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

• 한국초지조사료학회지
• /
• 제13권2호
• /
• pp.139-144
• /
• 1993

홀스타인 암소 육성우에 옥수수사일리지와 볏짚을 급여하면서 영양수준을 80, 100 그리고 12%(NRC 요구량 대비)로 급여할때 육성우의 중체량 및 영양소 섭취량을 조사하기 위하여 육성우 30두를 각 처리당 5두씩 완전임의 배치로 공시히여 체중 400kg까지 시험을 수행한 결과는 다음과 같다. 1. 옥수수사일리지 및 볏짚급여시 육성기 최대 일당중체량은 각각 체중 200과 250kg 일때였다. 2. 체중이 증가할수록 DM, CP 및 TDN 요구량은 증가되었으며 체중 250~300kg 일때 이들 영양소 요구량이 가장 높았다. 3. 체중 250~300kg일때 체중(X)과 DM, CP, TDN 섭취량(I)과의 관계는 다음과 같다. DMI = 8.0168X - 0.0209 (r=0.7986$^{**}$) CPI = 101428X - 0.0145 (r=0.5787$^{**}$) TDNI = 6.7620X - 0.3702 (r=0.6877$^{**}$)

• Asian-Australasian Journal of Animal Sciences
• /
• 제24권9호
• /
• pp.1318-1328
• /
• 2011

The tropics is not an ideal location for calf rearing as the high temperatures and humidities introduce many potential disease problems to milk fed calves. In addition, the type of dairy farming (generally poorly resourced small holder farming) and the general lack of awareness of the long term implications of poorly reared stock do not encourage farmers to pay close attention to their calf and heifer rearing systems. Surveys of calf rearing systems in Asia, tropical Africa and South America highlight the high calf and heifer mortalities. A range of 15 to 25% pre-weaning calf mortality is typical on many tropical dairy farms. It is often as high as 50%, indicating very poor calf management. This contrasts with US findings of less than 8% mortality from birth to 6 months while surveys of Australian farmers report only 3% losses. Simple extension programs on farms in Sri Lanka and Kenya have drastically reduced calf mortalities and improved pre-weaning growth rates. Improved management strategies leading to lower calving intervals, higher calving rates, reduced still born and pre-weaned calf mortalities and fewer non pregnant heifers can supply many more dairy herd replacements than currently occurs. Such strategies can increase the number of replacement heifer calves in the herd from 15 to over 35%, thus allowing farmers to increase their herd sizes through natural increases. Simple management procedures such as ensuring adequate intake of good quality colostrum within the first 12 hours of life, housing and good hygiene to minimise disease transfer, providing clean drinking water, developing appropriate feeding protocols to encourage early rumen development and paying closer attention to climate control and animal health can all lead to improved calf vigour and performance. Good record keeping is also important so farmers can more easily identify susceptible calves and quickly treat potential problems.

• Reproductive and Developmental Biology
• /
• 제37권1호
• /
• pp.29-33
• /
• 2013

The objective of this work was to analyze the concentrations of progesterone (P4) and estrogen (E2) hormones changed during estrus synchronization in dairy heifers. Estrus synchronization was carried out with CIDR$^{(R)}$ (Controlled Intravaginal Drug Release) devices. Corpus luteum (CL) was classified into three grades based on its size and palpable characteristics. The concentrations of P4 and E2 were measured by enzyme-amplified chemiluminescence. Serum P4 concentration was markedly low at the estrus stage (36 hrs after removal of CIDR) compared to other stages, while E2 concentration was kept high during estrus stage. The serum P4 concentration was highest in the CL classified into grade I. These results indicate that P4 concentration could be used as a criteria for determining recipients for artificial insemination or embryo transfer in dairy cattle.

