Background:Two experiments were conducted to establish an optimal NE challenge model and evaluate the efficacy of stimbiotic(STB)supplementation in necrotic enteritis(NE)challenged broilers.In Exp.1,a total of 120 Arb...Background:Two experiments were conducted to establish an optimal NE challenge model and evaluate the efficacy of stimbiotic(STB)supplementation in necrotic enteritis(NE)challenged broilers.In Exp.1,a total of 120 Arbor Acres(AA)broilers(45.0±0.21 g)were randomly assigned to 6 treatments in a 3×2 factorial arrangement.Vaccine treatments included non-challenge(0),×10 the recommended dose(×10)or×20 the recommended dose(×20)by the manufacturer.Clostridium perfringens(CP)treatments were non-challenge(No)or 3 mL of 2.2×10^(7)CFU CP challenge(Yes).In Exp.2,a total of 72 AA broilers(40.17±0.27 g)were randomly assigned to 6 treatments in a 3×2 factorial arrangement.Dietary treatments included non-additive(CON),100 mg/kg STB(STB)and 100 mg/kg STB on top of a typical commercial blend including an essential oil,probiotics,and enzyme(CB).Challenge treatments included non-NE challenge(No)and NE challenge(Yes)as established in Exp.1.Results:In Exp.1,CP and vaccine challenge decreased(P<0.05)body weight(BW),body weight gain(BWG)and feed intake(FI),and increased(P<0.05)the number of broilers with diarrhea and intestinal lesions.The oral administration of×20 recommended dose of vaccines coupled with 3 mL of 2.2×10^(7)CFU CP resulted in(P<0.01)a significantly increased incidence of wet litter and intestinal lesions.Thus,this treatment was chosen as the challenge model for the successful inducement of NE in Exp.2.In Exp.2,the NE challenge negatively affected(P<0.01)growth performance,ileal morphology,immunoglobulin contents in blood,caecal microbiota in the caecum,footpad dermatitis,intestinal lesion scores,tumour necrosis factor(TNF-α)and endotoxin in the serum compared with the non-NE challenged birds.The supplementation of STB and CB in diets enhanced(P<0.05)growth performance,intestinal microbiota,and blood profiles by stimulating ileal morphology(VH and VH:CD)and propionate production in the cecum,and there were no differences in measured variables between STB and CB supplemented birds.Conclusion:Overall,these results indicate that STB supplementation was able to reduce the inflammatory response and improve the performance of NE challenged birds,and the supplementation of STB alone was as effective as a typical commercial blend containing a number of other additives.展开更多
Kenaf (Hibiscus cannabinus L.) is a warm-season annual. Kenaf fibers are commonly used for paper pulp and cordage, but it is also a promising lignocellulosic feedstock for bioenergy production, although optimum plant ...Kenaf (Hibiscus cannabinus L.) is a warm-season annual. Kenaf fibers are commonly used for paper pulp and cordage, but it is also a promising lignocellulosic feedstock for bioenergy production, although optimum plant density for biomass production has not been determined for the northern region of the USA. The objective of this study was to determine the best plant density and row spacing of kenaf to maximize biomass yield and chemical composition for biofuel conversion. The experiments were conducted at Fargo and Prosper, ND, in 2010 and 2011. The experiment was a randomized complete block design with a split-plot arrangement where the main plot was tworowspacings (30 and60 cm) and the sub-plot fourplant densities (32, 16, 8, and 4 plants·m-2). Row spacing had a significant effect on both biomass and biofuel yield. Narrower rows had higher biomass and biofuel yield. Maximum biomass and estimated biofuel yield was obtained with the two highest plant densities of 16 and 32 plants·m-2 and fluctuated between 9.45 and 10.22 Mg·ha-1 and 1354 and1464 L·ha-1, respectively. Stem diameter increased with a decrease in plant density. Chemical composition varied with plant density;glucan (27%) and xylan (9.8%) content were lower at the lowest plant density. Ash content was not different among plant densities but it is interesting to mention the very low ash content of kenaf (0.15%). According to the results of this study, it is recommended to plant kenaf at 30-cm rows with a plant density of 16 to 32 plants·m-2 to maximize biomass yield. Kenaf has a tremendous potential as a cellulosic feedstock for biofuel and green chemicals in the Northern Great Plains because of high biomass yield and low ash content.展开更多
