The Liverpool Plains is a fertile agricultural region in New South Wales, Australia. Two sorghums from the2009 Liverpool Plains harvest, sorghums #3 and #5, were extensively characterised which included concentrations...The Liverpool Plains is a fertile agricultural region in New South Wales, Australia. Two sorghums from the2009 Liverpool Plains harvest, sorghums #3 and #5, were extensively characterised which included concentrations of kafirin and phenolic compounds plus rapid visco-analysis(RVA) starch pasting profiles. Diets based on these two sorghums were formulated to be iso-nitrogenous and iso-energetic and were offered to male Ross 308 broiler chicks from 7 to 28 days post–hatch as either intact pellets or reground mash following steam-pelleting at conditioning temperatures of either 65 or 97°C. Thus the feeding study consisted of a 2×2×2 factorial array of dietary treatments: two sorghum varieties, two feed forms and two conditioning temperatures. Each of the eight treatments was replicated six times with six birds per replicate cage.Assessed parameters included growth performance, nutrient utilisation, apparent starch and protein(N) digestibility coefficients and disappearance rates from the distal jejunum and distal ileum. Intact pellets supported higher(P <0.001) feed intakes and weight gains by 9.83 and 9.08%, respectively, than reground mash diets. Feed conversion ratios of broilers offered diets steam-conditioned at 97°C were 2.46% inferior(P <0.001) in comparison to 65°C diets and both apparent metabolizable energy(AME) and N-corrected AME(AMEn) were compromised. Broilers offered sorghum #3-based diets significantly(P <0.001) outperformed their sorghum #5 counterparts in terms of weight gain by 3.75%(1,334 versus 1,223 g/bird), FCR by 4.81%(1.524 versus 1.601), AME by 1.06 MJ(13.61 versus 12.55 MJ/kg), ME:GE ratio(ME:GE) by 4.81%(0.806 versus0.769) and AMEn by 1.03 MJ(12.38 versus 11.35 MJ/kg). The inferiority of sorghum #5 appeared to be associated with higher concentrations of kafirin(61.5 versus 50.7 g/kg) and conjugated phenolic acids,including ferulic acid(31.1 versus 25.6 mg/g). There were no significant differences in jejunal and ileal starch and protein(N) digestibility coefficients between the two sorghums. However, starch to protein(N) disappearance rate ratios from the distal jejunum were significantly(P <0.001) correlated with ME:GE and AME. The multiple linear regression equations indicated that energy utilisation was enhanced by coupling rapidly digestible protein with slowly digestible starch, which suggests that bilateral bioavailability of starch and protein is pivotal to efficient energy utilisation.展开更多
The objective of the study was to investigate the possibility that tandem inclusions of a reducing agent and a protease may advantage chicken-meat production and to ascertain if the established benefits of including s...The objective of the study was to investigate the possibility that tandem inclusions of a reducing agent and a protease may advantage chicken-meat production and to ascertain if the established benefits of including sodium metabisulphite in sorghum-based diets extend to wheat-based diets. The study comprised a 2 x 2 x 2 factorial array of treatments in which either nutritionally iso-nitrogenous and isoenergetic wheat-or sorghum-based diets, without and with sodium metabisulphite(2.75 g/kg), without and with protease(1,000 units/kg) were offered to broiler chickens from 7 to 28 days post-hatch. The effects of dietary treatments on growth performance, nutrient utilisation, protein(N) and starch digestibility coefficients and digestive dynamics were determined. A preliminary investigation into the effects of two treatments on concentrations of free amino acids and glucose in the portal circulation was conducted. There was significant feed grain by sodium metabisulphite interactions(P = 0.03 to 0.005) for parameters of nutrient utilisation(AME, ME:GE ratios, N retention, AMEn). For example, sodium metabisulphite inclusions in sorghum-based diets enhanced AME by 0.18 MJ(12.47 versus 12.29 MJ/kg) but depressed AME by 0.43 MJ(11.88 versus 12.31 MJ/kg) in wheat-based diets. There was a linear relationship between starch:protein disappearance rate ratios in the distal ileum with weight gain(r =-0.484; P = 0.0012) indicating that condensed ratios(or absorption of more protein relative to starch) advantaged growth performance. Concentrations of free amino acids in the portal circulation or the post-enteral availability of certain amino acids, including the branched-chain amino acids, methionine, phenylalanine and threonine, were significantly correlated to FCR. For example, threonine concentrations were negatively correlated to FCR(r =-0.773; P = 0.005). Finally, tandem inclusions of sodium metabisulphite and protease in sorghum-based diets may hold merit but it appears that the established 'energy sparing' effects of sodium metabisulphite inclusions in sorghum-based diets are not duplicated in wheat-based diets.展开更多
