Breed, transport and lairage effects on animal welfare and quality of Namibian beef

[摘要] ENGLISH ABSTRACT: Namibia by nature is very well suited for livestock production and is a net exporter of beef. Beef is currentlyexported to South Africa, the European Union (EU) and Japan while market access to the United States ofAmerica is being explored. Food safety, traceability and lately animal welfare are all aspects which arerequested by Namibians trading partners when exporting meat to those countries. The first two aspects havebeen addressed with the introduction of the Farm Assured Namibian Beef scheme (FAN Meat) which alsoprovides basic guidelines for animal welfare.Beef in Namibia is produced from extensively managed enterprises which are privately owned andmanaged, or state owned and communally utilized. The events of handling and transport are consideredstressful to all animals but especially so to extensively raised animals and their reaction to these events hasthe potential to severely infringe on their welfare. The aim of this study was to determine the effect of pre-,during, and post-transportation handling on animal welfare status under Namibian transport conditions. Thestudy also investigated the influence of breed on the meat quality of Namibian beef.The level of bruising recorded on slaughter was used to measure animal welfare. Interviews withproducers were conducted to describe the pre-transport handling. Questionnaires that included variablesconsidered as important indicators of animal welfare during transport were distributed to truck drivers.Observations of the off-loading event and animal behaviour were completed in lairage at the export abattoirin Windhoek. The variables that were identified as high risk factors and had a significant influence on thelevel of bruising under Namibian transport conditions include animal factors (i.e. breed type, age, sex,condition and subcutaneous fat cover), pre-transport handling (i.e. re-branding of animals), transport relatedrisks (loading density and animals lying down during transit) as well as lairage factors (i.e. fit of truck floor tooff-loading ramp, the way animals moved to holding pens, pen size and minimum environmentaltemperatures).The influence of breed on meat tenderness and water-holding capacity of the Longissimus dorsimuscle of the four main beef breeds (i.e. Brahman, Bonsmara, Simbrah and Simmental), as well as theeffect of different aging periods on meat quality (i.e. 2, 9, 16, 23, 30 & 37 days post mortem) wereinvestigated. The Brahman differed significantly (p < 0.05) from the other three breeds in terms of all agingtreatments; with higher Warner-Bratzler shear force values reported for this breed. Interactions between dayspost mortem and breed were found for the Simbrah, and Simmental breeds, which may be indicative of adelayed response to aging of meat samples obtained from Simbrah animals. This can possibly be ascribedto an increased calpastatin activity in these animals. Meat samples obtained from the Bonsmara steersshowed the highest rate of tenderization, with this effect retained until day 30 post mortem.Recommendations as pertaining to the ante mortem handling of cattle are made.

[发布机构] Stellenbosch University