• Asian-Australasian Journal of Animal Sciences
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• 제31권11호
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• pp.1700-1713
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• 2018

Objective: The aim of this study was to verify the usefulness of artificial neural networks (ANN), multivariate adaptive regression splines (MARS), naïve Bayes classifier (NBC), general discriminant analysis (GDA), and logistic regression (LR) for dystocia detection in Polish Holstein-Friesian Black-and-White heifers and cows and to indicate the most influential predictors of calving difficulty. Methods: A total of 1,342 and 1,699 calving records including six categorical and four continuous predictors were used. Calving category (difficult vs easy or difficult, moderate and easy) was the dependent variable. Results: The maximum sensitivity, specificity and accuracy achieved for heifers on the independent test set were 0.855 (for ANN), 0.969 (for NBC), and 0.813 (for GDA), respectively, whereas the values for cows were 0.600 (for ANN), 1.000 and 0.965 (for NBC, GDA, and LR), respectively. With the three categories of calving difficulty, the maximum overall accuracy for heifers and cows was 0.589 (for MARS) and 0.649 (for ANN), respectively. The most influential predictors for heifers were an average calving difficulty score for the dam's sire, calving age and the mean yield of the farm, where the heifer was kept, whereas for cows, these additionally included: calf sex, the difficulty of the preceding calving, and the mean daily milk yield for the preceding lactation. Conclusion: The potential application of the investigated models in dairy cattle farming requires, however, their further improvement in order to reduce the rate of dystocia misdiagnosis and to increase detection reliability.

• Asian-Australasian Journal of Animal Sciences
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• 제20권9호
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• pp.1402-1406
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• 2007

Thirty pregnant heifers (Jersey, Holstein Friesian and Hariana) were divided into three groups (10 animals/group) according to their stage of pregnancy viz. seven-month (181-210 days) pregnancy (SMP), eight-month (211-240 days) pregnancy (EMP) and nine-month (241-280 days) pregnancy (NMP) group. Time spent in various feeding activities (eating fodder, eating concentrate, standing rumination, sitting rumination and drinking) by each animal in the three pregnant groups was recorded in four different sessions (each session of 24 h per week). The time spent eating concentrate, eating fodder, standing rumination, sitting rumination and drinking was 61.4, 271.3, 84.6, 367.6 and 10.6 min/day, respectively in the SMP group; 52.7, 289.5, 103.3, 345.8 and 9.2 min/day, respectively in the EMP group and 65.0, 277.7, 138.1, 291.0 and 9.8 min/day, respectively in the NMP group. The animals in the EMP group spent significantly (p<0.01) more time on eating fodder and concentrate compared to the animals in SMP and NMP groups. The pregnant heifers preferred rumination in standing posture in comparison to sitting posture. The time spent on standing rumination was significantly higher in the NMP group whereas the time spent on sitting rumination was significantly lower in this group. Except for the sitting rumination activity, all the other activities were predominant in daytime compared to night time; the diurnal variation was significant (p<0.01) for all the activities.

• Asian-Australasian Journal of Animal Sciences
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• 제13권8호
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• pp.1059-1062
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• 2000

The objective of the investigation was to study the effect of intramuscular $PGF_2\;{\alpha}$ and GnRH on estrus behavior and ovarian response in Murrah buffalo heifers. Twelve Murrah buffalo heifers at 32 months of age that had not exhibited behavioral estrus symptom were included in the experiment. Out of 12,4 heifers were in follicular phase (plasma estradiol $57.05{\pm}12.52pg/ml$), another 4 heifers were in luteal phase (Plasma progesterone $2.24{\pm}0.25ng/ml$) while the ovaries of remaining four heifers were inactive (estradiol $23.70{\pm}1.66pg/ml$and progesterone $0.32{\pm}0.06ng/ml$). $PGF_2\;{\alpha}$ (25 mg, Lutalyse, im) and GnRH (200 ug, Fertagyl, iv) was administered to each heifer at interval of 10 days. The plasma progesterone concentration decreased within 48 hrs after $PGF_2\;{\alpha}$ injection and followed thereafter with follicular growth, estrus and ovulation. GnRH administration induced follicular growth, elevation of plasma estradiol concentration with subsequent exhibition of behavioral estrus in 2 out of 4 heifers having inactive ovary. The observation reveals that Murrah buffalo heifers at 32 months of age have developed receptors for $PGF_2\;{\alpha}$ and GnRH on ovarian and pituitary tissue respectively and response the single injection of $PGF_2\;{\alpha}$ and GnRH similar to the mature cycling animals.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2001년도 춘계학술발표대회
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• pp.53-53
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• 2001

