Mitigating heat stress of dairy cows bred in a free-stall barn by sprinkler systems coupled with forced ventilation

Abstract

This paper presents the results of a research study which had the objective of investigating the effect of a sprinkler system coupled with forced ventilation on the heat stress of dairy cows bred in a free stall barn without paddock. To this aim, an experiment was carried out inside a free-stall dairy house equipped with two different cooling systems: a fogging system associated with forced ventilation in the resting area and a sprinkler system associated with forced ventilation in the feeding alley. The experiment regarded two adjacent pens of the barn and was constituted by three different trials carried out in the following periods: 27 th June -7 th July (P1), 25 th July -4 th August (P2), 24 th August -3 rd September (P3). The experimental protocol of each trial required that the treatment group was housed in one pen where the two cooling systems were always activated following an established timetable, whereas the control group was housed in the other pen, where the sprinkler system associated with forced ventilation was always deactivated. Climatic parameters were measured inside each pen of the barn and outside. Then, thermal humidity index (THI) was calculated. Rectal temperature and respiration rate of a sample of dairy cows were monitored each day during the three periods considered (P1, P2 and P3). During the three trials the cows of both groups were subjected to climatic conditions that resulted in average daily THI values between 72.8 and 74.7, corresponding to mild or moderate heat stress. However, during daytime, air temperature and relative humidity reached values corresponding to a severe heat stress, as attested by the maximum THI values that were higher than or very close to 80. Furthermore, it was observed that the sprinklers do not influence the microclimatic conditions. However, the physiological parameters values of the treatment group were always significantly lower than the corresponding ones of the control group. Specifically, the system especially influenced the respiration rate that, in the treatment group, was close to 50 breath/min, while in the control group it reached 70 breath/min. The sprinkler system had more limited effects on rectal temperature that, however, in the treatment group was significantly lower than in the control group (38.7°C to 38.8°C vs 39.1°C to 39.4°C) in all the three periods of the experiment. These results show that the sprinkler system could be useful to mitigate heat stress in dairy cows.

Assessing Influence Factors on Daily Ammonia and Greenhouse Gas Concentrations from an Open-Sided Cubicle Barn in Hot Mediterranean Climate

“…Different operating conditions of the cooling systems were established during data acquisition. Specifically, the sprinkler system in the feeding alley was switched off during W2 in pen 2 in a contextual experiment described by D’Emilio et al [ 28 ].…”

“…However, in the literature the influence of animal-related parameters (e.g., THI, cow activity/lying/feeding index) on gas concentrations has not been thoroughly investigated. Attention has been focused mainly on the relation between concentration and ventilation rate or air exchange rate [ 14 , 15 , 16 , 17 ], emissions and climatic variables [ 8 , 18 , 19 , 20 , 21 , 22 , 23 ], emissions and barn management or animal activity [ 23 , 24 , 25 ], and barn management and animal behavior [ 10 , 26 , 27 , 28 ]. For instance, Saha et al [ 21 ] analyzed the influence of external wind speed and direction on sample point concentrations.…”

Improving natural ventilation in renovated free-stall barns for dairy cows: Optimized building solutions by using a validated computational fluid dynamics model

“…Heat stress induced by adverse hot climate conditions could cause feed intake reduction, decreased milk production, alteration of fertility and behavioural changes (Kadzere et al, 2002;Porto et al, 2017;D'Emilio et al, 2017). In this regard, as reported by D'Emilio et al (2017), heat stress affects the productivity of cows in a different way in relation to their production phase. Specifically, during the early lactation stages, cows are less able to counteract the adverse effects of heat stress and can have a decline in milk production.…”

“…As stated by Seo et al (2009), the control of microclimate parameters is required to increase the productivity of livestock farming and, in this context, many studies were carried out to investigate the efficacy of different cooling systems. Some papers studied the effects of systems equipped with sprinklers and fans for direct wetting of the animals combined with forced ventilation on both cow physiology (e.g., reduction in rectal temperature, respiratory rate, dry matter intake, rumination time, lying time), lactation performance (milk quality and yield) (Avendaño-Reyes et al, 2010;Berman, 2008Berman, , 2010Avendaño-Reyes et al, 2012) and cow behaviour (Porto et al, 2017;D'Emilio et al, 2017). However, some research works studied how to mitigate heat stress in dairy cows by using only passive systems, such as natural ventilation.…”

Development of an Energy­Efficient Microclimate System for Dairy Herd Loose Keeping

“…Недостаточное количество приточных и вытяжных шахт отрицательно сказывается на микроклимате как летом, так и зимой. Проблему теплового стресса молочных коров при беспривязном содержании можно решить с помощью системы автоматического орошения в сочетании с принудительной вентиляцией [22,23].…”