scholarly journals A heat load index for dairy cattle

2018 ◽  
Author(s):  
Jarrod Lees
Keyword(s):  
Dairy Cattle ◽  
Heat Load ◽  
Heat Load Index

Effects of heat load and photoperiod on milk yield and composition in three dairy herds in Israel

1999 ◽  
Vol 69 (1) ◽  
pp. 37-47 ◽  
Author(s):  
Y. Aharoni ◽  
A. Brosh ◽  
E. Ezra
Keyword(s):  
Milk Yield ◽  
Heat Load ◽  
Peak Effect ◽  
Day Length ◽  
Seasonal Effects ◽  
Lactation Performance ◽  
Annual Fluctuation ◽  
Load Effect ◽  
Ambient Temperatures ◽  
Heat Load Index

AbstractEffects of heat load and of photoperiod on lactation performance were evaluated using milk test data of three Israeli Holstein herds over a period of 3 years, from 1994 to 1996. All together 2209 cows, with 28029 milk records, were included. Photoperiod effects were examined as associated with day length and daily changes in day length and heat load index was formulated as a function of the seasonal day and night ambient temperatures, to account for the heat load effect. The regression model included effects of cow, herd, year, lactation number and days in milk in addition to the seasonal effects. The dependent variables were milk yield and fat, protein and lactose concentrations. Milk yield was affected by both photoperiod and heat load, with the peak photoperiod effect in May and amplitude of 3·1 (s.d. 0·9) kg/day and negative heat load effect of-1-8 (s.d. 0·4) kg/day at its peak. Protein concentration was affected by photoperiod, with the peak effect in January (amplitude of 1·7 (s.e. 0·5) g/kg) but not by heat load (-0-2 (s.d. 0·6) glkg). Fat concentration was affected primarily by heat load (-3-4 (s.d. 0·7) g/kg), with a photoperiod effect which peaked in October (amplitude of 1·8 (s.d. 0·8) g/kg). Lactose concentration was affected by both environmental factors to a lesser extent (photoperiod amplitude of 0·6 (s.d. 0·2) g/kg and heat load effect of-0-03 (s.d. 0·16) g/kg). Comparison of the predicted seasonal effects on milk yield and composition with the annual fluctuation in the national herd showed a good match of the predicted effects with the national observations. It is concluded that while heat load relief may be beneficial, manipulation of the photoperiod may induce adverse effects on milk yield and composition.

scholarly journals Microclimate in silvipastoral systems with eucalyptus in rank with different heights

2010 ◽  
Vol 39 (3) ◽  
pp. 685-694 ◽  
Author(s):  
Wander de Souza ◽  
Orlando Rus Barbosa ◽  
Jair de Araújo Marques ◽  
Marco Aurélio Teixeira Costa ◽  
Eliane Gasparino ◽  
...  
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Air Temperature ◽  
Thermal Load ◽  
Heat Load ◽  
Temperature Humidity Index ◽  
Heat Load Index ◽  
Humidity Index ◽  
Globe Temperature ◽  
Black Globe Temperature

The aim of this work was to verify if the presence of trees and its height in formed silvipastoral systems with eucalyptus planted in rank can modify the microclimate and improve the environment for bovine raising during the day in summer. It was evaluated the microclimate of the environment in formed silvipastoral systems in rank of eucalyptus with 8 m, 18 m and 28 meters of height, compared to a system no shade in the summer. The experimental design was a split plot with six hour time in sub parcels. The systems are made up of parcels and the months as block in four replications and the interaction hour × system. The air temperature, black globe temperature, relative humidity and wind speed were observed to create the following indexes for thermal comfort: temperature-humidity index; black globe-humidity index; heat load index and the radiant thermal load. Excepted for the relative humidity, there was interaction for time × system for all variables and indexes. Interaction occurred for: air temperature at 10 a.m. and 6 p.m.; wind speed from 8 a.m. to 4 p.m.; temperature humidity index at 10 a.m. and 12 p.m.; black globe temperature, black globe humidity index, heat load index, and radiant thermal load at all the hours. During the summer, the system with shade of 28 m trees had the lowest average of black globe temperature; wind speed; black globe humidity index; radiant thermal load index; and heat load index. There was a reduction of wind speed average in systems 8 m, 18 m and 28 m trees in, respectively, 20.7; 50.0 and 48.0% in relation to no shade system; however it was not proportional to the height, with influence of the rank porosity and pantries height. Nevertheless, for radiant thermal load index the reduction was proportional to the height of the trees with 10.24; 12.49 and 20.76%, respectively, for 8 m, 18 m and 28 meters of height. There was a reduction of the thermal stress in the environment due to the presence of trees, being the heat load index thermal the index that better demonstrated the effect, despite of not being proportional to the rank height.

