scholarly journals The effect of Brahman genes on body temperature plasticity of heifers on pasture under heat stress

2020 ◽  
Vol 98 (5) ◽  
Author(s):  
Raluca G Mateescu ◽  
Kaitlyn M Sarlo-Davila ◽  
Serdal Dikmen ◽  
Eduardo Rodriguez ◽  
Pascal A Oltenacu
Keyword(s):  
Heat Stress ◽  
Body Temperature ◽  
Repeated Measures ◽  
Mixed Model ◽  
Reaction Norm ◽  
Stress Conditions ◽  
Random Regression ◽  
Effective Strategies ◽  
Brahman Cattle ◽  
Unit Increase

Abstract Bos taurus indicus cattle have the superior ability for the regulation of body temperature during heat stress due to a number of physiological and cellular level adaptive traits. The objectives of this study were to quantify the change in body temperature in heifers with various proportions of Brahman genes per unit increase in heat stress as measured by temperature–humidity index (THI) and to assess how different breed groups responded to varying intensity and duration of heat stress. A total of 299 two-yr-old heifers from six breed groups ranging from 100% Angus to 100% Brahman were evaluated under hot and humid conditions during 2017 and 2018 summer days. Two strategies were used to estimate the plasticity in body temperature of breed groups in response to environmental challenges: 1) a random regression mixed model was used to estimate reaction norm parameters for each breed group in response to a specified environmental heat stress and 2) a repeated measures mixed model was used to evaluate the response to different environmental heat loads. The reaction norm model estimated an intercept and slope measuring the change in body temperature per unit increase in THI environmental heat stress for different breed groups of animals and allowed the identification of genotypes which are robust, with low slope values indicative of animals that are able to maintain normal body temperature across a range of environments. The repeated measures mixed model showed that Brahman cattle have an advantage under moderate or high heat stress conditions but both Angus and Brahman breed groups are greatly affected when heat stress is severe. A critical factor appears to be the opportunity to cool down during the night hours more than the number of hours with extreme THI. With heat stress conditions predicted to intensify and expand into currently temperate zones, developing effective strategies to ensure sustainable beef production systems are imperative. Effective strategies will require the identification of the genes conferring the superior thermotolerance in Brahman cattle.

scholarly journals 74 President Oral Presentation Pick: Phenotypic plasticity of heat tolerance in beef cattle

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 51-51
Author(s):  
Raluca G Mateescu ◽  
Kaitlyn M Sarlo Davila ◽  
Serdal Dikmen ◽  
Andrea Nunez ◽  
Eduardo Rodriguez ◽  
...  
Keyword(s):  
Heat Stress ◽  
Phenotypic Plasticity ◽  
Body Temperature ◽  
Sweat Gland ◽  
Mixed Model ◽  
The Body ◽  
Random Regression ◽  
Linear Effect ◽  
Gland Size ◽  
The Impact

Abstract Bos taurus indicus cattle have superior ability for regulation of body temperature during heat stress due to a number of physiological and cellular level adaptive traits. The objectives of this study were to quantify the change in body temperature in heifers with various proportions of Brahman genes per unit increase in heat stress as measured by THI and to assess the impact of skin properties on the phenotypic plasticity. A total of 299 two-year old heifers from six breed groups ranging from 100% Angus to 100% Brahman were evaluated under hot and humid conditions during 2017 and 2018 summer days. The plasticity in body temperature of breed groups in response to environmental challenges was estimated using a random regression mixed model. Six mm skin biopsies were collected from the right side of sixth thoracic bone of each heifer. Cross-sections of biopsy samples with a thickness of 7 µm were stained with Hematoxilin–Eosin technique. The number and area of sweat and sebaceous glands and the thickness of dermis and epidermis were determined using the ImageJ program. The 100% Brahman group had the lowest intercept and slope (38.66 and 0.18) representing the body temperature under the low THI conditions and the increase in body temperature for 2 units of THI, respectively. Except for the 100% Angus group, which had a slightly higher intercept (38.68), all other breed groups had lower intercepts. Body temperature in the 100% Angus heifers increases by 0.42 for every 2 units of THI. There was a significant linear effect of Brahman percentage on the sweat gland size, with the 100% Brahman having the largest sweat gland size (203.57µm2) and purebred Angus the smallest (94.31µm2). Effective strategies will require the identification of the genes conferring the superior thermotolerance in Brahman cattle.

