Association of a polymorphism in exon 3 of the IGF1R gene with growth, body size, slaughter and meat quality traits in Colored Polish Merino sheep.

This study aimed to genotype the polymorphism (c.654G > A) in the exon 3 of the insulin-like growth factor 1 receptor gene (IGF1R) and to analyze its association with growth, body size, slaughter and meat quality traits in Colored Polish Merino sheep. In total, 67 traits were analyzed. The IGF1R polymorphism was genotyped using the polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) method. The MIXED procedure of the SAS software was used to assess the genotypic effects of the polymorphism (c.654G > A) on production traits of interest. The IGF1R c.654G > A genotypes were found to have a significant effect on the average daily gain between the 56th and 78th day of life, cold carcass, leg part, leg cut, fore shank, and kidney weights, as well as eye of loin depth, intramuscular fat content, and water-holding capacity of meat. The results suggest that the studied polymorphism may provide useful information for marker-assisted selection for increased meat performance in Colored Polish Merino sheep.

Genotypic and allelic effects of the myostatin gene (MSTN) on carcass, meat quality, and biometric traits in Colored Polish Merino sheep.

The aim of this study was to identify polymorphisms in the first intron and c.*1232G>A position of the MSTN gene and analyze associations between the detected alleles/genotypes and carcass, meat quality, and biometric traits in Colored Polish Merino sheep. We analyzed 44 traits using the MIXED procedure of the SAS software. Five alleles (MSTN-A, MSTN-B, MSTN-C, MSTN-E and MSTN-E1) were detected. Significant genotypic effects were detected with regard to chest depth (live lamb) and fat depth over ribs, drip loss, subjective meat flavor and color, whereas significant allelic effects were found for chest depth (live lamb), pre-slaughter weight, hot carcass weight, cold carcass dressing out, leg depth (carcass), eye of loin width and area, intramuscular fat (IMF) content, water-holding capacity, and subjective meat tenderness, flavor and color. The results suggest MSTN gene polymorphisms may be considered a genetic marker of carcass quality, meat quality, and biometric traits in sheep.

Factors affecting the tissues composition of pork belly.

Bellies derived from the commercial population of pig carcasses are diverse in terms of tissue composition. Knowledge of the factors influencing it and the expected results, permits quick and easy evaluation of raw material. The study was designed to determine the factors affecting the tissues composition of pork bellies and to estimate their lean meat content. The research population (n=140 pig carcasses) was divided into groups according to sex (gilts, barrows), half-carcass mass (<40, 40 to 43.9, 44 to 46.9, ⩾47 kg) and lean meat content class: S (⩾60%), E (55% to 60%), U (50% to 55%), R (<50%). Bellies were subjected to a detailed dissection. Half-carcass mass affected the levels of all the analysed parameters. The only exception was the mass of the fat with the skin in the 40 to 43.9 kg group, for which the value did not differ statistically between the two groups <40 and 44 to 46.9 kg. Decrease in lean meat content affected the growth of the fat and skin mass in a linear way. No differences were observed between class S and E in terms of belly muscle mass. A 0.37% higher share of belly in the half-carcass was found for barrows (P<0.001), although bellies issued from barrows were characterized by a higher proportion of fat with skin compared with gilts (P=0.02). Interactions were observed between sex and half-carcass mass, so the sex of heavy half-carcasses becomes an important determinant for conditioning the muscle content. Equations were calculated and allow a fast and highly accurate determination of the lean meat content in bellies, suggesting they may be used directly in the production line.