• Asian-Australasian Journal of Animal Sciences
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• v.27 no.11
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• pp.1526-1531
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• 2014

Matrix metalloproteinases (MMP) are key enzymes involved in cell and tissue remodeling during ovarian follicle development and ovulation. The control of MMP9 transcription in ovarian follicles occurs through a core promoter region (-2,400 to -1,700 bp). The aim of this study was to screen genetic variations in the core promoter region and examine MMP9 transcription regulation and reproduction performance. A single cytosine deletion/insertion polymorphism was found at -1954 $C^+/C^-$. Genetic association analysis indicated significant correlation between the deletion genotype ($C^-$) with total egg numbers at 28 weeks (p = 0.031). Furthermore, luciferase-reporter assay showed the deletion genotype ($C^-$) had significantly lower promoter activity than the insertion genotype ($C^+$) in primary granulosa cells (p<0.01). Therefore, the identified polymorphism could be used for marker-assisted selection to improve chicken laying performance.

• Korean Journal of Animal Reproduction
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• v.13 no.1
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• pp.1-6
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• 1989

A field survey was conducted to obtain the data on reproductive performation of Korean native cattle. The data for this study were taken from 6,461 breeding records of cows raising at general farms in 8 Hanwoo(native cattle) pure breeding areas from June, 1984 through November, 1985. The recycling rate within 30 days, 31 to 60 days, and 61 to 90 days postpartum was 7.5%, 40.0%, and 32.8%, and it amounted to 80.3%, while the non-recyling rate up to 120days postcalving was 8.4%. Conception rate according to insemination(AI) frequencies was 65.7% at 1st AI, 21.3% at 2nd AI, and 8.4% at 3rd AI, respectively. It amounted to 95.4% up to 3rd AI. Clving rate during the spring time was the highest, 39.6%, and tended to be reduced according to summer(31.6%), autumn (16.3%), and winter (12.5%). Spring and summer were the highest seasons for pregnancy and their gestation rates are 33.7% in spring and 39.2% in winter, respectively. The days from calving to estrus and conception, and calving interval of the cows, which calved two or three times, tended to be reduced. However, the more parities, the more they are extended. According to parities, gestation length and services per conception showed irregular tendencies.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.4
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• pp.408-415
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• 1997

Data from 5,311 ewes and 13,076 lambing from 1977 through 1994 were used to analyse both annual and cumulative outputs in terms on total number of lambs born, total lamb weight weaned and total wool produced per ewe for ewe longevity 1 to 8 depending on their productive life in the flock. Ewes at Khushab produced 0.08 more lambs per parturition than ewes at Khizerabad; however, 0.39 less lambs were weaned at Khushab than at Khizerabad. Similarly, cumulative number of lambs born was more at Khushab flock than Khizerabad flock (p < .01). However, total weight of lambs weaned was greater at Khizerabad than Khushab flock (p < .01) for each ewe longevity. Most ewes (35%) were sold/replaced just after their first parturition (i. e. ewe longevity 1). The overall mean for annual sale/replacement was 32 and 23% at Khushab and Khizerabad, respectively. Distribution of growth and reproductive traits from 1977-94 did not show upward or downward trend inspite of heavy sale/replacement except yearly variation. Lack of any genetic progress over the year suggested that random breeding was employed without any scientific selection programme. Annual means for lambs born, lambs weaned and weight of lambs weaned per ewe present in the flock were the highest for ewe longevity 2 compared with other ewe longevity groups. Relative efficiency in terms of net income was highest for ewe longevity 5 followed by ewe longevity 4 and 6 in both flocks.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.3
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• pp.129-136
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• 2021

This study identified single nucleotide polymorphisms (SNPs) that affect the body weight of chickens. Analysis of body weight showed that the Cornish breed had the highest body weight, and the Korean native chicken (Gray Brown) had the lowest body weight. TSH is composed of an α-subunit and a β-subunit, and the TSH-β gene encoding the β-subunit has been reported to be associated with obesity. In chickens, it is located on chromosome 26 and is reported to be associated with growth. The calcium-sensing receptor gene (CaSR) plays a role in the regulation of extracellular calcium homeostasis and is responsible for calcium absorption in the urinary tract, which affects the eggshell quality in poultry. It was shown that TSH-β was strongly correlated with weight in Cornish and Korean native (Gray Brown) chickens, particularly in those with the CC trait. However, CaSR showed no association with body weight in poultry; it was associated with calcium and the eggshell. Thus, selection for TSH-β can be used to produce individuals with more favorable traits in terms of body weight.