Two trials were conducted in a commercial dairy farm on heifer synchronization with PGF$_2$ $\alpha$. Animals showing estrus following the first injection were bred and animals not showing estrus were given the second injection 10 days later. In the first trial, the injection sites were rump and rump. In the second trial, the injection sites were rump and shoulder. Estrous detection was peformed 24 h after injection. Animals were bred by the same technician. In the first trial, the response rate for the first injection was 51.4% and the subsequent pregnancy rate of these animals was 60.0%. The response rate in the second injection was 57.1% and the pregnancy rate was 50.0%. In the second trial, the response rate in the first injection on the rump was 48.7% and the subsequent pregnancy rate was 70.6%. The second injection was given on the shoulder and the response rate was 60.0% and the subsequent pregnancy rate was 25.0%. The data suggests that the site of PGF2 $\alpha$ administration was critical to achieve success in estrous synchronization and pregnancy rates.

• Asian-Australasian Journal of Animal Sciences
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• 제19권5호
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• pp.672-678
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• 2006

The objective of this study was to investigate whether milk performance is impacted by the housing of heifers from the second to the seventh day of life, the method of feeding milk from the second week of life to weaning, the sire lineage and by the season of birth and season of calving. From 32 Holstein heifer-calves, which spent their first day of life in a loose housing maternity pen with their mother, 19 heifers were randomly placed in hutches (IH), and 13 stayed in a loose housing maternity pen (MP). At the seventh day IH heifers were assigned to one of two treatments, 10 heifers were randomly taken from IH and relocated to a loose housing pen with an automatic feeding station (AD), 9 calves stayed in hutches with bucket drinking (BD). MP heifers were moved to a group pen with nursing cows (UD). All animals were weaned at the age of 8 weeks (56 days) and kept in group pens. After calving, they were in free-stall housing. Trial cows were divided according to the sire, season of birth and calving. The five-factorial ANOVA revealed that among all the factors taken into account in this study, only sire lineage and season of birth had significant effects. The production of milk, FCM and protein were higher in the MP group than in the IH group. The UD group tended to have the highest production of milk, FCM, protein, lactose, SNF and total solids (TS) and the AD group the lowest. The content of fat and TS were highest in the AD group. Effects of the sire were significant for average daily gains (ADG) from birth to weaning ($0.55{\pm}0.03kg$, p<0.05), contents of fat ($3.81{\pm}0.08%$, p<0.05), protein ($3.13{\pm}0.02%$, p<0.05), and TS ($12.67{\pm}0.12%$, p<0.05). In the season of birth evaluation, statistical difference was found only in the content of protein ($3.13{\pm}0.13%$, p<0.05). Cows born in March-May had the highest % protein and cows born in June-August the lowest ($3.21{\pm}0.04$ vs. $3.06{\pm}0.05%$). Dairy cows born and subsequently calving in December-February had the highest production of milk, protein and TS, and dairy cows born in June-August the lowest. FCM and fat yields were highest in the group born in September-November and lowest in the group born in June-August.

• 한국동물위생학회지
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• 제34권4호
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• pp.369-378
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• 2011

Incidence of mastitis is highest in dairy cows and it is a leader of all diseases and the economic losses, in dairy farms. The objective of this study is to analyse the incidence of clinical mastitis using the lactation number, lactation month and season of calving. In this study, we used 3,779 lactation data and animal health records collected from 1990 to 2006 at the National Institute of Animal Science. Out of 3,779 cows, a total of 1,721 cows were reported with clinical mastitis, which was 46.3%. The frequency of mastitis increased from 36.9% from first lactation to 56.0% by the fifth lactation. As many as 766 cows (46.9%) showed a recurrence of mastitis after 14 days, apart for two or more and chronic mastitis that were recorded for 657 cows (20.3%). This came to a total of 3,010 cases that had clinical mastitis in the herd for sixteen years. The distribution of incidence of clinical mastitis was highest during the first month of lactation at 24.4%, and it reached to 43.4% by the third month. The incidence of mastitis was even higher for cows in first lactation, showing 28.6% in the first month, and 42.9 percent by third month of lactation. Cows calved during the summer and winter months showed higher rate of incidence with 59.9% and 57.9% within 30 days of lactation, respectively. It is urgently needed to establish a preventative management for heifer cows during their expected first lactation and the clinical specific dry-period management strategies that influence the rate of clinical mastitis during the next lactation. The aim of this study is to present information that might be useful to improve clinical mastitis prevention.

