Postnatal myofibre characteristics and muscle mass are largely determined during fetal development and may be significantly affected by epigenetic parent-of-origin effects. However, data on such effects in prenatal muscle development that could help understand unexplained variation in postnatal muscle traits are lacking. In a bovine model we studied effects of distinct maternal and paternal genomes, fetal sex, and non-genetic maternal effects on fetal myofibre characteristics and muscle mass. Data from 73 fetuses (Day153, 54% term) of four genetic groups with purebred and reciprocal cross Angus and Brahman genetics were analyzed using general linear models. Parental genomes explained the greatest proportion of variation in myofibre size of Musculus semitendinosus (80-96%) and in absolute and relative weights of M. supraspinatus, M. longissimus dorsi, M. quadriceps femoris and M. semimembranosus (82-89% and 56-93%, respectively). Paternal genome in interaction with maternal genome (P<0.05) explained most genetic variation in cross sectional area (CSA) of fast myotubes (68%), while maternal genome alone explained most genetic variation in CSA of fast myofibres (93%, P<0.01). Furthermore, maternal genome independently (M. semimembranosus, 88%, P<0.0001) or in combination (M. supraspinatus, 82%; M. longissimus dorsi, 93%; M. quadriceps femoris, 86%) with nested maternal weight effect (5-6%, P<0.05), was the predominant source of variation for absolute muscle weights. Effects of paternal genome on muscle mass decreased from thoracic to pelvic limb and accounted for all (M. supraspinatus, 97%, P<0.0001) or most (M. longissimus dorsi, 69%, P<0.0001; M. quadriceps femoris, 54%, P<0.001) genetic variation in relative weights. An interaction between maternal and paternal genomes (P<0.01) and effects of maternal weight (P<0.05) on expression of H19, a master regulator of an imprinted gene network, and negative correlations between H19 expression and fetal muscle mass (P<0.001), suggested imprinted genes and miRNA interference as mechanisms for differential effects of maternal and paternal genomes on fetal muscle.
A rapid increase in corn use in ethanol plants, and subsequent creation of distillers dried grains with solubles (DDGS) by-products, has led to an increase in the use of DDGS in the diets of livestock. DDGS has been used all over the world as a dietary ingredient and this has necessitated more research to be conducted on its quality, nutritive values, and recommendations for feeding to poultry. Currently, there have been a limited number of research publications regarding corn DDGS as an ingredient of diets for poultry. Approximately 100 scientific papers can be found which cover a variety of topics, with various degrees of depth into each. The purpose of this review is to collate the available information to date on the application of corn DDGS as an ingredient of poultry diets that can be easily accessed by researchers and nutritionists. This review presents the current state of knowledge of nutritive values of various corn DDGS ingredients, summarizes recommendations for using DDGS in diets for laying hens, broilers and turkeys, and reports the environmental ramifications when utilizing corn DDGS in poultry feed. In spite of the great amount of variation in nutritional properties of corn DDGS originating from various sources, it has been concluded that good quality corn DDGS, especially when derived from new generation plants, can be a viable ingredient in poultry diets.