• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.255-260
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• 1994

Calving records of 107 heifers from two breed groups were used to identify the major factors contributing to calving difficulty (dystocia) and compare the influence of pelvic diameters, weight and height of heifers measured after breeding and before calving on dystocia. The horizontal and vertical pelvic diameters, hip height and weight of heifers were measured two months after breeding and again two months before calving. Snell transformed calving difficulty scores (0 = normal to 100 = surgical intervention) were used in analyzing the data by analysis of covariance. Body condition score of the heifer, sire birth weight of the calf, birth weight of the calf, and ratio of calf birth weight to pelvic area all had significant effects on dystocia. Calf birth weight, ratio of calf birth weight to pelvic area, and heifer's condition score were especially important. However, sex of calf did not have a significant influence on dystocia. Generally, the variables measured before calving accounted for a higher proportion of variation in dystocia than those measured after breeding. Thus, based on the relative importance of the major factors affecting dystocia, it is suggested that selection of bulls with low birth weight for breeding on normal size heifers with optimum body condition score, and well developed pelvic opening, would be effective in reducing the incidence and severity of dystocia in beef heifers.

• Asian-Australasian Journal of Animal Sciences
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• 제28권1호
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• pp.69-78
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• 2015

A non-traditional forage-based protocol was employed to evaluate replacement heifer growth, fertility, and economics between small frame (SF, 3.50; n = 50) and large frame (LF, 5.56; n = 50) heifers using three increasing gain growth phases. Preceding an 85 d growing-breeding period (Phase 3; P3) the heifers were managed as a common group for Phases 1 and 2 (P1 and P2). During P1, heifers grazed common fields of unharvested corn and corn residue (total digestible nutrients [TDN] 56%) with supplemental hay. For P2, heifers grazed early spring crested wheatgrass pasture (CWG; TDN 62%) that was followed by the final P3 drylot growing and breeding period (TDN 68%). Small frame heifers were lighter at the end of P1 in May and at the start of P3 breeding in August (p = 0.0002). Percent of mature body weight (BW) at the end of P1 (209 d) was 48.7% and 46.8%, respectively, for the SF and LF heifers and the percent pubertal was lower for SF than for LF heifers (18.0% vs 40.0%; p = 0.02). At breeding initiation (P3), the percentage of mature BW was 57.8 and 57.2 and the percentage pubertal was 90.0 and 96.0 (p = 0.07) for the SF and LF heifers, respectively; a 5-fold increase for SF heifers. Breeding cycle pregnancy on days 21, 42, and 63, and total percent pregnant did not differ (p>0.10). In drylot, SF heifer dry matter intake (DMI) was 20.1% less (p = 0.001) and feed cost/d was 20.3% lower (p = 0.001), but feed cost/kg of gain did not differ between SF and LF heifers (p = 0.41). Economically important live animal measurements for muscling were measured in May and at the end of the study in October. SF heifers had greater L. dorsi muscle area per unit of BW than LF heifers (p = 0.03). Small frame heifer value was lower at weaning (p = 0.005) and the non-pregnant ending heifer value was lower for SF heifers than for the LF heifers (p = 0.005). However, the total development cost was lower for SF heifers (p = 0.001) and the net cost per pregnant heifer, after accounting for the sale of non-pregnant heifers, was lower for SF heifers (p = 0.004). These data suggest that high breeding efficiency can be attained among March-April born SF and LF virgin heifers when transitioned to a more favorable May-June calving period through the strategic use of grazed and harvested forages resulting in a lower net cost per pregnant SF heifer.

• 한국수정란이식학회지
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• 제8권2호
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• pp.105-109
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• 1993

This study was carried out to propagate Korean native cattle using beef recipients by embryo transfer. Seven Korean native cattle donors were superovulated with FSH 32mg and Embryos collected from donors were frozen and preserved in National Animal Breeding Institute. Frozen-thawed embryos were transferred to synchronized 40 beef recipients nonsurgically in Daekwanryeong Branch of National Animal Breeding Institute. The results obtained were as follows : 1. Total ova and transferable embryos per donor were 11.4 and 11.1 from 7 donors, respectively. 2. Among 40 recipients transferred with frozen-thawed embryos, 20 were pregnant(50.0%). 3. The pregnancy rate according to time from embryo thawing to transfer was higher when transferred within 3 hours than after 3 hours(57.6% vs. 14.3%). 4. The cow recipients showed slightly higher pregnancy rate than the heifer(53.3% vs. 48.0%). 5. Two grade embryos showed higher pregnancy rate than 1 grade(66.7% vs. 45.2%).

