Compost barns for dairy cows are showing increased popularity also in Central Europe. A compost barn is used mainly as a two-area system with a bedded lying area and a solid feeding alley. Sawdust or dry fine wood sha...Compost barns for dairy cows are showing increased popularity also in Central Europe. A compost barn is used mainly as a two-area system with a bedded lying area and a solid feeding alley. Sawdust or dry fine wood shavings or wood chips are mostly used as bedding material, which has to be stirred twice a day. Stirring aerates and mixes faeces and urine into the bedding material, the mixture decomposes by means of aerobic microorganisms. A joint research project between the Agricultural Research and Education Centre Raumberg-Gumpenstein (HBLFA) and the Institute for Sustainability Sciences Tänikon (ISS) analyzed amongst other things, the cleanliness of the animals, integument alterations, lying behaviour and the current lameness situation of animals. A total of 138 cows were examined on five Austrian dairy farms. All cows were visually scored and animal behaviour was observed by data loggers as well as by direct observation. The mean value concerning cleanliness of animals was 0.44, while the udder was the cleanest and the lower leg the dirtiest area. Only a few lesions in carpal and tarsal joints could be found. Cows showed no differences in lying behaviour between times of day and temperatures. Large differences in lying behaviour were evident among farms. While on the compost barn farms only around 25% of all cows were scored to be lame, on cubicle-housing system farms 31% - 46% of the cows fell into that category (p < 0.001). From the present results, the compost barn can be seen as an animal-friendly system. In further investigations other factors affecting animal health and to resolve any outstanding issues concerning economy and alternative litter materials should be analyzed.展开更多
Curtain-sided barns with circulation fans above stall are commonly used to house dairy cows in China.Many farms equipped with circulation fans are unable to provide appropriate cooling,especially for the naturally ven...Curtain-sided barns with circulation fans above stall are commonly used to house dairy cows in China.Many farms equipped with circulation fans are unable to provide appropriate cooling,especially for the naturally ventilated shed,which can result in decreasing feed intake and milk production.For alleviating heat stress and improving animal comfort,a system consisting of an air cooler and a 30 m perforated air duct(PAD)was integrated to evenly distribute cooling air.The air was cooled by underground water and delivered to targeted zones above stall bed.The system was evaluated in an open sided dairy barn in Tianjin,China.For the stalls equipped with PAD system,air velocity reached above 1.1 m/s at 0.5 m height plane of the stall space,and was more uniformly distributed.Compared to the stalls equipped with circulation fans,the PAD system lowered air temperature by 1.5℃,and increased relative humidity by 8.1%.On average,Temperature Humidity Index(THI)and Equivalent Temperature Index(ETI)were decreased by 0.5 and 0.6,respectively.After a 15 days’operation of the system,rectal temperatures of the treated dairy cows were significantly lowered.The results also showed that the cows under PADs had a higher milk production.These findings suggest the PAD can be an effective cooling alternative for naturally ventilated dairy barns to alleviate heat stress.展开更多
Reliable estimation of the ventilation rate(VR)in intensive livestock buildings is necessary for studying building environmental control strategies and predicting indoor air quality and air emissions.As direct air exc...Reliable estimation of the ventilation rate(VR)in intensive livestock buildings is necessary for studying building environmental control strategies and predicting indoor air quality and air emissions.As direct air exchange measurements are time-consuming and expensive,it is environmentally inefficient to measure livestock building VR continuously in practice.Hence,indirect VR estimation methods have been widely used in modelling environmental control and air emissions,and also to measure airflow in the field.The accuracy of indirect measurement methods needs to be evaluated by comparing with direct measurements.In this study,the direct and indirect methods of determining hourly and