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Measurement Of Temperature And Humidity Inside A Dairy Plant Pdf

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The aim of this work was the presentation of an alternative method of determination of the total dry mass content in processed cheese. For the test purposes both reference method of determination of dry mass in processed cheese and moisture analyzer method were used.

Reducing Humidity in the Greenhouse

The severity of heat stress issues on dairy cows will increase as global warming progresses. Fortunately, major advances in environmental management, including fans, misters, sprinklers, and cooled waterbeds, can attenuate the effects of thermal stress on cow health, production, and reproduction.

These cooling systems were, however, tested in subtropical areas and their efficiency in northern regions is uncertain. This article assesses the potential of existing technologies to cool cows in humid continental climates through calculation of heat stress indices.

Heat stress negatively affects the health and performance of dairy cows, resulting in considerable economic losses for the industry. In future years, climate change will exacerbate these losses by making the climate warmer.

Physical modification of the environment is considered to be the primary means of reducing adverse effects of hot weather conditions. At present, to reduce stressful heat exposure and to cool cows, dairy farms rely on shade screens and various forms of forced convection and evaporative cooling that may include fans and misters, feed-line sprinklers, and tunnel- or cross-ventilated buildings.

Therefore, this study reviewed the available cooling applications and assessed their potential for northern regions. Thermal stress indices such as the temperature-humidity index THI were used to evaluate the different cooling strategies.

The physiological e. When environmental conditions exceed a threshold limit that increases the core-body temperature, heat stress sets in and animal welfare can be compromised. Moreover, cow health, production, and reproduction performance are reduced under heat stress [ 1 , 2 ].

Cows under heat stress also have elevated respiration and sweating rates, which results in greater body fluid losses that increase maintenance requirements to control dehydration and blood homeostasis [ 4 ]. For high-producing cows, Berman et al. Reproduction is affected by high temperature because it reduces the expression of oestrous behaviour, modifies follicular growth, and inhibits embryonic development.

A broad spectrum of strategies can be used to temper the impact of a hot climate on animal production and dairy profitability, but physical modification of the environment is the primary means.

The typical methods can be divided into two groups: i those modifying the environment to prevent or limit the degree of heat stress to which cows are exposed; or ii those enhancing heat exchange between cows and their environment. Practically, this means increasing the evaporative cooling rate by wetting cows or the air around them e.

Much of the research on cooling systems has been carried out in subtropical regions e. Nevertheless, representative hot environments in both climate zones nearly correspond to the same value 75—77 on a temperature-humidity index THI chart [ 1 ]. Therefore, a better understanding of the potential for cooling options to reduce heat stress on northern dairy farms from a global warming perspective may be relevant.

The evaluation and comparison of the different available practices in this paper are based on thermal stress indices that estimate the impact of ambient conditions around animals on their performance and comfort. The THI has been widely used for this purpose [ 2 , 14 ]. By capturing much of the heat exchange impact of warm environments through temperature and humidity, it often adequately represents the overall effect on livestock [ 1 ].

Other indices like the black globe-humidity index BGHI and the heat load index HLI that add the impact of solar radiation and convective cooling of wind limitations of the THI can also be used for certain situations [ 16 ]. It is then possible with these indicators to assess the efficiency of cooling systems used under different climates subtropical versus humid continental.

The environmental modifications presented in this section attempt to reduce the potential for heat stress by lowering the solar radiation or temperature around the animal. The first step that should be taken to moderate the stressful effects of a hot climate is to protect cows from direct solar radiation. Shading, either natural or artificial, is one of the most easily implemented and economical methods of minimising heat from solar radiation, but does not alter air temperature nor relative humidity around cows to maximise sensible routes of heat loss [ 9 , 17 , 18 ].

Trees can be very effective for providing shade to animals [ 2 , 3 , 9 , 21 , 22 ] as black globe temperature, which integrates effects of net radiation, dry-bulb temperature, and wind speed, measured under two tree shades In addition, rectal temperatures Artificial shades e.

Consequently, climate differences resulted in variation of thermal stress indicators such as BGHI 4 units and HLI 13 units for shaded and unshaded environments Table 1.

The THI values did not differ between both systems since THI does not fully predict heat stress if convective cooling is increased and if solar radiation is reduced under shades [ 32 ].

Meteorological and thermal stress attributes and physiological response for non-shaded NS and shaded S environments.

