Banca de DEFESA: HENRIQUE SONDA GALLINA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : HENRIQUE SONDA GALLINA
DATE: 29/11/2021
TIME: 13:30
LOCAL: Web Conferência - Google Meet - meet.google.com/vvi-wdsa-dod.
TITLE:

Productive and welfare effects in beak-trimmed hens: a systematic review-meta-analysis.

KEY WORDS:

Pecking, corticosterone, mortality, laying hens, egg production.

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

Currently, the animal protein consumer market is more demanding with the management practices that are adopted during the production cycle. The practice of beak trimming is common in the rearing of laying hens and consists of removing the lower and upper part of the beak and can be applied through different methods such as cutting and cauterization by hot blade or by infrared radiation. Despite bringing benefits from the productive point of view, beak trimming subjects the birds to stress, questioning welfare practices. Therefore, the objective of this study was to perform a systematic review (SR) and meta-analysis (MA) through the available data in the literature of the forms of beak trimming and their effects on mortality, egg production, feather pecking, and corticosterone levels. The search strategy was applied to three electronic databases - Scopus (Elsevier), MEDLINE/PubMed and Web of Science (Clarivate Analytics) and the inclusion criteria involved studies that evaluated the population (chicken, bird, layer, chick), the intervention (beak, cut) and the response (mortality, pecking, production, corticosterone). The literature search identified 1,775 publications, and 16 studies, reporting 19 trials on mortality, 20 on egg production, 6 on feather pecking, and 6 on corticosterone levels were considered eligible for the final SR and included in the MA. The total number of birds evaluated was 4,133, 3,642, 1,330, and 124 for mortality, egg production, feather pecking, and corticosterone levels, respectively. Birds subjected to hot blade beak trimming, regardless of the millimeters trimmed, showed higher mortality compared to birds in the control group without beak trimming (p= 0.054) with a high heterogeneity between studies (I2= 95.07%; 95%CI; 0.16 to 1.01). When combining the use of hot blade and infrared radiation at different ages, it increases the prediction of death by 4.3 compared to intervention with hot blade alone. The increase of one unit in the age of beak trimming increases the predicted value in egg production at a level of 0.99. No association between egg production and corticosterone levels was observed with beak trimming. Thus, we conclude that in the studies evaluated, beak trimming caused higher mortality and did not influence egg production and corticosterone levels compared to the control group with intact beak.

BANKING MEMBERS:
Externa à Instituição - IANÊ CORREIA DE LIMA ALMEIDA
Externo ao Programa - 1849719 - JUAHIL MARTINS DE OLIVEIRA JUNIOR
Presidente - 1085177 - VANESSA PERIPOLLI