of Broilers

[Objective] The aim of this study is to investigate the effects of Chinese medical herbs including astragali and taraxacum on health and growth performance of broilers.[Method] The tested Chinese medical herbs were added into the basal diet of avian broilers for measuring the variation of their health and growth performance.[Result]Compared to the control group(fed by basal diet and with antibiotics as additive),the body weight of broilers fed by compatibility A(0.8% astragali;0.4% haw;0.4% dried citrus peel;0.4% rhizoma atractylodis)and by compatibility B(1.2% taraxacum;0.8% smoked plums;0.8% amur cork-tree bark;0.4% astragali)increased by 6.12%(P<0.01)and 0.64%(P>0.05),respectively;feed intakes changed by-7.95% and 9.99%,respectively;feed conversion rates changed by-14.04% and 9.35%,respectively.The survival rate of compatibility B was similar to that of control group.[Conclusion]Compatibility of Chinese medical herbs containing astragali can improve the growth performance of avian broilers,and that containing taraxacum may to some extent result in the decrease of growth performance,but it can play the role instead of antibiotic additives.

Hair and Villus Production Performance of Tianzhu White Yak

[ Objective ] To analyze the hair and villus production performance of Tianzhu white yak and thus provide conditions for the genetic breed ing and product development. [Method] The hair and villus yield as well as villus rate of male and female Tianzhu white yaks from one year to six years old was detected and the villus yield was also determined. And these indexes of hair and villus were analyzed to evaluate the production per formance. [ Result] In Tianzhu white yaks from one year to two years old, the hair and villus yield was lower, but the villus rate and yield were high er. The hair and villus yield, villus rate, and villus yield were all higher in Tianzhu white yaks from three years to six years old but significantly de creased in 7yearold Tianzhu white yaks. In addition, the hair and villus yield was significantly （ P 〈 0.05） or very significantly （ P 〈 0.01 ） higher in male yaks than in female yaks. The villus rate was very significantly （ P 〈0.01 ） higher than in female yaks from five years to seven years old than in male yaks at the same age. [ Conclusion] Tianzhu white yaks from one year to two years old have the best hair and villus production perform ance; Tianzhu white yaks from three years to six years old are in the main phase of hair and villus production; Tianzhu white yaks older than seven years old should not be used for hair and villus production.

Effect of Phytase Enzyme on Organs Growth Performance and Blood Profile of Broiler

Enzymes which are biological catalyst composed of amino acids with minerals and vitamins. The use of enzymes has many benefits in poultry diets include not only enhanced feed conversion and bird performance but also reduced output of excreta problems of environment. The present research work was conducted to evaluate the effect of phytase enzyme on growth performance and blood profile of broiler. Birds were arbitrarily separated into four groups, i.e. Group A (control) was offered 0 g/kg, 0.05 g/kg (group B), 0.075 g/kg (group C) and 0.025 g/kg (group D) phytase enzyme provided in broiler feed. Parameters which were selected in present research work as, feed intake, live body weight, feed conversion ratio, growth performance and blood profile. Results showed that the maximum chicken body weight was noted in group C and feed intake was minimum in group C, as compared to other groups. Feed conversion ratio was significantly (p < 0.05) higher in group C, followed by other groups the non-significantly variance founded respectively, the highest weight of liver, gizzard, heart, intestine were noted in treated group C comparatively, highest spleen weight was in group B and in group A (control) the minimum weight of spleen was noted and the average blood profile of broiler chicks in different groups, the white blood cells was significantly higher in group D followed by group A, group B and C. Red blood cells was significantly (P < 0.05) better in group C. Haemoglobin was significant differences in different groups of trial. A significant (P < 0.05) difference in Packed cells volume in group A followed by group B, C and D. Total protein in group A was minimum followed by group B, C and D, respectively. From the present study, it was concluded that supplementation of 0.075 g/kg phytase enzyme has a better effect on growth performance and blood profile of broiler.

