In Japan, there are 420,000 ha of abandoned farmland.  Recently, cattle, sheep and/or goat have been grazed on there in some area.  This study aimed to make a comparison of grazing behavior of Suffolk and Paul Dorset ewes in a less favored hilly and mountainous area in Nagano Prefecture Japan. 

In observation 1, five Suffolk ewes (Group S) and three Suffolk and two Paul Dorset ewes (Group P) were introduced to formerly cultivated fields (0.5 ha each), and grazing behavior and place use were observed four times, 13 hrs (5 : 00-18 : 00) each, for two months (June 7─August 11, 2014).  The percentages of performed each behavior (feeding, exploration, stand-resting, lay-resting, migrating, and other) were significantly different between Groups S and P (P＜0.05).  The feeding behavior was observed more times, and average duration of feeding behavior was longer in Group P than Group S.  In Group P, behavior patterns of Suffolk and Paul Dorset ewes were almost the same, but the Suffolk ewes in Group P performed more feeding behavior than Suffolk ewes in Group S.  So, the Paul Dorset ewes might lead the active behavior.

In observation 2, four Suffolk and two Paul Dorset ewes were introduced to one of the same areas, and grazing behavior, place use, and migrating order of individuals were observed four times, 13 hrs (5 : 00-18 : 00) each, for two months (June 27─August 18, 2015).  When the herd was moving, Paul Dorset ewes leaded the Suffolk ewes in most cases (P＜0.001).

Suffolk has been the major breed in Japan.  However, a few active breed ewes like a Paul Dorset are mixed with Suffolk group, the behavior of them might be activated.  But further studies of the effects of mixed grazing on growing rate, and the data of breeding performance and meet quality of F1 are needed.

The objective of the present study was to conduct an adipogenic evaluation of different roughage sources and feeding period during sheep preadipocyte differentiation.  Seven Suffolk wether sheep (3-4 months of age) were used in this study.  Six wether sheep were divided into a timothy hay feeding group (TH, n＝3) and an Italian ryegrass straw feeding group (IR, n＝3) for 11 months of feeding period.  The both forages were offered to the animals at 2% BW (dry matter (DM) basis), and concentrate was fed at 40% of forage intake (as fed basis).  The both diets were offered to achieve 100 g of daily gain (DG).  A single sheep was used for preadipocyte isolation.  Sheep serum samples collected on the 4 and 11 months of feeding period of each dietary treatment were added to an adipogenic induction medium for differentiation of preadipocytes derived from sheep subcutaneous adipose tissue.  The cytoplasmic lipid accumulations in the TH serum-treated preadipocytes were significantly higher than those of the IR-serum treated preadipocytes on day 7.  Messenger RNA expression of PPARγ, C/EBPα, aP2 and LPL were up-regulated by TH serum treatment.  This study shows that timothy hay diets can up-regulate adipocyte differentiation in adipose tissue of young sheep.