Limits...
Infrared Thermography to Evaluate Heat Tolerance in Different Genetic Groups of Lambs.

McManus C, Bianchini E, Paim Tdo P, de Lima FG, Neto JB, Castanheira M, Esteves GI, Cardoso CC, Dalcin VC - Sensors (Basel) (2015)

Bottom Line: Heat stress is considered a limiting factor for sheep production.Forty-eight four-month-old male lambs from eight genetic groups were used.Statistical analyses included variance, correlations, factor, discrimination and regression.

View Article: PubMed Central - PubMed

Affiliation: Faculdade de Agronomia e Medicina Veterinária, Universidade de Brasília, Brasília 70910-900, DF, Brasil. concepta.mcmanus@ufrgs.br.

ABSTRACT
Heat stress is considered a limiting factor for sheep production. We used information from physiological characteristics linked to heat tolerance to determine whether infrared thermography temperatures were able to separate groups of animals and determine the most important variables in this differentiation. Forty-eight four-month-old male lambs from eight genetic groups were used. Physiological (rectal temperature-RT, heart rate-HR, respiratory rate-RR) and blood traits, infrared thermography temperatures, heat tolerance indices, body measurements, weight and carcass traits were measured. Statistical analyses included variance, correlations, factor, discrimination and regression. Observing the correlations between physiological characteristics (RT, RR and HR) with temperatures measured by infrared thermography, regions for further studies should include the mean temperature of flank, nose and rump. Results show that there are strong relationships between thermograph measurements and RR, RT and HR in lambs, which are suggested to be directly correlated with heat tolerance capacity of the different genetic groups evaluated in this study. The assessment of body surface temperature measured by the thermograph could be used as a noninvasive tool to assess heat tolerance of the animals.

No MeSH data available.


Related in: MedlinePlus

Cluster analysis of variables in the morning (A) and afternoon; (B) based on thermograph and physiological measures in lambs during the morning (A) and afternoon; (B) 1: EFSI; 2: PRSI; 3: 87PDSI; 4: SI; 5: DOPD; 6: PDSI; 7: WDPD; 8: 75PDSI.
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sensors-15-17258-f004: Cluster analysis of variables in the morning (A) and afternoon; (B) based on thermograph and physiological measures in lambs during the morning (A) and afternoon; (B) 1: EFSI; 2: PRSI; 3: 87PDSI; 4: SI; 5: DOPD; 6: PDSI; 7: WDPD; 8: 75PDSI.

Mentions: The cluster analysis, in the morning, indicated that the SI, PDSI and 75PDSI genetic groups were closely related in terms of response to the environment. All groups contained PD or SI genotypes (Figure 4). The PRSI differentiate from other genetic groups in the morning and afternoon, which is probably related to results obtained in adaptability tests (RY and Ibéria), infrared temperature and rectal temperature in the afternoon, that demonstrate a better adaptation of this group to heat stress.


Infrared Thermography to Evaluate Heat Tolerance in Different Genetic Groups of Lambs.

McManus C, Bianchini E, Paim Tdo P, de Lima FG, Neto JB, Castanheira M, Esteves GI, Cardoso CC, Dalcin VC - Sensors (Basel) (2015)

Cluster analysis of variables in the morning (A) and afternoon; (B) based on thermograph and physiological measures in lambs during the morning (A) and afternoon; (B) 1: EFSI; 2: PRSI; 3: 87PDSI; 4: SI; 5: DOPD; 6: PDSI; 7: WDPD; 8: 75PDSI.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541933&req=5

sensors-15-17258-f004: Cluster analysis of variables in the morning (A) and afternoon; (B) based on thermograph and physiological measures in lambs during the morning (A) and afternoon; (B) 1: EFSI; 2: PRSI; 3: 87PDSI; 4: SI; 5: DOPD; 6: PDSI; 7: WDPD; 8: 75PDSI.
Mentions: The cluster analysis, in the morning, indicated that the SI, PDSI and 75PDSI genetic groups were closely related in terms of response to the environment. All groups contained PD or SI genotypes (Figure 4). The PRSI differentiate from other genetic groups in the morning and afternoon, which is probably related to results obtained in adaptability tests (RY and Ibéria), infrared temperature and rectal temperature in the afternoon, that demonstrate a better adaptation of this group to heat stress.

Bottom Line: Heat stress is considered a limiting factor for sheep production.Forty-eight four-month-old male lambs from eight genetic groups were used.Statistical analyses included variance, correlations, factor, discrimination and regression.

View Article: PubMed Central - PubMed

Affiliation: Faculdade de Agronomia e Medicina Veterinária, Universidade de Brasília, Brasília 70910-900, DF, Brasil. concepta.mcmanus@ufrgs.br.

ABSTRACT
Heat stress is considered a limiting factor for sheep production. We used information from physiological characteristics linked to heat tolerance to determine whether infrared thermography temperatures were able to separate groups of animals and determine the most important variables in this differentiation. Forty-eight four-month-old male lambs from eight genetic groups were used. Physiological (rectal temperature-RT, heart rate-HR, respiratory rate-RR) and blood traits, infrared thermography temperatures, heat tolerance indices, body measurements, weight and carcass traits were measured. Statistical analyses included variance, correlations, factor, discrimination and regression. Observing the correlations between physiological characteristics (RT, RR and HR) with temperatures measured by infrared thermography, regions for further studies should include the mean temperature of flank, nose and rump. Results show that there are strong relationships between thermograph measurements and RR, RT and HR in lambs, which are suggested to be directly correlated with heat tolerance capacity of the different genetic groups evaluated in this study. The assessment of body surface temperature measured by the thermograph could be used as a noninvasive tool to assess heat tolerance of the animals.

No MeSH data available.


Related in: MedlinePlus