• Asian-Australasian Journal of Animal Sciences
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• 제19권11호
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• pp.1524-1528
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• 2006

A total of 437 animals, comprising lambs aged between 3 and 12 months and adults of either sex of Muzaffarnagari sheep maintained at the Central Institute for Research on Goats, Makhdoom, Farah, Mathura, India were screened to assess the prevalence of Haemonchus contortus infection following natural infection and to identify the various factors affecting faecal egg count (FEC) and packed cell volume (PCV) of ewes and their genetic control. The relationships between FEC, PCV and body weight were also estimated. The prevalence rate for H. contortus infection in the flock under study was 15.7% indicating much lower occurrence of worm infection in lambs up to one year of age. On the other hand, a large proportion i.e., 67.7% of sheep was refractive to natural H. contortus infection. The random effect of sire significantly contributed (p<0.01) variation in log-transformed FEC (LFEC) of ewes. The season of birth had a significant (p<0.01) effect on LFEC of ewes. The lactating ewes had significantly (p<0.01) higher faecal egg counts compared to dry and pregnant ewes. The linear regression effects of the age of ewes on LFEC of animals were significant (p<0.01) in the present study. The heritabilities of LFEC, PCV and body weights of ewes during the course of infection were moderate to high in magnitude and ranged from 0.24 to 0.47. The LFEC of ewes was significantly (p<0.05) and negatively correlated with PCV at both genetic and phenotypic level. The genetic and phenotypic relationships between LFEC and body weights of ewes were -0.26 and -0.06 for this breed. The genetic correlation of PCV and body weight of ewes was positive and high (0.58) and statistically significant (p<0.05) but it was negatively correlated (-0.01) with body weight at the phenotypic level.

• Animal Bioscience
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• 제36권7호
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• pp.991-1002
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• 2023

Objective: This study aimed to elucidate the underlying gene regions responsible for productive, phenotypic or adaptive traits in different ecological types of Tibetan sheep and the discovery of important genes encoding valuable traits. Methods: We used whole-genome resequencing to explore the genetic relationships, phylogenetic tree, and population genetic structure analysis. In addition, we identified 28 representative Tibetan sheep single-nucleotide polymorphisms (SNPs) and genomic selective sweep regions with different traits in Tibetan sheep by fixation index (Fst) and the nucleotide diversity (θπ) ratio. Results: The genetic relationships analysis showed that each breed partitioned into its own clades and had close genetic relationships. We also identified many potential breed-specific selective sweep regions, including genes associated with hypoxic adaptability (MTOR, TRHDE, PDK1, PTPN9, TMTC2, SOX9, EPAS1, PDGFD, SOCS3, TGFBR3), coat color (MITF, MC1R, ERCC2, TCF25, ITCH, TYR, RALY, KIT), wool traits (COL4A2, ERC2, NOTCH2, ROCK1, FGF5, SOX9), and horn phenotypes (RXFP2). In particular, a horn-related gene, RXFP2, showed the four most significantly associated SNP loci (g. 29481646 A>G, g. 29469024 T>C, g. 29462010 C>T, g. 29461968 C>T) and haplotypes. Conclusion: This finding demonstrates the potential for genetic markers in future molecular breeding programs to improve selection for horn phenotypes. The results will facilitate the understanding of the genetic basis of production and adaptive unique traits in Chinese indigenous Tibetan sheep taxa and offer a reference for the molecular breeding of Tibetan sheep.

• 한국의류학회지
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• 제32권10호
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• pp.1559-1570
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• 2008

Since brought into from the economic life of nomads, the felt, the target of this study, has been developed in various ways of giving the functions of class symbol as well of protection against the cold and of ornamentation. Therefore, the study on how the felt was developed in Joseon Dynasty and how different culture from nomadic tribes it formed is significant in comprehensively under,;landing the economic, social and natural environmental factors in the Dynasty. The felt named "Jeon" has been constantly appearing in Korea from the ancient time, but it was not produced actively in the early part of Joseon Dynasty. That's why it was not a climatic condition suitable for sheep-breeding, and the government managed sheep-breeding but it aimed primarily at not producing clothing materials but having memorial ceremonies. Since sheep-breeding was not widely spreaded, production of Jeon was limited and some part was imported from China, so it was one of rare valuable goods. Therefore, the felt of wools named "Yangmojeon", the colored felt named "Chaejeon", etc. were used as liking items in the high-class society, and their materials and components were a little different depending on the official post. On the other hand, people in the low-class society used to wear the felt hats made of cattle feathers and miscellaneous fur, named "Jeonlip" and "Beougeoji". Since the middle of Joseon Dynasty, use of the felt was divided into two groups according to the users and the function, along with successful spreading of cotton and development of market economy. The function of Jeon to protect against the cold was replaced by cotton, but the felt hats of Beongeoji, Jeonlip, etc. were worn by common people continuously. As seen above, it is considered that the felt culture in Joseon Dynasty was formed very differently from the nomadic culture, because of its historical and sociocultural characteristics, and it had unique developing progress among all available fabrics.

