Title: Short distance transport of fattening pigs. Influences and influencing: welfare and meat quality
Other Titles: Korte afstandstransporten van vleesvarkens. Invloeden en beïnvloeding: dierenwelzijn en vleeskwaliteit
Authors: Driessen, Bert
Issue Date: 23-Jun-2015
Abstract: Transport, marked by intensive handling of live animals, is a crucial step in the animal production process, involving many different operators (farmers, transporters and slaughterhouses), possibly affecting the environment, animal health, animal welfare, product (meat) quality and the spread of animal diseases. During the past decades consumers have become more and more concerned about factors such as ethical animal production and animal welfare. This does not only include animal housing aspects but also,nbsp;even more, the transport of animals. Because more consumers are faced with road transport. So, there is a social demand to monitor and improve animal welfare during the transportnbsp;In addition, consumers are interested in high quality meat which is influenced by stress and welfare during the last day before slaughter. The aim of this thesis was to study the influences of housing, transport and slaughterhouse aspects on skin lesions and meat quality. Furthermore, some possible aspects to optimise welfare and meat quality were investigated.
The purpose of the study in chapter 2 was to determine (the variation of) effects of farm management, climate parameters, transport and lairage conditions on meat quality of fattening pigs, heterozygous for the halothane gene. A total of 4,763 fattening pigs were transported from the Zootechnical Centre (Belgium) to a commercial slaughterhouse (distance 110 km) in 121 transports through 5 years. From 2,404 carcasses, carcass temperature and pH were measured 45 min post-mortem; 48 h post-mortem pH, electrical conductivity, drip loss and meat colour were registered. During the raising period gender, conditions at weaning (purchased or not as piglet, vaccination against Mycoplasma) and (type of) room during fattening (i.e. from about 22 kg to 105 kg) were registered to relate with pork quality. Transport season, weather parameters, regrouping or not during loading, transport combination (truck, trailer and driver), transport compartment and transport conditions (loading density, transport duration and unloading time)nbsp;monitored. At the slaughterhouse, duration of lairage and carcass conformation were followed up to examine correlations with meat quality parameters. In conclusion, effects of farm management, climate parameters during transport, transport and slaughterhouse conditions on pork quality were demonstrated.
In the next chapter, the effects of transport and lairage conditions on skin lesions of carcasses of fattening pigs, heterozygous for the halothane gene, were studied. A total of 4,507 fattening pigs were transported from a farm to a commercial slaughterhouse (distance 110 km) in 111 transports spread over 5 years. Skin lesions were visually assessed in the slaughter line in different parts of the carcass, i.e. shoulder, middle and ham, using a 4-point scale. The incidence of skin lesions was most prevalent (31%) in the shoulder region of the pig carcass. Gender, wind velocity, regrouping, transport combination, transport compartment, lairage time and ham angle affected the skin lesion incidence. In conclusion, scoring the incidence of skin lesions is an indicator of the level of welfare exercised during transport and the slaughterhouse conditions. Furthermore, skin lesion monitoring can be used to determine critical control points in the transport procedure. Given the importance from both a commercial and welfare perspective, it should be a powerful incentive to handle fattening pigs with care duringnbsp;transport process and the lairage period.
In chapter 4 the effect of olfactory substances on the heart rate and lying behaviour of pigs during transport simulation is investigated. Five treatments were tested in which a substance was applied to pigs’ snouts with a paintbrush. These consisted of: 1) control treatment (wiping without product); 2) 2 ml of a synthetic, maternal-like pheromone; 3) 5 ml of a synthetic, maternal-like pheromone; 4) a commercial, non-relevant odour and 5) 2 ml of a placebo (solvent of the synthetic pheromone without active ingredients). In total, 90 pigs took part in this study and each treatment was tested on a group of three pigs with six replicates per treatment. Pigs were vibrated in the vertical direction in a transport simulator with a frequency of 8 Hz and an acceleration of 3 m s–2. Cardiac activity and lying behaviour during vibration were quantified. The effect of vibration was found to be statistically significant, i.e. causing an increase in heart rate and numbers of ventricular ectopic beats (VEB). Both 2 and 5 ml of synthetic pheromone were found to decrease minimum heart rate significantly. However, the number of VEB was highest for these two synthetic pheromone groups during vibration. No dose-dependent synthetic pheromone effects were found and there were no differences in the amount of time pigs spent lying.
In practice, unfamiliar pigs are frequently mixed prior to loading in order to obtain groups of uniform weight and to adjust the group size to the dimensions of the trailer compartments. Mixings pigs induces aggressive interactions to establish a new social rank. Fighting results innbsp;lesions and pre-slaughter stress and on his turn reduced meat quality. A three-year study was performed to compare the effect ofnbsp;and regrouping at fattening, loading and lairage. A total of 1,332 pigs were included over 30 transports from one pig farm to one slaughterhouse (110 km). Skin lesions were determined on 1,314 carcasses. Meat quality was measured on 620 pigs. The temperature and pH in the longissimus dorsi muscle were measured 45 min post-mortem. Forty-eight hours later pH, electrical conductivity, drip loss and the colour of the longissimus dorsi muscle were measured. The non-regrouped treatment showed less skin lesions and better meat quality than the groups regrouped at loading or in lairage. Pigs mixed at 80 kg at the farm have in general a comparable amount of skin lesions and comparable meat quality as the non-mixed group. If mixing is unavoidable, due to large within-group weight variations, mixing at 80 kg can be an alternative to reduce skin lesions at slaughter and to optimise meat quality.
Finally, from previous studies, it appears that the transport of fattening pigs is characterized by a strong human-animal interaction. Consequent handling is important because of animal welfare, meat quality and matching economic consequences. Therefore, chapter 6 presents practical information to ease the handling of fattening pigs. During road transport, human impact can be divided in different steps: 1) driving pigs from the pens via an alley to the trailer, 2) loading, 3) actual transport, 4) unloading to the lairage, and 5) driving pigs in the final stage to the stunning. Inadequate design and poor condition of the facilities will negatively affect the ease of handling. Because of the consequences, acute stress during transport and slaughter should be minimized by improving education of people, equipment and preparation of animals for the journey. Education programmes have to be repeated regularly so that knowledge can be refreshed.
In general, it can be concluded that there are some main effects (see chapter 2 and 3) affecting welfare and meat quality. Initially, animal welfare and meat quality can be optimised by focusing on thesenbsp;effects. Preparing animals with olfactory substances, odours or feed additives has minor effects. After more than 30 years, there is still research going on about the impact of transport on welfare of animals and meat quality. Thereby, the optimization of welfare monitoring and training programmes are important study aspects.
Publication status: published
KU Leuven publication type: TH
Appears in Collections:Bioengineering Technology TC, Technology Campus Geel
Division of Livestock-Nutrition-Quality (-)
Technologiecluster Bioengineering Technologie

Files in This Item:
File Status SizeFormat
PhD-def.versie-BD.pdf Published 1637KbAdobe PDFView/Open Request a copy

These files are only available to some KU Leuven Association staff members


All items in Lirias are protected by copyright, with all rights reserved.