The use of simple physiological and environmental measures to estimate the latent heat transfer in crossbred Holstein cows

Santos, Severino Guilherme Caetano Gonçalves dos; Saraiva, Edílson Paes; Filho, Edgard Cavalcanti Pimenta; Neto, Severino Gonzaga; Fonsêca, Vinícius de França Carvalho; Pinheiro, A. da C.; Almeida, Maria Elivânia Vieira; Amorim, Mikael Leal Cabral Menezes de

doi:10.1007/s00484-016-1204-1

Cited by 15 publications

(10 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the other hand, the respiratory frequency ranged from 80 ± 13 to 102 ± 12 breaths min −1 in Holstein cows protected or not from direct solar radiation (Gebremedhin et al 2010). Similar results were reported by Santos et al (2017) with Holstein cows managed under direct solar radiation in a tropical environment. Beatty et al (2006), working with Bos taurus (Angus) and Bos indicus (Brahma) in climatic chambers, found that when these animals were submitted to a temperature of 35°C and humidity of 80% for 5 days, the R R remained at 126 and 125 breaths min −1 , respectively.…”

Section: Resultssupporting

confidence: 82%

Thermal balance of Nellore cattle

et al. 2017

View full text Add to dashboard Cite

This work aimed at characterizing the thermal balance of Nellore cattle from the system of indirect calorimetry using a facial mask. The study was conducted at the Animal Biometeorology Laboratory of the São Paulo State University, Jaboticabal, Brazil. Five male Nellore weighing 750 ± 62 kg, at similar ages and body conditions were distributed in four 5 × 5 Latin squares (5 days of records and five schedules) during 20 days. Physiological and environmental measurements were obtained from the indirect calorimetry system using a facial mask. Respiratory parameters, hair coat, skin, and rectal temperature were continuously recorded. From this, metabolic heat production, sensible and latent ways of heat transfer were calculated. Metabolic heat production had an average value of 146.7 ± 0.49 W m and did not change (P > 0.05) over the range of air temperature (24 to 35 °C). Sensible heat flow reached 60.08 ± 0.81 W m when air temperature ranged from 24 to 25 °C, being negligible in conditions of temperature above 33 °C. Most of the heat produced by metabolism was dissipated by cutaneous evaporation when air temperature was greater than 30 °C. Respiratory parameters like respiratory rate and ventilation remained stable (P > 0.05) in the range of temperature studied. Under shade conditions and air temperature range from 24 to 35 °C, metabolic heat production, respiratory rate, and ventilation of mature Nellore cattle remain stable, which is indicative of low energetic cost to the thermoregulation.

show abstract

Section: Resultssupporting

confidence: 82%

Thermal balance of Nellore cattle

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Respiration LHL increased with increasing ambient T. Both the respiration SHL and LHL were higher under long exposure, most probably caused by the higher respiration rate and rectal T after long exposure (Zhou et al, 2022). The values of respiration SHL and LHL differed from other studies Santos et al, 2017): especially under cool conditions, the respiration LHL was much higher in this study. This could be explained by our methods for measuring exhaled air T and respiratory volume.…”

Section: Heat Loss Through Respirationcontrasting

confidence: 79%

“…The lowest experimental RH level in our study was 30%, and the effect of different RH levels on respiration LHL was very small. Actually, the total respiration heat loss did not increase as fast as was estimated in previous studies (da Silva et al, 2012;Santos et al, 2017) because of the lower measured exhaled air T by these authors at the lower ambient T range as discussed before. The increase of respiration rate or respiratory volume was mostly to offset the decreasing T gradient between ambient T and exhaled air T. Under high ambient T conditions, skin LHL accounted for about 75% of the total LHL and the rest was accounted for by respiration LHL.…”

Section: Heat Loss Through Respirationsupporting

confidence: 53%

See 1 more Smart Citation

Effects of increasing air temperature on skin and respiration heat loss from dairy cows at different relative humidity and air velocity levels