• Animal Bioscience
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• 제34권9호
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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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• 제24권6호
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• pp.739-743
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• 2011

The aim of this paper was to estimate genetic parameters for body weight and five body measurements for an experimental population of Iranian Makooei sheep maintained at the Makooei Sheep Breeding Station at Makoo, Iran. To do this, yearling live weight (YW), and five body measurements, i.e., body length (BL), heart girth (HG), height at withers (HW), height at back (HB) and scrotal circumference (SC), were analyzed in a multi-trait animal model using the DXMUX program of DFREML software package. Heritability estimates were $0.22{\pm}0.08$, $0.11{\pm}0.06$, $0.21{\pm}0.07$, $0.17{\pm}0.06$, $0.17{\pm}0.06$ and $0.32{\pm}0.10$ for YW, BL, HG, HW, HB and SC, respectively. These estimates indicate that selection in Makooei sheep would generate moderate genetic progress in body weight and body measurements. Scrotal circumference, as an indicator of reproductive potential, exhibited the highest heritability. This trait, therefore, could successfully be used to increase productivity of males and, indirectly, female fertility. Genetic correlations between traits studied were all positive and ranged from 0.15 (YW/HB) to 0.99 (HW/HB). Phenotypic correlations were also positive and ranged from moderate (0.32, HW/SC) to high (0.94, HW/HB). Positive genetic and phenotypic correlations indicate that improvement in body measurements both at the genetic and phenotypic levels is expected through selection on body weight and vice versa.

• Asian-Australasian Journal of Animal Sciences
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• 제25권3호
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• pp.428-434
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• 2012

The aim of this study was to determine the quality of modified atmosphere (MA) packaged meat from Pomeranian rams slaughtered at 50 and 100 days of age. Determined: chemical composition, physicochemical and sensory properties of meat, and the fatty acid profile of intramuscular fat. Meat from 100-d-old lambs was characterized by a significantly higher content of dry matter, total protein and crude fat, a darker color and higher physiological maturity ($p\leq0.01$). Meat from younger lambs was marked by a better water-holding capacity ($p\leq0.05$), a lower energy value and higher concentrations of monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). An increase in the content of dry matter, total protein and ash, and energy value was noted in MA-stored meat. Meat pH decreased over MA storage and the sensory properties deteriorated. The studied meat remained safe from microbial contamination during storage.

• Asian-Australasian Journal of Animal Sciences
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• 제17권5호
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• pp.594-597
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• 2004

A pedigree file of 4,628 records of Muzaffarnagari sheep, maintained at Central Institute for Research on Goats (CIRG), Makhdoom, was used to calculate the inbreeding coefficient of the flock. The flock had been closed for about 25 years (1978 to 2002). The investigation was aimed to study the effects of inbreeding on survivability of lambs. The cumulative survivability of lambs i.e., lambs survived up to 3, 7 and 15 days, 1, 2, 3, 6, 9 and 12 months after birth was considered for the study. The average level of inbreeding of lambs was 1.60%, ranging from 0 to 26.4%. The average inbreeding coefficient of dam over the periods was 1.00% and it ranged from 0 to 25.0%. Significant (p<0.05) adverse effect of lamb's inbreeding was observed on survivability of lambs at all ages except up to 3 and 7 days after birth. On an average, 1% increase in individual inbreeding coefficient should reduce the 0.31, 0.34, 0.32, 0.31, 0.33, 0.44 and 0.49 percent lamb survival up to the age of 15 day and 1, 2, 3, 6, 9 and 12 months, respectively. Ewes inbreeding had non-significant effects on lamb survival at all ages.

