Comparison of non-carriers and heterozygous carriers of the RN(-) allele for carcass composition, muscle distribution and technological meat quality in Hampshire-sired pigs

The aim of this experiment was to compare non-carriers and heterozygous carriers of the dominant RN(-) allele (Rendement Napole) for carcass composition, muscle distribution and technological meat quality in pigs. Crossbred slaughter pigs (n = 79), from Hampshire sires, heterozygous for the RN(-) allele, and Swedish Yorkshire x Swedish Landrace dams were used. The animals were classified into RN(-) genotype according to the estimated glycogen level at slaughter (glycolytic potential) in the longissimus dorsi muscle. Carriers of the RN(-) allele had higher daily gain, fewer days on test and produced carcasses with higher lean meat content, and a larger proportion of ham. The major ham muscles were larger in the RN(-) carriers than in the non-carriers. The proportions between the individual muscles were changed due to the RN(-) allele, with a greater content of glycolytic ham muscles (M. semimembranosus et adductor, M. biceps femoris, M. gluteus) and a smaller content of M. quadriceps femoris in RN(-) carriers. RN(-) carriers had lower values for ultimate pH, Napole yield (yield after curing and cooking), crude protein, and dry matter, and higher values for glycolytic potential, drip losses, filter paper wetness, internal reflectance and ash content. No effect of the RN(-) allele was found regarding lactate and surface reflectances. (C) 1997 Elsevier Science B.V.