This study was performed to investigate immune changes by comparing the proportion and function of immune cells in the blood under high-temperature period and convalescence temperature period in Holstein dairy cows. The experiment was conducted using Holstein dairy cows of five animals per group (60 ± 20 months old, 175 ± 78 non-day) from the National Institute of Animal Science at high-temperature period (THI: 76 ± 1.2) and convalescence temperature period (THI: 66 ± 1.3). Complete blood count results showed no change in the number of immune cells between groups. In the analysis using Flow Cytometry of PBMCs, no significant differences were observed among B cells, Helper T cells, cytotoxic T cells, and γδ T cells between groups. However, there was an increase in Th17 cells producing IL-17a, while Th1 cells decreased during the convalescence temperature period. The results of gene expression analysis using qRT-PCR in PBMCs revealed an increase in IL-10 during the convalescence temperature period, while a decrease in HSP70 and HSP90 was observed. In conclusion, the increased expression of IL-10 and the decrease in HSP expression suggest the possibility of a weak recovery from heat stress. However, the lack of observed changes in B cells, T cells, and other immune cells indicates incomplete recovery from heat stress during the convalescence temperature period.

In this study, the effect of daily short-distance walking exercise on milk production and metabolic status of the lactating dairy cows was investigated. The experiment was conducted with 10 lactating dairy cows comprising 2 groups (5 dairy cows/group), which were walking activity and non-walking activity. The walking activity (WA) group lactating dairy cows walked outdoors for 1 km/d, and the non-walking activity (non-WA) lactating dairy cows were maintained within a cowshed from 18thApril to30th May. The activity volume of the neck was not significantly different between the groups, but the activity volume of the leg was higher in WA group compared with non-WA (p<0.05). The rectal temperature was higher in the WA group (38.6 ℃) compared with non-WA (38.2 ℃) (p<0.05). No significant differences in dietary NE intake, milk production and milk composition were found between the groups. The plasma cortisol concentration was higher in WA group (2.14 μg/dl) compared to non-WA (0.95 μg/dl) (p<0.05). However, plasma cortisol level of WA dairy cows was significantly decreased as compared with non-WA cows. On the contrary, the level of plasma melatonin was increased in WA cows than that of non-WA dairy cows. It may be interpreted as a change in physical fitness. From this study, we suggest that walking activity can be improved energy balance. Further investigation is needed to determine whether different combinations of distance, rate or doing in morning or afternoon will stimulate energy balance.

In this study, the effect of energy and protein ratio on the nutrient availability and body weight gain was determined to find the proper nutrient level for the stage of replacement dairy heifers before fertilization at approximately 12~24 months old after birth. Dry matter intake showed that the TDN/CP rate of T1 (5.0:1), T2 (4.5:1) and T3 (4.0:1) resulted in similar values. Among feces, the ash content of T1 was 11.07%, which was significantly (p < 0.05) higher than that of T3 (9.69%). It was also significantly (p < 0.05) higher than that of T2 (10.32%). When the TDN/CP rate was increased, the ash content in the feces was also increased. Regardless of the initial weight, weight gain was increased significantly as the CP rate in the feed was increased on the 30th day. On the 60th day, T2 showed the highest rate of gain (p < 0.05). As the TDN rate was decreased or the protein rate was increased, weight gain was significantly (p < 0.05) increased. Regarding GPT level in the blood after finishing the test, T1 and T3 (112.6, 88.3 u/l) showed significantly (p < 0.05) higher value than T2 (50.9 u/l). For phosphorus level, T1 (46.3 mg/dl) showed significantly (p < 0.05) higher value than other treatments. For HDL cholesterol level, T2 (145.2 mg/dl) had significantly (p < 0.05) higher level than T1 (121.0 mg/dl) or T3 (132.3 mg/dl). For triglyceride levels, T3 (40.6 mg/dl) had significantly (p < 0.05) higher value than T1 (20.7 mg/dl) and T2 (29.0 mg/dl). For other blood parameters including BUN concentration, there were no significant (p > 0.05) difference among treatments. As a result, although feed intake and weight gain with TDN/CP rate of 4:1 showed best results, considering the excess body fat accumulation possibilities or blood metabolism, it seems 4.5:1 ratio is most appropriate.

