The objective of this study was to in- vestigate the effect of dietary protein level on nitrogen retention and compare nitrogen metabolism in Lohm- ann Brown adult roosters and layers. The nitrogen ma- intenance requi...The objective of this study was to in- vestigate the effect of dietary protein level on nitrogen retention and compare nitrogen metabolism in Lohm- ann Brown adult roosters and layers. The nitrogen ma- intenance requirement （Nm ） was determined based on the nitrogen balance. Thirty Lohmann Brown adult roosters and 30 laying hens at 27 weeks of age were randomly divided into five groups of six birds per group. The birds were fed with one of five diets con- taining 10.46%, 11.77%, 13.79%, 16.77% or 18.29% of crude protein. Nitrogen intake, nitrogen retention and nitrogen retention efficiency were higher in roost- ers than in laying hens, and the average nitrogen re- tention rate for groups fed with CP level of 11.77%, 13.79%, 16.77% and 18. 29% was improved by9.14%. The nitrogen maintenance requirement for Lohmann Brown roosters and laying hens at 27 weeks of age were 0.4245 g/d and 0.5059 g/d, respective- ly, and Nm based on average body weight （BW） and metabolic body weight （ BW^Ts ） was 0.2364 g/kg BW and 0. 2739 g/kg BW~＇75 for laying hens and 0. 2754 g/kg BW and 0. 3208 g/kg BW^72 for roost- ers, respectively. The regression equations for daily N gain （NB, protein accretion） vs. daily N intake （NI ） for Lohrnann Brown layers and roosters were NB = 0.3743NI -0.1589（R2 =0.79） and NB =0.6228NI - 0.3151 （ R2 = 0.85 ）, respectively. The results of this study indicate that nitrogen intake and nitrogen reten- tion at the same dietary CP level were higher in roost- ers than in laying hens.展开更多
This study examines the water-use efficiency and conservation potential of Guangzhou Railway Polytechnic(GRP)using an integrated methodology that combines water balance testing,functional-zone diagnostics,and behavior...This study examines the water-use efficiency and conservation potential of Guangzhou Railway Polytechnic(GRP)using an integrated methodology that combines water balance testing,functional-zone diagnostics,and behavioral surveys conducted between 2022 and 2024.Technical results show robust performance,with per capita consumption averaging 32.83 m3/person∙year—far below the provincial benchmark of 80 m3—and a distribution-network leakage rate of 3.5%.Functional-zone analysis identifies dormitories(44.9%)and laboratory/practical buildings(20.9%)as the dominant water-use areas,underscoring the need for zone-specific strategies.Behavioral findings reveal that although students and faculty exhibit high awareness and positive conservation attitudes,students demonstrate weaker behavioral execution and limited familiarity with institutional policies(62.8%),contributing to elevated residential consumption.Drawing on the Theory of Planned Behavior and Triple-Loop Learning,the study concludes that while GRP has established a strong technical and governance foundation,further gains depend on digital monitoring,differentiated management,and targeted behavioral interventions.These findings provide actionable insights for developing data-driven and behavior-responsive water management systems in vocational institutions.展开更多
基金supported by the National System of Layer Producing Technology (nycytx-41)
文摘The objective of this study was to in- vestigate the effect of dietary protein level on nitrogen retention and compare nitrogen metabolism in Lohm- ann Brown adult roosters and layers. The nitrogen ma- intenance requirement （Nm ） was determined based on the nitrogen balance. Thirty Lohmann Brown adult roosters and 30 laying hens at 27 weeks of age were randomly divided into five groups of six birds per group. The birds were fed with one of five diets con- taining 10.46%, 11.77%, 13.79%, 16.77% or 18.29% of crude protein. Nitrogen intake, nitrogen retention and nitrogen retention efficiency were higher in roost- ers than in laying hens, and the average nitrogen re- tention rate for groups fed with CP level of 11.77%, 13.79%, 16.77% and 18. 29% was improved by9.14%. The nitrogen maintenance requirement for Lohmann Brown roosters and laying hens at 27 weeks of age were 0.4245 g/d and 0.5059 g/d, respective- ly, and Nm based on average body weight （BW） and metabolic body weight （ BW^Ts ） was 0.2364 g/kg BW and 0. 2739 g/kg BW~＇75 for laying hens and 0. 2754 g/kg BW and 0. 3208 g/kg BW^72 for roost- ers, respectively. The regression equations for daily N gain （NB, protein accretion） vs. daily N intake （NI ） for Lohrnann Brown layers and roosters were NB = 0.3743NI -0.1589（R2 =0.79） and NB =0.6228NI - 0.3151 （ R2 = 0.85 ）, respectively. The results of this study indicate that nitrogen intake and nitrogen reten- tion at the same dietary CP level were higher in roost- ers than in laying hens.
文摘This study examines the water-use efficiency and conservation potential of Guangzhou Railway Polytechnic(GRP)using an integrated methodology that combines water balance testing,functional-zone diagnostics,and behavioral surveys conducted between 2022 and 2024.Technical results show robust performance,with per capita consumption averaging 32.83 m3/person∙year—far below the provincial benchmark of 80 m3—and a distribution-network leakage rate of 3.5%.Functional-zone analysis identifies dormitories(44.9%)and laboratory/practical buildings(20.9%)as the dominant water-use areas,underscoring the need for zone-specific strategies.Behavioral findings reveal that although students and faculty exhibit high awareness and positive conservation attitudes,students demonstrate weaker behavioral execution and limited familiarity with institutional policies(62.8%),contributing to elevated residential consumption.Drawing on the Theory of Planned Behavior and Triple-Loop Learning,the study concludes that while GRP has established a strong technical and governance foundation,further gains depend on digital monitoring,differentiated management,and targeted behavioral interventions.These findings provide actionable insights for developing data-driven and behavior-responsive water management systems in vocational institutions.