• 한국유기농업학회지
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• 제31권4호
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• pp.327-341
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• 2023

The Ministry of Agriculture, Food and Rural Affairs, Hanwoo Association and Nonghyup have discussed proactive reduction measures for cows in response to concerns about an oversupply of hanwoo to ensure supply stability. This study aims to empirically analyze whether the cow fattening support program is being implemented in line with its objectives. Based on the analysis of beef traceability data, the slaughter age of participating cows was reduced by 7.6 to 14.7 months compared to non-participating cows. And heifer was reduced 1.5 months in their slaughter age. In case of parity, participating cows showed a reduction of 1.4 compared to non-participating cows. Through the SUR model, an analysis was conducted to examine the effect of the cow fattening support program on the suppression of calf production numbers. The analysis results showed that the calf production numbers are positively influenced by the number of fertile cow and the quantity of semen sales. Furthermore, it is estimated that calf production decreased as the fat index increased, and during the period when the cow fattening support program was implemented, an average monthly suppression of 3,558 calves was observed.

• 한국수정란이식학회지
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• 제31권3호
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• pp.261-265
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• 2016

The aim of the present study was to evaluate and estimate timing of artificial insemination (AI) in Hanwoo heifer (Korean native cattle) that is the most popular breed of beef cattle in Korea. To determine changes in body weight of heifers around AI, body weight were measured at different stages either before or after AI. We found that daily body weight gain was higher in the pregnant cows after AI. We also investigate correlation between body mass measured by shoulder height and body length, and conception rates, used (body length+ height)2 instead of height2 for body mass index (BMI), and found that relatively more BMI heifers (>55) showed higher conception rates. Finally, we estimated body weight by measuring should height (SH), heart girth (HG), and body length (BL); $BW=3.93372^*HG-2.90985^*SH-0.021^*BL$. In addition, we observed that HG is most closely correlated with BW; $y(BW)=1.77355^*x(HG)$, $R^2=0.98881$. In summary, we can determine the best timing of AI using body measurement and its application including BMI.

• Asian-Australasian Journal of Animal Sciences
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• 제12권6호
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• pp.850-853
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• 1999

Angus postweaning daily gain (PWDG) was analyzed to investigate effects of the heterogeneous variance and the genotypes by sex interaction on prediction of EBVs with data sets of various environmental levels. A whole data (16,239 records) was divided into six data sets according to averages of the best linear unbiased estimator (BLUE) of herd environment. The results comparing prediction models showed that single-trait model is adequate for most of the data sets except for the data set of poor environment for both of the bulls and the heifers where the heterogeneity of variance and the genotypes by sex interaction exists. In the prediction with the data set of the low environment level, the bull's EBVs by single-trait models had high product moment correlations with male EBVs of the bulls by the multitrait model. Whereas the heifer's EBVs had moderate correlations with female EBVs by the multitrait model. This moderate correlation seems to be resulted by the heterogeneity of variance and low heritability of the heifer's PWDG. The prediction models with heterogeneity of variance had little effect on the prediction of EBVs for the data sets with moderate to high genetic correlations.

• Asian-Australasian Journal of Animal Sciences
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• 제12권6호
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• pp.846-849
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• 1999

Angus postweaning daily gain (PWDG) were analyzed to investigate heterogeneous variance by sex. A set of data (16,239 records) was divided into six sub-data sets according to level of environment. REML estimation was conducted by a multitrait model, where PWDG in each sex was treated as a separate trait. Estimates showed diversity among environmental levels, where the heritability for heifers was high in good environment but low in poor environment. The bull's estimates varied among environmental levels. The largest heterogeneity of phenotypic variance between sexes was estimated in a data set of the poor environment level. The genetic correlations between the heifer's PWDG and the bull's PWDG were high in the good environment and low in the poor environment (-0.17). The results suggest existence of genotype by sex interaction in the poor environment.

• Asian-Australasian Journal of Animal Sciences
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• 제10권5호
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• pp.471-477
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• 1997