Glucose is universal and essential fuel of energy metabolism and in the synthesis pathways of all mammalian cells. Glucose is the one of the major precursors of lactose synthesis using glycolysis result in producing milk fat and protein. During the milk fat synthesis, lipoprotein lipase (LPL) and CD36 are required for glucose uptake. Various morecules such as acyl-CoA synthetase 1 (ACSL1) activity of acetyl-CoA synthetase 2 (ACSS2), ACACA, FASN AGPAT6, GPAM, LPIN1 are closely related with milk fat synthesis. Additionally, glucose plays a major role for synthesizing lactose. Activations of lactose synthesize enzymes such as membranebound enzyme, beta-1,4-galactosyl transferase (B4GALT), glucose-6-phosphate dehydrogenase (G6PD) are changed by concentration of glucose in blood resulting change of amount of lactose production. Glucose transporters are a wide group of membrane proteins that facilitate the transport of glucose over a plasma membrane. There are 2 types of glucose transporters which consisted facilitative glucose transporters (GLUT); and sodium-dependent transport, mediated by the Na+/glucose cotransporters (SGLT). Among them, GLUT1, GLUT8, GLUT12, SGLT1, SGLT2 are main glucose transporters which involved in mammary gland development and milk synthesis. However, more studies are required for revealing clear mechanism and function of other unknown genes and transporters. Therefore, understanding of the mechanisms of glucose usage and its regulation in mammary gland is very essential for enhancing the glucose utilization in the mammary gland and improving dairy productivity and efficiency.

This study was conducted to investigate the effects of supplementing additional sucrose, in the form of black sugar (BS), into the diet of Holstein dairy cows on dry matter intake (DMI), milk yield, and milk composition. Eight Holstein dairy cows (741 ± 65.8 kg body weight) were divided into two groups, including the control and BS groups. Animals in the control group were offered a total mixed ration (TMR) ad libitum, and the BS group was offered TMR with 300 g of BS/head/d. After two weeks of adaptation period, the animal performance, including DMI, milk yield and milk composition, was measured. Cows supplemented with BS appeared to consume more feed than that by the controls (i.e., 17.08 and 18.28 kg/d for the control and BS groups, respectively). However, there were no significant differences between treatments. Milk yield or milk composition, such as milk fat, milk protein, lactose, solids-non-fat, total solids and pH, did not differ between treatments. However, there was a significant difference (p<0.05) in the concentration of milk urea nitrogen (MUN). The MUN concentration of the BS group was approximately 15% lower than that of the control group (i.e., 18.75 vs. 16.05 mg/dL for the control and BS groups, respectively), which suggests improved nitrogen metabolism in the animals. The somatic cell count was numerically lower in the cows of the BS group compared to those in the control group. However, a significant difference was not noted due to the substantial amount of variation among cows. In terms of the trace mineral composition for milk, the concentration of Cu from BS animals was higher (p<0.05) than that of the control animals. In summary, supplementing the diets of dairy cows with BS marginally affected animal performance and improved nitrogen metabolism. The level of supplementation and other factors, such as animal variation were discussed.

today's dairy production management systems, reproductive efficiency affects the income of any farm by influencing overall milk production, genetic gain, amount of replacement heifers, and wise cullling decisions. Nutrition, management, and genetics play a major role achieving this maximum herd-reproductive performance. Several reports using trace minerals on the diet of cattle have shown reproductive effects. The main justification for using blocks, to provide deficient nutrients is, therefore, their convenience for packaging, storage, transport and ease of feeding. Dairy cattle are annually exposed to prolonged periods of elevated humidity and heat which reduce feed intake and reproductive performance. The objectives of the present study were to evaluate the effects of mineral on reproductive performance of dairy cows during Summer. The experimental group of cows had access ad libitum to the mineral lick in the following composition : Zn, Fe, Mn, Cu, I, Co, Se. Environmental heat load was described using the THI (temperature humidity index) because thermoregulation in cows is affected by both Temp and RH. The THI was calculated: THI=(0.8×Temp)+[RH×(Temp— 14.4)]+ 46.4. All cows were monitored for estrus twice daily in the morning and late afternoon. And any animal found in estrus was artificially inseminated. Pregnancy diagnosis was performed via ultrasonography at 45 to 70 d after insemination. The visitation and intake of mineral were higher with the maximum THI. The mean intake of mineral block was 23.1 kg in Summer and 17.7 kg in other seasons. The reproductive performance was considerably improved by mineral supplementation. The factors influencing consumption of mineral mixtures include: soil fertility and forage type, available energy and protein, individual requirements, salt content of the water, palatability of mineral mixture, availability of fresh minerals and physical form of minerals. These results show that minerals have a great impact on animal's reproductive physiology.

