scholarly journals Intake, physiological parameters and behavior of Angus and Nellore bulls subjected to heat stress

2015 ◽  
Vol 36 (6Supl2) ◽  
pp. 4565 ◽  
Author(s):  
Ériton Egidio Lisboa Valente ◽  
Mario Luiz Chizzotti ◽  
Cristiane Viol Ribeiro de Oliveira ◽  
Matheus Castilho Galvão ◽  
Silas Sebastião Domingues ◽  
...  

<p>Genetics differences between breeds may determine the tolerance to high temperature, effect dry matter intake and consequently cattle performance. The effect of temperature and humidity index (THI) on diurnal, nocturnal and daily intake, water intake, physiologic parameters and behavior of Nellore (<em>B. indicus</em>) and Angus (<em>B. taurus</em>) bulls were evaluated. Eight Angus and eight Nellore young bulls (337±7.4 kg and 16 months of age) were allocated in two climate-controlled rooms for 32 days. In the period 1, all bulls were housed in thermoneutral conditions (TN, THI = 72.6) for 10 days. In period 2 (10 days), four Angus and four Nellore bulls were subjected to low heat stress (LHS, THI = 76.4) in daytime, and four Angus and four Nellore bulls were subjected to high heat stress (HHS, THI = 81.5) in daytime. The diurnal and daily dry matter intake (DMI) of Nellore were not affected (P&gt;0.05) by heat stress. However, Angus bulls decreased diurnal DMI by 24% and daily DMI decreased (P&lt;0.05) by 15% on HHS. In TN Angus bulls had higher (P&lt;0.05) daily DMI (36.2 g/kg of BW) than Nellore (29.1 g/kg of BW), but in HHS they had similar (P&gt;0.05) daily DMI (31.6 and 30.2 g/kg of BW, respectively). We observed an increase (P&lt;0.05) in respiratory frequency, but water intake was not affected (P&gt;0.05) by heat stress. The heart rate decreased (P&lt;0.05) with heat stress. No differences were found (P&gt;0.05) in feeding behavior. Therefore, THI stress threshold should distinct for Angus and Nellore bulls. The use of feed intake information may improve the prediction of thermic discomfort on specific climate condition. </p>

2015 ◽  
Vol 36 (6Supl2) ◽  
pp. 4565
Author(s):  
Ériton Egidio Lisboa Valente ◽  
Mario Luiz Chizzotti ◽  
Cristiane Viol Ribeiro de Oliveira ◽  
Matheus Castilho Galvão ◽  
Silas Sebastião Domingues ◽  
...  

Genetics differences between breeds may determine the tolerance to high temperature, effect dry matter intake and consequently cattle performance. The effect of temperature and humidity index (THI) on diurnal, nocturnal and daily intake, water intake, physiologic parameters and behavior of Nellore (B. indicus) and Angus (B. taurus) bulls were evaluated. Eight Angus and eight Nellore young bulls (337±7.4 kg and 16 months of age) were allocated in two climate-controlled rooms for 32 days. In the period 1, all bulls were housed in thermoneutral conditions (TN, THI = 72.6) for 10 days. In period 2 (10 days), four Angus and four Nellore bulls were subjected to low heat stress (LHS, THI = 76.4) in daytime, and four Angus and four Nellore bulls were subjected to high heat stress (HHS, THI = 81.5) in daytime. The diurnal and daily dry matter intake (DMI) of Nellore were not affected (P>0.05) by heat stress. However, Angus bulls decreased diurnal DMI by 24% and daily DMI decreased (P<0.05) by 15% on HHS. In TN Angus bulls had higher (P<0.05) daily DMI (36.2 g/kg of BW) than Nellore (29.1 g/kg of BW), but in HHS they had similar (P>0.05) daily DMI (31.6 and 30.2 g/kg of BW, respectively). We observed an increase (P<0.05) in respiratory frequency, but water intake was not affected (P>0.05) by heat stress. The heart rate decreased (P<0.05) with heat stress. No differences were found (P>0.05) in feeding behavior. Therefore, THI stress threshold should distinct for Angus and Nellore bulls. The use of feed intake information may improve the prediction of thermic discomfort on specific climate condition.


