This study was conducted for SNPs in the 5'-regions of estrogen receptor-α(ESR-α), and association with calving interval (CI), service per conception (SPC) and 305 days milk yield in Hanwoo and Holstein dairy cattle. The genet-ic improvement was incurred low reproduction performance. The objective of this study was to investigate connec-tions between single nucleotide polymorphisms (SNP) of Estrogen receptor-α (ESR-α) with reproduction performance (calving interval, service per conception, and 305 d milk yield) in Hanwoo and Holstein dairy cattle. Hanwoo and Holstein blood samples were collected from 183 and 124 dam of breeding farms and DNA was extracted. Primer design was based on NCBI GenBank (Accession No. AY340579). The PCR-RFLP method with Bgl I was used to ge-notype the cattle. The result showed two variants of the ESR-α gene. The Bgl I cut the 492 bp amplification pro- duct into 322 bp and 170 bp fragments for allele G, while allele A remained uncut, resulting in two restriction frag-ments for homozygote G/G and three fragments for heterozygote A/G. We found two of different genotypes in the-se breeds, A/G and G/G. In Hanwoo, the A/G genotype frequency was 0.13, and G/G was 0.87. The CI of A/G was 382.18±10.03 days, and G/G was 381.69±5.22 days. The SPC of A/G was 1.62±0.16, and G/G was 1.32±0.04. While CI showed no significance difference, SPC exhibited significant difference (p<0.05). In Holstein cattle, the frequency of genotype A/G was 0.02 and G/G was 0.98. The 305 days milk yield of A/G was 7,253.00±936.00 kg and of G/G was 8,747.51±204.88 kg, showing no significant difference.

분만 후 최적 수정시기를 탐색하기 위한 초기의 연구에서는 분만 후 경과일 수에 따라 분만 후 60일 이내, 61 90일 및 90일 이상으로 구분하여 시험이 수행되었는데 처리별 첫수정 수태율이 각각 48%, 70% 및 76%였고, 수태당 수정횟수가 2.09회, 1.55회 및 1.54회였다고 보고하였으며(George, 1955), 분만간격이 360 374일인 젖소의 첫수정 수 태율에 있어서 분만 후 0 45일 38%, 46 60일 47%, 61 90일 55% 91 120일 59% 및 121 180일 59%로 분만 후 일수가 경과됨에 따라 수태율이 증가되는 양상을 나타내었다 고 보고하였다(Bozworth 등, 1972). 그리고 분만 후 50일 및 80일에 발정이 발견된 경우 의 수태일수는 각각 88일 및 121일이었고, 수태당수정횟수는 각각 1.50회 및 1.96회였다 고 보고하였다(Schneider 등, 1981). 또한, 분만 후 50 75일, 76 100일 및 100일 이상 에서 인공수정 시 임신율이 각각 36%, 47% 및 43%로 76 100일이 가장 높은 것으로 보고되었다(Pursley 등, 1998). 분만 후 비유단계에 따른 발정발현율, 수태율 등이 연구자 들에 따라 다소 의견을 달리하고 있고, 특히 산유능력(평균능력 및 고능력)에 따른 조사 는 이루어지지 않고 있다. 따라서 본 연구에서는 비유단계 및 산유능력에 따른 발정발현 율, 수태율을 조사하고, 차기의 번식에 좋지 않은 영향을 주지 않는 적정 수정시기를 구 명하기 위하여 수행하였다. 분만 후 기간에 따라, 분만 후 30 59일(30일구), 60 89일(60 일구), 90 110일(90일구) 및 111일 이후(111일구)로 구분하여 조사하였다. 분만 후 발정 발현율은 30일구가 16.7%(17/102), 60일구가 28.4%(29/102), 90일구가 20.6%(21/102) 및 111일구가 34.3%(35/102)였고, 분만 후 수태율은 30일구가 52.9%(9/17), 60일구가 51.7 %(15/29), 90일구가 47.6%(10/21) 및 111일구가 48.6%(17/35)였다. 산유능력별로 보면, 발정발현율에 있어서 30일구의 경우 평균능력우 및 고능력우가 각각 25.0% 및 16.7%, 60일구의 경우 각각 40.6% 및 20.8%, 90일구의 경우 25.0% 및 12.5%, 111일구의 경우 9.4% 및 50.0%였고, 수태율에 있어서 30일구의 경우 평균능력우 및 고능력우가 각각 87.5% 및 25.0%, 60일구의 경우 각각 61.5% 및 0%, 90일구의 경우 75.0% 및 33.3%, 111일구의 경우 66.7% 및 50.0%였다.

본 연구는 젖소의 산유 능력에 따른 번식 성적을 조사하기 위하여 축산과학원 시험우사에서 사육중인 젖소를 이용하여 분만 후 유즙중 P4농도를 분석하였고, 전문경영체농장 22개 소에서 사육중인 젖소에 대한 번식 기록을 이용하여 고능력우(305일 유량 10,000 kg 이상)와 평균 능력우(305일 유량 10,000 kg이하)의 번식 성적을 조사한 결과는 다음과 같다. 1. 젖소의 분만 후 progesterone peak는 고능력 및 평균 능력우의 경우에 각

대상방목 체계하에서 Lolium perenne초생의 채식 허용량을 3 수준으로 달리 하여 고능력 착유우에 의한 방목시험으로부터 얻은 채식량과 산유량을 조사하여 얻을 결과를 요약하면 아래와 같다. 채식된 사포로부터 배설된 분증질소, 크롬 및 회분 함량은 시험시기가 늦을수록, 채식허용량이 낮을수록 약간 감소되는 경향이었다. 시험시기별 채식 허용량의 수준에 따른 채식초의 소화율은 시험시기 1의 82.7%에서 시험시기 3의 79.1%로 감소하였고, 고수준의 채

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.

This experiment was conducted to determine the effect of nattokinase (NK) additives on milk production and composition, and blood metabolites in dairy cows. The two kinds of nattokinase with high fibrinolytic activity were produced by two strains of bacteria, Bacillus amyloliquefacines (NK1) and Bacillus subtilis (NK2). Total fifteen Holstein cows (average 1.83±0.37 parity; average milk yield 23.2±3.2 ㎏/d) were randomly assigned to three treatments (5 animals per treatment). Cows were fed TMR supplemented with 0g, 100g and 100g for control, NK1 and NK2 treatment, respectively for 4 weeks. Milk yield was significantly higher (p＜0.05) for NK1 (22.89 ㎏/d) than for control (21.07 ㎏/d) and NK2 (21.36 ㎏/d). Somatic cell counts in NK treatments were significantly lower than that in control group (58,000 vs. 21,000 and 35,000 cells/㎖, control vs. NK1 and NK2). Serum ALT levels in all treatment were similar to the range of 32.00~35.83 IU/L, but AST levels in NK1 (85.67 IU/L) was significantly decreased compared with those in control and NK2 (121.67 and 117.67 IU/L respectively). Serum T-CHO levels in NK1 (145.33 ㎎/㎗) was significantly decreased (p＜0.05) compared with that in control (179.00 ㎎/㎗) and NK2 (176.17 ㎎/㎗). This finding showed that NK1 additives could possibly have a positive effect in lactation performance of mid-lactation dairy cows by increasing milk yield, reducing somatic cell count, improving liver function and decreasing cholesterol in blood.