A Cross-regional Comparison of Growth in Japanese Black Calves

Abstract

Factors Affecting the Growth of Japanese Black Calves Climate conditions in Japan are characterized by four distinct seasons, with a large variation in temperature and humidity; this variation is expected to significantly impact calf health and growth. The Japanese Black cattle are widely raised for their meat. Their calves are characterized by a lower-than-normal birth weight (Ogata et al. 1999). In addition, these calves are more susceptible to illness or death compared with Holstein calves in Japan (Ohtsuka et al. 2011). Nabenishi & Yamazaki (2017) demonstrated the effects of the temperature-humidity index (THI) on the health and growth of Japanese Black calves in Southwestern Japan. Many studies have focused on either regional or seasonal impacts on cattle production but not on both on a comprehensive, national scale. In addition, the Japanese archipelago is extremely elongated longitudinally, and its topography varies considerably. Therefore, regional differences in the climate are vast, and calf growth may vary because of seasonal fluctuations and the diverse geographic and climatic landscape of Japan. This study aimed to quantify and compare regional and