The objective of this study was to compare the accuracy analysis and the effect of field application of a newly developed automatic heat detector in dairy cows. From 2009 to 2010, we used 48 Holstein cows (mounting cows : 38 heads, standing cows : 10 heads) raised in experimental barn of National Livestock Research Institute (RDA) for the accuracy analysis of automatic heat detector, and 14 Holstein cows raised in three commercial dairy farms of Cheonan and Pochun area for comparison of the effect of field application. The accuracy of response in cows attached with automatic heat detector was 86.8% (33/38) displayed on board when mounting activity observed, and 100% (10/10) when standing activity observed, and on average, 90.0% (43/48) displayed on board. The accuracy of automatic heat detector in on-farm test was 85.7% (12/14), and conception rate was 75.0% (9/12).

본 연구는 허브 부식토를 이용하여 첨가 수준별 in vitro 반추위 발효특성 평가와 젖소를 이용하여 급여시 유생산성에 미치는 영향을 조사하기 위하여 본 연구를 수행하였다. 시험 1에서는 티머시 건초를 기질로 하여 허브부식토(herbaceous peat)를 0,1 및 5%를 3반복으로 각각 첨가하여 in vitro 반추위내 pH, 가스발생량, VFA (volatile fatty acid), ammonia-N 및 건물분해율을 조사하여 반추위내 발효성상의

젖소의 분만 전․후기는 일반적으로 전환기라고 칭하며 분만후 유생산을 준비하기 위해 동물체내 대사 및 생리적 상태가 급격히 변화하는 시기라 할 수 있다. 젖소는 이 시기에 간조직에서 당신합성을 통해 유당합성을 위한 glucose의 생산을 촉진하고, 지방조직에서는 분만 전부터 지질을 축적하고 비유개시에 맞추어 혈중 NEFA (nonesterified fatty acid)의 농도를 증가시켜 유지방 합성을 준비한다. 이러한 대사조절에 epinephrine 및 insulin이 조절 호르몬으로 작용하여 유생산을 위한 탄수화물 및 지질대사를 변화시키고 사료 섭취량의 부족에 기인한 전체 에너지의 감소를 체내 영양소의 재분배로 충족시킨다.

전국 65개 시군에 소재하는 착유우 20두 이상 규모의 760개 목장에서 85,983두를 대상으로 초음파 번식 검진 및 치료를 실시하여 다음과 같은 결과를 얻었다. 번식 검진우 85,983두 중 난소 질병이 40,399(47.0 %)로 가장 많았으며 자궁 질병 11,912두(13.9%), 임신 및 임신기 사고가 26,587두(30.9%), 난소나 자궁의 유착이 172두(0.2%), 프리마틴 8두(0.01%)그리고 분만 후 50일 이내로서 정상적인 발정

본 연구는 후산정체 젖소에 있어서 Lipopolysaccharide(LPS)의 처리가 번식 성적에 미치는 영향을 구명하기 위하여 분만 후 12시간이 경과하여도 후산이 배출되지 않은 홀스타인 개체 33두 및 대조구 12두에 대하여 분만후 20일째에 LPS 100 g을 자궁 내에 주입한 다음 7일후에 발정이 발현되었을 때 인공수정을 실시하여 다음과 같은 결과를 얻었다. 후산정체 젖소에 있어서 첫 수정에 의한 수태율은 대조구의 경우 공시한 12두가 모두 첫 수정에 의해 수태가 되지 않았고 처리구는 33두중 11두가 수태되어 33.3%의 수태율을 나타내었다. 후산정체 젖소에 있어서 대조구 및 처리구의 분만후 수태까지의 일수는 각각 149.6±34.3일 및 53.0±12.5일로 처리구가 대조구에 비하여 유의적(p<0.01)으로 단축되는 경향을 나타내었다. 후산정체 젖소에 있어서 대조구 및 처리구의 수태당 종부 횟수는 각각 3.6±0.8회 및 2.1±0.3회로 처리구가 대조구에 비하여 유의적(p<0.05)으로 낮은 경향을 나타내었다.

본 연구는 젖소에 있어서 삭제가 번식효율에 미치는 영향을 구명하기 위하여 2003년부터 2004년까지 2년간에 걸쳐 축산연구소 개방형 깔짚 우사에서 사육중인 홀스타인 착유우 17두를 대상으로 처리구 9두 및 대조구 8두를 공시하였고 삭제는 분만 후 20일을 전후하여 1회에 한해 실시하여 다음과 같은 결과를 얻었다. 1. 삭제에 따른 분만 후 첫 수정일수는 대조구가 180.931.6, 삭제구가 111.917.1일로 삭제구가 대조구에 비하여 분만 후 첫 수

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.