美国大豆工业海洋网箱水产养殖技术近海海水鱼类养殖网箱工程技术手册(三十二)

(上接2012年第3期) (3)减阻设计方案3评估 第三种设计方案将减阻物放在相邻的两个侧面上.它的响应和设计方案1相同并且当网箱一开始运行时就沉入水中.当水速达到32厘米/秒时停止测试,因为此时可以观察到网箱沉至离水面7.3米一下(满标度),而且速度再增大时将撞击测试槽底部了(图28).     

Ribosomal DNA Sequence Comparisons of Colletotrichum Graminicola from Turfgrasses and other Hosts

The 5.8S ribosomal gene and the flanking internal transcribed spacers (ITS) 1 and 2 from Colletotrichum graminicola isolates causing anthracnose disease of Agrostis palustris and Poa species were sequenced. Although bootstrap support was not high, two major groups were observed with both UPGMA and parsimony algorithms, one containing isolates from A. palustris and another with isolates from Poa spp. The ITS sequences were also compared with those of isolates of C. graminicola and C. sublineolum from Sorghum spp., Zea mays and Rottboellia cochinchinesis as well as other Colletotrichum species. Except for one isolate from P. annua in Texas, the ITS1 and ITS2 sequences of turfgrass isolates always grouped separately from C. graminicola or C. sublineolum from non-turfgrass hosts with high bootstrap support. ITS sequences of the turfgrass isolates were more similar to those of other species of Colletotrichum, such as C. coccodes and C. dematium, than they were to C. graminicola isolates from other hosts. Turfgrass isolates have ITS sequences which are not identical to those of isolates from Zea mays and Sorghum species demonstrating diversity among fungi conventionally classified as C. graminicola.     

基于无线传感器网络的奶牛行为特征监测系统设计

奶牛等大型动物的疾病和发情状况目前主要依赖饲养员目测判断,大规模集约化养殖仍采用人工观测方法,这不仅带来繁重的人力负担,也容易误判。为了能自动准确地识别奶牛是否发情或生病,该文提出在奶牛颈部安装无线传感器节点,通过各种传感器获取奶牛的体温、呼吸频率和运动加速度等参数,采用K-均值聚类算法对提取的各种参数进行行为特征多级分类识别,以此建立的动物行为监测系统能准确区分奶牛静止、慢走、爬跨等行为特征,从而可以长时间监测奶牛的健康状态。而且,这种监测系统易于推广到对其他动物的监测,对促进养殖业和畜牧业的发展也具有指导意义。     

Effects of Pre‐Weaning Energy Substitutions on Post‐Weaning Follicle Development,Steroid Hormones and Subsequent Litter Size in Primiparous Sows

The present study investigated the effects of pre‐weaning energy substitutions on follicular development, endocrine characteristics and subsequent litter size in primiparous sows. Sows were fed a standard lactation diet (14.1 DE MJ/kg) and then allocated to a Control (C, n = 24), Fat (F, n = 23), Sugar (S, n = 23) or post‐weaning Regumate (positive control; R, n = 22) treatment at 9 days before weaning of the C, F and S treatments. During the treatment period (8 days), 1 kg of the lactation diet was substituted with 1 kg of a fat‐rich (F, 23.85 DE MJ/kg) or sugar‐rich (S, 15.75 DE MJ/kg) substitution for F and S sows, respectively. For the R treatment, sows were weaned 8 days earlier than other treatments and fed a lactation diet at 3.5 kg with two doses of altrenogest as topdressing from 1 day before weaning until the day on which the other sows were weaned. The F treatment aimed to increase energy intake, and the S treatment aimed to elevate post‐prandial glucose and insulin concentrations. Weaning‐to‐ovulation interval tended to be reduced in the S treatment compared with C (p = 0.06) and F (p = 0.08) treatments. Body weight (BW) loss during the treatment period, post‐weaning follicle development, plasma oestradiol and pre‐weaning leptin did not differ among C, F and S sows, although BW loss was lower and leptin was higher in the R treatment. Post‐ovulatory progesterone concentration in the S treatment was higher (p < 0.05). Sows in the S and R treatments had a greater proportion of litters with larger litter sizes (p < 0.05). The outcome suggests that increasing circulating insulin and glucose concentrations during late lactation or a week of metabolic recovery positively improves subsequent litter size in primiparous sows.     

Gonadotropin‐Releasing Hormone Administration to Dairy Cows without a Corpus Luteum 4 Weeks after Calving Increases Reproductive Performance

This field study investigated whether the administration of a single dose of gonadotropin‐releasing hormone (GnRH) to dairy cows without a corpus luteum (CL) 4 weeks after calving can improve reproductive performance. Holstein dairy cows underwent ultrasonography to assess the presence of ovarian structures at 29.2 ± 5.2 days post‐partum, and cows were divided into two main groups based on the presence (CL group, n = 230) or absence (non‐CL group, n = 460) of a CL. The non‐CL group was further randomly divided into two subgroups based on the administration of GnRH (non‐CL GnRH group, n = 230) or no GnRH (non‐CL control group, n = 230). Subsets of cows from non‐CL control (n = 166) and non‐CL GnRH (n = 175) groups received a second ultrasonography at 44.5 ± 5.4 days post‐partum to assess CL formation. The percentage of cows with CL at the second ultrasonography was greater in the non‐CL GnRH group (70.9%) than in the non‐CL control group (53.0%, p = 0.0006). The hazard of the first post‐partum insemination by 150 days in milk (DIM) was higher in the CL group than in the non‐CL control group (hazard ratio [HR]: 1.36, p = 0.001). The probability of a pregnancy to the first insemination was higher in non‐CL GnRH (odds ratio [OR]: 1.50, p = 0.04) and CL groups (OR: 1.55, p = 0.03) compared to the non‐CL control group. Furthermore, the hazard of pregnancy by 210 DIM was higher in non‐CL GnRH (HR: 1.30, p = 0.01) and CL (HR: 1.51, p = 0.0001) groups than in the non‐CL control group. In conclusion, administration of GnRH to dairy cows without a CL 4 weeks after calving was associated with an increase in ovulation and improved reproductive performance.     

