• Journal of Veterinary Clinics
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• v.13 no.2
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• pp.153-157
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• 1996

Ketosis can exist in both clinicla and subclinical forms. Detection of the subclinical form of ketosis by the use of a nitroprusside based test powder gas been shown to be a relatively simple and reliable procedure. Howere, very liffle is known about the indcidence or prevalence of the subclinical ketosis in Korea. In the present study, samples of urine taken from 288 dairy cows in Chonnam area were examined to demonstrate the presence of ketone bodies, using ross test. All the cows were within 4 weeks either before or after parturition. The gerd size was from 10 to more than 100 cows, and the cows did not show any clinical signs of ketosis. Of the 288 cows, 85 (29.5%) were positive to Ross test; of the positive cases 42.4% were +, 44.7% were ++, and the remaining 12.9% were +++. The prevalence increased from 3rd parity, peaked at 6th parity and thereafter decreased. The prevalence was higher after parturition than before parturition, with the highest occurrence during the 2nd week after calving. The prevalence was higher during winter. Also cows kept indoor throughout the year showed higher occurrence of the subclinical ketosis. The subclinical ketosis did not affect the specific gravity of the urine; however, increasing amount of ketone bodies in the urine decreased the pH of urine.

• Journal of Veterinary Clinics
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• v.21 no.4
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• pp.355-362
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• 2004

The purpose of this study was to herd management and control of dairy cows by milk components analysis in Gyeongsangnamdo. Milk components analysis were carried out milk yield (MY), milk fat (MF), milk protein (MP), milk urea nitrogen (MUN) and somatic cell count (SCC) but, milk solid (MS), day of non-pregnant condition (DNPC), and days of primipara (DPRI) involved in report. Dairy farms were divided high group, middle group, low group according to the standard records for milk components. Examination records were divided by farm, parity, year, season and month, the number of samples were 28,957. Feeding management practice and the prediction for the risk possibility of productive disease such as reproductive and metabolic disorders by evaluating fat, protein, solids. Determination of MY, MF, MP, MS were Milkoscan 4,000~5,000 Serier (FOSS Electric Co., Copenhagen, Denmark). Correlation coefficient of milk protein (MP) and milk solid (MS) was ascertain r=0.759. SCC was ascertain 372.8$\pm$11.34 (thousand unit) and DNPC was ascertain 155.3$\pm$5.15 (days) in seven parity.

• Journal of Animal Science and Technology
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• v.63 no.6
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• pp.1265-1274
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• 2021

Two field experiments were conducted to improve the conception rate of Hanwoo cow. The first experiment aimed to investigate the physiological condition of Hanwoo cows on estrus, including metabolic profiles and body condition score (BCS). The second experiment investigated the effect of a novel estrus detector on the artificial insemination (AI) conception rate for Hanwoo cows. For the first experiment, 80 Hanwoo cows (2.5 ± 0.10 of parity), approximately one month before estrus, were housed in 16 pens and offered the experimental diets twice daily with free water access. The BCS were recorded, and blood was collected from the jugular veins just before AI. The collected blood was used to measure physiological conditions, such as metabolite and hormone levels. For the second experiment, each cow was equipped with a neck-mounted estrus detector collar, which had a sensor connected through the internet. Approximately one month before estrus, three hundred sixty Hanwoo cows (2.4 ± 0.21 of parity) were assigned into groups with or without W-Tag collar treatments. The animals were managed the same as in the first experiment. The pregnancy rate reached 55% in the first experiment. The concentration of luteinizing hormone (LH) was higher (p < 0.012; 1.56 vs. 1.08 ng/mL) in cows that were not pregnant (NPG) than in cows that were pregnant (PG) after AI. The BCS and other concentrations of metabolites and hormones in the blood were not different in both NPG and PG cows. The ranges of estrogen, LH, and follicle-stimulating hormone for PG cows were 11.9 to 39.0 pg/mL, < 0.25 to 1.98 ng/mL, and < 0.50 to 0.82 ng/mL, respectively. In the second experiment, cows with the estrus detector had lower days open (p < 0.001; 78.1 vs. 84.8 d), insemination frequency (p < 0.001; 1.26 vs. 2.52), and return of estrus (p < 0.001; 70.9 vs. 79.1 d) than those in cows without the estrus detector. In conclusion, the present study indicated that lower LH concentration just before AI potentially increased the pregnancy rate of Hanwoo cows. Furthermore, the application of estrus detectors to Hanwoo cows could improve the conception success rate for AI.

