This study was carried out in order to find out better ways for superovuiation and egg collection by checking some factors affecting on donor cows such as iactating and dried, age, season of treatment and sequence of treatment. The results were summarized as follows:1. Number of corpus luteum and collected eggs of eactating and dried doner were 9.8 vs 8.0 and 9.6 vs 7.9,respectively. However, the rate of transferable embryos of lactating doner were higher than that of dried, 82.5% vs 48.1%. 2. The average number of corpus luteum and collected eggs of lactating donors under 7 years of age (6.7 vs lactating 5.3) were slightly lower than those of over 8 years of age (11.1 vs 9.2). But the rate of transferable embryoswas better in under 7 years old donors than over 8 years (81.1% vs 49.3%). were 6.0, 4.8, 1.5, 1.8 and 75%, and those in the summer were 2.9, 3.8, 2.2 and 46.7%, respectively. 3. The average number of corpus luteum was the highest in winter (10.5) and the rate of egg collection was the best in autumn (94.7%). The rate of the transferable embryo was the highest in winter (64.3%). 4. The average number of corpus luteum was the lowest (5.5) in the animals treated six or more superovulating treatments. The rate of egg collection was the best in the third treatment group (90.2%), but it was getting worse after fifth treatment, The rate of transferable embryos was the highest in the second treatment group (94.1%), and it was decreased thereafter.

A light-emitting diode (LED) is most efficient in terms of economic benefits. The aim of the present study was to evaluate the effects of LED lighting intensity on milk production, milk composition, and the immune response of Holstein cows. Thirty-eight lactating cows were assigned to four experimental groups: control group (exposed natural daylight without LED light) and three LED treatment group (50 lux; natural daylight and 6 h LED light of 50 lux intensity, 100 lux; natural daylight and 6 h LED light of 100 lux intensity, 200 lux; natural daylight and 6 h LED light of 200 lux intensity). There was a significant effect on the decrease ratio in milk production in 200 lux group. Lactose was significantly increased in 100 lux than the other LED treated groups. In addition to the hemolytic biochemical analysis, AST and β-HB were significantly increased in the 50 lux than the other groups. Prolactin and IGF-1 levels were significantly increased in 200 lux compared to other groups. Besides, cortisol was significantly higher in 50 lux and lowered in the 200 lux than the control, while IgA and IgG were not significant among the groups. Therefore, it was concluded that LED lighting intensity had some impact on blood parameters and immune responses in dairy cows with increased milk production.

This study was conducted to evaluate roughage to concentrate ratio on the changes of productivity and metabolic profiling in milk. Six lactating Holstein cows were divided into two groups, T1 group was fed low-concentrate diet (Italian ryegrass to concentrate ratio = 8:2) and T2 group was fed high-concentrate diet (Italian ryegrass to concentrate ratio = 2:8). Milk samples were collected and its components and metabolites were analyzed by 1H-NMR (Nuclear magnetic resonance). The result of milk components such as milk fat, milk protein, solids-not-fat, lactose and somatic cell count were not significantly different between two groups. In carbohydrate metabolites, trehalose and xylose were significantly higher (P<0.05) in T1 group, however lactose was not significantly different between two groups. In amino acid metabolites, glycine was the highest concentration however, there was no signifi-cant difference observed between two groups. Urea and methionine were significantly higher (P<0.05) in the T2 group. In lipid metabolites, carnitine, choline and O-acetylcarnitine there were no significant difference observed between the two groups. In benzoic acid metabolites, tartrate was significantly higher (P<0.05) in T2 group. In organic acid metabolites, acetate was significantly higher (P<0.05) in T1 group and fumarate was significantly higher (P<0.05) in T2 group. In the other metabolites, 3-methylxanthine was only significantly higher (P<0.05) in T2 group and riboflavin was only significantly higher (P<0.05) in T1 group. As a result, milk components were not significantly different between two groups. However, metabolites concentration in the milk was significantly different depends on roughage to concentrate ratio.

