• Animal Bioscience
• /
• 제36권4호
• /
• pp.591-600
• /
• 2023

Objective: We aimed to evaluate the efficacy of a modified Double-Ovsynch protocol vs artificial insemination following estrus detection (AIED) for the enhancement of reproductive performance in Hanwoo cattle. Methods: Four hundred twelve Hanwoo cows were allocated to two treatment groups. The first group of cows were administered gonadotropin releasing hormone (GnRH) on Day 36 (±0.6), prostaglandin F_2α (PGF_2α) on Day 46 (8 to 12 days later), and GnRH on Day 49, which was followed by Ovsynch, consisting of an injection of GnRH on Day 56, PGF_2α on Day 63, and GnRH 56 h and timed AI (TAI) 16 h later (modified Double-Ovsynch group, n = 203). The second group of cows underwent AIED (AIED group, n = 209) and were designated as controls. Results: The pregnancy per AI 60 days after the first AI was higher in the modified Double-Ovsynch (68.5%) than in the AIED (56.5%) group, resulting in a higher probability of pregnancy per AI (odds ratio: 1.68, p<0.05). Moreover, cows in the modified Double-Ovsynch group were more likely (hazard ratio: 1.28, p<0.05) to be pregnant by 150 days after calving than cows in the AIED group, and this difference was associated with a lower mean number of AIs per conception (1.27 vs 1.39, p<0.05) and a shorter median interval between calving and pregnancy (72 vs 78 days, p<0.1). Conclusion: The modified Double-Ovsynch protocol, adjusted according to the herd visit schedule, can be readily used to increase the pregnancy per AI following the first AI and to shorten the interval between calving and pregnancy in beef herds.

• Fisheries and Aquatic Sciences
• /
• 제22권12호
• /
• pp.30.1-30.11
• /
• 2019

Marine natural products isolated from the sponge Fascaplysinopsis cf reticulata, in French Polynesia, were investigated as an alternative to antibiotics to control pathogens in aquaculture. The overuse of antibiotics in aquaculture is largely considered to be an environmental pollution, because it supports the transfer of antibiotic resistance genes within the aquatic environment. One environmentally friendly alternative to antibiotics is the use of quorum sensing inhibitors (QSIs). Quorum sensing (QS) is a regulatory mechanism in bacteria which control virulence factors through the secretion of autoinducers (AIs), such as acyl-homoserine lactone (AHL) in gram-negative bacteria. Vibrio harveyi QS is controlled through three parallel pathways: HAI-1, AI-2, and CAI-1. Bioassay-guided purification of F. cf reticulata extract was conducted on two bacterial species, i.e., Tenacibaculum maritimum and V. harveyi for antibiotic and QS inhibition bioactivities. Toxicity bioassay of fractions was also evaluated on the freshwater fish Poecilia reticulata and the marine fish Acanthurus triostegus. Cyclohexanic and dichloromethane fractions of F. cf reticulata exhibited QS inhibition on V. harveyi and antibiotic bioactivities on V. harveyi and T. maritimum, respectively. Palauolide (1) and fascaplysin (2) were purified as major molecules from the cyclohexanic and dichloromethane fractions, respectively. Palauolide inhibited QS of V. harveyi through HAI-1 QS pathway at 50 ㎍ ml^-1 (26 μM), while fascaplysin affected the bacterial growth of V. harveyi (50 ㎍ ml^-1) and T. maritimum (0.25 ㎍). The toxicity of fascaplysin-enriched fraction (FEF) was evaluated and exhibited a toxic effect against fish at 50 ㎍ ml^-1. This study demonstrated for the first time the QSI potential of palauolide (1). Future research may assess the toxicity of both the cyclohexanic fraction of the sponge and palauolide (1) on fish, to confirm their potential as alternative to antibiotics in fish farming.

• 농업과학연구
• /
• 제22권1호
• /
• pp.69-81
• /
• 1995

본 연구는 축산기술연구소 대관령지원에서 사육하고 있는 Hereford, Angus 및 Charolais 육우품종에서 혈액을 채취하여 이들의 혈액내에 존재하는 transferrin(Tf), post-transferrin-2(pTf-2), albumin(Alb), post-albumin(pAlb), ceruloplasrmin(Cp), amylase-I(Am-I) 및 hemoglobin(Hb)의 혈액단백질 및 효소좌위의 유전적다형을 분석하여 이들 집단의 유전적 변이체를 조사하고자 PAGE(polyacrylamide gel electrophoresis)와 STAGE(starch gel electrophoresis)방법으로 분석하였던바 그 결과는 다음과 같다. 1. Tf좌위는 A, $D_1$, $D_2$ 및 E와 pTf-2좌위는 F와 S의 공우성 대립유전자의 지배를 받는 것으로 생각되며, 유전자형의 빈도에 있어서는 Hereford 종에서는 Tf $D_1D_2$와 pTf-2 SS 형이 각각 25 및 90%이었고, Angus종에서는 Tf $AD_1$와 pTf-2 FF형이 각각 25와 100%이었으며, Sharolais종에서는 Tf $D_1D_1$와 pTf-2 FS형이 각각 50%로 높은 빈도를 보였다. 유전자빈도에 있어서는 Hereford종에서 Tf E와 pTf-2 S 빈도가 각각 0.400과 0.900이었고, Sharolais종에서는 Tf $D_1$과 pTf-2 S가 각각 0.678 및 0.607로 높은 빈도를 보였다. 2. Alb좌위는 A, 그리고 pAlb좌위는 F와 S의 대립유전자의 지배를 받는것으로 사료되며, 유전자형 빈도에 있어서는 Hereford, Angus와 Sharolais종에서 각각 pAlb SS, FF 및 SS가 각각 70, 90 및 57.15%로 높은 빈도를 나타냈으며, pAlb의 유전자 빈도에 있어서는 Hereford와 Sharolais종에서 pAlb S가 각각 0.825와 0.750이었고, Angus종에서는 pAlb F가 0.900으로 높은 빈도를 보였다. 3. Cp 좌위는 F 및 S와 Am-I 좌위는 B와 C의 대립유전자의 지배를 받는 것으로 생각되며, 유전자형 빈도에 있어서는 Herford종에서는 Cp FF와 Am-I BB형의 빈도가 각각 100 및 85%이었고, Angus종에서는 Cp FF와 Am-I CC형이 각각 45 및 85%이였으며, Sharolais종에서는 Cp FF와 Am-I BC형이 각각 50 및 64.29%로 높은 빈도를 보였다. 유전자 빈도에서 있어서는 Herford, Angus와 Sharolais 종에서 Cp F가 각각 0.800, .875 및 0.680이었고 Hereford종에서 Am-I A가 0.800이었으며, Angus와 Sharolais종에서 Am-I C가 각각 0.875 및 0.680이었다. 4. Hb좌위 는 Hereford종과 Angus종에서는 Hb A, Sharol ais종에서는 Hb A와 B의 대립유선자가 검출 되었으며, Sharolais종에서 유전자형 빈도는 Hb AA 및 AB가 각각 57.14 및 42.88%이었고, 유전자빈도에 있아서는 Hb A와 B가 각각 0.785 및 0.215이었다.