• Asian-Australasian Journal of Animal Sciences
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• 제13권8호
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• pp.1162-1172
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• 2000

The research was conducted to quantify farm and household characteristics of sheep farmers, evaluate farmer access to and the effectiveness of livestock services in sheep farming areas, and examine regional constraints to improving sheep productivity and profitability in Nepal. A rapid diagnostic socioeconomic survey of 200 sheep farmers was carried out in 1996 and all four ecological regions (Trans-Himalayan, Mountains, Hills and Terai), each with a distinct local sheep breed, were represented in the survey. Six major constraints were identified: (a) poor performance of local sheep breeds, (b) a serious seasonal deficit of pasture and other feed, (c) the lack of an organized market for wool and meat, (d) poor access to agricultural credit, (e) primitive shearing equipment, and (f) an inadequate supply of drinking water for sheep. Strategies to assist farmers develop their sheep management skills, improve access and quality of support services, improved technology adaptable to local conditions and effective linkages with local carpet and meat industry are likely to overcome the constraints and alleviate persistent poverty faced by sheep farmers in Nepal.

• Asian-Australasian Journal of Animal Sciences
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• 제19권10호
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• pp.1390-1393
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• 2006

Data spread over 11 years (1986-1996) pertaining to a synthetic population developed by inter se mating of half-breds of Corriedale and Russian Merino with Nali maintained at CCS Haryana Agricultural University, Hisar were utilized for the estimation of genetic parameters for growth traits. The means for birth weight (BWT), weaning weight (WWT), six month body weight (SWT), yearling weight (YWT), preweaning daily gain (PRW) and post weaning daily gain (POW) were 3.35 kg, 10.79 kg, 13.28 kg, 18.96 kg, 82.6 gm and 27.6 gm, respectively. The effects of year and season of birth and sex of lamb were significant for all the traits under study except the effect of season of birth for WWT, SWT and PRW. No definite trend was observed over the years for the averages of body weight and gain. Lambs born during the spring season performed better for BWT, WWT and PRW while the performance of lambs born during autumn was better for the other traits included in the study. The male lambs were heavier than the females for body weight at all stages and gain in weight. The heritability estimates for WWT and PRW were low; for BWT and SWT were moderate and for YWT and POW were high. Birth weight had high heritability and high genetic correlations with subsequent body weights and gains but due to the presence of a maternal effect on BWT and WWT, a sequential selection procedure is recommended for the improvement of growth rate in sheep.

• Asian-Australasian Journal of Animal Sciences
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• 제33권9호
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• pp.1369-1377
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• 2020

Objective: The main objectives of the present study were to assess the genetic diversity, population structure and to appraise the efficiency of ongoing selective breeding program in the closed nucleus herd of Nellore sheep through pedigree analysis. Methods: Information utilized in the study was collected from the pedigree records of Livestock Research Station, Palamaner during the period from 1989 to 2016. Genealogical parameters like generation interval, pedigree completeness, inbreeding level, average relatedness among the animals and genetic conservation index were estimated based on gene origin probabilities. Lambs born during 2012 and 2016 were considered as reference population. Two animal models either with the use of F_i or ΔF_i as linear co-variables were evaluated to know the effects of inbreeding on the growth traits of Nellore sheep. Results: Average generation interval and realized effective population size for the reference cohort were estimated as 3.38±0.10 and 91.56±1.58, respectively and the average inbreeding coefficient for reference population was 3.32%. Similarly, the effective number of founders, ancestors and founder genome equivalent of the reference population were observed as 47, 37, and 22.48, respectively. Fifty per cent of the genetic variability was explained by 14 influential ancestors in the reference cohort. The ratio f_e/f_a obtained in the study was 1.21, which is an indicator of bottlenecks in the population. The number of equivalent generations obtained in the study was 4.23 and this estimate suggested the fair depth of the pedigree. Conclusion: Study suggested that the population had decent levels of genetic diversity and a non-significant influence of inbreeding coefficient on growth traits of Nellore lambs. However, small portion of genetic diversity was lost due to a disproportionate contribution of founders and bottlenecks. Hence, breeding strategies which improve the genetic gain, widens the selection process and with optimum levels of inbreeding are recommended for the herd.