Light is an essential and powerful element to animals. A light-emitting diode (LED) is most efficient in terms of economic benefits. The aim of the present study was to evaluate the effects of LED lighting time on milk production, milk composition, and the immune response of Holstein cows. Forty lactating cows were assigned to four experimental groups: control; natural daylight, treatment; am3-6, pm6-12 and pm6-am6. We found that there was no significant effect on the decrease ratio in milk production among the groups. Milk urea nitrogen (MUN) was significantly decreased in pm6-am6 and pm6-12 than the control. With regard to the hemolytic biochemical analysis, GLU was significantly increased and CRE, T-BIL were significantly decreased in the pm6-12 than the control. IGF-1 levels were significantly increased in pm6-12 compared to other groups. Besides, cortisol was significantly lowered in the pm6-12 than the control, while prolactin, IgA and IgG were not significant among the groups. In addition, catalase and glutathione peroxidase were also significantly increased in pm6-12 than the control. However, antioxidant enzyme activity and superoxide dismutase were not significant among the experimental groups. Therefore, it was concluded that LED lighting time had some impact on blood parameters and immune responses in dairy cows without any changes in milk production.

본 연구는 지방산 함량 및 배합사료와 조사료 비율을 기초로 한 유기농 사료 급여가 홀 스타인 착유우에서 생산된 원유의 CLA 및 지방산 함량에 미치는 연구를 조사하기 위한 목 적으로 실시하였다. 총 290두의 홀스타인 착유우를 산차 및 유량에 따라 3개 group으로 나 누었다. 대조구는 C16:00, C18:2 그리고 SFA를 높게 설계하였고, 처리구 1은 C18:1, C18:2 그리고 UFA 함량을 높게 설계하였으며 처리구 2는 MUFA, C18:3 그리고 PUFA 함량을 높 게 설계하였다. 결과를 요약하면 다음과 같다. 유기농 원유 내 C16:0 함량은 처리구 2에서 가장 높은 것으로 나타났다(p<0.05). 그 이유는 반추위 내 미생물의 de novo 생합성 때문인 것으로 판단된다. 처리구 2의 C18:0 함량은 7.92%로 대조구(11.39%)와 처리구 1(10.88%)보 다 높았다(p<0.05). CLA 함량도 처리구 2가 처리구 1이나 대조구에 비하여 높은 것으로 나 타났다(p<0.05). 원유 내에서 검출된 대부분의 CLA는 착유우 유선조직내의 △9-desaturase에 의하여 합성된 것으로 판단된다. n-3/n-6 비율도 처리구 2에서 가장 높은 것으로 나타났다 (p<0.05). 본 연구 결과를 종합해 보면, 착유우에게 혼합 목건초 등을 급여하면 CLA, n-3 농 도는 증가하며 C18:0 농도는 낮아지는 것으로 조사되었다. 본 연구는 유기농 인증된 조사 료 및 농후사료를 이용하여 결과를 도출하였다. 그러나 유기농 사료를 사용할 경우에만 원 유 내 CLA 및 n-3 농도는 증가한다고 볼 수 없다. 원유 내 고농도의 CLA 및 n-3 지방산 생 산을 위해서는 반추위 미생물 및 유선세포의 지방 대사를 통한 CLA 생산 메커니즘에 대한 충분한 이해와 급여 사료 내 지방산 구성 등이 중요한 것으로 판단된다.

