To prevent bark damage, beet pulp blocks have been fed to deer on the shore of Lake Akan in Akan-cho, Kushiro City, Hokkaido since 1999, and the amount made available has been increasing yearly. The effect of providing only intermittent feeding in order to decrease the amount of feed on bark damage and the number of deer coming to the area where feeding has been discontinued and the adjacent feeding area was examined. Feeding was discontinued twice in 2004 and 2005 at one of 17 feeding areas. The movement of deer from the area where was feeding discontinued to the adjacent areas was examined using a feed marker. A limited amount of bark damage was observed 3 days after the discontinuation of feeding in 2004. In 2005, a limited amount of bark damage was also observed 4 days later around the area where feeding was discontinued, while the area around the adjacent feeding areas showed moderate bark damage. In both survey years, the number of deer coming to the area where feeding was discontinued decreased, while that to the adjacent feeding area increased. After the restart of feeding, the number of deer returning to the area where feeding had previously been discontinued return to the number before discontinuing feedings. The movement of deer to the adjacent feeding areas during the discontinuation period was confirmed by the feed marker. These findings indicate that the discontinuation of feeding could be performed for up to 3 days, although the degree of bark damage varied with the period of the year and feeding area, bark damage was detected.

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L-carnitine plays a pivotal role for shuttling process of long chain fatty acid into mitochondrial matrix that eventually promoting lipid catabolism to produce ATP. This study aimed to evaluate some effects of L-carnitine supplementation to bull on its sperm motility under high environmental temperature. Prior to experimental feeding, a preliminary test of spermatozoa was conducted. Six Holstein bulls with the same sperm motility were divided into 2 groups; a control group and an experimental group supplemented with L-carnitine. Feedstuff and feed amounts for bulls in both groups were the same, however feedstuff for the experimental group was supplemented with 0.9g/d L-carnitine, with a final concentration of 50ppm. Experimental feeding began on 1 August and ended on 30 September. Experimental semen collection was carried out twice on 5 and 30 September. In addition, motility of thawed sperm was observed in order to recognize the effect of L-carnitine supplementation on freezing. For the first semen collection, the mean value of sperm motility was ca.10% higher in the experimental group than that in the control group. For the second semen collection, the mean value of sperm motility was also ca.15% higher in the experimental group than that in the control group. Significant differences were not recognized in both data. Present results suggested that the supplementation of L-carnitine recovers a course of energy metabolism reduced by the high environmental temperature. L-carnitine supplementation halted the reduction of sperm motility due to heat stress. This tendency was especially noticeable in the results of sperm motility in frozen semen kept in liquid nitrogen. It appeared that the decrement in sperm motility observed in high environmental temperatures was due to the difference of sperm maturity. The ratio of abnormal sperm in the experimental group was less than that in the control group. L-carnitine supplementation to bulls plays a favorable role in the maturity of sperm while sperm motility is maintained at its usual level under high environmental temperatures.

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The objective of this study was to examine work efficiency for breeding management using synchronized ovulation followed by timed-artificial insemination (Ovsynch-TAI) in pasturage. A total of 55 Japanese Black beef cows were divided into three groups: (1) synchronized ovulation followed by timed-artificial insemination group (Ovsynch; n=18), (2) synchronized estrus followed by AI in proper time (normal AI) group (Es-Syn; n=18), (3) natural estrus followed by normal AI group (control; n=19). As work conditions, the necessary number of people to accommodate a cow or herd in the workshop was three. One person observed the estrus behavior twice a day, at morning and evening; in addition, when estrus behavior was observed in the morning, observations were increased to three times a day (including noon) for judgment of the proper time of AI. The required number of people per cow for AI, the Ovsynch group, the Es-Syn group, and the control group were 1.4, 5.1, and 7.5, respectively; the Ovsynch group required significantly fewer human workers than the Es-Syn group and the control group (P<0.05). As the conception rates were 38.9%, 72.2%, and 47.4% for the respective methods, the necessary number of people per conception was 3.5, 7.3, and 17.2, respectively. The Ovsynch group required significantly fewer human workers than the control group (P<0.05). The results described above suggest that, in breeding management in pasturage, Ovsynch-TAI can decrease manpower requirements by about 77% compared with the control group.

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