504 Late-Breaking: Automatic Monitoring Systems to Detect Behavioral and Productive Variations during Heat Stress in Dairy Cows

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 180-181
Author(s):  
Ludovica Mammi ◽  
Damiano Cavallini ◽  
Alberto Palmonari ◽  
Alessandro Concolino ◽  
Francesca Ghiaccio ◽  
...  
Keyword(s):  
Heat Stress ◽  
Dairy Cows ◽  
Milk Production ◽  
Repeated Measures ◽  
Mixed Model ◽  
Random Effect ◽  
Automatic Monitoring ◽  
Environmental Data ◽  
Monitoring Systems ◽  
Different Seasons

Abstract Aim of the project was to evaluate behavioral and productive variations of dairy cows detected by automatic monitoring systems, during different seasons. Environmental data (Temperature (T, °C), Relative Humidity, (RH, %) and Temperature and Humidity Index (THI)), were recorded inside the pens by electronic probes during 4 periods over 2 years, for a total of 473 days. Fans and sprinklers were activated at THI >60. Hundred lactating and dry cows were equipped with monitoring tag (Heatime-Pro, SCR Engineers Ltd.) that recorded continuously time (min/d) spent ruminating (RT), panting (PT) and feeding (FT). Daily PT and FT data were recorded as group average [lactating (LC) or dry], while RT and milk production were extracted as individual data. Four classes of environmental stress were identified based on maximum THI: comfort (C, THI < 60, 101d), moderate stress (MS, 60< THI >69, 92d), stress (S, 70< THI >75, 102d), severe stress (SS, THI >75, 178d). Behavioral and productive data were compared between classes. Data were analyzed by mixed model with repeated measures, with environmental class, group (dry or lactating), parity and interactions as fixed effect. Cow was included as random effect for RT and milk production. Means comparison was performed by Tukey post hoc test. All behavioral outcomes were influenced by heat stress (P < .001, table 1). Panting increased linearly with maximum THI recorded, being highest during SS days in LC (49.6 min/d, P < .001). FT and RT (min/d) were lowest (P < .001) during S days (206.9, FT and 473.1, RT) and RT reached the lowest values in cows within 15 DIM (456.4). Milk production was affected in multiparous cows, with a linear reduction from C to SS days (P < .001). Heat stress deeply affected cows behavior and performances, despite cooling systems. Automatic monitoring of these parameters can effectively help in detecting heat stress and consequently adopt strategies to improve animal welfare.

Effect of feed intake level on the body temperature of pigs exposed to heat stress conditions

2018 ◽  
Vol 76 ◽  
pp. 1-7 ◽  
Author(s):  
M. Cervantes ◽  
D. Antoine ◽  
J.A. Valle ◽  
N. Vásquez ◽  
R.L. Camacho ◽  
...  
Keyword(s):  
Heat Stress ◽  
Body Temperature ◽  
Feed Intake ◽  
The Body ◽  
Stress Conditions ◽  
Intake Level

Comparison of estimated core body temperature measured with the BioHarness and rectal temperature under several heat stress conditions

2016 ◽  
Vol 13 (8) ◽  
pp. 612-620 ◽  
Author(s):  
Yongsuk Seo ◽  
Travis DiLeo ◽  
Jeffrey B. Powell ◽  
Jung-Hyun Kim ◽  
Raymond J. Roberge ◽  
...  
Keyword(s):  
Heat Stress ◽  
Body Temperature ◽  
Rectal Temperature ◽  
Core Body Temperature ◽  
Stress Conditions ◽  
Core Body

scholarly journals Genetic effects of season on the preweaning growth of beef cattle: A first approach to Retinta calves

2019 ◽  
Vol 33 (2) ◽  
pp. 134-143
Author(s):  
Rosa M Morales ◽  
Alberto Menéndez-Buxadera ◽  
Sebastián Demyda-Peyrás ◽  
Antonio Molina
Keyword(s):  
Heat Stress ◽  
Growth Traits ◽  
Climatic Factors ◽  
Methodological Approach ◽  
Warm Season ◽  
Cattle Breed ◽  
Live Weight ◽  
Reaction Norm ◽  
Random Regression ◽  
Economic Losses

Background: Heat stress derived from global warming is causing major economic losses in the livestock industry. Objective: To develop a novel methodological approach for determining the influence of climatic factors on the estimation of genetic parameters for growth traits in Retinta cattle breed by using reaction-norm models. Methods: Live weight records (n=7,753) from 3,162 Retinta calves born from 1,249 dams and 85 sires and raised in the Andalusian region (Spain) were analyzed. The effect of heat stress was measured using the temperature-humidity index, calculated with climatological data obtained from four weather stations. A bivariate-random-regression reaction-norm model was used to estimate the (co)variance components of weight until weaning in two different climatic seasons corresponding to warm and cold months. Results: The heritability pattern of individuals reared under diverse environments during the first 90 days of age was different. However, differences were not significant at the end of the growing period. Weaned calves reared during the cold season showed greater growth from 70 to 160 days in comparison with those reared during the warm season. Conclusions: Highly significant evidence of genotype-climatic condition interaction was found during the calf´s first three months of growth.