• Journal of Animal Reproduction and Biotechnology
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• v.38 no.4
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• pp.247-253
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• 2023

Revolutionary advancements, such as the reduction in DNA sequencing costs and genome editing, have transformed biotechnology, fostering progress in manipulating biomolecules, engineering cells, and computational biology. Agriculture and food production have significantly benefited from tools like high-throughput microarrays, accelerating the selection of desired traits. Genetic engineering, especially utilizing genome editing, facilitates precise alterations in plants and animals, harnessing microbiomes and fostering lab-grown meat production to alleviate environmental pressures. The emergence of new biotechnologies, notably genome editing, underscores the necessity for regulatory frameworks governing LM (living modified) organisms. Global regulations overseeing genetically engineered or genome-edited (GE) organisms, encompassing animals, exhibit considerable diversity. Nonetheless, prevailing international regulatory trends typically exclude genomeedited plants and animals, employing novel biotechnological techniques, from GMO/ LMO classification if they lack foreign genes and originate through natural mutations or traditional breeding programs. This comprehensive review scrutinizes ongoing risk and safety assessment cases, such as genome-edited beef cattle and fish in the USA and Japan. Furthermore, it investigates the limitations of existing regulations related to genome editing in Korea and evaluates newly proposed legislation, offering insights into the future trajectory of regulatory frameworks.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.5
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• pp.666-671
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• 2017

Objective: Aim of the current comparative study was to evaluate production outputs, reproduction efficiency and functional traits in dual-purpose Fleckvieh and Braunvieh cows, reared under temperate European conditions. Methods: A data-set from 414 Fleckvieh and 42 Braunvieh cows and 799 lactations was analysed. ID tag number, milk yield per milking session, number of steps/interval and milk conductivity were recorded and collected daily using AfiMilk 3.076 A-DU software (Afimilk Ltd., Kibbutz, Israel). Production and milk quality data were taken from the results of the official performance recordings and the reproductive outputs of cows were recorded by the research stations veterinarians. Comparisons between the two genotypes were carried out using the one way analysis of variance protocol, with categorical factor being considered the breed of cows. All the statistical inferences were carried out using Statistica software (StatSoft Inc., Tulsa, OK, USA). Results: Fleckvieh cows significantly outperformed ($p{\leq}0.05$) the Braunvieh herd, with average milk yields of $5,252.1{\pm}35.79kg$ and $4,897.6{\pm}128.94kg$, respectively. Age at first calving was significantly ($p{\leq}0.01$) influenced by the breed, with Fleckvieh heifers being more precocious ($32.8{\pm}0.29mo$) compared to those of Braunvieh breed ($35.7{\pm}0.84mo$). Reproduction efficiency as defined by the number of inseminations per gestation, calving interval, dystocia, days dry and days open, was not influenced by genotype (p>0.05). Incidences of sub-clinical mastitis, clinical mastitis, lameness and abortions were not influenced by the breed factor (p>0.05). Stay-ability of cows was significantly ($p{\leq}0.001$) influenced by genotype, with Braunvieh cows having an average age at culling of $117.88{\pm}11.78$ months compared to $90.88{\pm}2.89$ months in Fleckvieh. Conclusion: Overall, results have shown that genotype significantly influenced milk yield, age at first calving and longevity.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.9
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• pp.1342-1348
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• 2007

POU1F1 is a positive regulator for GH, PRL and TSH${\beta}$ and its mutations associate with production traits in ruminant animals. We described a DdeI PCR-RFLP method for detecting a silent allele in the goat POU1F1 gene: TCT (241Ser)>TCG (241Ser). Frequencies of $D_1$ allele varied from 0.600 to 1.000 in Chinese 801 goats. Significant associations of DdeI polymorphism with production traits were found in milk yield (*p<0.05), litter size (*p<0.05) and one-year-old weight (*p<0.05) between different genotypes. Individuals with genotype $D_1D_1$ had a superior performances when compared to those with genotype $D_1D_2$ (*p<0.05). Hence, the POU1F1 gene was suggested to the potential candidate gene for superior milk performance, reproduction trait and weight trait. Genotype $D_1D_1$, characterized by a DdeI PCR-RFLP detection, was recommended to geneticists and breeders as a molecular marker for better performance in the goat industry.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.9
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• pp.1353-1362
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• 2016