Thirteen extensively characterised grain sorghum varieties were evaluated in a series of 7 broiler bioassays. The efficiency of energy utilisation of broiler chickens offered sorghum-based diets is problematic and the...Thirteen extensively characterised grain sorghum varieties were evaluated in a series of 7 broiler bioassays. The efficiency of energy utilisation of broiler chickens offered sorghum-based diets is problematic and the bulk of dietary energy is derived from sorghum starch. For this reason, rapid visco-analysis(RVA)starch pasting profiles were determined as they may have the potential to assess the quality of sorghum as a feed grain for chicken-meat production. In review, it was found that concentrations of kafirin and total phenolic compounds were negatively correlated with peak and holding RVA viscosities to significant extents across 13 sorghums. In a meta-analysis of 5 broiler bioassays it was found that peak, holding,breakdown and final RVA viscosities were positively correlated with ME:GE ratios and peak and breakdown RVA viscosities with apparent metabolizable energy corrected for nitrogen(AMEn) to significant extents. In a sixth study involving 10 sorghum-based diets peak, holding and breakdown RVA viscosities were positively correlated with ME:GE ratios and AMEn. Therefore, it emerged that RVA starch pasting profiles do hold promise as a relatively rapid means to assess sorghum quality as a feed grain for chicken-meat production. This potential appears to be linked to quantities of kafirin and total phenolic compounds present in sorghum and it would seem that both factors depress RVA starch viscosities in vitro and, in turn, also depress energy utilisation in birds offered sorghum-based diets. Given that other feed grains do not contain kafirin and possess considerably lower concentrations of phenolic compounds, their RVA starch pasting profiles may not be equally indicative.展开更多
基金funding the sorghum steam-pelleting temperatures project
文摘The Liverpool Plains is a fertile agricultural region in New South Wales, Australia. Two sorghums from the2009 Liverpool Plains harvest, sorghums #3 and #5, were extensively characterised which included concentrations of kafirin and phenolic compounds plus rapid visco-analysis(RVA) starch pasting profiles. Diets based on these two sorghums were formulated to be iso-nitrogenous and iso-energetic and were offered to male Ross 308 broiler chicks from 7 to 28 days post–hatch as either intact pellets or reground mash following steam-pelleting at conditioning temperatures of either 65 or 97°C. Thus the feeding study consisted of a 2×2×2 factorial array of dietary treatments: two sorghum varieties, two feed forms and two conditioning temperatures. Each of the eight treatments was replicated six times with six birds per replicate cage.Assessed parameters included growth performance, nutrient utilisation, apparent starch and protein(N) digestibility coefficients and disappearance rates from the distal jejunum and distal ileum. Intact pellets supported higher(P <0.001) feed intakes and weight gains by 9.83 and 9.08%, respectively, than reground mash diets. Feed conversion ratios of broilers offered diets steam-conditioned at 97°C were 2.46% inferior(P <0.001) in comparison to 65°C diets and both apparent metabolizable energy(AME) and N-corrected AME(AMEn) were compromised. Broilers offered sorghum #3-based diets significantly(P <0.001) outperformed their sorghum #5 counterparts in terms of weight gain by 3.75%(1,334 versus 1,223 g/bird), FCR by 4.81%(1.524 versus 1.601), AME by 1.06 MJ(13.61 versus 12.55 MJ/kg), ME:GE ratio(ME:GE) by 4.81%(0.806 versus0.769) and AMEn by 1.03 MJ(12.38 versus 11.35 MJ/kg). The inferiority of sorghum #5 appeared to be associated with higher concentrations of kafirin(61.5 versus 50.7 g/kg) and conjugated phenolic acids,including ferulic acid(31.1 versus 25.6 mg/g). There were no significant differences in jejunal and ileal starch and protein(N) digestibility coefficients between the two sorghums. However, starch to protein(N) disappearance rate ratios from the distal jejunum were significantly(P <0.001) correlated with ME:GE and AME. The multiple linear regression equations indicated that energy utilisation was enhanced by coupling rapidly digestible protein with slowly digestible starch, which suggests that bilateral bioavailability of starch and protein is pivotal to efficient energy utilisation.
