Earticle

This study was conducted to find out the environmental, service sire and genetic effects for reproductive trait in certain purebred of pigs on Landrace and Yorkshire, and to suggest selection indicator which is to improve genetic capability on reproductive traits. There are five traits used on this analysis which are total number of born (NBT), number of born alive (NBA), piglets weight within litter (LW), average of birth weight on piglets within litter (ABW) and variation of birth weight on piglets within litter (VBW). With these data, the mixed model was established using 10,342 records collected from 2,527 sows of Landrace and 13,817 records collected from sows of 3,056 Yorkshire breeds and the variation of random effects and the genetic parameter were estimated by the REML method including service sire effects, permanent environmental effects and sow genetic effects. Due to characteristics of closed nucleus herd for using data on this study, given that it has been isolated breeding for about 19 years that progressed over 16 generations, genetic analysis was performed on all of these data and partial data of the current genetic group in which animals were born after 2011. The effects of service sire were estimated to be less than about 8% of total variation in all traits considered in the analysis. Permanent environmental effects were estimated about 2~14% of total variation in all traits considered. The heritability, which is the ratio of genetic variance among the total variance, was estimated to be 20~35% for LW and ABW in Landrace and Yorkshire, while it was about 10~14% for NBT. The genetic correlations between NBT and LW were 62~74% and between NBT and ABW were –28~-7%. Therefore, indirect selection for improving litter size could be possible with considering LW. Whereas, the genetic effect of the service sire effects for litter traits would be trivial.

This study was to investigate effect of tunicamycin (TM) on sperm viability, mitochondrial activity and motility in boar semen. Collected sperm were incubated with semen extender containing 0, 1, 2, and 5 μM TM for 3, 6 and 9 h. Sperm viability was analyzed using SYBR14/PI doubling staining, and mitochondrial activity was detected using Rhodamine123/PI staining methods. Sperm viability, mitochondrial activity and motility were measured every 3 h during incubation. In results, boar sperm viability, mitochondrial activity and motility were significantly decreased in 2 and 5 μM TM groups compare to control group at all incubation time (p<0.05). In addition, mitochondrial activity and motility were significantly decreased in 1, 2, and 5 μM TM groups compare to control group at 9 h after incubation (p<0.05). These results suggest that TM can inhibit sperm viability, mitochondrial activity and motility in boar semen, and it may influence on the fertility of sperm.

The objective of this study was to evaluate the accuracy of equation being used to estimate the total digestible nutrients (TDN) of whole crop rice silage (WCRS) in sheep. To compare the observed and estimated TDN contents [estimated TDN content=87.57-(0.737×ADF)], two varieties of WCRS from Nokyang (NS) and Samgwang (SS) as forage and food source, respectively, were used as a treatment. Nine female Corriedale sheep (average body weight: 49.2±6.3 kg) were used as the experimental animals. The ewes were fed according to their nutrient requirements at the maintenance level. To check the difference between the observed and estimated TDN contents, one sample non-parametric t-test was applied. The CP, NFE and CF contents of the NS were 43.6, 74.2 and 64.2%, respectively, and that of the SS were 46.2, 58.1 and 44.9%, respectively. The observed and estimated TDN contents of the NS were 63.5 and 61.5%, where there was no significant difference. The observed and estimated TDN contents of the SS were 48.9 and 59.0%, where there was significant difference (p<0.05) This research confirmed the validity of TDN estimation equation being used for estimation of TDN of WCRS as forage source, but further research is recommended on the equation for estimating TDN contents of WCRS as food source.

This study was conducted to clarify behavior and body weight of weaned piglets between different social experiences during suckling period. Control (no social experience) and treatment (social experience) groups of weaned piglets were housed and observed with the aid of video technology for 8 consecutive hours in early (days 1 and 2) and late (days 22 and 23) periods after mixing. Inactive, locomotion and exploration were significantly different between control and treatment groups in early mixed period. Feeding differed between groups in late mixed period. In social behaviors, agonistic and interaction with adjacent pen were significantly higher in treatment group than in control group during early mixed period. However, social behaviors dramatically decreased in late mixed period. There was negative correlation between average daily gain of body weight and agonistic behavior. In social experienced weaned piglet groups, there were less agonistic behavior and more daily gain of body weight in this study. Social experience during suckling period would be useful for stable group management in swine industry.

The aim of the study was to set up assessment indicators for early elimination of horses that are not trainable or low efficient for training by comparing difference of behavioral response and heart rate on stimulation of desensitization training in horses. The animals used in this study were 8 untrained cross-bred horses (Thoroughbred and Jeju-horse) in Jeju island. Changes of heart rates and behavioral response of each horses were compared before and after desensitization training using a plastic bag on its tip. The result showed that the horses with their severe behavioral response were also high in heart rate during early stage of desensitization training, and the increased heart rates were recovered back to the base level according to the process of the training. The horses that quickly recovered in heart rate also showed same tendency in behavioral response. The horses that their recovery in heart rate and behavioral response in early stage of the desensitization training were late, showed insufficient results of the additional desensitization training. We conclude that assessment of heart rate and behavioral response in the early stage of desensitization training could be used as indicators to predict the effectiveness of desensitization or other kinds of training in horses.