Hanwoo, a Korean native cattle (Bos taurus coreana), has great economic value due to high meat quality. Also, the breed has genetic variations that are associated with production traits such as health, disease resistance, reproduction, growth as well as carcass quality. In this study, next generation sequencing technologies and the availability of an appropriate reference genome were applied to discover a large amount of single nucleotide polymorphisms (SNPs) in ten Hanwoo bulls. Analysis of whole-genome resequencing generated a total of 26.5 Gb data, of which 594,716,859 and 592,990,750 reads covered 98.73% and 93.79% of the bovine reference genomes of UMD 3.1 and Btau 4.6.1, respectively. In total, 2,473,884 and 2,402,997 putative SNPs were discovered, of which 1,095,922 (44.3%) and 982,674 (40.9%) novel SNPs were discovered against UMD3.1 and Btau 4.6.1, respectively. Among the SNPs, the 46,301 (UMD 3.1) and 28,613 SNPs (Btau 4.6.1) that were identified as Hanwoo-specific SNPs were included in the functional genes that may be involved in the mechanisms of milk production, tenderness, juiciness, marbling of Hanwoo beef and yellow hair. Most of the Hanwoo-specific SNPs were identified in the promoter region, suggesting that the SNPs influence differential expression of the regulated genes relative to the relevant traits. In particular, the non-synonymous (ns) SNPs found in CORIN, which is a negative regulator of Agouti, might be a causal variant to determine yellow hair of Hanwoo. Our results will provide abundant genetic sources of variation to characterize Hanwoo genetics and for subsequent breeding.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.3
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• pp.427-433
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• 1992

Reproduction and growth to weaning were compared for Brahman crossbred (BX) and a local strain of South-East Asian cattle, "Javanese Zebu" (JZ) and their reciprocal crosses at "Erap" in the humid equatorial lowlands of Papua New Guinea. Forty heifers of each breed were mated continuously, half to bulls of each breed, for five years. BX calved first at 35 months while JZ calved at 31 months. Subsequent calving intervals were very short, at 370 and 341 days. JZ cows weighed about two thirds of the BX cattle at each stage of reproduction. Birth weights and growth to weaning were : BX 35 kg and 0.68 kg/d ; BX male $\times$ JZ female 29.3 kg and 0.53 kg/d ; JZ male $\times$ BX female 30.8 kg and 0.61 kg/d ; JZ 25 kg and 0.50 kg/d. The combination of small cow size, short calving interval and rapid calf growth resulted in the BX male $\times$ JZ female being the most efficient producer, in kg of calf weaned per cow mated per year while the reciprocal cross was the least efficient ; both straight-breds were equal and intermediate. These data show that indigenous equatorial cattle may not be inferior under good grazing conditions. For all traits, breed interactions (heterosis) was small and non-significant.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.1
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• pp.13-16
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• 2010

The effect of exogenous administration of tamoxifen (TAM) on hormonal profile and sexual maturity in Indian native Kadaknath (KN) fowl was investigated. Day-old chicks from the same hatch were randomly divided into 15 groups with 20 chicks in each group (5 treatments${\times}$3 replicates). The chicks were placed in battery brooders with wire-mesh floors and reared under uniform husbandry conditions (14 h light/d, 25-32${^{\circ}C}$) on a standard basal diet. At the age of two weeks (wk), birds from the control group ($T_{1}$) were injected with maize oil intramuscularly (I/M), whereas the other four experimental groups $T_{2}$, $T_{3}$, $T_{4}$ and $T_{5}$ were given tamoxifen (I/M) dissolved in maize oil at the rate of 0.5 mg (0.5 TAM), 1.0 mg (1.0 TAM), 2.5 mg (2.5 TAM) and 5.0 mg (5.0 TAM)/kg body weight, respectively, up to 30 wks on every alternate day. At every 6-wk interval, blood samples were collected from nine birds of each treatment group for estimation of estrogen and progesterone. The same birds were sacrificed for determination of the weight of ovary, oviduct, liver and adipose tissue. There was no significant difference in egg production traits except onset of lay and egg number. Low doses of TAM ($T_{3}$) advanced the onset of egg laying by 15 days over the control. Tamoxifen influenced the hormonal profile (estrogen and progesterone) in a dose dependent manner. However, higher doses of TAM suppressed ovary and oviductal growth. From this study, it may be concluded that lower doses of TAM enhanced sexual maturity while higher doses suppressed ovary and oviductal growth.