1717 Responses of hair sheep breeds to high heat load index conditions

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 837-837
Author(s):  
D. Tadesse ◽  
R. Puchala ◽  
T. A. Gipson ◽  
Y. Tsukahara ◽  
A. L. Goetsch
Keyword(s):  
Heat Load ◽  
High Heat ◽  
Hair Sheep ◽  
Sheep Breeds ◽  
Heat Load Index ◽  
High Heat Load

scholarly journals Sprinkler flow rate affects dairy cattle preferences, heat load, and insect deterrence behavior

2016 ◽  
Vol 182 ◽  
pp. 1-8 ◽  
Author(s):  
Jennifer M. Chen ◽  
Karin E. Schütz ◽  
Cassandra B. Tucker
Keyword(s):  
Dairy Cattle ◽  
Flow Rate ◽  
Heat Load

scholarly journals Characteristics of Cowsheds in Vietnamese Smallholder Dairy Farms and Their Associations with Microclimate—A Preliminary Study

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 351
Author(s):  
Nguyen N. Bang ◽  
John B. Gaughan ◽  
Ben J. Hayes ◽  
Russell E. Lyons ◽  
Nguyen V. Chanh ◽  
...  
Keyword(s):  
Heat Stress ◽  
Heat Load ◽  
Linear Models ◽  
Dairy Farms ◽  
High Heat ◽  
Future Research ◽  
Heat Load Index ◽  
Smallholder Dairy ◽  
Air Speed ◽  
Smallholder Dairy Farms

In smallholder dairy farms (SDFs), farmers often build cowsheds using local materials and based on self-accumulated experience without due consideration to reducing the risk of heat stress. This study aimed to characterise the heat stress abatement strategies and microclimate within SDF cowsheds from four typical dairy regions of Vietnam (south lowland, south highland, north lowland and north highland) and identify the housing parameters most associated with the microclimate. The study was conducted on 32 SDFs (eight SDFs per region) in autumn 2017. Twelve housing management variables, illustrating cowshed design and heat stress abatement methods of each SDF, were collected. Six microclimate parameters, collected within the cowshed, were temperature (AT), humidity, air speed (AS), heat load index (HLI), Temperature-humidity index (THI) and accumulated heat load units (AHLU) during a day (06:00 h to 18:00 h). Factor analysis and cluster analysis was applied to group cowsheds of SDFs into clusters where SDFs in the cluster had the same cowshed characteristics. Multivariable linear models were applied to define the parameters most likely to inform future research into heat stress mitigation on SDF. Averaged from 08:00 h to 18:00 h, microclimate inside the cowsheds was considered hot (HLI > 79) in the highland and very hot (HLI > 86) in the lowland regions. Cows in the lowland regions accumulated high heat load (AHLU > 50) by 18:00 h. Cowsheds of SDFs varied widely and grouped into seven cowshed types, but no type was more effective than others in reducing heat stress conditions within cowsheds. Using roof soakers together with fans decreased AT and HLI by 1.3 °C and 3.2 units, respectively, at 14:00 h compared to 11:00 h. Each 100 m increase in altitude was associated with decreases of 0.4 °C in AT, 1.3 units in HLI and 0.8 units in THI (p < 0.001). Each meter increase in the eave height of the cowshed roof was associated with decreases of 0.87 °C in AT, 3.31 units in HLI and 1.42 units in THI, and an increase of 0.14 m/s in AS (p < 0.05). The cowshed parameters that should be prioritised for future research into the amelioration of heat stress in SDF cows include using the roof soakers together with fans, increasing altitude, eave roof height and floor area per cow.

scholarly journals Evaluation of thermal stress indexes for dairy cows in tropical regions

2007 ◽  
Vol 36 (4 suppl) ◽  
pp. 1192-1198 ◽  
Author(s):  
Roberto Gomes da Silva ◽  
Débora Andréa Evangelista Façanha Morais ◽  
Magda Maria Guilhermino
Keyword(s):  
Dairy Cows ◽  
Heat Load ◽  
Selection Criterion ◽  
Equivalent Temperature ◽  
Temperature Index ◽  
Tropical Regions ◽  
Heat Load Index ◽  
Humidity Index ◽  
Index Value ◽  
Jersey Cows

Data from 359 Holstein and 54 Jersey cows (total of 1359 observations) collected in commercial herds in the northeast of Brazil were used to evaluate six environmental stress indexes. The selection criterion was the correlation between the index value with the rectal temperature (RT) and the respiratory rate (RR) of cows. Both Temperature-Humidity Index (THI) and Black Globe-Humidity Index (BGHI) had the lowest correlations with animal RT and RR. The selected indexes were the Equivalent Temperature Index (r = 0.293 and 0.520 with RT and RR, respectively) and the Heat Load Index (0.286 and 0.542, respectively).

scholarly journals 10 Finishing beef cattle under cover reduces heat load and improves efficiency during the summer