daily mean VRs were applied to a mechanically-ventilated dairy free stall barn monitored by the 24-month National Air Emissions Monitoring Study.The direct method was used to continuously monitor fan rotational speeds,and differential static pressures,coupled with periodic in-situ fan performance assessments,to calculate the VR.The indirect method consisted of estimating the VR using CO2 concentration measurements and the CO2 mass balance method.The average daily and hourly means(mean±SD)of directly measured barn ventilation rates for two years were(246±73)m3/s and(245±77)m3/s,respectively.The average daily and hourly means(mean±SD)of barn ventilation rates estimated by the CO2 mass balance method were(287±93.4)m3/s and(287±118)m3/s,respectively.Correlation analyses showed a strong correlation between the indirect CO2 mass balance method and direct measurement methods(r=0.93 for daily means and r=0.85 for hourly means).展开更多
This research aimed to quantify concentrations of ammonia(NH3),carbon dioxide(CO_(2))and methane(CH_(4)),estimate emissions,and analyze the factors influencing them during warm periods in an open dairy barn equipped w...This research aimed to quantify concentrations of ammonia(NH3),carbon dioxide(CO_(2))and methane(CH_(4)),estimate emissions,and analyze the factors influencing them during warm periods in an open dairy barn equipped with two cooling systems in a Mediterranean climate zone.Gas distribution within the barn was observed to vary both vertically and horizontally,with the highest gas concentrations observed in the central area of the barn.NH_(3),CH_(4)and CO_(2)ranged in 1.7–7.4,7–18,560–724μg·g^(–1),respectively.Natural ventilation through openings and the operation of cooling systems induced changes in indoor microclimate conditions,influencing cow behavior and,consequently,gas production.Gas concentrations were the highest at air velocities below 0.5 m·s^(–1).The highest concentration of NH_(3)was observed when the temperature-humidity index(THI)was>72 and≤78;and CO_(2)and CH_(4)concentrations were the highest with THI≥72 and decreased with THI≤72.NH_(3)concentrations when barn management included three daily milkings were higher than those measured when barn management was based on two daily milkings,and lower for CH_(4)and CO_(2).NH_(3)and CH_(4)emissions were the highest during barn cleaning,while the lowest NH_(3)emissions occurred during activity of the cows(i.e.,feeding,walking).展开更多
文摘Compost barns for dairy cows are showing increased popularity also in Central Europe. A compost barn is used mainly as a two-area system with a bedded lying area and a solid feeding alley. Sawdust or dry fine wood shavings or wood chips are mostly used as bedding material, which has to be stirred twice a day. Stirring aerates and mixes faeces and urine into the bedding material, the mixture decomposes by means of aerobic microorganisms. A joint research project between the Agricultural Research and Education Centre Raumberg-Gumpenstein (HBLFA) and the Institute for Sustainability Sciences Tänikon (ISS) analyzed amongst other things, the cleanliness of the animals, integument alterations, lying behaviour and the current lameness situation of animals. A total of 138 cows were examined on five Austrian dairy farms. All cows were visually scored and animal behaviour was observed by data loggers as well as by direct observation. The mean value concerning cleanliness of animals was 0.44, while the udder was the cleanest and the lower leg the dirtiest area. Only a few lesions in carpal and tarsal joints could be found. Cows showed no differences in lying behaviour between times of day and temperatures. Large differences in lying behaviour were evident among farms. While on the compost barn farms only around 25% of all cows were scored to be lame, on cubicle-housing system farms 31% - 46% of the cows fell into that category (p < 0.001). From the present results, the compost barn can be seen as an animal-friendly system. In further investigations other factors affecting animal health and to resolve any outstanding issues concerning economy and alternative litter materials should be analyzed.
基金This study was funded by National High Technology Research and Development Program(2013AA10230602)China Agricultural Research System(CARS-36).A special thank for all the help from Hailin Dairy Farm,Tianjin,China,where the field evaluation was conducted.