PSV-16 Effects of the Inclusion of a Capsicum Oleoresin-based Additive on Growth Performance, Carcass Composition and Meat Quality of Pigs Under Heat Stress Conditions

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 190-190
Author(s):  
Gemma Tedo ◽  
Alba Cerisuelo ◽  
Benjamin Bass ◽  
Clemente Lopez ◽  
Luis Calvo
Keyword(s):  
Heat Stress ◽  
Growth Performance ◽  
Meat Quality ◽  
Repeated Measures ◽  
Quality Parameters ◽  
Carcass Composition ◽  
Stress Conditions ◽  
Environmental Data ◽  
Control Group ◽  
Post Mortem

Abstract Capsicum oleoresin has recognized effects on digestion and fat metabolism. A total of 100 PIC x Danbred female pigs were divided in two experimental groups (10 pens/group) from 60Kg body weight (BW) to slaughter: one control group (T1) and another group (T2) where the sensorial additive (350ppm) was added from 90Kg to 130Kg BW. The study was carried out in Mediterranean summer conditions. Experimental rooms turned off their cooling systems at 90Kg BW to the end of the study. Temperature and humidity were recorded using dataloggers (HOBO®). Pig BW and intake were recorded before exposure to the additive and at the end of the administration of experimental feeds. Additionally, backfat thickness (BF) and loin depth (LD) were measured. Respiration rate (RR) and rectal temperature (RT) were also recorded at 0800, 1100, 1400 and 1700h. Carcass and meat quality parameters were measured in the slaughterhouse. Data was analyzed using Proc GLM (performance, carcass and meat quality) and Proc MIXED of repeated measures (RR, RT) of SAS. Environmental data confirmed heat stress conditions for finishing pigs (THI >71 from 0800 to 2200h). Growth performance, BF and LD did not differ between groups. Animals from T2 showed higher (P< 0.05) RR and lower (P< 0.05) RT compared to T1 at 17:00h. At slaughter, animals from T2 tended (P< 0.10) to have a higher fat content (3-4th rib level and ham) compared to T1. Ham pH at 25min and at 20h post-mortem, and drip losses at 48h post-mortem were lower (P< 0.05) in T2 group vs. T1. Concerning the fatty acid profile, the T2 showed a greater concentration of C18:1 and C20:1 compared to T1. In conclusion, the addition of the sensorial additive at the end of the growing period changed carcass composition and quality traits under heat stress conditions.

Effects of Aging on the Subcortical Encoding of Stop Consonants

2020 ◽  
Vol 29 (3) ◽  
pp. 391-403
Author(s):  
Dania Rishiq ◽  
Ashley Harkrider ◽  
Cary Springer ◽  
Mark Hedrick
Keyword(s):  
Older Adults ◽  
Repeated Measures ◽  
Mixed Model ◽  
Auditory Brainstem ◽  
Auditory Brainstem Responses ◽  
Aging Effects ◽  
Formant Frequency ◽  
Place Of Articulation ◽  
Second Formant ◽  
Effects Of Aging

Purpose The main purpose of this study was to evaluate aging effects on the predominantly subcortical (brainstem) encoding of the second-formant frequency transition, an essential acoustic cue for perceiving place of articulation. Method Synthetic consonant–vowel syllables varying in second-formant onset frequency (i.e., /ba/, /da/, and /ga/ stimuli) were used to elicit speech-evoked auditory brainstem responses (speech-ABRs) in 16 young adults ( M age = 21 years) and 11 older adults ( M age = 59 years). Repeated-measures mixed-model analyses of variance were performed on the latencies and amplitudes of the speech-ABR peaks. Fixed factors were phoneme (repeated measures on three levels: /b/ vs. /d/ vs. /g/) and age (two levels: young vs. older). Results Speech-ABR differences were observed between the two groups (young vs. older adults). Specifically, older listeners showed generalized amplitude reductions for onset and major peaks. Significant Phoneme × Group interactions were not observed. Conclusions Results showed aging effects in speech-ABR amplitudes that may reflect diminished subcortical encoding of consonants in older listeners. These aging effects were not phoneme dependent as observed using the statistical methods of this study.

