• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1210-1213
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• 2004

Quantitative trait loci (QTL) mapping can be applied to detect chromosomal locations that control economic traits in farm animals. Teat number has been considered as one of the most important factors to evaluate mothering ability of sow. Especially, teat number is more important when the number is less than the litter size. This study was conducted to identify QTL affecting teat number in the Korean native pig${\times}$Landrace resource family. A total of 240 animals was genotyped for 132 polymorphic microsatellites covering the 18 pig autosomes. Mean and standard deviation of teat number in $F_2$animals is 13.46${\pm}$1.40. QTL was analyzed using F2 QTL Analysis Servlet of QTL express. A QTL for teat number on SSC9 was significant at the 1% chromosome-wide level and three suggestive QTL were detected on SSC3, 7 and 14. All QTL detected in this study had additive effect and Landrace alleles were associated with higher teat number in comparison with Korean native pig for three of four QTL.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.7
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• pp.1138-1147
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• 2020

Objective: A study was made investigate factors affecting body surface temperature changes after weaning in sows, whether these can be used to aid detection of natural estrus and how they relate to subsequent reproductive performance. Methods: A total of 132 sows were selected during summer from a breeding farm, with mean parity of 3.6±2.3 and 28.5±0.9 days lactation length. Four daily measurements (6:00, 8:00, 16:00, and 18:00) of vulva (VST), udder (UST), ear base and central back skin temperatures for individual sows were taken by an infrared thermometer, continuing up to 8 days post weaning. Results: The VST obtained from sows showing estrus at 4 days post-weaning (4DPW), 5DPW, and 6DPW showed a peak at the fourth day post-weaning, but then started to decrease. The VST of sows not detected in standing heat (NDPW) remained at a lower level during the experiment, but UST was increased soon after weaning. The VST-UST temperature differences during daytime of sows that were showing behavioural standing heat on 4DPW, 5DPW, 6DPW, and 7DPW were 0.46℃±0.123℃, 0.71℃±0.124℃, 0.66℃ ±0.171℃, and 0.58℃±0.223℃, respectively. The NDPW sows had the highest UST observed, but also the lowest VST so that a more negative value of temperature difference (-0.31℃) was seen during first few days post-weaning. A total of 119 sows were observed to show standing heat and were bred. The later the estrus, the smaller the litter size (p = 0.005). Conclusion: Sows which did not show behavior indicative of stable standing heat after weaning had a VST which remained at a lower level, but the UST increased soon after weaning. Therefore, for sow heat detection under field conditions, the changes of VST and UST and difference between the two should be considered together to increase the accuracy of detection.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.1
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• pp.72-78
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• 2002

The effects of housing and nutrition on the performance of growing gilts of the Nepalese Pakhribas breed were investigated. A total of 36 pigs were allocated according to a factorial design with 3 levels of nutrition, provided to achieve a target growth rate of 200, 300 or 400 g/day, and two types of housing, traditional or improved. The growth rate and body composition were monitored during the growing period and subsequent pregnancy. There was a significantly higher growth rate (p<0.01), greater $P_2$ backfat thickness (p<0.01), and greater eye muscle depth (p<0.01) at service in pigs given the higher level of nutrition. Similarly, there was a significantly higher growth rate (p<0.05), and greater eye muscle depth (p<0.10) with improved housing but no significant difference in $P_2$ backfat thickness. The conception rate was 90% at first service, with no difference between treatments. Gilts from the high plane of rearing produced a mean litter size of one piglet greater than those on the low plane, but this was not significant with the limited numbers. However, both improved plane of nutrition and reduced climatic penalty by improving housing resulted in increased birthweight of piglets (p<0.05). It is concluded that improvement in housing can give benefits equivalent to at least a 7% improvement in efficiency of feed use under traditional Nepalese circumstances for pig rearing.