文摘Curtain-sided barns with circulation fans above stall are commonly used to house dairy cows in China.Many farms equipped with circulation fans are unable to provide appropriate cooling,especially for the naturally ventilated shed,which can result in decreasing feed intake and milk production.For alleviating heat stress and improving animal comfort,a system consisting of an air cooler and a 30 m perforated air duct(PAD)was integrated to evenly distribute cooling air.The air was cooled by underground water and delivered to targeted zones above stall bed.The system was evaluated in an open sided dairy barn in Tianjin,China.For the stalls equipped with PAD system,air velocity reached above 1.1 m/s at 0.5 m height plane of the stall space,and was more uniformly distributed.Compared to the stalls equipped with circulation fans,the PAD system lowered air temperature by 1.5℃,and increased relative humidity by 8.1%.On average,Temperature Humidity Index(THI)and Equivalent Temperature Index(ETI)were decreased by 0.5 and 0.6,respectively.After a 15 days’operation of the system,rectal temperatures of the treated dairy cows were significantly lowered.The results also showed that the cows under PADs had a higher milk production.These findings suggest the PAD can be an effective cooling alternative for naturally ventilated dairy barns to alleviate heat stress.
文摘Reliable estimation of the ventilation rate(VR)in intensive livestock buildings is necessary for studying building environmental control strategies and predicting indoor air quality and air emissions.As direct air exchange measurements are time-consuming and expensive,it is environmentally inefficient to measure livestock building VR continuously in practice.Hence,indirect VR estimation methods have been widely used in modelling environmental control and air emissions,and also to measure airflow in the field.The accuracy of indirect measurement methods needs to be evaluated by comparing with direct measurements.In this study,the direct and indirect methods of determining hourly and daily mean VRs were applied to a mechanically-ventilated dairy free stall barn monitored by the 24-month National Air Emissions Monitoring Study.The direct method was used to continuously monitor fan rotational speeds,and differential static pressures,coupled with periodic in-situ fan performance assessments,to calculate the VR.The indirect method consisted of estimating the VR using CO2 concentration measurements and the CO2 mass balance method.The average daily and hourly means(mean±SD)of directly measured barn ventilation rates for two years were(246±73)m3/s and(245±77)m3/s,respectively.The average daily and hourly means(mean±SD)of barn ventilation rates estimated by the CO2 mass balance method were(287±93.4)m3/s and(287±118)m3/s,respectively.Correlation analyses showed a strong correlation between the indirect CO2 mass balance method and direct measurement methods(r=0.93 for daily means and r=0.85 for hourly means).
基金received funding from the European Union NextGeneration EU(Piano Nazionale di Ripresa e Resilienza-Missione 4,Componente 2,Investimento 1.4-D.D.103217/06/2022,CN00000022)partially funded by European Union(Next Generation EU),through the MUR-PNRR project SAMOTHRACE(CUP:E63C22000900006CODE_ECS00000022)
文摘This research aimed to quantify concentrations of ammonia(NH3),carbon dioxide(CO_(2))and methane(CH_(4)),estimate emissions,and analyze the factors influencing them during warm periods in an open dairy barn equipped with two cooling systems in a Mediterranean climate zone.Gas distribution within the barn was observed to vary both vertically and horizontally,with the highest gas concentrations observed in the central area of the barn.NH_(3),CH_(4)and CO_(2)ranged in 1.7–7.4,7–18,560–724μg·g^(–1),respectively.Natural ventilation through openings and the operation of cooling systems induced changes in indoor microclimate conditions,influencing cow behavior and,consequently,gas production.Gas concentrations were the highest at air velocities below 0.5 m·s^(–1).The highest concentration of NH_(3)was observed when the temperature-humidity index(THI)was>72 and≤78;and CO_(2)and CH_(4)concentrations were the highest with THI≥72 and decreased with THI≤72.NH_(3)concentrations when barn management included three daily milkings were higher than those measured when barn management was based on two daily milkings,and lower for CH_(4)and CO_(2).NH_(3)and CH_(4)emissions were the highest during barn cleaning,while the lowest NH_(3)emissions occurred during activity of the cows(i.e.,feeding,walking).