• Asian-Australasian Journal of Animal Sciences
• /
• 제17권2호
• /
• pp.174-178
• /
• 2004

The objectives of this study were to investigate the ovarian responsiveness of juvenile calves to exogenous gonadotropin treatments and to establish the oocyte retrieval technique for prepubertal heifers. Three 78-day-old calves were treated with 4 doses (40, 30, 30 and 30 mg) of FSH (Folltropin V) at 12 h interval up to 229 day-old. Surgical oocyte retrieval was performed 24 h after the last injection of FSH. Calves with good ovarian responses to FSH treatment had an average ovarian size of $5{\times}3$ cm compared to $3{\times}2$ cm in the less-responsive animals. Large variations were observed in the number of total follicles ($51{\pm}45$), aspirated follicles ($39{\pm}36$), oocytes recovered ($23{\pm}25$) and usable oocytes recovered ($11{\pm}19$) during 78 to 229 day-old. Oocytes derived from prepubertal calves had significantly lower maturation rate than those from cows (34 vs. 100%, p<0.05). Mean diameters of calf oocytes ($144{\pm}1{\mu}m$) and ooplasm ($110{\pm}1 {\mu}m$) were significantly lower than those of cows ($149{\pm}1$ and $25{\pm}1{\mu}m$, respectively). The diameter of the ooplasm also increased significantly after in vitro maturation (IVM) ($108{\pm}1$ vs. $112{\pm}1{\mu}m$). However, further studies are required to optimize the IVP system for the oocytes derived from prepubertal heifers.

• Asian-Australasian Journal of Animal Sciences
• /
• 제6권2호
• /
• pp.271-274
• /
• 1993

Four Holstein heifers were used in the present study to investigate the effect of standing and lying behaviors on heat production and physiological responses under low (L), medium (M) and high (H) levels of TDN intake. Rectal temperature (RT), respiration rate (RR), heart rate (HR), heat production (HP) and animals behavior (standing time, ST) were measured continuously for 5h (11:00-16:00) periods. There was a tendency for increased RT with TDN intake, and no difference in RT was observed between standing and lying. The RR, HR and HP during standing were significantly higher (p<0.05) than during lying. The difference between standing and lying HP were 4.41, 4.68 and $5.37kJ/kg^{0.75}$ h for L, M and H of TDN intake, respectively. These values showed that standing HP was 18.6-20.9% higher than lying HP. A multiple regression analysis of HP ($kJ/kg^{0.75}$ h) on TDN intake ($g/kg^{0.75}$ d) and ST (min/h) was HP = 7.75 + 0.28 TDN intake + 0.12 ST (R = 0.84). This analysis showed that the total HP not only depend on feed intake levels, but also depends on animal behavior. It was suggested that the change in HP due to the change in feed intake and animal behavior would influence the level of heat loss which was indicated by the changes in the RR and HR.

• Asian-Australasian Journal of Animal Sciences
• /
• 제33권10호
• /
• pp.1691-1698
• /
• 2020

Objective: The study sought to estimate the relationship between body surface temperature (BST) and temperature humidity index (THI) and to present the validity of THI as a heat stress index in the field. Methods: Eight Hanwoo heifers (20 to 32 month) were examined in a field trial, with a space allowance of 10 ㎡ per head. The BST was measured using an infrared thermographic camera. The BST of five body regions (eyes, hindquarters, nose, part of horns, and ears), ambient temperature (AT), and relative humidity (RH) were measured 7 times daily (07, 09, 11, 13, 15, 17, and 19 h) during each season with three replicates. Results: The THI ranged 34.0 to 56.9 during spring (AT, -1.0℃ to 13.4℃), 75.1 to 84.7 during summer (AT, 24.9℃ to 33.6℃), 55.8 to 70.9 during autumn (AT, 13.0℃ to 26.0℃) and 17.5 to 39.2 during winter (AT, -10.4℃ to 1.0℃). In the regression analysis, the coefficient of determination (R²) between THI and BST was 0.88, 0.72, 0.83, 0.86, and 0.85 for the eyes, hindquarters, nose, part of horn, and ears area, respectively. This indicates that BST has a strong correlation with AT and RH. Expression equations were estimated as Y (THI) = 31.54+0.1085X (BST of eyes) and Y (THI) = 30.48+0.1147X (BST of hindquarters) by simple linear regression analysis in this experiment. Conclusion: Consequently, the upper bound for heat stress estimation can be specified ranging from THI of 65 (eyes) to 70 (hindquarters). From this we can expect a precise feeding system for Korean native cattle in the field.