2021 ◽  
Vol 2 ◽  
Author(s):  
Véronique Ouellet ◽  
Izabella M. Toledo ◽  
Bethany Dado-Senn ◽  
Geoffrey E. Dahl ◽  
Jimena Laporta

The effects of heat stress on dry cows are profound and significantly contribute to lower overall welfare, productivity, and profitability of the dairy sector. Although dry cows are more thermotolerant than lactating cows due to their non-lactating state, similar environmental thresholds are currently used to estimate the degree of heat strain and cooling requirements. Records of dry cow studies conducted over 5 years in Gainesville, Florida, USA were pooled and analyzed to determine environmental thresholds at which dry cows exhibit signs of heat stress in a subtropical climate. Dry-pregnant multiparous dams were actively cooled (CL; shade of a freestall barn, fans and water soakers, n = 107) or not (HT; shade only, n = 111) during the last 7 weeks of gestation, concurrent with the entire dry period. Heat stress environmental indices, including ambient temperature, relative humidity, and temperature-humidity index (THI), and animal-based indices, including respiration rate, rectal temperature and daily dry matter intake were recorded in all studies. Simple correlations were performed between temperature-humidity index and each animal-based indicator. Differences in respiration rate, rectal temperature and dry matter intake between treatments were analyzed by multiple regression. Using segmented regression, temperature-humidity thresholds for significant changes in animal-based indicators of heat stress were estimated. Stronger significant correlations were found between the temperature-humidity index and all animal-based indices measured in HT dry cows (−0.22 ≤ r ≤ 0.35) relative to CL dry cows (−0.13 ≤ r ≤ 0.19). Although exposed to similar temperature-humidity index, rectal temperature (+0.3°C; P &lt; 0.001) and respiration rate (+23 breaths/min; P &lt; 0.001) were elevated in HT dry cows compared with CL cows whereas dry matter intake (−0.4 kg of dry matter/d; P = 0.003) was reduced. Temperature-humidity index thresholds at which respiration rate and rectal temperature began to change were both determined at a THI of 77 in HT dry cows. No significant temperature-humidity threshold was detected for dry matter intake. At a practical level, our results demonstrate that dry cow respiration rate and rectal temperature increased abruptly at a THI of 77 when provided only shade and managed in a subtropical climate. Therefore, in the absence of active cooling, dry cows should be closely monitored when or before THI reaches 77 to avoid further heat-stress related impairments during the dry period and the subsequent lactation and to mitigate potential carry-over effects on the offspring.


2017 ◽  
Vol 57 (7) ◽  
pp. 1233 ◽  
Author(s):  
J. B. Garner ◽  
M. Douglas ◽  
S. R. O. Williams ◽  
W. J. Wales ◽  
L. C. Marett ◽  
...  

The objective of the present research was to describe the physiological and production responses of lactating dairy cows during and after sudden exposure to temperate-climate heat-wave conditions, compared with cows in thermoneutral conditions. Twelve lactating multiparous Holstein–Friesian dairy cows were housed in controlled-climate chambers for 4 days. Six were exposed to a short-term temperature and humidity challenge (THc, diurnal temperature and humidity fluctuations inducing moderate heat stress; temperature humidity index 74–84) and six cows were exposed to thermoneutral conditions (THn, temperatur humidity index 55–61). Cows were also measured during a 7-day pre-experimental and 14-day post-experimental period. Physiological indicators of heat stress were measured, including rectal and vaginal temperature and respiration rate, which indicated that the THc in controlled-climate chambers induced moderate heat stress. The cows exposed to the 4-day THc reduced their milk yield by 53% and their dry-matter intake by 48%, compared with the cows in the THn treatment. Milk yield of THc cows returned to pre-experimental milk yield by Day 7 and dry-matter intake by Day 4 of the post-experimental period. The short-term heat challenge induced metabolic adaptations by mobilising adipose tissue, as indicated by increased non-esterified fatty acids, and amino acids from skeletal muscle, as indicated by increased urea nitrogen to compensate for reduced nutrient intake and increased energy expenditure. Endocrine responses included greater prolactin concentrations, which is associated with thermoregulation and water metabolism. The cows exposed to THc displayed production and physical responses that facilitated lower metabolic heat production and greater heat dissipation in an attempt to maintain homeostasis during the short-term heat exposure. These results indicated that the conditions imposed on the cows in the controlled-climate chambers were sufficient to induce heat-stress responses and adversely affected production in the lactating dairy cow, and the delay between the return to normal feed intake and milk yield following the heat challenge suggests a period of metabolic recovery was occurring.


Author(s):  
J. Chang-Fung-Martel ◽  
M. T. Harrison ◽  
J. N. Brown ◽  
R. Rawnsley ◽  
A. P. Smith ◽  
...  