• 한국유기농업학회지
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• 제21권3호
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• pp.391-401
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• 2013

본 연구는 국내 유기축산물(시유) 생산농가에 대한 사양관리 실태 및 생산수준에 관한 조사 연구를 통해 애로사항을 파악하고 개선방안을 모색하고자 수행하였다. 2010년 말 현재 전체 낙농가 6,347호 중 유기축산물(시유) 인증 농가수는 35호로 0.57%였다. 유기축산물 인증농가 35호 중 11농가에 대한 조사결과, 호당 평균 총사육두수는 142두로 그 중 평균 착유우 69두, 건유우 13두, 육성우 및 송아지 60두였다. 성우 대비 후보축의 비율은 42.4%를 차지하고 있었다. 조사농가의 평균 산유량은 분포는 20kg 미만이 14.3%, 25~30kg 미만이 57.1%, 30kg 이상 28.6%로 분포되어 있었다. 조사농가의 유성분 및 유질분포를 보면, 유지율은 3.3%로 전국 평균 유지율 3.95%보다 많이 낮았다. 평균 세균수는 5,775개/ml로 1A 등급, 체세포수는 192,500개/ml로 1등급에 해당되어 유질등급은 우수한 것으로 나타났다. 유기축산물(시유) 생산이 농가소득에 도움이 되는지에 대한 조사결과, 도움이 된다는 응답이 90%로 나타났으나 실제적인 경영자료를 분석한 연구가 추가적으로 수행되어야 할 필요가 있다고 생각된다. 일반 우유 생산에서 유기축산물(시유)로 전환한 이유는 친환경적 목장경영을 위해서라고 응답한 비율이 54.5%로 가장 높았다. 일반 낙농에 비해 유기낙농의 어려운 점으로는 유기사료 공급의 어려움이라고 대답한 비율이 45.5%로 가장 높았다. 실제적으로 유기 조사료 자가 생산 이용률은 43.0%였고, 구입하여 이용하는 비율은 57.0%로 나타나 유기 조사료 자급에 대한 비율을 더 높이는 것이 유기낙농 발전을 위해 해결해야 할 과제임을 알 수 있다. 평균 조농비율은 38.6:61.4로 조사료 급여비율이 매우 낮음을 알 수 있었다. 향후 유기축산물(시유) 확대를 위해서는 유기사료의 안정적인 공급이 우선되어야 할 과제라 생각된다.

• Asian-Australasian Journal of Animal Sciences
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• 제26권10호
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• pp.1379-1387
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• 2013

In a majority of mammals, male infants have heavier body mass and grow faster than female infants. Accordingly, male offspring nursing requires a much greater maternal energy contribution to lactation. It is possible that the maternal-fetal immunoendocrine dialog plays an important role in female preparation for lactation during pregnancy. Immune system genes are an integral part of gene regulatory networks in lactation and tumor necrosis factor alpha ($TNF{\alpha}$) is a proinflammatory cytokine that also plays an important role in normal mammary gland development. The aim of this study was to evaluate the influence of the sex of calf and/or the -824A/G polymorphism in the promoter region of $TNF{\alpha}$ gene on milk performance traits in Black Pied cattle over the course of lactation. We also studied the allele frequency differences of -824A/G variants across several cattle breeds, which were bred in different climatic conditions. The G allele frequency decreased gradually over the course of lactation events in the Black Pied dairy cattle because of a higher culling rate of cows with the G/G genotype (p<0.001). In contrast to the genotypes A/A and A/G, cows with G/G genotype showed significant variability of milk and milk fat yield subject to sex of delivered calf. Milk yield and milk fat yield were significantly higher in the case of birth of a bull calf than with a heifer calf (p<0.03). The G allele frequency varies from 48% to 58% in Grey Ukrainian and Black Pied cattle to 77% in aboriginal Yakut cattle. Our results suggest that the $TNF{\alpha}$-824A/G gene polymorphism may have an influence on the reproductive efforts of cows over the course of lactation events depending on the sex of progeny. Allocation of resources according to sex of the calf allows optimizing the energy cost of lactation. This may be a probable reason for high G allele frequency in Yakut cattle breeding in extreme environmental conditions. Similarly, the dramatic fall in milk production after birth of a heifer calf increases the probability of culling for the cows with the G/G genotype in animal husbandry.

