Banca de DEFESA: LUCIANO ARAUJO AZEVEDO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : LUCIANO ARAUJO AZEVEDO
DATE: 10/12/2021
TIME: 14:00
LOCAL: Web Conferência - Google Meet - https://meet.google.com/bjb-qhmv-gtf?hs=224
TITLE:

Effects of using mitigation strategies on performance and physiological parameters of beef cattle finished in feedlot under heat stress: systematic review and meta-analyses.

KEY WORDS:

consumption, conversion efficiency, respiration rate, shade, sprinkler, weight gain.

PAGES: 45
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUMMARY:

The heat stress resulting from high temperature and humidity is a great challenge for the farms and for the beef cattle industry, resulting in large annual losses to the sector. Aiming to determine the influence of mitigation strategies on performance and physiological parameters in beef cattle finished in feedlot under heat stress, a systematic review (SR) and meta-analysis (MA) was carried out from primary studies, where 31 articles were included in the MA, after assessing the risk of publication bias. The search was carried out in three electronic databases - Scopus (Elsevier), MEDLINE/PubMed and Web of Science (Clarivate Analytics). Cattle that were subjected to some mitigation strategy showed a higher weight gain than cattle in the control group (p = 0.0001), with a mean difference of - 0.094 Kg and a high heterogeneity between studies (I² = 99.16%; CI95%: -0.141 to 0.047). In addition, cattle that underwent some mitigation strategy had a lower respiratory rate than cattle in the control group (p = 0.000), with a mean difference of 7.627 movements per minute (Mpm) and a high heterogeneity between studies (I²= 99.37%; CI95%: 6.132 to 9.122). Shaded cattle showed greater weight gain, higher conversion efficiency and lower respiratory rate compared to unshaded cattle (p= 0.000; p= 0.001; p= 0.000, respectively). Cattle finished in THI_LCI NORMAL had a higher consumption compared to bovines finished in THI_LCI ALERT, DANGER and EMERGENCY (p=0.035; p=0.013; p=0.004, respectively). The weight gain of bovines finished in THI_LCI NORMAL was higher than the weight gain of bovines finished in THI_LCI ALERT and DANGER (p=0.034; p=0.013, respectively). Shade, sprinkler and ventilation mitigation strategies improved weight gain and respiratory rate in beef cattle finished in feedlot under heat stress. Unshaded cattle showed lower weight gain, lower conversion efficiency and higher respiratory rate. Artificial shade improved weight gain, conversion efficiency and respiratory rate compared to non-shade cattle. The materials used for shade, in general, improve the weight gain, the conversion efficiency and the respiratory frequency of beef cattle finished in feedlot under heat stress.

BANKING MEMBERS:
Externo à Instituição - DANIELE ZAGO - UFRGS
Interno - 1760760 - CARLOS EDUARDO NOGUEIRA MARTINS
Presidente - 1046884 - ELIZABETH SCHWEGLER