Effect of deffrent level of ZnMet on performance and immunity of broilers

试验采用完全随机试验设计，将1日龄的罗斯308肉鸡360只分成6组，每组3个重复，每个重复20只鸡，研究蛋氨酸锌（ZnMet）对肉鸡平均日增重（ADG）、平均日采食量（ADFI）和料重比（F／G）以及免疫器官指数和ND抗体效价的影响。目粮处理组为在不添加锌的玉米-豆粕型基础饲粮基础上分别添加20、40、60、80和100mg／kg水平的蛋氨酸锌（以锌计），结果表明，饲粮中添加蛋氨酸锌能提高肉鸡的平均日增重，改善料重比和免疫功能，60～80mg／kg为适宜添加量。

Light demand characteristics,production performance,and changes in the feeding patterns of broilers

Poultry is a light-sensitive animal and the light environment has an important influence on the growth and development of these animals.Previous studies have mainly focused on the effects of the light environment on various physiological indicators of poultry but seldom explored the light demand characteristics of broilers under free selection.This experiment mainly studied the light demand characteristics of broilers under a yellow LED light environment and the influence of different breeding densities[low-density(2.5 broilers/m^(2)),high-density(7.5 broilers/m^(2))]on the production performance and diet characteristics of broilers.Studies showed that the production performance indexes of low-density groups are higher than those of high-density groups.The feed and water consumption in the light area of the two experimental groups were significantly higher than those in the dark area,which means that the broilers showed a great preference for the light area.However,as the age of the broilers increased,the food and water consumption of the broilers decreased,indicating that broilers had a lower preference for light in the middle and late stages of growth.The statistical results for the residence frequency distribution characteristics showed that broiler chickens had different light requirements at different growth stages under the condition of active selection:1)low-density breeding environment:23.8L(light):0.2D(dark)for chicks and 22.3L:1.7D for adult broilers;2)high-density breeding environment:22.6L:1.4D for chicks and 15.0L:9.0D for adult broilers.This study will provide a reference for the optimization and control of light environment in broiler breeding.

Black soldier fly defatted meal as a dietary protein source for broiler chickens:Effects on growth performance,blood traits,gut morphology and histological features

Background: The present study has evaluated the effects of different inclusion levels of a partially defatted black soldier fly(Hermetia illucens L.; HI) larva meal on the growth performance, blood parameters and gut morphology of broiler chickens. A total of 256 male broiler chickens(Ross 308) were reared from d 1 to d 35 and assigned to4 dietary treatments(8 replicates/treatment and 8 birds/replicate). HI larva meal was included at increasing levels(0, 5%, 10% and 15%; HI0, HI5, HI10 and HI15, respectively) in isonitrogenous and isoenergetic diets formulated for 3 feeding phases: starter(1–10 d), growing(10–24 d) and finisher(24–35 d). Two birds per pen were slaughtered at d 35 and morphometric investigations and histopathological alterations were performed.Results: The live weight(LW) showed linear and quadratic responses to increasing HI larva meal(maximum for HI10 group). Average daily gain(ADG) showed a linear and quadratic responses to HI meal(maximum for HI10 group) during starter and growing periods. A linear decrease was observed for ADG during the finisher period. The daily feed intake(DFI) showed a linear and quadratic effect during the starter period(maximum for HI10 group).Linear and quadratic responses were observed for the feed conversion ratio(FCR) in the growing period and for the whole period of the experiment. The FCR showed a linear response in the finisher period(maximum for HI15).No significant effects were observed for the blood and serum parameters, except for the phosphorus concentration,which showed linear and quadratic responses as well as glutathione peroxidase(GPx) activity, the latter of which showed a linear response. The HI15 birds showed a lower villus height, a higher crypt depth and a lower villus height-to-crypt depth ratio than the other groups.Conclusions: Increasing levels of dietary HI meal inclusion in male broiler chickens may improve the LW and DFI during the starter period, but may also negatively affect the FCR and gut morphology, thus suggesting that low levels may be more suitable. However, no significant effects on the haematochemical parameters or histological findings were observed in relation to HI meal utilization.

