Phenotypic and genetic analysis of carcass quality traits in pigs

Abstract

The study of genetic quality traits included 284 randomly selected pig carcasses, derived from Landrace (96), Yorkshire (92) and Hampshire (96). Carcasses dissection was carried out by the model of EU 1992. With the average pig weight of 103 kg, the highest percentage of muscle with the smallest proportion of fat tissue was found in the neck (72.48 or 11.43%), all pig breeds, while in the abdominal rib part there was determined most fat tissue (36.19%), and the least muscle tissue was found in the back (55.94%). Also, the largest proportion of bones was found in the back and neck (15.82 or 15.64%) and lowest in the shoulder (9.92%). The largest share of muscle tissue was determined in the ham, followed by shoulder, abdominal rib part, back and finally neck. Most fat tissue was found in the ham, followed by abdominal rib part of the rib, back, shoulder and neck. The share of bones is greatest in the back and ham, followed by abdominal rib part, and shoulder and neck. Comparing the proportion of muscle tissue in the carcasses within the breeds, no statistically significant differences in the percentage of meat between two fertile breeds (Landrace and Yorkshire) was found, while there was statistically significant difference between the two fertile breeds and terminal Hampshire breed. On the other hand the influence of breed was highly significant on share of bones in the carcass, muscle tissue in the neck, bones in the ham, muscle tissue and bones in the abdominal rib part and shoulder, while it was of no importance on the share of fat tissue in the back, fat tissue and bones in the neck, muscle tissue in the ham, fat tissue in the abdominal rib part and shoulder. Breed had a highly significant impact on the amount of meat and bones in the carcasses. Because of the large influence breed on the tested quality traits, as well as the set selection criteria, the influence of breed is important. In other words, it is possible by proper selection, that is, in pure breed, to increase meat contents and reduce intramuscular fat in pig carcasses. Additive genes share, measured by heritability and repeatability coefficients, align the given qualities in medium and high genetic. The genetic variability is stabile and clear so it makes the guidance of genetic changes in desired direction justified.

Genetska analiza svojstava kvaliteta polutki urađena je na 284 grla poreklom od landrasa (96), jorkšira (92) i hempšira (96). Disekcija polutki izvedena je po modelu EU 1992. Pri prosečnoj telesnoj masi svinja od 103 kg, najveći procenat mišićnog, uz najmanji udeo masnog tkiva, utvrđen je u vratu (72,48 odnosno 11,43%) kod svih rasa svinja. U trbušno-rebarnom delu izmereno je najviše masnog tkiva (36,19%), a najmanje mišićnog tkiva utvrđeno je na leđima (55,94%). Takođe, najviši udeo kostiju utvrđen je na leđima i vratu (15,82 odnosno 15,64%), a najniži u plećki (9,92%). Najviše mišića nalazi se u butu, zatim slede plećka, trbušno-rebarni deo, leđa i vrat. Masnog tkiva takođe najviše ima u butu, zatim sledi trbušno-rebarni deo, leđa, plećka i vrat. Udeo kostiju najveći je u leđima i butu, zatim u trbušno-rebarnom delu, plećki i vratu. Poređenjem udela mišićnog tkiva u polutkama unutar rasa utvrđeno je da nema statistički značajne razlike u procentu mesa između dve plodne rase (landras i jorkšir). Ustanovljena je statistički značajna razlika između dve plodne i terminalne rase tj. hempšira. Veoma značajan uticaj je imala rasa na udeo kosti u trupu, mišićnog tkiva u vratu, kosti u butu, mišićnog tkiva i kosti u trbušno-rebarnom delu i plećki, dok nije imala uticaj na udeo masnog tkiva u leđima, masnog tkiva i kosti u vratu, mišićnog tkiva u butu, masnog tkiva u trbušnorebarnom delu i plećki. Rasa je imala veoma značajan uticaj na količinu mesa i kosti u trupu. Kako se radi o visoko naslednim svojstvima kao i postavljenim kriterijumima selekcije, uticaj rase na ispitivane osobine je opravdan. Pravilnom selekcijom, dakle, u čistoj rasi, moguće je povećati sadržaj mesa i težinu kostiju uz istovremeno smanjenje ukupne masnoće i intramuskularne masti u trupu svinja. Udeo aditivnih gena meren koeficijentima naslednosti i ponovljivosti svrstava data svojstva u nivo srednje i visoko naslednih. Genetska varijabilnost je stabilna i izražena, i opravdava dalja očekivanja genetskih promena u poželjnom pravcu.