Ken-ichi Takeda

The number of farm mates influences social and maintenance behaviours of Japanese Black cows in a communal pasture

The objective of the present study was to investigate optimal group size in cattle in communal pastures where cattle from various farms are turned out: (1) to ascertain if cows derived from each farm form an affiliative group and (2) to investigate the effect of the number of farm mates on social and maintenance behaviours when farm mates form an affiliative group. Farm mates were defined as cows from the same farm. A total of 27 cows having zero, one, two to four, or sixteen farm mates were selected as focal animals in two communal pastures. Each focal animal was followed by an individual observer for 8 h from sunrise. The nearest neighbour and the distance to the nearest neighbour were recorded at 10-min intervals, and maintenance behaviours at 1-min intervals; social behaviours and participants were recorded continuously. Most focal animals frequently choose cows from the same farm as their nearest neighbours allogroomed with these farm mates significantly more (P<0.001). Two focal animals did not form affiliative groups with farm mates. The mean distance to the nearest neighbours, whether farm mates or non-farm mates from focal animals having one and two to four farm mates was shorter than cows turned out with no farm mate (1.4 vs. 1.9 times as long as a cows body length, P<0.05). Cows having two to four farm mates performed (7.8 s/h/cow, P=0.06) and received allogrooming more (9.8 s/h/cow) and escaped less during agonistic encounters (0.1 frequencies/h/cow, P<0.01) than ones having other numbers of farm mates. The mean duration of grazing behaviour per bout tended to increase with the number of farm mates (5.2 to 10.3 min, P<0.05). The mean duration of recumbency behaviour of cows having two to four farm mates (44.0 min/bout) was longer than the ones having other numbers of farm mates. Social and maintenance behaviours of cows having 16 farm mates were like those having zero or one farm mates, which suggested that the social bond among them was weak. It is concluded that a group of cows having two to four farm mates, that is, a group size of three to five cows, may be optimal for a stable life in a communal pasture.

The Effect of Hunting on the Behavior and Habitat Utilization of Sika Deer (Cervus nippon)

Abstract. The effect of hunting on sika deer (Cervus nippon) was investigated through detailed investigations of their pasture utilization during autumn and winter by using a Global Positioning System (GPS) tracking collar. The study was conducted around a pasture in Nagano Prefecture, Japan. Before the hunting season, while the stockmen stayed in the pasture during the daytime, the collared deer preferred to utilize the pasture during the nighttime. However, at the beginning of the hunting season, the collared deer moved to a precipitous plantation of Japanese larch, located approximately 4 km north-east of the pasture. During the hunting season, the collared deer stayed there and avoided the pasture during the entire day, while after the hunting season, the collared deer preferred to utilize the sunny and clement pasture during the day as there was no human disturbance. These results showed that the behavior and habitat utilization of sika deer were affected by hunting. Thus, it was concluded that sika deer sensed the hunting activities and the presence of humans in the pasture, and altered their behavior to utilize the pasture when it was comparatively safer and more comfortable.

Distribution of radioactive cesium in edible parts of cattle

After the disastrous incident of the Fukushima Daiichi Nuclear Power Station, various agricultural, livestock and fishery products have been inspected for radioactive contamination with cesium in Japan. In this study, radioactive cesium was measured in various edible parts of cattle to verify the current inspection method for cattle, in which the neck tissues are generally used as samples. Radioactive cesium concentration in the short plate, diaphragm, liver, lung, omasum, abomasum and small intestine were lower and sirloin, tenderloin, top round meat and tongue were higher than that in the neck. There was no significant difference between the other organs (heart, kidney, lumen and reticulum) and the neck. Ninety-five percent upper tolerance limits of the relative concentration to the neck were 1.88 for sirloin, 1.74 for tenderloin, 1.87 for top round and 1.45 for tongue. These results suggest that a safety factor of 2 is recommended for the radioactivity inspection of cattle to prevent a marketing of meat with higher cesium than the legal limit. Re-inspection should be conducted using another part of muscle, for example, top round, when suspicious levels of 50-100 Bq/kg are detected in the neck.

Influence of feed type and its effect on repressing wool‐biting behavior in housed sheep

Sheep sometimes develop an abnormal behavior termed as wool-biting when kept in an indoor system; however, little is known about this behavior. As the provided feed type may affect the foraging behavior and repress abnormal behavior in animals, we tested the effect of feed type on repressing wool-biting behavior in this study. We used hay prepared in three forms, that is hay bales, rolls and cubes. The wool-biting frequency associated with hay bales was significantly higher than that associated with rolls (P < 0.05) and cubes (P < 0.05); however, there was no significant difference between rolls and cubes. For hay rolls, wool-biting significantly decreased after feeding (P < 0.05), suggesting that rolls may provide sheep with appropriate oral stimulation; thus, decreasing the post-feeding oral abnormal behavior. An individual difference of wool-biting behavior between sheep was also detected, and an unexpected bed-eating behavior was found in the hay cube treatment. We suggest that sheep performing movements that are similar to their natural foraging behavior while grazing would repress wool-biting behavior, which happened in hay roll and hay cube treatments. Considering sanitation and animal welfare, providing sheep with hay rolls may provide an easier method to control wool-biting behavior in housed sheep.

Effect of the proportion of roughage fed as rolled and baled hay on repressing wool-biting behavior in housed sheep

Wool-biting behavior in housed sheep is a serious animal welfare problem and is difficult to control. Since we have found that sheep fed on rolled hay performed less post-feeding wool-biting than those fed on baled hay, here we mixed these two kinds of hay in four different proportions (0%, 33%, 67% and 100% of rolled hay) to test the effect of rolled hay on repressing wool-biting behavior. We also measured the pulling force needed to remove a piece of rolled hay, baled hay, wool and fresh grass. Wool-biting occurred most frequently in the treatment containing 0% rolled hay; however, there was no significant difference between the other three treatments. The pulling force needed to remove a piece of baled hay was significantly weaker than that for the other three objects; no other significant differences in pulling force were found. Our results suggest that the wool-biting behavior of sheep was due to feeding frustration, which arises when they lack the appropriate oral stimulation from performing their normal foraging movement; this then redirects to the wool on their pen-mates. Feeding sheep rolled hay, even in low quantities, can provide them with appropriate oral stimulation and was effective in repressing wool-biting behavior.