A shaded environment also impacts physiological responses of lactating dairy cows Table 1. Research works [ 29 , 30 , 33 , 34 ] have found an average drop of 0. Other studies [ 24 , 26 , 35 ] showed that cows with access to shade had lower rectal temperatures than those without Shaded cows generally produce 0. The conception rate can be increased by the use of shade, passing from Preventing excess solar heat from entering the building can help to reduce heat load on the animal.

The first design criteria to consider should be the orientation of the structure. For example, naturally-ventilated barns with north-to-south orientations have greater solar radiation exposures than barns with east-to-west orientations since sunlight can directly enter both in the morning and afternoon [ 2 ]. Otherwise, appropriate window glazing and fixed or seasonal shading options, including overhangs, awnings, and trees, may be used to avoid or reduce the need for cooling [ 38 ].

A good thermal insulation of the barn roof is another technique that physically modifies the barn environment and that can limit the adverse effects of high ambient temperature [ 39 ]. In warm weather, insulation reduces the flow of heat into the barn and keeps it cooler [ 10 , 40 ].

Indeed, it was found that the addition of insulation beneath the roof of an open shelter reduced dry-bulb temperature and black globe temperature by 1.

Consequently, animals in the insulated area consumed more feed 0. However, differences were not significant for body temperature and respiration rate [ 41 , 42 ]. A combination of insulated shade and sprinklers was tested by Fuquay et al. This type of environmental modification improved cow comfort as indicated by lower rectal temperatures Meteorological and thermal stress attributes and physiological response of dairy cows for non-insulated NI and insulated I shades.

Air conditioning is the most effective option for reducing air temperature and relative humidity. In Arizona, Wiersma and Stott [ 47 ] and Stott and Wiersma [ 48 ] maintained the conditions inside a refrigerated dairy barn at a THI of 71 and found that fertility was improved.

In Missouri, Hahn et al. The cooling system, which provided better environmental conditions Table 3 , resulted in an average reduction in rectal temperature 0. Recently, environmental conditions in an air-conditioned barn and in evaporatively cooled sprinkler and fan and tunnel-ventilated buildings were compared by Bucklin et al.

All cooling methods generally provided conditions more comfortable in the facilities than those outside. However, only the air-conditioned barn maintained the THI consistently below 72 Table 3. Meteorological attributes and THI calculations for control treatments and air-conditioned dairy barns.

Zone cooling or inspired-air cooling applies a jet of cooled air onto the head and neck of animals [ 17 , 38 ]. Early studies conducted by Kleiber and Regan [ 53 ] and Hahn [ 54 ] indicated that cooling the inspired air Similarly, Hahn et al. Roussel and Beatty [ 56 ], Fuquay et al. Roussel and Beatty [ 56 ] and Gomila et al. Meteorological attributes, THI calculations, and physiological response of dairy cows in shaded environments S with or without zone cooling systems ZC.

Evaporative cooling systems use the energy from the air to evaporate water. The evaporation of water into warm air reduces the air temperature while increasing relative humidity [ 9 , 38 ]. Water can be evaporated from atomizing nozzles next paragraphs or cooling pads Section 2. The first group includes foggers and misters.

Animals are chilled as cooled air is blown over their bodies and as they inspire cooled air [ 10 , 22 , 58 , 59 ]. Bucklin et al. It also contained feed faced sprinklers that worked only at night when foggers were turned off. The THI in the barn with foggers was slightly lower compared with the other treatments, resulting in lower body temperatures of cows.

Brouk et al. Meteorological attributes and THI calculations between different housing systems for dairy cows in the study of Bucklin et al. Misting systems were used with good success in the US Arizona, Kansas, and California and Saudi Arabia where humidity is typically low [ 62 , 63 , 64 , 65 , 66 ]. Numerous studies [ 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 ] compared the environmental conditions and physiological responses of dairy cows under misters with those obtained under an open-sided barn alone or equipped with fans Table 6.

Overall, misting systems reduced THI by 1 to 5 units [ 66 , 67 , 71 , 73 ]. This is in accordance with the formula developed by St-Pierre et al. Only Chan et al. Meteorological attributes, THI calculations, and physiological response of dairy cows for control treatments and barns equipped with mist-fan systems. Evaporative cooling pads made of fibrous material woven together with large gaps in the grooves are generally added to the air inlets of tunnel-ventilated barns Section 3.