A study detennined whether certain biochemical and physiological variables were altered during marginal Zn deficiency. Ten weaned crossbred Hereford Angus heifer calves, weighing $163{\pm}2kg$, were utilized. Five calves were fed a Zn - deficient (- Zn) brome-alfalfa hay diet containing 17 mg Zn/kg diet DM, and five calves were fed a Zn-adequate (+Zn) diet with 23 mg Zn/kg diet DM from $ZnSO_4$ added to the - Zn diet (total diet, 40 mg Zn/kg diet DM), for 32 d. At 21 d the - Zn calves had a reduction (p < .05) in feed efficiency. By 25 d, plasma Zn and alkaline phosphatase concentrations were reduced (p < .05) in the - Zn calves. Blood urea nitrogen, glucose, insulin, IGF-I, Cu plasma concentration and Zn and Cu concentrations of red blood cell (RBC) and liver were not altered (p > .05) by the - Zn diet through 25 d. In response to a single i. m. injection of dexamethasone (20 mg) on d 25, calves fed the two dietary Zn amounts showed no changes (p > .05) in plasma or RBC Zn and Cu concentrations, serum IGF-I, insulin, and glucose when measured at 6, 12, 24, 48, 72, and 96 h after injection. In response to an intradermal injection of phytohemagglutinin on d 30, cell mediated immune (CMI) response was reduced (p < .05) in the - Zn calves. These observations indicate that during a marginal Zn deficiency in calves, there was a decrease in feed efficiency, plasma Zn, serum alkaline phosphatase, and CMI response.

• Asian-Australasian Journal of Animal Sciences
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• 제15권4호
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• pp.549-554
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• 2002

An experiment was conducted to examine the performance and carcass characteristics of Hanwoo (Korean native beef cattle) heifers and the fatty acid composition of muscle tissues of the heifers when the animals fed diets containing four levels of dried wormwood (Artemisia sp.). For the experiment the animals were given a basal diet consisting of rice straw and concentrate mixed at 3:7 ratio (on DM basis). The treatments were designed as a completely randomized design with two feeding periods. Heifers were allotted in one of four dietary treatments, which were designed to progressively substitute dried wormwood for 0, 3, 5 and 10% of the rice straw in the basal diet. There was no difference in body weight gain throughout the entire period between the treatment groups. Feed conversion rate was improved (p<0.05) only by the 3% dried wormwood inclusion treatment compared with the basal treatment. Carcass weight, carcass yield and backfat thickness of all treatment groups were not altered by wormwood inclusion. The 5% dried wormwood inclusion significantly increased (p<0.05) the size of loin-eye area over the other treatments. The higher levels (5 and 10%) of dried wormwood inclusion resulted in the higher (p<0.05) water holding capacity (WHC) in loin than the lower levels (0 and 3%) of wormwood inclusion. The redness ($a^*$) and yellowness ($b^*$) values of meat color were significantly lower (p<0.05) in the top round muscle of heifers fed the diet containing 3% dried wormwood. There was a profound effect of the progressively increased intake of dried wormwood led to the linear increase of unsaturated fatty acid content and the linear decrease of saturated fatty acid content in the muscle tissues of Hanwoo heifers. It is concluded that the feeding diets containing dried wormwood substituted for equal weights of rice straw at 5% levels would be anticipated to provide better quality roughage for beef heifer production and economical benefits for beef cattle producers.

• 현장농수산연구지
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• 제13권1호
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• pp.103-114
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• 2011

본 연구는 설문조사를 통하여 한우 송아지의 이유월령이 거세한우의 출하체중 및 송아지 폐사에 미치는 영향을 조사하고자 수행되었다. 설문은 방문을 통하여 진행되었고, 조사된 총 농가수는 862농가로서, 가임암소사육규모별 조사 농가수는 10~19두 188호, 20~49 364호, 50~99두 227호, 100두 이상 83호로 나타났다. 이유시기는 3개월령 농가의 비율이 40.4%로 가장 높게 나타났으며, 각 사육규모별로도 3개월령이 가장 높은 비율을 차지하였다. 이유월령 3개월을 초과하는 각 사육규모별 농가의 비율은 10~19두 규모가 53.5%로서 가장 높게 나타났으며, 20~49두 규모 37.5%, 50~59두 규모 43.7%, 100두 이상 규모는 39.0%로 조사되었다. 조사 농가의 사육규모는 거세한우 출하개월령, 출하시 생체중 및 도체중에 영향을 미치지 않았다. 그러나 이유월령의 증가와 도체중은 유의적으로 음(-)의 상관관계를 가지고 있는 것으로 조사되었다. 따라서 도체중은 이유월령이 짧을수록 증가하는 것으로 나타났다. 조사 농가의 평균 한우 송아지 폐사율은 5.6%로 나타났으며, 사육규모는 한우 송아지의 폐사율에 영향을 미치지 않았다. 반면에 이유월령과 한우 송아지 폐사율 및 폐사 원인인 설사 비율은 유의적으로 양(+)의 상관관계를 가지고 있는 것으로 조사되었다. 따라서 한우 송아지 폐사율은 이유월령이 짧을수록 감소하는 것으로 나타났다. 본 설문조사의 결과, 이유시기의 단축은 거세한우의 도체중 증가와 송아지 폐사율 감소의 효과로 한우 번식우 농가의 수익성을 향상시킬 수 있음을 보여주고 있다.