2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 13-13
Author(s):  
William M Sims ◽  
Lawton Stewart ◽  
Jacob R Segers ◽  
Robert W McKee ◽  
Macc Rigdon ◽  
...  
Keyword(s):  
Heat Stress ◽  
Heat Load ◽  
Mixed Model ◽  
Significant Risk ◽  
Environmental Data ◽  
Marbling Score ◽  
Finishing Cattle ◽  
Heat Load Index ◽  
Cooling Fans ◽  
Globe Temperature

Abstract Heat-stress in finishing cattle presents a significant risk to efficiency and economic viability. The project objective was to quantify the effects of long-term heat stress when finishing cattle during the summer in the southeastern United States. Forty-five Angus crossbred steers (446±23 kg) were blocked by weight and randomly assigned to environmental finishing treatments including: covered with fan (CWF), covered without fan (CNF), or outside without shade (OUT). For 92 d steers were individually fed a typical feedlot ration. Environmental data were continuously recorded including: black globe temperature (BG), heat load index (HLI), and accumulated heat load units (AHLU). Feed intake was recorded daily, and steers were weighed every 20–25 days. When the first treatment averaged 613-kg all steers were slaughtered, and carcass data were collected. Data were analyzed as a Mixed Model (JMP V13; SAS Inst.) and means were separated (Least Squares Means). Average maximal BG was lower for covered finishing than OUT (P < 0.01) however for HLI CWFCNF>OUT, while G:F was similar (P = 0.22) between CWF and CNF, which were greater (P < 0.01) than OUT. Hot carcass weights were heavier for CWF than OUT (P < 0.01) and CNF was similar to both (P ≥ 0.11). There was no difference for USDA Yield Grade (2.6; P = 0.44), or marbling score (Modest20; P = 0.76). Steers finished under cover were more efficient than steers finished in open dry-lots. The addition of cooling fans further improved steer gains over those that were covered without fans.

scholarly journals Conditions to evaluate differences among individual sheep and goats in resilience to high heat load index

2017 ◽  
Vol 147 ◽  
pp. 89-95 ◽  
Author(s):  
U.L. Mengistu ◽  
R. Puchala ◽  
T. Sahlu ◽  
T.A. Gipson ◽  
L.J. Dawson ◽  
...  
Keyword(s):  
Heat Load ◽  
High Heat ◽  
Sheep And Goats ◽  
Heat Load Index ◽  
High Heat Load

scholarly journals 199 Effects of high heat load conditions on Dorper, Katahdin, and St. Croix sheep from different regions of the USA

2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 76-76
Author(s):  
Dereje Tadesse ◽  
Ryszard Puchala ◽  
Terry A Gipson ◽  
Arthur L Goetsch
Keyword(s):  
Respiration Rate ◽  
Rectal Temperature ◽  
Heat Load ◽  
High Heat ◽  
Heat Load Index ◽  
The Usa ◽  
Central Texas ◽  
Commercial Farms ◽  
High Heat Load ◽  
Female Sheep

Abstract Forty-six Dorper, 46 Katahdin, and 43 St. Croix female sheep (initial BW of 58, 59, and 46 kg, respectively, SEM = 1.75; 3.3 ± 0.18 yr of age, 2.6 - 3.7) from 45 commercial farms in four regions of the USA (Midwest, Northwest, Southeast, and central Texas) were used to evaluate responses to high heat load index (HLI) conditions in a central facility. The four trials entailed sequential 2-wk periods with target HLI during day/nighttime of 70/70 (thermoneutral zone conditions during the day and night), 85/70, 90/77, and 95/81, with weekly measures at 0700 (before increased daytime HLI), 1300, and 1700 h (preceding lower nighttime HLI). Rectal temperature (ºC) in period 3 (38.64, 38.66, and 38.48 at 0700 h, 39.08, 39.23, and 38.84 at 1300 h, and 39.20, 39.15, and 38.99 at 1700 h) and period 4 (38.71, 38.90, and 38.51 at 0700 h, 39.18, 39.12, and 38.83 at 1300 h, and 39.45, 39.34, and 39.07 at 1700 h for Dorper, Katahdin, and St. Croix, respectively) (SEM = 0.054, 0.037, and 0.038 at 0700, 1300, and 1700 h, respectively) ranked St. Croix < Katahdin < Dorper. Nonetheless, there were corresponding differences in respiration rate (breaths/min) in period 3 (63.1, 56.8, and 49.6 at 0700 h, 133.8, 125.8, and 115.7 at 1300 h, and 125.5, 114.7, and 106.8 at 1700 h) and period 4 (81.6, 72.2, and 54.5 at 0700 h, 149.2, 143.6, and 137.3 at 1300 h, and 147.0, 141.4, and 134.2 at 1700 h for Dorper, Katahdin, and St. Croix, respectively) (SEM = 3.12, 4.11, and 3.62 at 0700, 1300, and 1700 h, respectively). In conclusion, based on rectal temperature and respiration rate the overall impact of region was minimal and resilience to high HLI was greatest for St. Croix and lowest for Dorper sheep

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