Pre-mortem conditions and pork quality

Cilj istraživanja u okviru ove doktorske disertacije bio je da se ispita uticaj uslova sredine i postupaka sa svinjama na farmi, tokom transporta, istovara i boravka u depou na kvalitet mesa svinja. Takođe, cilj je bio i da se utvrdi međusobna povezanost između prisustva i stepena patoloških promena na organima svinja i kvaliteta mesa. Genotipizacijom svinja za polimorfizam u Ryanodine receptor (RYR-1) genu, kod 63,75% jedinki je utvrđen NN genotip, kod 36,25% Nn genotip, dok ni kod jedne jedinke nije utvrđen nn genotip. Svinje Nn genotipa su imale veću debljinu dugačkog leđnog mišića i veću mesnatost u poređenju sa svinjama NN genotipa. Kod svinja Nn genotipa je utvrđena veća koncentracija laktata u krvi, niža pH vrednost mesa, veća L* i manja a* vrednost instrumentalno određene boje. Svinje Nn genotipa imale su veći gubitak tečnosti tokom ceđenja i kuvanja, veći procenat bledog, mekog i vodnjikavog (BMV) i crvenog, mekog i vodnjikavog (CMV) mesa, a manji procenat bledog, čvrstog i nevodnjikavog (BČN) i crvenog, čvrstog i nevodnjikavog (CČN) mesa u odnosu na svinje NN genotipa. Sa povećanjem telesne mase svinja došlo je do povećanja mase toplog i hladnog trupa, učestalosti povreda na trupu i debljine leđne slanine, a smanjenja mesnatosti. Svinje telesne mase preko 130 kg imale su manju L* vrednost instrumentalno određene boje mesa i gubitak tečnosti tokom kuvanja, a veću a* vrednost instrumentalno određene boje mesa, veću mramoriranost i procenat CČN mesa nego svinje telesne mase oko 100 kg i 115 kg. Nazimice su imale manju telesnu masu, masu toplog i hladnog trupa i debljinu leđne slanine, a veću mesnatost u poređenju sa kastratima. Nije utvrđena značajna razlika između nazimica i kastrata u biohemijskim pokazateljima stresa i kvalitetu mesa, izuzev u mramoriranosti, koja je bila značajno veća kod kastrata. Svinje zaklane u zimskim mesecima imale su najslabiji kvalitet trupa, odnosno, najveću telesnu masu i masu trupa, uz svinje zaklane u jesenjem periodu i najmanju mesnatost. Sa druge strane, svinje zaklane u letnjoj sezoni imale su najbolji kvalitet trupa, tj. najmanju debljinu leđne slanine i najveći procenat mesa u trupovima. Najslabiji kvalitet mesa utvrđen je kod svinja zaklanih u letnjoj (najveći procenat BMV mesa) i zimskoj (najveći procenat CMV mesa) sezoni, dok je najbolji kvalitet mesa dobijen klanjem svinja u jesen (najveći procenat CČN mesa, a najmanji BMV mesa)...The aim of this study was to determine the effects of environmental conditions and procedures on the farm, during transportation, unloading and lairaging on pork quality. In addition, the aim was to determine the association between the presence and the degree of pathological lesions in organs and meat quality of slaughtered pigs. Of the 240 pigs, 63,75% contained the normal RYR-1 genotype (NN genotype), 36,25% contained stress-susceptible n allele (Nn genotype), while none of the animals had a double recessive RYR-1 genotype (nn genotype). Nn pigs had higher loin thickness and meatiness compared to NN pigs. Also, Nn pigs had higher blood lactate level, lower pH value and higher drip and cooking loss. Furthermore, meat obtained from Nn pigs had higher lightness (L* value) and lower redness (a* value), as well as higher incidence of pale, soft and exsudative (PSE) and red, soft and exsudative (RSE) meat, but lower percentage of pale, firm and non-exudative (PFN) and red, firm and non-exudative (RFN) meat than NN pigs. The increase in slaughter weight resulted in the increased hot carcass and cold carcass weights, backfat thickness and number of skin lesions on the carcass, but decreased meatiness. Pigs heavier than 130 kg had lower lightness (L* value) and cooking loss, but higher redness (a* value), marbling score and the prevalence of RFN meat compared to pigs with a body weight of 100 kg and 115 kg. Gilts had lower live weight, hot and cold carcass weights, backfat thickness and higher meatiness compared to barrows. Gender did not affect biochemical stress indicators and meat quality parameters, except marbling, which was higher in barrows than in gilts. Pigs slaughtered in winter had the highest live weight, hot and cold carcass weights. In addition, pigs slaughtered in winter and autumn had less carcass meat than those slaughtered in all other seasons. On the other hand, the pigs slaughtered in summer had the lowest backfat thickness and the highest meatiness. The lowest pork quality was obtained from pigs slaughtered in summer (the highest prevalence of PSE meat) and winter (the highest prevalence of RSE meat), while the pigs slaughtered in autumn produced the highest meat quality (the highest prevalence of RFN meat and the lowest prevalence of PSE meat..