Effect of Piglet Birth Weight on Carcass Muscle and Fat Content and Pork Quality – A Review

Piglet birth weight is determined by the maternal environment, intrauterine crowding, and nutrition, which influence embryonic and fetal survival and, as a result, fertility. The internal environment regulates prenatal myogenesis and muscle fibre number nutritionally and hormonally. The growth and metabolic differentiation of muscle fibres take place during the postnatal period. The effect of intrauterine undernutrition on myogenesis and on fetal growth and development (IUGR) is reflected in the low piglet birth weight and its high within-litter variation. Slaughter traits are determined by many factors, including genetic (breed), environmental (nutrition) and preslaughter handling. Slaughter traits and the physico-chemical and sensory characteristics of meat are dependent on prenatal myogenesis and neonatal weight. Optimized body weight of newborn piglets is conducive to improving quantitative traits (meatiness, fatness) and qualitative traits. However, slaughter traits are also influenced by many other differentiating factors, which is reflected in research results. Muscle fibres become metabolically differentiated during postnatal development, and one of the factors of large variation in pig meat quality traits is variation in the proportions of different fibre types in mature muscle. Considering the divergent opinions among scientists about the effect of prenatal myogenesis and piglet birth weight on slaughter value and pork quality, as well as the existence of areas that have received little investigation, it is justified to continue research in this area.