This study was undertaken to investigate the effects of dicarboxylic acid supplementation, as replacement antibiotics, of on in vitro ruminal parameters and milk yield and milk composition in lactating cows. in vitro treatments were 1) Con (4 g of basal diet), 2) CM (4 g of basal diet + 0.05 ml of monensin), 3) CR (4 g of basal diet + 0.1 ml of dicarboxylic acid) and in vivo treatments were 1) Con (25 kg of basal diet/head/day), and 2) CR (25 kg of basal diet + 5 g of dicarboxylic acid/head/day), respectively. A total 10 lactating dairy cows (649±19 kg average body weight, 99±65 average milking days) were divided in to two groups according to mean milk yield and number of days of postpartum. The cows fed a basal diet during adaptation (2 wk) and experimental diets during the treatment periods (4 wk). In the first in vitro experiment, there were no statistical differences between treatments in pH, gas production, and ammonia-N and lactic acid concentration during incubation. However, dry matter digestibility was significantly higher in CR treatment compared to control or CM treatment (P<0.05). Total VFA was tended to higher in CR treatment than those of control and CM treatment (P> 0.05). In the second experiment, milk yield was significantly higher in treatment (40.39 kg) compared to control (35.19 kg), (P<0.05). Milk composition and MUN were not changed by dietary supplementing dicarboxylic acid. Therefore the present results reporting that supplementation of dicarboxylic acid might enhance the stabilization of ruminal fermentation and increase the milk yield of lactating cows.

This study was conducted to evaluate effects of chopped and non-chopped rice straw on characteristics of silage-basedtotal mixed ration (TMR) according to the particle size, laceration, and in situ dry matter (DM) degradation. The threerice straw silages as low moisture unchopped (LMUC; 32.75% of moisture, unchopped), high moisture unchopped(HMUC; 42.05% of moisture, unchopped), and high moisture chopped (HMC; 44.71% of moisture, chopped to 30cmlengths) were tested. Samples were collected at every 5 minutes from 10 min of pre-mixing to 50 min. The percentageof >19mm in LMUC and HMC was decreased to 7.23% and 7.74% (p<0.05), respectively, and the percentage of 8mm>was increased to 5.81% and 5.24%, respectively. Furthermore, the laceration of forage by a TMR mixer showed that therewas little change in the reduction of 1.26% in HMC, but was reduced to 7.53% and 16.06% in LMUC and HMUC,respectively. The peNDF>8 was maintained 17~18.5% of the optimal requirement level for 15 to 45 min mixing in LMUCand for 30 to 50 min mixing in HMC, but it exceeded the level of peNDF>8 in the range of 21.49 to 22.53% for 50minmixing in HMUC. However, ruminal in situ DM degradation appeared as LMUC>HMUC>HMC. Therefore, theseresults suggest that the rice straw silage may be useful for high-yielding lactating cows, if it can be supplied with theadequate peNDF, and the limiting factor on DMI and DM degradation was reduced by crushing of the plant tissue, althoughthe rice straw silage was concerned to low quality forage.

Twenty four Holstein steers (average body weight 714 ± 13.60 kg) were used in this experiment to determine the effect of supplementing of microbial culture and coated vitamin-C on growth performances and carcass characteristics in finishing Holstein steers. Holstein steers were randomly assigned to feeding groups of control group (Con, 12 kg of basal diet/head/day), microbial culture group (MC, 12 kg of basal diet + 30 g of microbial culture/head/day) and coated vitamin-C group (CVC, 12 kg of basal diet + 10 g of coated vitamin-C/head/day). MC and CVC groups were higher in ADG compared to control (P<0.05). FCR was also lower in MC and CVC groups than control group (P<0.05). Back fat thickness, rib-eye area, marbling score, meat color and yield index were not changed by supplementing microbial culture and coated vitamin-C. MC group was higher for maturity compared to control and CVC group (P<0.05). CVC group was higher for fat color compared to control and MC group (P<0.05). Based on the results obtained from the current study, supplementation of microbial culture and coated vitamin-C as an alternative to antibiotic might increase growth performances and enhance carcass characteristics in finishing Holstein steers. However, more studies are needed to find out the optimum supplementing period of microbial culture or coated vitamin-C for high quality meat production from Holstein steers.