• Asian-Australasian Journal of Animal Sciences
• /
• 제10권5호
• /
• pp.519-522
• /
• 1997

Buffalo heifers weighing from 400 - 500 kg and having a history of reproductive problems like anestrus, irregular estrus or failure to conceive after repeated inseminations were administered subcutaneously with estradiol-$17{\beta}$ and progesterone in two dosage rate 0.1 mg and 0.25 mg, respectively, per kg body weight per day for 7 days in experiment-I and 0.1 mg and 0.125 mg, respectively, per kg body weight per day for 7 days in experiment II. In experiment-I, 9 out of 10 buffaloes responded positively to the hormonal treatment. Milk secretion started between 14-20 days after the start of the treatment. The total milk yield in the successfully induced animals varied from 471.98-625.40 kg. The average daily milk yield varied from 2.08-2.76 kg and peak yield from 3.6-5.3 kg. The time taken to reach peak yield varied from 12-14 weeks. In experiment - II, the established lactation response was absent, although milk secretion process was initiated, the yield could not reach more than 50 - 100 gm at each milking. In experiment - I, the first estrus occurred between days 87 - 231 following the hormonal treatment. Four animals in which lactation was established successfully got pregnant after one or two services. In experiment - II the first estrus occurred between 85 - 173 days following the treatment and only one animal got pregnant.

• 한국가축번식학회지
• /
• 제24권1호
• /
• pp.77-82
• /
• 2000

한우에 있어서 생체내 난자 채취기술과 체외수정 기술을 접목하여 고능력 한우로부터 수정란을 대량 생산하기 위한 기초 연구로서, 발정주기에 따른 난소의 크기와 난포의 발육 양상을 초음파진단기를 이용하여 조사하였으며, 여러 마취.진정제를 조합 이용하여 마취효과를 조사하여 얻어진 결과는 다음과 같다. 1. 한우의 난소의 크기는 도축 난소의 실측치와 생체에서 초음파진단기를 이용한 측정치간에 유의적인 차이가 인정되지 않았으며, 발정주기중 난포기때와 황체기때 크기를 비교해도 유의적인 차는 인정되지 않았다. 2. 한우의 발정주기중 난소내 발육하는 소난포와 중난포의 수는 3일과 12일 째에 증가하는 한 발정주기에 2회의 난포발육기가 있었다. 3. 한우의 최적 마취조합은 0.3$m\ell$ 의 Rompun(equation omitted)을 근육주사하고 5$m\ell$의 lidocaine 을 경막외 마취한 후 lidocaine 2$m\ell$을 자궁경에 도포하는 경우였다.

• Reproductive and Developmental Biology
• /
• 제36권1호
• /
• pp.87-93
• /
• 2012

The purpose of this experiment is to compare the pregnancy rate (PR) according to the state of the ovaries and uterus, according to the number of embryos transferred from cows and heifers and to investigate the method of artificial twin induction with Hanwoo $in$ $vitro$ fertilized (IVF) embryos by embryo transfer (ET). Looking at the PR according to the condition of the ovaries and uterus, the result was not influenced by the condition of the ovaries, but was significantly influenced by the state of the uterus. The PR according to the number of embryos transferred from cows was 36.8%, 53.0%, 50.5% for 1, 2, and 3 embryos respectively, and although there was a higher frequency of twin calves with 3 embryos than with 2, the calving rate was the highest with 2 embryos. In case of heifers, the transfer of 1 embryo showed the best pregnancy and calving rate, and although the PR was similar with 2 embryos (67.7 versus 66.4), in case of 2 embryos transferred there was high frequency of embryonic loss( 6.1%) occurred when a cow was diagnosed at 28 and 53 d after ET, total loss (21.3%; sum of fetal death, abortion and stillbirth after pregnant diagnosis at 60 day).