AbstractChanges in frequency and severity of heat waves due to climate change pose a considerable challenge to livestock production systems. Although it is well known that heat stress reduces feed intake in cattle, effects of heat stress vary between animal genotypes and climatic conditions and are context specific. To derive a generic global prediction that accounts for the effects of heat stress across genotypes, management and environments, we conducted a systematic literature review and a meta-analysis to assess the relationship between dry matter intake (DMI) and the temperature-humidity index (THI), two reliable variables for the measurement of feed intake and heat stress in cattle, respectively. We analysed this relationship accounting for covariation in countries, breeds, lactation stage and parity, as well as the efficacy of various physical cooling interventions. Our findings show a significant negative correlation (r =  − 0.82) between THI and DMI, with DMI reduced by 0.45 kg/day for every unit increase in THI. Although differences in the DMI-THI relationship between lactating and non-lactating cows were not significant, effects of THI on DMI varied between lactation stages. Physical cooling interventions (e.g. provision of animal shade or shelter) significantly alleviated heat stress and became increasingly important after THI 68, suggesting that this THI value could be viewed as a threshold for which cooling should be provided. Passive cooling (shading) was more effective at alleviating heat stress compared with active cooling interventions (sprinklers). Our results provide a high-level global equation for THI-DMI across studies, allowing next-users to predict effects of heat stress across environments and animal genotypes.


2004 ◽  
Vol 55 (3) ◽  
pp. 253 ◽  
Author(s):  
John B. Gaughan ◽  
M. Shane Davis ◽  
Terry L. Mader

A controlled crossover experimental design was used to determine the effect of altered water sprinkling duration on heifers subjected to heat stress conditions. Heifers were subjected to 3 days of thermoneutral conditions followed by 3 days of hot conditions accompanied by water sprinkling between 1300 and 1500 h (HOT1–3). Then on the following 2 days (HOT4–5), environmental conditions remained similar, but 3 heifers were sprinkled between 1200 and 1600 h (WET) and 3 were not sprinkled (NONWET). This was followed by a 1-day period (HOT6) in which environmental conditions and sprinkling regimen were similar to HOT1–3. Rectal temperature (RT) was collected hourly, and respiration rate (RR) was monitored every 2 h on HOT Days 2, 4, 5, and 6. Dry matter intake and rate of eating were also determined. Sprinkling reduced RR and RT (P < 0.01) of all heifers during HOT1–3. During HOT4–5, WET heifers had lower (P < 0.05) RT than NONWET from 1300 to 700 h and lower RR from 1400 to 2000 h. Dry matter intake of NONWET heifers was reduced by 30.6% (P < 0.05) during HOT4–5 and by 51.2% on HOT6. On HOT4–5 the dry matter intakes of WET heifers were similar to intakes under thermoneutral conditions. During HOT6, RT was again reduced following sprinkling in all heifers. Comparison of RT and RR of NONWET and WET heifers on HOT1–3 v. HOT6 revealed that under similar environmental conditions, NONWET heifers had increased RT, partially due to carry-over from HOT4–5. However, NONWET heifers had 40% lower feed intake but tended to have lower RR on HOT6 v. HOT1–3. Only RR of WET heifers was greater on HOT6, possibly a result of switching from a 4-h back to a 2-h sprinkling period, while maintaining a 62% greater intake (5.80 v. 3.58 kg/day) than NONWET heifers during this time. Results suggest that inconsistent cooling regimens may increase the susceptibility of cattle to heat stress and elicit different physiological and metabolic responses.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 478-478
Author(s):  
Matthew E Wilson ◽  
Kevin Shaffer ◽  
Shane Plum ◽  
Kevin Garossino ◽  
Nicky Lansink ◽  
...  

