ABSTRACT. This study evaluated the effect of butylated hydroxytoluene (BHT), a lipid-soluble antioxidant, on dog sperm in chilling storage and cryopreservation. In Experiment 1, 0.2, 0.4, 0.8 and 1.6 mM BHT were added to egg yolk Tris extender (EYT), and sperm were stored at 4C for 96 hr. Sperm motility, viability, acrosomal integrity and morphological abnormality in the BHT treatment groups were not different from those of the control (0 mM BHT). In Experiment 2, the effect of BHT in EYT containing 0.75% Equex STM paste and 5% glycerol on survivability of cryopreserved sperm was examined after culture at 39C for 3 hr. Sperm motility, viability and acrosomal integrity in the 0.2 to 0.8 mM BHT treatment groups were not different from those of the control. However, sperm motility, viability and acrosomal integrity decreased when 1.6 mM BHT was added to the extender (P<0.05). In conclusion, supplementation of the extender with 0.2 to 0.8 mM BHT did not affect characteristics of dog sperm in chilling storage and cryopreservation. Supplementation of 1.6 mM BHT did not affect characteristics of chilled sperm but impaired longevity of cryopreserved sperm in the dog.KEY WORDS: butylated hydroxytoluene, canine, freezing, sperm.J. Vet. Med. Sci. 73 (7): [895][896][897][898][899] 2011 Semen collection and artificial insemination (AI) play an important role for breeding of purebred dogs. In spite of the important potential applications of semen preservation, chilled and cryopreserved sperm are not generally used for AI in the dog [8,9,15,19,21]. For successful conception, the fertilizing capacity of sperm must be maintained until AI is performed. Many studies about chilled and cryopreservation techniques for dog sperm have been reported. Fertility of chilled dog sperm can be maintained for 4 days [15]. However, post-thaw motility of dog sperm decreases markedly within 1 hr [8,9,21], resulting in a lower whelping rate and litter size [22]. Therefore, improvement of sperm longevity is desirable for both chilling storage and cryopreservation of dog sperm.Injury of sperm by reactive oxygen species (ROS) during chilled storage and cryopreservation may result in a low success rate of AI. Supplementation of semen extenders with antioxidant compounds could overcome this problem. Butylated hydroxytoluene (BHT), a synthetic phenolic antioxidant, is not only commonly used as a food additive [26], but is also widely used for low-temperature preservation of mammalian [2, 3,11,13,14,17,18,24,25] and avian sperm [6]. It was reported that BHT suppressed sperm mitochondrial metabolism and protected the cell membranes from cold shock by decreasing oxygen toxicity in the bull [12].Protection of sperm by BHT against cold shock has been reported in the bull [11], ram [25] and boar [3]. Addition of BHT to semen extender also maintained the motility and viability of chilled turkey sperm [6] and frozen sperm of boars [18], goat bucks [14], cattle [24] and buffalo bulls [13]. Recently, addition of 1 mM BHT to the freezing medium reportedly in...

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This research analyzed the effects of two safety management approaches with respect towards teamwork. An approach based on a conventional safety perspective called Safety-I has contributed to improving industrial safety by eliminating failures or mistakes as much as possible. In such a case, any mistake would be punished, even if it’s done trying to help a colleague, for example. One concern, therefore, is that this seemingly harsh Safety-I approach can promote self-protective behaviors to minimize mistakes on an individual level but not on a team level. Considering complex systems require entire teams to function properly, such as in aviation where two pilots work together, teamwork should be promoted to achieve higher levels of safety. Under Safety-I management, there is no incentive promoting team-oriented behavior, but it encourages self-protective behavior making it an unbalanced trade-off. On the other hand, a new safety perspective, termed Safety-II, has been recently developed. Safety-II gives an alternative approach to improve safety by increasing the number of things going well. Under such a perspective, team-oriented behavior might be rewarded by considering it as one of the things that go well. Previous research, however, never gave us experimental evidence showing how the two different safety approaches can affect teamwork. The research focuses on answering the following two research questions: (1) Does the safety-I based approach demonstratively have a negative effect on teamwork?, and (2) How effectively is the Safety-II approach at motivating people to pay attention to each other’s activities. The results from our experiment will give us insights to understand how effective safety management can be utilized on-site.An experiment was designed based on regulatory focus theory to simulate the two safety approaches. The theory has two focuses termed promotion and prevention focus which delineate motivation when people pursue their goals. Prevention focus was considered as utilizing the Safety-I perspective while promotion focus was considered as utilizing Safety-II perspective. In the experiment, participants were required to perform a prevention focus task: to avoid violations; and a promotion focus task: to earn incentives that could lead to supporting their partners. Participants received either positive feedback which would induce promotion focus, or negative feedback which would induce prevention focus during main tasks. We then analyzed how the participants' behaviors changed following the feedback.The experimental results showed that participants who received positive feedback were inclined to make more incentives even though they had to sacrifice a few more violations. As we expected, the number of violations were lower in the prevention focus group. However, the prevention focus feedback didn’t encourage participants to work on the prevention focus task to the degree that the promotion focus feedback encouraged participants to work on the promotion focus task. These results might indicate that emphasizing “Do not make mistakes” is not the most effective approach for achieving higher levels of safety. The results also suggest that safety management with a promotion focus might cause people to focus on teamwork, consequently leading to higher levels of safety.