• Animal Bioscience
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• v.36 no.6
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• pp.869-878
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• 2023

Objective: Hyperketonemia remains a major metabolic issue of serious milk production and a major health concern in early lactation cows. Oral supplementation of glucose precursors (GP) can be used to prevent hyperketonemia in dairy cows. The objective of this study was to compare the beneficial effects of orally supplementing a mixture of GP on metabolic health indicators and milk production status of primiparous (PP) and multiparous (MP) dairy cows. Methods: Twenty-eight Holstein cows were blocked by expected date of parturition, previous lactation yield, and parity. The cows were randomly allocated to one of the four treatment groups (n = 7 cows/group) based on their parity and GP supplementation: i) PP cows fed basal diet only (PP-CON), ii) PP cows with oral supplementation of GP (PP-GP), iii) MP cows fed basal diet only (MP-CON), and iv) MP cows with oral supplementation of GP (MP-GP). Glucose precursor (glycoline liquid) was orally drenched (300 mL/d) in GP cows from 7 days prepartum through 7 days postpartum. Other than GP supplementation, all cows were fed similar pre- and postpartum basal diets. Results: In both pre- and postpartum periods, serum glucose concentration was increased, whereas β-hydroxybutyrate and free fatty acids were decreased in GP cows compared with the CON cows. Milk yield and milk components were statistically not different between GP and CON cows over the first 9 week of lactation. The yield of actual milk, energy-corrected milk, 63-days cumulative milk, colostrum yield, and calf birth weight remained higher in MP cows compared with PP cows. Conclusion: Oral drenching of GP around calving can be recommended to successfully improve the metabolic health and reduce the negative effects of hyperketonemia not only in MP but also in PP dairy cows.

• Journal of Dairy Science and Biotechnology
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• v.34 no.3
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• pp.193-198
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• 2016

This study examined changes in the components of dairy cow colostrum 1-5 days post delivery and between 1-5 days post-delivery, the contents of major proteins were largest on the first day, but declined gradually over time. Immunoglobulin, lactoferrin, bovine serum albumin, and lactoperoxidase exhibited the highest concentrations one day post-delivery. However, these levels decresed significantly on the second day and remained at a low level on the third. An examination of daily changes in colostrum composition in dairy cows after delivery, according to parity, could not detect changes in the levels of most proteins.

• Animal Bioscience
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• v.34 no.4
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• pp.575-583
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• 2021

Objective: The aim of the study was to determine the effect of parity and the stage of lactation on the metabolic profile of cows based on the basic chemical milk components and the blood parameters. Methods: The study material consisted of high-yielding Holstein-Friesian cows. In total, 473 cows were examined. According to the parity, cows were divided into four groups: primiparous (P), and multiparous in the second (M2), in the third (M3), and in subsequent lactations (M4). The feeding of cows was based on total mixed ration (TMR) ad libitum. Milk and blood samples were collected individually from each cow three times per standard lactation period. Results: Greater exacerbation of changes in the dynamics of the blood plasma parameters examined was proved for multiparous cows. The highest value of β-hydroxybutyrate acid (0.946 mmol/L) was found for multiparous cows from group M3 at the beginning of lactation. However, it was still in the normal range. The results showed aspartate aminotransferase, and gamma-glutamyl transferase (GGT) activities in dairy cows during lactation had significant variations taking in to account stage of lactation. The highest activity of GGT was found in the group of the oldest cows and measured from 26.36 U/L at the beginning of lactation to 48.75 U/L at the end of the lactation period. Conclusion: The time-related changes in the concentrations of the biochemical parameters described differ markedly among lactating cows, though the housing conditions on the research dairy farm are highly standardised. This indicates that the ability to cope with metabolic stress is mainly affected by the individual predispositions of cows and feed nutrient supply in different stage of lactation. Especially, the feed nutrient supply (in net energy for lactation), which was the best in TMR 1 in comparison TMR 3.

• Journal of Veterinary Clinics
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• v.34 no.4
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• pp.255-260
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• 2017

Ketosis has become a very common and important metabolic disorder that causes substantial economic loss in modern dairy herds. We determined the risk factors for ketosis and associations with some blood metabolite concentrations in dairy cows. Blood from 475 Holstein cows on four dairy farms was collected weekly until 4 weeks after calving to measure blood ${\beta}$-hydroxybutyrate (BHBA) concentrations using electronic handheld meters. Cows were grouped based on the BHBA concentration into two groups: a ketosis group (${\geq}1.2mmol/L$, n = 150) and a non-ketosis group (< 1.2 mmol/L, n = 325). Peripartum health status (dystocia, retained placenta, and metritis), cow parity, and calving season were recorded to identify the risk factors for ketosis. Serum albumin, total cholesterol (TCH), and haptoglobin concentrations were compared between sub-groups of cows selected from the ketosis (n = 92) and non-ketosis (n = 50) groups 1 week postpartum ($7.5{\pm}0.2days$). The farm influenced the incidence of ketosis (P < 0.05). Cows calved during summer tended to have a higher risk (odds ratio [OR]: 1.61, P < 0.1) of ketosis than cows calved during spring. Cows with parities of two (OR: 1.95, P < 0.05) and three or higher (OR: 2.55, P < 0.01) were at higher risk than primiparous cows. Cows with metritis had a higher risk (OR: 7.02, P < 0.0001) of ketosis than cows without metritis. Serum albumin and TCH concentrations were lower (P < 0.01) in the ketosis group than in the non-ketosis group, whereas haptoglobin concentration was higher (P < 0.05) in the ketosis group than in the non-ketosis group. In conclusion, our results indicate that farm, summer calving, parity greater than one, and postpartum disease (metritis) were risk factors for ketosis. In addition, lower serum albumin and TCH concentrations and higher haptoglobin concentration were also associated with the incidence of ketosis in dairy cows.