Abstract Technology that facilitates estimation of individual animal intake rates in group-housed settings will result in improvements in animal production and management efficiency. Estimating intake in pasture settings may benefit from models that use other variables as proxies. Relationships among dry matter intake (DMI), animal performance variables, and environmental variables to model DMI were investigated. 202 animals were studied in a drylot setting (153 bulls for 85 days and 55 steers for 55 days) using VYTELLE SENSETM In-Pen-Weighing and Feed-Intake nodes. A machine learning model was calibrated using: DMI, sex, age, full body weight, ADG, water intake, water visit frequency and duration. DMI was positively related to full body weight (r = 0.39, P &lt; 0.001), water intake (r=0.23, P &lt; 0.001), and ADG (r=0.18, P &lt; 0.001). In addition, DMI had significant but weak correlations with water visit frequency (r=0.031, P &lt; 0.001). DMI exhibited weak negative relationships with maximum air temperature (r=-0.094, P &lt; 0.001) maximum relative humidity (r=-0.056, P &lt; 0.001), net radiation (r=-0.040, P &lt; 0.001), and precipitation (r=-0.022, P &lt; 0.001). Weak positive relationships were observed between DMI and maximum wind speed (r=0.031, P &lt; 0.001) and direction (r=-0.022, P &lt; 0.001). The model was validated with resultant average RMSE of 1.06 kg for daily predicted DMI compared to measured daily DMI. In addition, when daily predicted DMI was averaged for each animal, the accuracy of model results improved with RMSE of 0.11 kg. Study results demonstrate that inclusion of water intake and animal performance variables improves predictive accuracy of DMI. Validating and refining the model used to predict DMI in drylots will facilitate future extrapolation to larger group field settings. Vytelle and its logo are trademarks of Vytelle, LLC.


2018 ◽  
Vol 19 (4) ◽  
pp. 381-390 ◽  
Author(s):  
Ana Barros Oliveira ◽  
Wandrick Hauss Sousa ◽  
Flávio Gomes Oliveira ◽  
Felipe Queiroga Cartaxo ◽  
Edgard Cavalcante Pimenta Filho ◽  
...  

SUMMARY This study aimed to evaluate the bio-economic performance in confinement crossbred goats from different genetic groups. Were used 30 goats, crossbred (F1) intact male, 10 goats Boer x SPRD (undefined breed), 10 x Savannah SPRD and 10 Oberhasli x SPRD, with an average weight of 15 kg and an average age of 100 days. The initial weight was evaluated, final body weight, average daily gain, total weight gain, dry matter intake, water intake, feed conversion and days on feed. As an economic indicator was calculated gross profit margin (MB), the average dry matter intake, the confinement period, the cost of each diet and the cost of vaccines and medicines. We used the 5% Tukey test for comparisons between treatment means. For the variables weight gain, dry matter intake, water intake and body condition score averages observed did not differ between the genetic groups. There was significant effect (P> 0.05) of genetic groups on days on feed. The biological performance of the goats finished in feedlot was not influenced by genetic group. In bioeconomic analysis was no significant difference (P> 0.05) between the evaluated racial groups. Gross profit margin was negative for the mestizos Pardo Alpine x SPRD. The cross between the Boer breed and without defined breed results in premature animals, reaching slaughter weights with reduced confinement period. In the feedlot finishing system crossbred Boer goats x SPRD showed better economic performance, providing greater profitability to the creator.


2009 ◽  
Vol 92 (10) ◽  
pp. 4937-4944 ◽  
Author(s):  
K.L. Proudfoot ◽  
J.M. Huzzey ◽  
M.A.G. von Keyserlingk

Animals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 925
Author(s):  
Zhao ◽  
Min ◽  
Zheng ◽  
Wang

Heat stress negatively impacts the health and milk production of dairy cows, and ruminal microbial populations play an important role in dairy cattle’s milk production. Currently there are no available studies that investigate heat stress-associated changes in the rumen microbiome of lactating dairy cattle. Improved understanding of the link between heat stress and the ruminal microbiome may be beneficial in developing strategies for relieving the influence of heat stress on ruminants by manipulating ruminal microbial composition. In this study, we investigated the ruminal bacterial composition and metabolites in heat stressed and non-heat stressed dairy cows. Eighteen lactating dairy cows were divided into two treatment groups, one with heat stress and one without heat stress. Dry matter intake was measured and rumen fluid from all cows in both groups was collected. The bacterial 16S rRNA genes in the ruminal fluid were sequenced, and the rumen pH and the lactate and acetate of the bacterial metabolites were quantified. Heat stress was associated with significantly decreased dry matter intake and milk production. Rumen pH and rumen acetate concentrations were significantly decreased in the heat stressed group, while ruminal lactate concentration increased. The influence of heat stress on the microbial bacterial community structure was minor. However, heat stress was associated with an increase in lactate producing bacteria (e.g., Streptococcus and unclassified Enterobacteriaceae), and with an increase in Ruminobacter, Treponema, and unclassified Bacteroidaceae, all of which utilize soluble carbohydrates as an energy source. The relative abundance of acetate-producing bacterium Acetobacter decreased during heat stress. We concluded that heat stress is associated with changes in ruminal bacterial composition and metabolites, with more lactate and less acetate-producing species in the population, which potentially negatively affects milk production.


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