Productivity and Quality of Mulberry Leaves under Cattle Grazing in a Wasted Mulberry Plantation

다국어 초록 (Multilingual Abstract)

Mulberry (Morus sp.) plantations have been deteriorating in Japan due to decline of silk industry. In mountainous areas, large part of the mulberry plantations has been wasted. Cattle grazing in the wasted mulberry plantations is a practical system to reuse the wasted areas for food production, because mulberry leaves are highly nutritive (Ezenwa and Kitahara, 2001), productive (Kitahara et al., 2002) and palatable to cattle (Ogura et al., 2008). In this study, the productivity and quality of mulberry leaves were investigated for 3 years in a wasted mulberry plantation grazed with beef cows, in Minamisanriku town, Miyagi, Japan. Cattle grazing started in September 2005 (paddock A, 44 a) and June 2006 (paddock B, 96 a). For each paddock, two pregnant cows were grazed from June to August-October in 2006-2008. In the paddocks A and B, four mulberry trees were chosen and the leaf mass and chemical composition were measured in mid-June and late August (pre-grazing leaf mass) during 2006-2008. A non-grazed paddock was also measured in 2007-2008. Leaf productivity of mulberry trees significantly decreased with cattle grazing; pre-grazing leaf mass changed from 246.8 g to 10.4 g DM/tree and 286.2 g to 17.6 g DM/tree in the paddock A and B, respectively (Fig 1). In contrast, 149.2-365.1 g DM/tree of leaves was produced in the non-grazed paddock. Chemical composition was stable during the three years in all paddocks. It is concluded that cattle grazing gives severe damage to leaf production of mulberry trees in three years.