• Korean Journal of Agricultural Science
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• v.38 no.4
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• pp.667-672
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• 2011

This study was carried out to increase the breeding rate using sustained recombinant bovine somatotropin (bST) and examine the reproductive disorder and disease prevalencies of cow and calf, respectively. Sixty cows were allotted randomly to three groups in randomized complete block design; (1) No treatment, (2) 500 mg bST two times + 250 mg bST SC injection five times from 3 weeks before to 9 weeks after parturition every two weeks, (3) 500 mg bST two times before 3 weeks parturition + 250 mg bST SC injection three times from five to 9 weeks after parturition every two weeks. Developmental data of birth weight, weaning weight, total gain and average daily gain in control was $22.9{\mu}0.45$ kg, $88.0{\mu}1.13$ kg, $65.1{\mu}0.74$ kg and $0.54{\mu}0.08$ kg, respectively. There is no significant difference between Group 1 and 3 in the examined factors. However, there is significant difference between Group 1 and 2 in the birth weight ($24.4{\mu}0.88$ kg), weaning weight ($101.0{\mu}1.77$ kg), total gain ($76.7{\mu}0.9$ kg) and average daily gain ($76.7{\mu}0.9$ kg). Total gain was showed higher in Group 2 and 3 than Group 1 in the >2nd parity, and in Group 2 than Group 1 and 3 in the 1st parity. There is no significant difference in the BCS, no return days and disease occurrence of cow and calf by bST treatment. Number of service per conception was slightly increased in the Group 3 compared to Group 1 and 2. To increase the breeding ability of Hanwoo, it is recommended that 500 mg bST two times + 250 mg bST injection five times from 3 weeks before to 9 weeks after parturition every two weeks.

• Animal Bioscience
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• v.34 no.4
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• pp.567-574
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• 2021

Objective: In this study we investigated the effect of seasonal thermal stress on milk production and milk compositions between Holstein and Jersey dairy cows under the temperate-climate in Korea. Methods: A total of 9 Holstein lactating dairy cows (2.0±0.11 parity) which had a daily milk yield of 29.77±0.45 kg, and days in milk of 111.2±10.29 were selected similarly at the beginning of the experiments in each season. Also, a total of 9 Jersey lactating dairy cows (1.7±0.12 parity) which had a daily milk yield of 20.01±0.43 kg, and days in milk of 114.0±9.74 were selected similarly at the beginning of the experiments. Results: Results showed that the average ambient temperature (℃) and temperature-humidity index (THI) were higher in summer, and were lower in winter (p<0.05). The average relative humidity (RH, %) was higher in autumn than that of other seasons (p<0.05). Milk production was significantly decreased (Holstein 29.02 kg/d and Jersey 19.75 kg/d) in autumn than in other seasons (Holstein 30.14 kg/d and Jersey 20.96 kg/d). However, the milk production was negatively correlated in Holstein cows, and positively correlated in Jersey cows with THI values increased from 16 to 80. In addition, milk yield was increased by 15% in Holstein cows and decreased by 11% in Jersey cows with the THI values increased from 16 to 20. The fat and protein content percentage was significantly higher in Jersey milk than in Holstein milk, furthermore the fat and protein content yield was higher in Jersey cow milk than that of Holstein cow's milk with all THIs. Conclusion: From the study results, we concluded that Jersey cows might be less adaptable to low temperature of the winter, and this would have a negative impact on dairy farmer income since Korea's milk price estimation system places a higher value on milk yield than on milk compositions or sanitary grades.

• Parasites, Hosts and Diseases
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• v.39 no.2
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• pp.185-192
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• 2001

To evaluate the factors that determine the transmission level of vivax malaria using vectorial capacity, entomological surveys were conducted from .lune to August, 2000. From 6 nights of human-bait collection in Paju, the human biting rate (ma) was counted as 87.5 bites/man/night. The parity of Anopheles sinensis from human baiting collections fluctuated from 41% to 71% (average 48.8%) of which the rate gradually increased as time passed on: 35.2% in Jun. ; 55.0% in July; 66.2% in Aug. From this proportion of parous, we could estimate the probability of daily survival rate of An. sinensis to be 0.79 assumed with 3 days gonotrophic cycle and the expectancy of infective life through 11 days could be defined as 0.073. Blood meal analysis was performed using ELISA to determine the blood meal source. Only 0.8% of blood meals were from human hosts. We could conclude that An. sinensis is highly zoophilic (cow 61.8%) Malaria is highly unstable (stability index < 0.5) in this area. From these data, vectorial capacity VC) was determined to be 0.081. In spite of a high human biting rate (ma), malaria transmission potential is very low due to a low human blood index. Therefore, we could conclude that malaria transmission by An. sinensis is resulted by high population density, not by high transmission potential. For this reason, we need more effort to decrease vector population and vector-human contact to eradicate malaria in Korea.