Influence of metabolic imprinting during early growth period on muscle development and intramuscular adipogenesis in Japanese Black steers

摘要

Wagyu (Japanese Black cattle) are known for their excellent marbled beef which is achieved by feeding them with a considerable amount of concentrate (4000 to 5000 kg altogether, until slaughter at 28-30 mo of age). More than 90% of this feed has beenimported from the USA and other countries, which imposes a heavy dependence on imported feed on the Japanese economy. Cattle are ruminants, which means they have an important ecological niche that capitalises on the symbiotic relationship between fibre fermenting ruminal microbes and mammalian demand for usable nutrients. We aim to produce a high-quality safe beef product while maximising the use of domestic grass resources. It has been shown, however, that alterations in foetal and early postnatal nutrition and endocrine status may result in developmental adaptations that permanently change the structure, physiology, and metabolism in adult life in rats, domestic species and mice and humans (Levin et al, 2000). This phenomenon is referred to as 'metabolic imprinting'. However, there are very few reports of metabolic imprinting in cattle.