Effects of RYR1 gene mutation on the health, welfare, carcass and meat quality in slaughter pigs

Abstract

This study assessed the effects of RYR1 mutation on the health, welfare, and carcass and meat quality in slaughter pigs. Any signs of pneumonia, pleurisy, pericarditis, and liver milk spots were recorded as present or absent. At exsanguination, blood samples were collected and RYR1 genotype, blood lactate and glucose concentrations were determined. The following carcass quality traits were measured: live, hot and cold carcass weights, backfat thickness, loin muscle thickness, lean meat content and skin lesion score. pH and temperature of M. longissimus dorsi and M. semimembranosus were measured 45 minutes postmortem. Nn pigs were more affected by pneumonia, had higher blood lactate and glucose concentrations and more developed rigor mortis than NN pigs. NN pigs had lower daily weight gain, produced lighter carcasses, more fat and less meat than Nn pigs. Meat obtained from Nn pigs was of a lower quality class than meat obtained from NN pigs, as shown by the lower pH and higher temperatures measured 45 minutes post mortem in both muscles and higher prevalence of pale, soft and exudative meat. In conclusion, the presence of a mutant n allele in pigs positively affected carcass quality traits, but had a deleterious effect on health, welfare and meat quality.

Prevalence of carcass lesions and their effects on welfare, carcass composition and meat quality in slaughtered pigs

“…In the present study, higher frequencies of severe carcass lesions and lesions on the anterior and middle carcass parts were recorded in NN pigs. This could be connected with the fact that stress resistant pigs show less anxiety, higher levels of activity and pronounced exploratory behaviour, which leads to contacts with other pigs within the batch and provokes aggressive and fighting behaviour (Čobanović et al, 2019;Guàrdia et al, 2009). On the contrary, stress-carrier pigs are more fearful and less prone to explore, and, thus, infrequently come into confrontation with other conspecifics (Čobanović et al, 2019;Guàrdia et al, 2009).…”

Identifying Physiological Stress Biomarkers for Prediction of Pork Quality Variation

“…Although the prevalence of the stress-susceptible n allele in pigs was not evaluated in this study, more than a third of the examined slaughter pigs (36.25%) were heterozygous (Nn genotype) in the ryanodine receptor (RYR1) gene (unpublished data). Genetic selection of pigs for improved meatiness has led to increased numbers of white muscle fibers that are extremely rich in glycogen, which resulted in two to three times higher muscle glycogen content in stress-carrier pigs (Nn genotype) than in stress-resistant pigs (NN genotype) [32,42]. This can explain a greater potential for accumulating lactate and glucose in the circulation of pigs with a higher percentage of meat [10,11].…”

“…This formula is valid for hot carcasses weighing between 60 kg and 120 kg. The numbers of skin lesions on the left side of the carcasses were counted by two trained observers in the chilling room 45 min postmortem using the Welfare Quality ® (Lelystad, The Netherlands) protocol [31], as described inČobanović et al [32].…”

“…Angle size and rigor intensity are inversely proportional (i.e., a smaller angle means a higher degree of rigor mortis). Subjective assessments of the rigor development were made 45 min postmortem on the Musculus semimembranosus in the split carcass using a three-point scale according toČobanović et al [32]: (1) muscle not in rigor; (2) muscle partly in rigor; and (3) muscle in full rigor. Semimembranosus muscle is normally exposed on the carcass medial surface and can be assessed by gauging its surface firmness using finger pressure, whereby in a muscle not in rigor the surface feels soft, while a muscle in rigor feels quite firm.…”

Thermoregulation mechanisms and perspectives for validating thermal windows in pigs with hypothermia and hyperthermia: An overview

“…The dysfunction of calcium channels in skeletal muscle cells caused by mutations of the RYR1 gene produces a high concentration of intraplasmatic calcium because the Ca 2+ - releasing channels anchored to the membrane of the endoplasmic reticulum stay open ( 99 ). This disorder has become more rare due to the extensive removal of carriers of this gene mutation ( 100 – 102 ); the environment and the facilities where the animals are kept continue to be a factor in the development of disrupted thermal states.…”