In this way, the incoming air is pulled through a saturated medium where the conversion of water from a liquid to a vapour phase removes heat energy from the incoming air, which lowers its temperature but increases its relative humidity. Tunnel-ventilated, water-padded barns reportedly lower room temperature during the hottest part of the day by 2. However, because relative humidity is increased 22—27 units of percentage , the impact of combined tunnel ventilation and cooling pads on THI is usually minor 2 units.

The installation of wetting pads in a housing facility may reduce core-body temperature up to 1. The effect was slightly different for Shiao et al. Finally, pads had some or no effect on dry matter intake and milk yield Table 7. Meteorological attributes, THI calculations, and physiological response of dairy cows for control treatments and barns equipped with evaporative cooling pads. In one case [ 77 ], BT location was unknown. Increased heat exchange generally involves increasing heat loss from the body surface by enhancing heat loss mechanisms that include conduction direct contact with a surface , convection contact with a moving fluid , and evaporation liquid-to-vapour phase change for water through the respiratory system and skin.

Air movement is an important factor in the relief of heat stress, as it affects both convective and evaporative heat losses. Additional circulation fans can be installed in the barns if airflow provided by natural or mechanical ventilation is not sufficient [ 9 ].

Panel or basket fans are usually selected for cooling. They should be spaced at a distance of 10 times their diameter, positioned so they blow air in the direction of the prevailing winds, and tilted downwards to aim their airflow at a point directly below the next fan in line [ 2 , 10 , 84 , 85 ]. Physiological response of dairy cows for control treatments and barns equipped with high-speed fans.

An alternative to panel or basket fans for hot weather ventilation is high volume, low speed HVLS fans.

The Dairy Industry: Process, Monitoring, Standards, and Quality

Production during weeks with relatively high THI values 70 or over was higher than production in weeks with lower temperature-humidity stress. In autumn and winter when THI values were low, the quantity and quality of pasture available was inadequate to sustain high levels of milk production. Short-term weekly responses of milk output to changes in temperature-humidity conditions above THI values of 70 were not consistent, either in terms of the direction or magnitude of production change. THI values may not have been high enough to adversely affect week-to-week production from predominantly Jersey herds, although some depression in lactation yields may have occurred. The reduction in digestibility and palatability of grasses during late summer appeared to be of greater importance in influencing production patterns than the direct effects of stressful temperature-humidity conditions on cows. This is a preview of subscription content, access via your institution. Rent this article via DeepDyve.

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The severity of heat stress issues on dairy cows will increase as global warming progresses. Fortunately, major advances in environmental management, including fans, misters, sprinklers, and cooled waterbeds, can attenuate the effects of thermal stress on cow health, production, and reproduction. These cooling systems were, however, tested in subtropical areas and their efficiency in northern regions is uncertain. This article assesses the potential of existing technologies to cool cows in humid continental climates through calculation of heat stress indices. Heat stress negatively affects the health and performance of dairy cows, resulting in considerable economic losses for the industry. In future years, climate change will exacerbate these losses by making the climate warmer.


For estimation of the effect of THI on daily production of dairy cows fixed-effect Average temperature-humidity indexes during the autumn (C) and the winter (D) season ly farm, the HPA control assistant (A) or the farmer Microclimate conditions in the stables during measuring months in.


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By Niamh Burke, Krzysztof A. Ryan and Catherine C. Sampling and analysis occur along the milk processing train: from collection at farm level, to intake at the diary plant, the processing steps, and the end products. Milk has a short shelf life; however, products such as milk powders have allowed a global industry to be developed. Quality control tests are vital to support activities for hygiene and food standards to meet regulatory and customer demands.

Skip to content. The fall and spring are times when humidity related diseases usually peak in greenhouses. Sunny days increase the transpiration of moisture from leaf surfaces and evaporation from soil. The warm air holds the moisture in the vapor form.

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 Если честно… - Он вытянул шею и подвигал головой влево и вправо.  - Мне не помешала бы еще одна подушка, если вас это не затруднит. - Нисколько.  - Беккер взял подушку с соседней койки и помог Клушару устроиться поудобнее. Старик умиротворенно вздохнул. - Так гораздо лучше… спасибо. - Pas du tout, - отозвался Беккер.

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