Low levels of haptoglobin and putative amino acid sequence in Taiwanese Lanyu miniature pigs

Porcine haptoglobin (Hp) is an acute phase protein. Its plasma level increases significantly during inflammation and infection. One of the main functions of Hp is to bind free hemoglobin (Hb) and inhibit its oxidative activity. In the present report, we studied the Hp phenotype of Taiwanese Lanyu miniature pigs (TLY minipigs; n=43) and found their Hp structure to be a homodimer (beta-alpha-alpha-beta) similar to human Hp 1-1. Interestingly, Western blot and high performance liquid chromatographic (HPLC) analysis showed that 25% of the TLY minipigs possessed low or no plasma Hp level (<0.05 mg/ml). The Hp cDNA of these TLY minipigs was then cloned, and the translated amino acid sequence was analyzed. No sequences were found to be deficient; they showed a 99.7% identity with domestic pigs (NP_999165). The mean overall Hp level of the TLY minipigs (0.21 +/- 0.25 mg/ml; n=43) determined by enzyme-linked immunosorbent assay (ELISA) was markedly lower than that of domestic pigs (0.78 +/- 0.45 mg/ml; p<0.001), while 25% of the TLY minipigs had an Hp level that was extremely low (<0.05 mg/ml). In addition, the initial recovery rate (first 40 min) in the circulation of infused fluorescein isothiocyanate (FITC)-Hb was significantly higher in the TLY minipigs with extremely low Hp levels than those with high levels. This data suggests that the low concentration of Hp-Hb complex is responsible for the higher recovery rate of Hb in the circulation. TLY minipigs have been used as an experimental model for cardiovascular diseases; whether they can be used as a model for inflammatory diseases, with Hp as a marker, remains a topic of interest. However, since the Hp level varies significantly among individual TLY minipigs, it is necessary to prescreen the Hp levels of the animals to minimize variation in the experimental baseline. The present study may provide a reference value for future use of the TLY minipig as an animal model for inflammation-associated diseases.     

Elevating glucose and insulin secretion by carbohydrate formulation diets in late lactation to improve post‐weaning fertility in primiparous sows

Primiparous (P1) sows commonly lose excessive body reserves to meet energy requirements for maintenance and milk production during lactation, and consequently, post‐weaning reproductive performance may be compromised. The present studies determined whether ad libitum feeding a glucogenic carbohydrate diet (CHO) during late lactation could stimulate insulin and glucose secretion (experiment 1) and improve subsequent litter size (experiment 2). For experiment 1, 15 P1 sows, and for experiment 2, 99 P1 sows (198.5 ± 2.7 kg) were allocated randomly according to suckled litter size (≥10 piglets), either to a CHO diet (14.3 MJ DE/kg, 19.8% crude protein) or a standard lactation diet (control; 14.2 DE MJ/kg, 19.5% crude protein) at 8 days before weaning. The CHO diet aimed to provide glucogenic content (extruded wheat, dextrose and sugar) as energy sources instead of fat sources without changing total dietary energy. Pre‐prandial plasma glucose and insulin concentrations were not influenced by treatments. However, post‐prandial plasma glucose and insulin concentrations and their peaks were both higher (p < .05) compared to the control treatment. Body weight loss during lactation was relatively low at 3%–4% for both treatments and did not differ between control and CHO treatments (?7.6 ± 1.6 vs ?5.4 ± 1.2 kg; p > .05). Second litter size was not influenced by diet (p > .05), but the weaning‐to‐mating interval was shorter in CHO sows (p < .05). This study demonstrates that providing an enriched CHO diet in late lactation did influence post‐weaning follicle growth but did not improve subsequent litter size. This may be due to the primiparous sows in this study not experiencing severe negative energy balance and there was no second litter syndrome in this farm which limited the ability of diet to improve sow fertility.     

美国大豆工业海洋网箱水产养殖技术近海海水鱼类养殖网箱工程技术手册（二十）

（3）带有水流负载网箱的模拟 表10中所示为八种水流状态下锚链和拉紧绳的平均张力。而表11中所列是网箱的相关深度响应。正如预期的那样,锚链和拉紧绳的张力随水流的速度增加而加大。     

美国大豆工业海洋网箱水产养殖技术近海海水鱼类养殖网箱工程技术手册（二十六）

ⅤⅢ物理模型 1．综述 2007年,美国大豆工业协会与New Hampshire（UNH）,大学机械工程部和海洋工程中心签订了合同要求建立一个OCAT海洋网箱系统的比例模型并用此模型对OCAT网箱在不同的海洋波浪中和海流级别中的状态进行分析研究。此海洋网箱养殖系统（OCAT）的比例模型在UNH大学的波浪／牵引槽内进行了建造和试验。