• Animal Bioscience
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• v.34 no.9
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• pp.1451-1459
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• 2021

Objective: The objectives of the study were to evaluate reproductive performance and selection response through genetic trend of community-based breeding programs (CBBPs) of Bonga sheep. Methods: Reproduction traits data were collected between 2012 and 2018 from Bonga sheep CBBPs. Phenotypic performance was analyzed using the general linear model procedures of Statistical Analysis System. Genetic parameters were estimated by univariate animal model for age at first lambing (AFL) and repeatability models for lambing interval (LI), litter size (LS), and annual reproductive rate (ARR) traits using restricted maximum likelihood method of WOMBAT. For correlations bivariate animal model was used. Best model was chosen based on likelihood ratio test. The genetic trends were estimated by the weighted regression of the average breeding value of the animals on the year of birth/lambing. Results: The overall least squares mean±standard error of AFL, LI, LS, and ARR were 375±12.5, 284±9.9, 1.45±0.010, and 2.31±0.050, respectively. Direct heritability estimates for AFL, LI, LS, and ARR were 0.07±0.190, 0.06±0.120, 0.18±0.070, and 0.25±0.203, respectively. The low heritability for both AFL and LI showed that these traits respond little to selection programs but rather highly depend on animal management options. The annual genetic gains were -0.0281 days, -0.016 days, -0.0002 lambs and 0.0003 lambs for AFL, LI, LS, and ARR, respectively. Conclusion: Implications of the result to future improvement programs were improving management of animals, conservation of prolific flocks and out scaling the CBBP to get better results.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.8
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• pp.1108-1117
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• 2003

In Guadeloupe small ruminants (SR) are reared for meat production under pasture conditions. Intensive rotational grazing systems (irrigated, fertilised and high stocked) allow reasonable levels of production but generate high post-grazing residues. Experiments were designed to control them. A system in which residuals were mown (RM) was tested in comparison to the control system (Residuals Remained, RR). The same design was carried out for two years with Creole goat (G) and Martinik sheep (S). An accelerated reproductive rate (3 parturitions over 2 years) was carried out. Systems were compared at three parturition seasons per year(dry, intermediate and rainy seasons). Each group was composed of 20 goats ($36.0{\pm}2.5kg$) or 20 ewes ($46.8{\pm}2.4kg$). The female body traits did not vary according to pasture management and seasons. The stocking rate averaged 1,400 kg LW/ha. The mean fertility rate for does varied significantly (p<0.05) within the kidding season, from $80.4{\pm}0.5%$ to $93.7{\pm}2.9%$ while the mean litter size was $2.30{\pm}0.07$ total kids born. No effect of pasture system was observed. Corresponding values for ewes were $83.2{\pm}12.8%$ vs. $75.6{\pm}12.5%$ (p<0.05) and $2.43{\pm}0.24$ vs. $2.03{\pm}0.29$ (p<0.01) total lambs born for SRM and SRR ewes, respectively. A seasonal effect was observed upon ewe performances. The preweaning mortality of kids and lambs averaged 16.3% and 14.4%, respectively. It was 7 and 9 percentage points more (p<0.01) for RR than for RM kids and lambs, respectively. For both species, weaning took place at an average age of $81.4{\pm}3.6days$. In Creole kids, live weight at birth and at weaning were $1.9{\pm}0.2kg$ and $8.9{\pm}0.8kg$, respectively. In the Martinik sheep, the traits averaged $2.9{\pm}0.2kg$ and $18.9{\pm}0.9kg$. For both traits in both species, significant (p<0.05) group${\times}$season interactions were recorded. The consequences of elimination of post-grazing residues varied according to the SR species, the environmental conditions and the animal physiological status. The forage characteristics were not limiting factors since forage availability in the RM systems (2,300 and 2,600 kg DM/ha, respectively) and chemical composition were at satisfactory levels (CP content averaged 12 and 10%). It is recommended to develop new grazing system which would allow the use of post-grazing residues instead of mowing the refusals.