Zhou

Huynh

Koerkamp

et al. 2022

Journal of Dairy Science

View full text Add to dashboard Cite

The focus of this study was to identify the effects of increasing ambient temperature (T) at different relative humidity (RH) and air velocity (AV) levels on heat loss from the skin surface and through respiration of dairy cows. Twenty Holstein dairy cows with an average parity of 2.0 ± 0.7 and body weight of 687 ± 46 kg participated in the study. Two climate-controlled respiration chambers were used. The experimental indoor climate was programmed to follow a diurnal pattern with ambient T at night being 9°C lower than during the day. Night ambient T was gradually increased from 7 to 21°C and day ambient T was increased from 16 to 30°C within an 8-d period, both with an incremental change of 2°C per day. A diurnal pattern for RH was created as well, with low values during the day and high values during the night (low: RH_l = 30-50%; medium: RH_m = 45-70%; and high: RH_h = 60-90%). The effects of AV were studied during daytime at 3 levels (no fan: AV_l = 0.1 m/s; fan at medium speed: AV_m = 1.0 m/s; and fan at high speed: AV_h = 1.5 m/s). The AV_m and AV_h were combined only with RH_m. In total, there were 5 treatments with 4 replicates (cows) for each. Effects of short and long exposure time to warm condition were evaluated by collecting data 2 times a day, in the morning (short: 1-h exposure time) and afternoon (long: 8-h exposure time). The cows were allowed to adapt to the experimental conditions during 3 d before the main 8-d experimental period. The cows had free access to feed and water. Sensible heat loss (SHL) and latent heat loss (LHL) from the skin surface were measured using a ventilated skin box placed on the belly of the cow. These heat losses from respiration were measured with a face mask covering the cow's nose and mouth. The results showed that skin SHL decreased with increasing ambient T and the decreasing rate was not affected by RH or AV. The average skin SHL, however, was higher under medium and high AV levels, whereas it was similar under different RH levels. The skin LHL increased with increasing ambient T. There was no effect of RH on the increasing rate of LHL with ambient T. A larger increasing rate of skin LHL with ambient T was observed at high AV level compared with the other levels. Both RH and AV had no significant effects on respiration SHL or LHL. The cows lost more skin sensible heat and total respiration heat under long exposure than short exposure. When ambient T was below 20°C the total LHL (skin + respiration) represented approx. 50% of total heat loss, whereas above 28°C the LHL accounted for more than 70% of the total heat loss. Respiration heat loss increased by 34 and 24% under short and long exposures when ambient T rose from 16 to 32°C.

show abstract

“…According to Santos et al (2017) latent heat loss by sweating could account for 88% of the total latent heat loss under high ambient temperature. However, the latent heat lost from the skin might be limited by the actual evaporation rate (Berman, 2009, Foroushani andAmon, 2022), which means not all produced sweat is evaporated for heat dissipation.…”

Section: Heat Loss Mechanismsmentioning

confidence: 99%

Heat stress in dairy cows : Measuring and modelling the effects of environmental conditions on thermoregulatory responses

Zhou¹

View full text Add to dashboard Cite

This study determined the effects of increasing the ambient temperature (T) at different relative humidity (RH) and air velocity (AV) levels on the physiological and productive responses of dairy cows. Twenty Holstein dairy cows were housed inside climate-controlled respiration chambers, in which the climate was programmed to follow a daily pattern of lower night and higher day temperatures with a 9°C difference, excluding effects from sun radiation. Within our 8-d data collection period, T was gradually increased from 7 to 21°C during the night (12 h) and 16 to 30°C during the day (12 h), with an incremental changes of 2°C per day for both nighttime and daytime temperatures. During each research period, RH and AV were kept constant at one of five treatment levels. A diurnal pattern for RH was created, with lower levels during the day and higher levels during the night: low (RH_l: 30-50%), medium (RH_m: 45-70%), and high (RH_h: 60-90%). The effects of AV were studied during the day at three levels: no fan (AV_l: 0.1m/s), fan at medium speed (AV_m: 1.0m/s), and fan at high speed (AV_h:1.5m/s). Effects of short and long exposure time to increasing T were evaluated by collecting data two times a day: in the morning (short: 1 h (or less) -exposure time) and afternoon (long: 8 h -exposure time). The animals had free access to feed and water and both were ad lib.Respiration rate (RR), rectal temperature (RT), skin temperature (ST), DMI, water intake, milk yield and composition were measured. The inflection point temperatures (IPt) at which a certain variable started to change were determined for the different RH and AV levels and different exposure times. Results showed that IPt under long exposure time for RR (first indicator) varied between 18.9 and 25.5°C but was between 20.1 and 25.9°C for RT (a delayed indicator). The IPt for both RR and RT decreased with higher RH levels, while IPt increased with higher AV for RR but gave a minor change for RT. The ST was positively correlated with ambient T and ST was not affected by RH but significantly affected by AV. For RR, all IPt was lower under long exposure time than under short exposure time. The combination of higher RH levels and low AV levels negatively affected DMI. Water intake increased under all treatments except RH_l*AV_l. Treatment (RH_h*AV_l) negatively affected milk protein and fat yield while treatments (RH_m*AV_m and RH_m*AV_h) reduced milk fat yield. We concluded that RH and AV levels affected significantly the responses of RR, RT, ST and productive performance of high-producing Holstein cows. These responses already occurred at moderate ambient temperatures of 19 to 26°C.

show abstract

The use of simple physiological and environmental measures to estimate the latent heat transfer in crossbred Holstein cows

Cited by 15 publications

References 22 publications

Thermal balance of Nellore cattle

Thermal balance of Nellore cattle

Effects of increasing air temperature on skin and respiration heat loss from dairy cows at different relative humidity and air velocity levels

Heat stress in dairy cows : Measuring and modelling the effects of environmental conditions on thermoregulatory responses

Contact Info

Product

Resources

About