• Current Research on Agriculture and Life Sciences
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• 제4권
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• pp.102-108
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• 1986

본 시험에서는 저수태우로 판단된 우수한 형질의 젖소를 공란우로 사용하여 과배란처리에 대한 반응 및 수태율에 영향을 주는 계절, 연령, 생식기관내의 이상유무 및 반복사용에 따른 반응을 검토하였던 바 그 결과는 다음과 같다. 1. 이른 봄(2월~4월)이 좋은 수정란 생산에 제일 좋았으며 수태율은 2월에서 7월까지는 좋았으나 그 이후 저하되었다. 2. 공란우 생식관내의 이상이 있는 경우는 과배란처리 반응 및 수태율이 예상대로 정상우보다 나빴다. 3. 8세우가 4세우보다 수태율이 높았고, 과배란처리 반응에서도 8세우가 4세우보다 약간 좋은 결과를 보였다. 4. 과배란처리 횟수가 많을 수록 첫 번째 과배란처리 보다 배란수(32:41) 및 수태율(68.4:85.7%)이 증가되었다.(단 3차반복까지) 5. 6두의 공란우에서 9회의 채란을 하여 좋은 수정란 38개를 생산했고, 이중 33개를 이식하여 25두가 임신되었다. 6. 본 실험에서 저수태우를 수정란 이식을 위한 공란우로 재이용하여 그 경제성을 높일 수 있는 가능성을 확실히 제시하고 있다.

• Animal Bioscience
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• 제35권3호
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• pp.503-510
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• 2022

Objective: This study was performed to determine the effects of stress after road transportation and oral administration of chromium and meloxicam on growth performance, plasma cortisol, serum metabolites, and behavior in dairy calves. Methods: A total of 50 Holstein heifers (average body weight [BW]: 172±4.19 kg; average age: 5.53±0.12 months) were randomly assigned to five groups including NL (not transported + D-lactose; 1 mg/kg BW), TL (transported + D-lactose; 1 mg/kg BW), TC (transported + chromium; 0.5 mg/kg dry matter [DM] feed), TM (transported + meloxicam; 1 mg/kg BW), and TMC (transported + combination of meloxicam and chromium; 1 mg/kg BW and 0.5 mg/kg DM, respectively). Doses of D-lactose monohydrate, meloxicam, and chromium were prepared for oral administration by suspension in 15 mL of water in a 20-mL dosing syringe. Blood was collected before transportation, immediately after 120 km of transportation (IAT), and at 6, 24, and 48 h after transportation. Results: Neither transportation nor administration of meloxicam and/or chromium affected (p = 0.99) average daily gain and feed intake. Plasma cortisol concentrations in the NL group (average 0.13 and 0.18 nmol/L, respectively) were lower (p<0.001) compared to the TL group (average 0.39 and 0.61 nmol/L, respectively) at IAT and 48 h after transportation. At 48 h after transportation, cortisol concentrations were lower (p<0.05) in the TC group (average 0.22 nmol/L) than in the TL group (average 0.61 nmol/L), and TC calves had similar cortisol concentrations to NL calves. Lying duration (min/d) was shorter (p<0.05) in the TL group than in the NL group at 2 d after transportation. Lying duration was longer (p<0.05) for the TC and TMC groups than for the TL group at 2 d after transportation. Conclusion: Transportation increased cortisol concentrations and affected lying behavior, while chromium administration reduced cortisol concentrations and changed lying behavior. Thus, chromium administration before transportation may be a viable strategy to alleviate stress elicited by road transportation.