지난 25년간 지구온난화로 인한 국내 기후변화 양상은 지역 간에 차이가 있어, 고온지역은 평균온도의 증가를 보이지는 않았으나, 최저기온의 지속적인 상승과 그에 따른 열대야 발생을 확인할 수 있었다. 또한 그로 인한 젖소의 고온스트레스 발생, 섭취량의 감소 및 생산성 저하가 예상된다. 저온지역의 경우에는 여름철 평균온도 및 최저온도의 상승으로 인해 연평균기온이 유의적으로 상승한 반면, 겨울철에는 오히려 최저기온의 지속적인 하강이 관찰됨에 따라 동물의 저온스트레스가 가중될 것으로 예상된다. 착유우가 저온스트레스 상태에 있을 때는 에너지요구량과 건물섭취량이 증가하여 생산 효율이 떨어지며, 사료효율의 감소로 경제성은 감소되고 우유 생산비는 증가한다. 특히, 극심한 저온스트레스 또는 사료, 음수 및 우사바닥의 결빙은 섭취량 감소를 야기하며 이에 따른 생산성의 저하는 더욱 가중될 것으로 예상된다. 결론적으로 지구온난화로 인한 기후변화에 따른 지역별 영향은 다르며, 온도 스트레스에 의한 낙농우의 생산성 저하를 최소화하고, 동물의 복지와 건강을 증진시키기 위해서는 지역별 기후변화 특성에 맞춘 사양기술의 개발이 필요하다.

The study was performed to evaluate the effects of soybean meal (T1) and corn distillers dried grains with solubles (DDGS, T2) hydrolyzed by microbial proteolytic enzyme of Protame® on milk production and protein contents in dairy cows. Total of nine Holstein cows (i.e., 1.67 ± 0.47 average parity and 23.7 ± 1.2 kg/d average milk yield) were randomly assigned to control, T1, and T2 (e.g., 3 animals per group) and treated for 4 weeks. Milk yield of 3 different groups was similar in the beginning of the study, however the milk yield of T1 and T2 treatment group had increased by 0.93 kg/d and 1.89 kg/d, respectively. Milk protein level of T2 treatment group was increased by 0.19% (e.g., 0.14 kg/d protein content), whereas there was no significant different in control and T1 group. In conclusion, blood metabolites were ranged in normal level, but BUN content was reduced from 19.03 mg/dl to 17.70 mg/dl in T2 treatment group. This result suggests that DDGS hydrolysate supplement efficiently increase milk yield and milk protein level as well as feed protein availability in dairy cattle.

This experiment was conducted to determine the effect of increasing the dietary levels of nattokinase (NK) addi-tives on milk production and composition, and blood metabolites in dairy cows. NK additives with high fibrinolytic activity were produced by the strain with similarity to the Bacillus amyloliquefacines. A total 20 mid-lactating Holstein cows (average body weight 652.00 ± 4.38 kg; average 2.25 ± 0.35 parity; average milk yield 24.4 ± 0.38 kg/d) were randomly assigned to three treatments (5 animals per treatment). Cows were fed TMR supplemented with DDGS 100 g for control, NK additives 100 g and 200 g for T1 and T2 treatment, respectively for 4 weeks. By the increases of NK additives, milk yield increased for T1 (1.35 kg/d) and T2 (0.98 kg/d) at the final period than at the initial period (p < 0.05). But milk protein content decreased for T1 (3.20%) and T2 (3.24%) than for control (3.56%) (p < 0.05). Blood triglyceride, T-CHO and BUN levels in T1 decreased compared with that in control and T2 (p < 0.05). This finding showed that 100g of NK additives could possibly have a positive effect in lactation performance of mid-lactation Holstein cows by increasing milk yield, improving protein metabolism and decreasing cholesterol in blood.

The objective of this study was to evaluate the effect of GnRH or estradiol in a CIDR-based timed Al (TAI) protocol on follicular turnover, synchronized ovulation and pregnancy rates in Holstein cows. Cows were treated at random stages of the estrus cycle with an insertion of an intravigal progesterone (1.9 g) device (CIDR, Day 0) and either no other treatment (control group; n=10), injection of 100 ug fertirelin acetate (GnRH group; n=10) or 4 mg estradiol benzoate (estradiol group; n=10). Seven days later devices were removed and an injection of 25 mg PGF2a was administered. On Day 9, 100 ug GnRH was administered. Cows received a fixed-time insemination 16 h after injection of the GnRH.