Genetic parameters for calf mortality in Japanese Black cattle
The Japanese Black cattle is the predominant beef breed in Japan. In Japan, calves are sold at action, so, the death of calves is an economic loss for the reproductive farm. In spite of the economic importance of calf mortality, studies of the genetic parameters of calf mortality are few. Because, calf mortality is not a continuous trait such as body weight, but a threshold trait, classified only as live or dead. However, in recent years, the genetic parameters of threshold traits can be analyzed. Therefore, we investigate the genetic parameters of calf mortality in Japanese Black cattle.
Genetic parameters for reproduction traits in Japanese Black cattle
In recent years, Japanese Black cattle have been selected mainly for their meat quality, especially the degree of (intramuscular) marbling. In practice, genetic improvement for meat quality is very high. On the other hand, fertility performance is falling. Therefore, it is very important for genetic improvement of fertility performance to investigate the genetic parameters for reproduction traits and the genetic correlation between reproduction traits and carcass traits in Japanese Black cattle. Moreover, we investigate the genes responsible for reproduction traits with another institute.