Effects of dietary supplementation of probiotic,Clostridium butyricum,on growth performance,immune response,intestinal barrier function,and digestive enzyme activity in broiler chickens challenged with Escherichia coli K88

Background： Colibacillosis caused by enterotoxigenic Escherichia coil （E. coil} results in economic losses in the poultry industry. Antibiotics are usually used to control colibacillosis, however, E. coli has varying degrees of resistance to different antibiotics. Therefore the use of probiotics is becoming accepted as an alternative to antibiotics. In this study, we evaluated the effects of Clostfidium butyricum （C. butyficum） on growth performance, immune response, intestinal barrier function, and digestive enzyme activity in broiler chickens challenged with Eschefichia coli （E. coil） K88. Methods： The chickens were randomly divided into four treatment groups for 28 days. Negative control treatment （NC） consisted of birds fed a basal diet without E. coil K88 challenge and positive control treatment （PC） consisted of birds fed a basal diet and challenged with E. coil K88. C. buO/ricum probiotic treatment （CB） consisted of birds fed a diet containing 2 x 107 cfu C. buO/ricum/kg of diet and challenged with E. coil K88. Colistin sulfate antibiotic treatment （CS） consisted of birds fed a diet containing 20 mg colistin sulfate/kg of diet and challenged with E. coil K88. Results： The body weight （BW） and average day gain （ADG） in the broilers of CB group were higher （P 〈 0.05） than the broilers in the PC group overall except the ADG in the 14-21 d post-challenge. The birds in CB treatment had higher （P 〈 0.05） concentration of tumor necrosis factor-a （TNF-a） at 3 and 7 d post-challenge, and higher （P 〈 0.05） concentration of interleukin-4 （IL-4） at 14 d post-challenge than those in the PC treatment group. The concentration of serum endotoxin in CB birds was lower （P 〈 0.05） at 21 d post-challenge, and the concentrations of serum diamine oxidase in CB birds were lower （P 〈 0.05） at 14 and 21 d post-challenge than in PC birds. Birds in CB treatment group had higher （P 〈 0.05） jejunum villi height than those in PC, NC, or CS treatment at 7, 14, and 21 d post-challenge. In comparison to PC birds, the CB birds had lower （P 〈 0.05） jejunum crypt depth during the whole experiment. The birds in CB or CS treatment group had higher （P 〈 0.05） activities of amylase and protease at 3, 7, and 14 d post-challenge, and higher （P 〈 0.05） activity of lipase at 3, 7 d post-challenge than PC birds.

Unevenly distributed LED light produces distinct behavioral preferences and production performance of broilers

LED has shown great advantages in poultry husbandry.This study focused on the behavioral preferences and production performance of chicken broilers reared under unevenly distributed yellow LED light.Four pens were divided into two groups adopting respective maximum light intensities(MLIs,60 lx and 30 lx).Because of different distances from the installation position of the LED pipe,each pen was distributed with unevenly distributed light.Each pen consisted of four subzones indicated by their light intensities-high intensity(HI),medium intensity(MI),low intensity(LI)and weak intensity(WI).Four subzones were the same size and provided with a feeder and a drinker,respectively.The broilers moved freely across the four subzones.No significant differences in body weight(BW),uniformity of final BW and feed conversion ratio(FCR)were observed between the two experimental groups.However,greater feed intake and water intake were found in HI than those in other subzones.The drinking preference changed with age for four subzones and was more likely to appear at the later stage,despite substantial fluctuations within the replicates.The feeding preference was more constant than the drinking preference and appeared mainly at the early and middle stages of this study.These findings could provide implications for broiler production reared under unevenly distributed LED light condition.

Effects of Feed-grade Proteinase on the Production Performance of Piglets

In this study, feed-grade proteinase was added into conventional diets of three-line crossbred （Duroc x Landrace x Large White） piglets, to investigate the effects of feed-grade proteinase on anti-diarrhea capacity, daily weight gain, feed intake and feed conversion ratio of piglets. The results showed that adding feed-grade proteinase in diets enhanced anti-diarrhea capacity of piglets and improved signifi- cantly production performance and breeding efficiency of piglets. This study provided the reference for rational utilization of feed-grade proteinase in actual production.