• Journal of Embryo Transfer
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• v.15 no.1
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• pp.9-14
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• 2000

This experiment was undertaken to investigate the effect of administration of Agyoju or Mokhyang on the maintenance of pregnancy, delivery and sex ratio in the mice in different gestation periods. Adult female mice were administered orally at three different periods, from ovulation to implantation (Exp.1), from post-implantation to organogenesis (Exp.2), and from fetal growth to parturition (Exp.3). In Experiment 1, number of fetus implanted and mean body weight were not significantly different. However, the delivery of male offspring was significantly increased in Agyoju and Mokhyang administrated groups than control group. In Experiment 2, the number of fetuses implanted, live offsprins and their body weight at delivery were significantly increased in the Agyoju administered group than Mokhyang and control groups. In Experiment 3, the number of live offspring and sex ratio were not different in both treatments and control group. However, mean body weight at delivery was significantly increased in both treatment groups than that of control group. These results suggest that 1) Agyoju and Mokhyang have beneficial effects in maintenance of pregnacy, and that 2) The action of unknown component(s) in Agyoju may be related to selection of male spermatozoa for fertilization in vivo, and that 3) the administration of Agyju of Mojhyang during mid-and late-pregnance periods were shown the increment of body weight of live offspring without decrease of litter size.

• Korean Journal of Environment and Ecology
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• v.31 no.2
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• pp.152-165
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• 2017

The greater long-tail hamster, Tscherskia triton, is widely distributed in Northern China, Korea and adjacent areas of Russia. Except for its distribution, biological characteristics related to life history, behavior, and ecological influences for this species are rarely studied in Korea. This study was conducted to obtain biological information on breeding, growth and development that are basic to species-specific studies. The study adopted laboratory management of a breeding programme for T. triton collected in Jeju Island from March, 2015 to December, 2016. According to the study results, the conception rate was 31.67% and the mice in the large cages had a higher rate of conception than those in the small cages (56.7 vs. 6.7%). The gestation period was $22{\pm}1.6days$ (ranges from 21 to27 days), and litter size ranged from 2 to 7, with a mean of $4.26{\pm}1.37$ in the species. The minimum age for weaning was between $19.2{\pm}1.4days$ (range of 18-21 days). There were no significant differences by sex between mean body weight and external body measurements at birth. However, a significant sexual difference was found from the period of weaning (21 days old) in head and body length, as well as tail length (HBL-weaning, $106.50{\pm}6.02$ vs. $113.34{\pm}4.72mm$, p<0.05; HBL-4 months, $163.93{\pm}5.42$ vs. $182.83{\pm}4.32mm$, p<0.05; TL-4 months, $107.23{\pm}3.25$ vs. $93.95{\pm}2.15mm$, p<0.05). Gompertz and Logistic growth curves were fitted to data for body weight and lengths of head and body, tail, ear, and hind foot. In two types of growth curves, males exhibited greater asymptotic values ($164.840{\pm}7.453$ vs. $182.830{\pm}4.319mm$, p<0.0001; $163.936{\pm}5.415$ vs. $182.840{\pm}4.333mm$, p<0.0001), faster maximum growth rates ($1.351{\pm}0.065$ vs. $1.435{\pm}0.085$, p<0.05; $2.870{\pm}0.253$ vs. $3.211{\pm}0.635$, p<0.05), and a later age of maximum growth than females in head and body length ($5.121{\pm}0.318$ vs. $5.520{\pm}0.333$, p<0.05; $6.884{\pm}0.336$ vs. $7.503{\pm}0.453$, p<0.05). However, females exhibited greater asymptotic values ($105.695{\pm}5.938$ vs. $94.150{\pm}2.507mm$, p<0.001; $111.609{\pm}14.881$ vs. $93.960{\pm}2.150mm$, p<0.05) and longer length of inflection ($60.306{\pm}1.992$ vs. $67.859{\pm}1.330mm$, p<0.0001; $55.714{\pm}7.458$ vs. $46.975{\pm}1.074mm$, p<0.05) than males in tail length. These growth rate constants, viz. the morphological characters and weights of the males and females, were similar to each other in two types of growth curves. These results will be used as necessary data to study species specificity of T. triton with biological foundations.