Power of Modified Brown-Forsythe and Mixed-Model Approaches in Split-Plot Designs

Methodology ◽  
2017 ◽  
Vol 13 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Pablo Livacic-Rojas ◽  
Guillermo Vallejo ◽  
Paula Fernández ◽  
Ellián Tuero-Herrero
Keyword(s):  
Repeated Measures ◽  
Statistical Power ◽  
Mixed Model ◽  
Covariance Structure ◽  
Simulation Method ◽  
Future Research ◽  
Repeated Measures Design ◽  
Fixed And Random Effects ◽  
Split Plot ◽  
High Level

Abstract. Low precision of the inferences of data analyzed with univariate or multivariate models of the Analysis of Variance (ANOVA) in repeated-measures design is associated to the absence of normality distribution of data, nonspherical covariance structures and free variation of the variance and covariance, the lack of knowledge of the error structure underlying the data, and the wrong choice of covariance structure from different selectors. In this study, levels of statistical power presented the Modified Brown Forsythe (MBF) and two procedures with the Mixed-Model Approaches (the Akaike’s Criterion, the Correctly Identified Model [CIM]) are compared. The data were analyzed using Monte Carlo simulation method with the statistical package SAS 9.2, a split-plot design, and considering six manipulated variables. The results show that the procedures exhibit high statistical power levels for within and interactional effects, and moderate and low levels for the between-groups effects under the different conditions analyzed. For the latter, only the Modified Brown Forsythe shows high level of power mainly for groups with 30 cases and Unstructured (UN) and Autoregressive Heterogeneity (ARH) matrices. For this reason, we recommend using this procedure since it exhibits higher levels of power for all effects and does not require a matrix type that underlies the structure of the data. Future research needs to be done in order to compare the power with corrected selectors using single-level and multilevel designs for fixed and random effects.

Long-term seizure outcomes after pediatric temporal lobectomy: does brain MRI lesion matter?

2019 ◽  
Vol 24 (2) ◽  
pp. 200-208
Author(s):  
Ravindra Arya ◽  
Francesco T. Mangano ◽  
Paul S. Horn ◽  
Sabrina K. Kaul ◽  
Serena K. Kaul ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Hippocampal Sclerosis ◽  
Brain Mri ◽  
Temporal Lobectomy ◽  
Seizure Freedom ◽  
Seizure Onset

OBJECTIVEThere is emerging data that adults with temporal lobe epilepsy (TLE) without a discrete lesion on brain MRI have surgical outcomes comparable to those with hippocampal sclerosis (HS). However, pediatric TLE is different from its adult counterpart. In this study, the authors investigated if the presence of a potentially epileptogenic lesion on presurgical brain MRI influences the long-term seizure outcomes after pediatric temporal lobectomy.METHODSChildren who underwent temporal lobectomy between 2007 and 2015 and had at least 1 year of seizure outcomes data were identified. These were classified into lesional and MRI-negative groups based on whether an epilepsy-protocol brain MRI showed a lesion sufficiently specific to guide surgical decisions. These patients were also categorized into pure TLE and temporal plus epilepsies based on the neurophysiological localization of the seizure-onset zone. Seizure outcomes at each follow-up visit were incorporated into a repeated-measures generalized linear mixed model (GLMM) with MRI status as a grouping variable. Clinical variables were incorporated into GLMM as covariates.RESULTSOne hundred nine patients (44 females) were included, aged 5 to 21 years, and were classified as lesional (73%), MRI negative (27%), pure TLE (56%), and temporal plus (44%). After a mean follow-up of 3.2 years (range 1.2–8.8 years), 66% of the patients were seizure free for ≥ 1 year at last follow-up. GLMM analysis revealed that lesional patients were more likely to be seizure free over the long term compared to MRI-negative patients for the overall cohort (OR 2.58, p < 0.0001) and for temporal plus epilepsies (OR 1.85, p = 0.0052). The effect of MRI lesion was not significant for pure TLE (OR 2.64, p = 0.0635). Concordance of ictal electroencephalography (OR 3.46, p < 0.0001), magnetoencephalography (OR 4.26, p < 0.0001), and later age of seizure onset (OR 1.05, p = 0.0091) were associated with a higher likelihood of seizure freedom. The most common histological findings included cortical dysplasia types 1B and 2A, HS (40% with dual pathology), and tuberous sclerosis.CONCLUSIONSA lesion on presurgical brain MRI is an important determinant of long-term seizure freedom after pediatric temporal lobectomy. Pediatric TLE is heterogeneous regarding etiologies and organization of seizure-onset zones with many patients qualifying for temporal plus nosology. The presence of an MRI lesion determined seizure outcomes in patients with temporal plus epilepsies. However, pure TLE had comparable surgical seizure outcomes for lesional and MRI-negative groups.

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