基金established and supported under the Australian Government's Cooperative Research Centres Programthe Poultry CRC for funding the project and support of Ms Ha Truong's PhD candidature
文摘The objective of the study was to investigate the possibility that tandem inclusions of a reducing agent and a protease may advantage chicken-meat production and to ascertain if the established benefits of including sodium metabisulphite in sorghum-based diets extend to wheat-based diets. The study comprised a 2 x 2 x 2 factorial array of treatments in which either nutritionally iso-nitrogenous and isoenergetic wheat-or sorghum-based diets, without and with sodium metabisulphite(2.75 g/kg), without and with protease(1,000 units/kg) were offered to broiler chickens from 7 to 28 days post-hatch. The effects of dietary treatments on growth performance, nutrient utilisation, protein(N) and starch digestibility coefficients and digestive dynamics were determined. A preliminary investigation into the effects of two treatments on concentrations of free amino acids and glucose in the portal circulation was conducted. There was significant feed grain by sodium metabisulphite interactions(P = 0.03 to 0.005) for parameters of nutrient utilisation(AME, ME:GE ratios, N retention, AMEn). For example, sodium metabisulphite inclusions in sorghum-based diets enhanced AME by 0.18 MJ(12.47 versus 12.29 MJ/kg) but depressed AME by 0.43 MJ(11.88 versus 12.31 MJ/kg) in wheat-based diets. There was a linear relationship between starch:protein disappearance rate ratios in the distal ileum with weight gain(r =-0.484; P = 0.0012) indicating that condensed ratios(or absorption of more protein relative to starch) advantaged growth performance. Concentrations of free amino acids in the portal circulation or the post-enteral availability of certain amino acids, including the branched-chain amino acids, methionine, phenylalanine and threonine, were significantly correlated to FCR. For example, threonine concentrations were negatively correlated to FCR(r =-0.773; P = 0.005). Finally, tandem inclusions of sodium metabisulphite and protease in sorghum-based diets may hold merit but it appears that the established 'energy sparing' effects of sodium metabisulphite inclusions in sorghum-based diets are not duplicated in wheat-based diets.
基金RIRDC Chicken-meat for funding the majority of the relevant studies
文摘Thirteen extensively characterised grain sorghum varieties were evaluated in a series of 7 broiler bioassays. The efficiency of energy utilisation of broiler chickens offered sorghum-based diets is problematic and the bulk of dietary energy is derived from sorghum starch. For this reason, rapid visco-analysis(RVA)starch pasting profiles were determined as they may have the potential to assess the quality of sorghum as a feed grain for chicken-meat production. In review, it was found that concentrations of kafirin and total phenolic compounds were negatively correlated with peak and holding RVA viscosities to significant extents across 13 sorghums. In a meta-analysis of 5 broiler bioassays it was found that peak, holding,breakdown and final RVA viscosities were positively correlated with ME:GE ratios and peak and breakdown RVA viscosities with apparent metabolizable energy corrected for nitrogen(AMEn) to significant extents. In a sixth study involving 10 sorghum-based diets peak, holding and breakdown RVA viscosities were positively correlated with ME:GE ratios and AMEn. Therefore, it emerged that RVA starch pasting profiles do hold promise as a relatively rapid means to assess sorghum quality as a feed grain for chicken-meat production. This potential appears to be linked to quantities of kafirin and total phenolic compounds present in sorghum and it would seem that both factors depress RVA starch viscosities in vitro and, in turn, also depress energy utilisation in birds offered sorghum-based diets. Given that other feed grains do not contain kafirin and possess considerably lower concentrations of phenolic compounds, their RVA starch pasting profiles may not be equally indicative.