• Journal of Animal Science and Technology
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• v.45 no.4
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• pp.627-632
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• 2003

Piglets communicate with their sow by using special sounds and synchronize their suckling behavior with their mother’s grunting. This study sought to find an effective sound for controlling the nursing/suckling behavior of pigs. Eighteen crossbred Landrace${\times}$Yorkshire sows and their piglets were studied on days 1, 7, and 14 post-partum. The parity of the sows was three or four. The litter size ranged from 9 to 11, with a mean of 10.4 piglets. Thirty minutes after the end of the last suckling, either the nursing-suckling sound (NSS) or the nursing-suckling sound + click sound (NSSCS) was played for 90 s randomly, and this experiment was repeated three times. The behavior of the sows and their piglets was recorded using camcorders and observed each second. When comparing NSS and NSSCS, there was less lying and sleeping and more sitting, standing, walking, and massaging when NSSCS was played than when NSS was played. These results suggest that NSSCS may induce more nursing and suckling in pigs than NSS.

• Journal of Veterinary Clinics
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• v.22 no.3
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• pp.253-258
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• 2005

The aim of this study was to estimate the time of ovulation and mating derived by plasma progesterone and estradiol-$17{\beta}$ concentrations. The 11 pregnant Shih-tzu bitches were investigated the plasma progesterone and estradiol-$17{\beta}$ concentrations from proestrus to parturition. Gestation length in the 11 pregnant bitches was $61.9{\pm}1.1\;(mean{\pm}SD)$ days when Day 0 was timed from the day that plasma progesterone concentration was first increased above 4.0 ng/ml. The litter size was $3.8{\pm}0.3$ pups. Plasma progesterone concentrations were increased at the first day of vulvar bleeding and showed at Day 0 with $5.2{\pm}0.3$ ng/ml. It was gradually increased to reach a peak at Day 15 with $42.6{\pm}3.7ng/ml$, thereafter it was gradually decreased to below Day 62. Plasma estradiol-$17{\beta}$ concentrations were increased above 1.0 pg/ml at the first day of vulvar bleeding and showed a peak at Day -2 with $33.5{\pm}8.0$ pg/ml, thereafter it was gradually decreased. When Day 0 was timed from the day that plasma progesterone concentration was first increased above 4.0 ng/ml, plasma estradiol-$17{\beta}$ concentration reached a peak at Day -2. In conclusion, these results indicated that ovulation was estimated to occur the day when plasma progesterone concentration was first increased above 4.0 ng/ml after the first day of bleeding. It was estimated that mating time was the day when plasma progesterone concentration was between $3.0{\~}8.0$ ng/ml.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.1089-1096
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• 2003

We investigated postpartum behaviors of sows and their litters. The aim of this study was to determine the behavioral recovery of sows and the behavioral development of their piglets postpartum. Five multiparous sows(Landrace${\times}$Yorkshire) and their litters were studied over a period of 5 days postpartum. The litter size varied from 8 to 13 with a mean of 11.2 piglets. The behaviors of sows and their piglets were recorded using five CCD cameras, a multiplexer and a time lapsed VCR. The videotapes were scanned every 2 min to obtain an instantaneous behavioral sample. In the behaviors of sows, ‘Lying ventrally’ increased from 1 h postpartum to 26 h postpartum, then decreased gradually, and stabilized after 80 h postpartum. ‘Lying laterally’ decreased from 1 h postpartum to 26 h postpartum and stabilized after 80 h postpartum. ‘Standing, drinking and feeding’ increased from 1 h postpartum to 23 h postpartum, then decreased gradually, and increased again from 60 h postpartum. ‘Sitting’ increased from 1 h postpartum to 46 h postpartum and then decreased. In the behaviors of piglets, ‘Lying’ increased rapidly from 1h postpartum to 45h postpartum, and then was maintained at an almost constant level. ‘Massaging and Suckling’ decreased rapidly from 1 h postpartum to 36 h postpartum, and then was maintained at an almost constant level. ‘Walking’ increased from 1 h postpartum to 21 h postpartum, then decreased gradually. These results suggest that the behavioral recovery of the sow is almost completed at 80h postpartum and that the behavioral development of the piglet is almost completed at 45h postpartum.