Feed fasting pre-slaughter of feedlot-finished cattle: hygienic and safety evaluation, animal welfare, post-mortem energetic metabolism and meat quality

• Grant number: 15/02208-3
• Support Opportunities: Regular Research Grants
• Start date: November 01, 2015
• End date: October 31, 2017
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Products of Animal Origin Inspection
• Principal Investigator: Roberto de Oliveira Roça
• Grantee: Roberto de Oliveira Roça
• Host Institution: Faculdade de Ciências Agronômicas (FCA). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Associated researchers: Carla Maris Machado Bittar ; Carlos Adam Conte Junior ; João Pessoa Araújo Junior ; Ricardo Seiti Yamatogi

Abstract

This project aims to investigate the most suitable pre-slaughter feed fasting period for cattle (Bos indicus) finished in feedlot and submitted to short journey transportation considering veterinary hygiene and public health aspects (Study 01) as well as animal welfare and meat quality (Study 02). The project will consist of four slaughter of 45 cattle randomly divided into three treatments: 6 hours, 12 hours and 24 hours of pre-slaughter fasting, 15 animals in each. Two slaughter will be carried out jointly Studies 01 and 02, and the other two slaughter only Study 01. The selection criteria for the four Bos indicus cattle lots will be, predominantly Nelore, male, uncastrated, up to four permanent teeth, weight range between 480 and 540 kg and from the same pen (lot) of confinement. In Study 01, variations in the concentration of hygienic-sanitary indicators and pathogens excreted in feces, environmental contamination (transport and lairage), as well as the hygienic and sanitary condition of the skin and the carcass by effect of feed fasting pre-slaughter time will be checked by occurrences and counts of mesophilic aerobic bacteria and Escherichia coli, and the occurrence of Salmonella spp. and E. coli STEC. In Study 02, the possible relationship between animal welfare and the feed fasting pre-slaughter time will be investigated by blood parameters related to stress, dehydration and animal energy balance, measured before loading and during bleeding in the slaughter establishment. Only with serum cortisol also evaluated before the fasting and after unloading. Possible variations in energy metabolism will be investigated by monitoring the pH, temperature and glycolytic potential of Musculus longissimus thoracis during cooling of the carcasses. The potential effect on meat quality (color, exudation, tenderness) will be investigated in M. longissimus thoracis cuts. The data will be submitted to normality tests and homoscedasticity to adapt the analysis of variance and multiple comparison test at 5% probability. Logistic regression model and Goodman test will be used to estimate the chances of isolation of enteric pathogens among groups. We hope to get technical and scientific subsidy to show the feed fasting pre-slaughter period most suitable for the production scenario evaluated, with the possibility to help in the updating of cattle slaughter regulations from Brazil. In addition to, enabling greater profitability for the farmer and the industry, reducing the production cost, which added to the increase in product quality and encouraging the rational production, will result in stimulating consumption. (AU)