基金AB Vista(Marlborough,Wiltshire,UK)for providing the feed additives and funding this research。
文摘Background:Two experiments were conducted to establish an optimal NE challenge model and evaluate the efficacy of stimbiotic(STB)supplementation in necrotic enteritis(NE)challenged broilers.In Exp.1,a total of 120 Arbor Acres(AA)broilers(45.0±0.21 g)were randomly assigned to 6 treatments in a 3×2 factorial arrangement.Vaccine treatments included non-challenge(0),×10 the recommended dose(×10)or×20 the recommended dose(×20)by the manufacturer.Clostridium perfringens(CP)treatments were non-challenge(No)or 3 mL of 2.2×10^(7)CFU CP challenge(Yes).In Exp.2,a total of 72 AA broilers(40.17±0.27 g)were randomly assigned to 6 treatments in a 3×2 factorial arrangement.Dietary treatments included non-additive(CON),100 mg/kg STB(STB)and 100 mg/kg STB on top of a typical commercial blend including an essential oil,probiotics,and enzyme(CB).Challenge treatments included non-NE challenge(No)and NE challenge(Yes)as established in Exp.1.Results:In Exp.1,CP and vaccine challenge decreased(P<0.05)body weight(BW),body weight gain(BWG)and feed intake(FI),and increased(P<0.05)the number of broilers with diarrhea and intestinal lesions.The oral administration of×20 recommended dose of vaccines coupled with 3 mL of 2.2×10^(7)CFU CP resulted in(P<0.01)a significantly increased incidence of wet litter and intestinal lesions.Thus,this treatment was chosen as the challenge model for the successful inducement of NE in Exp.2.In Exp.2,the NE challenge negatively affected(P<0.01)growth performance,ileal morphology,immunoglobulin contents in blood,caecal microbiota in the caecum,footpad dermatitis,intestinal lesion scores,tumour necrosis factor(TNF-α)and endotoxin in the serum compared with the non-NE challenged birds.The supplementation of STB and CB in diets enhanced(P<0.05)growth performance,intestinal microbiota,and blood profiles by stimulating ileal morphology(VH and VH:CD)and propionate production in the cecum,and there were no differences in measured variables between STB and CB supplemented birds.Conclusion:Overall,these results indicate that STB supplementation was able to reduce the inflammatory response and improve the performance of NE challenged birds,and the supplementation of STB alone was as effective as a typical commercial blend containing a number of other additives.
文摘Kenaf (Hibiscus cannabinus L.) is a warm-season annual. Kenaf fibers are commonly used for paper pulp and cordage, but it is also a promising lignocellulosic feedstock for bioenergy production, although optimum plant density for biomass production has not been determined for the northern region of the USA. The objective of this study was to determine the best plant density and row spacing of kenaf to maximize biomass yield and chemical composition for biofuel conversion. The experiments were conducted at Fargo and Prosper, ND, in 2010 and 2011. The experiment was a randomized complete block design with a split-plot arrangement where the main plot was tworowspacings (30 and60 cm) and the sub-plot fourplant densities (32, 16, 8, and 4 plants·m-2). Row spacing had a significant effect on both biomass and biofuel yield. Narrower rows had higher biomass and biofuel yield. Maximum biomass and estimated biofuel yield was obtained with the two highest plant densities of 16 and 32 plants·m-2 and fluctuated between 9.45 and 10.22 Mg·ha-1 and 1354 and1464 L·ha-1, respectively. Stem diameter increased with a decrease in plant density. Chemical composition varied with plant density;glucan (27%) and xylan (9.8%) content were lower at the lowest plant density. Ash content was not different among plant densities but it is interesting to mention the very low ash content of kenaf (0.15%). According to the results of this study, it is recommended to plant kenaf at 30-cm rows with a plant density of 16 to 32 plants·m-2 to maximize biomass yield. Kenaf has a tremendous potential as a cellulosic feedstock for biofuel and green chemicals in the Northern Great Plains because of high biomass yield and low ash content.
