Artificial Propagation of Mutton Snapper Lutjanus analis, A New Candidate Marine Fish Species for Aquaculture

Abstract Wild-caught mutton snapper Lutjanus analis , a high-value marine food fish species, matured in flow-through seawater (36 g/L) tanks after 3 yr in captivity. On 31 May 1995, a female with a mean oocyte diameter of 382 μm was injected with human chorionic gonadotropin (HCG) (500 IU/kg body wt.) followed 24 h later by a second injection (1,000 IU/kg body wt.). At the time of the second injection, three males were injected with HCG (500 IU/ kg body wt.). Voluntary spawning occurred 33 h after the first injection, with a total of 534, 781 eggs released. Fertilization rate was 75.7%, while average diameter of fertilized eggs was 783 μm. Embryos were stocked in a 30-m³ outdoor tank at a density of 10.5/L. On day 2 post-hatching (d2ph), larval density was 8.61 larvae/L, and average notochord length was 2.6 mm. Larvae were fed ss-type rotifers from dl-d28ph, Artemia nauplii from 0–08ph, and artificial diets (52–48% protein) from d24-d38ph. On d38ph, fish averaged 0.308 g and 22.2 mm standard length. Survival (from d2ph) was 14.3%, with a total of 36,900 post-metamorphic juveniles produced. On d97ph, 1,390 hatchery-reared juveniles (avg. wt. = 10.5 g) were stocked into two 14.5-m³ recirculating seawater tanks (695 fish/tank; 48 fish/m³) and fed a 56% protein pellet. After 168 d, fish averaged 140.8 g, with a survival rate of 97.8% and a feed conversion ratio (dry wt./wet wt.) of 1.2. These preliminary results reveal the mutton snapper to be a prime, new candidate species for commercial cultivation.     

Lipid profiles of canine spermatozoa as revealed via matrix‐assisted laser desorption/ionization mass spectrometry

In this study, we investigated the ability of matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) to characterize the lipid contents of canine spermatozoa. For that, samples of pure semen were analysed. Indeed, quite comprehensive lipid coverage was observed, and the most abundant phospholipid ions detected were from four phosphatidylcholines, that is those of m/z 760.6; 782.6; 808.6; and 830.6 and one of m/z 725.6 from a sphingomyelin. In conclusion, MALDI‐MS was found to offer an easy, fast, accurate, and sensitive analytical method for lipid profiling in canine spermatozoa and could be used as a tool to select sires by assessing the relationship between sperm lipid profiles and variables such as age and breeding history as well as to study the effects of cryopreservation on lipid contents.     

不同化学杀雄剂对甘蓝型油菜的杀雄效果研究

化学杀雄是油菜杂种优势利用的一条重要途径,本试验选用3种化学杀雄剂(苯磺隆、WP 1和WP 2)并设置不同的浓度,对4个甘蓝型油菜常规品种(杨4、中11、早熟1号和早熟2号)和1个质不育系(中11 A)进行杀雄效果研究,获得了各供试油菜品种适宜的化学杀雄剂类型及施用浓度,为分别利用这4个油菜品种和质不育系中11 A作亲本进行杂交制种生产提供了一定的技术基础,对化杀油菜品种的种子生产有一定的实际指导作用。     

Systemic Immunosuppression by Methylprednisolone and Pregnancy Rates in Goats Undergoing the Transfer of Cloned Embryos

The presence of the zona pellucida has been perceived as a requirement for the oviductal transfer of cloned embryos at early stages of development while protecting the embryo from an immune system response. We hypothesized that steroid hormone therapy could reduce a potential cellular immune response after the transfer of zona‐free cloned embryos into the oviduct of recipient female goats. In Experiment 1, seven does were used to study the systemic immunosuppressant effect of the methylprednisolone administration (for 3 days) on blood cell counts. Whole blood was collected prior to treatment with methyprednisolone and then on Days 1, 2, 3, 4, 7, 14, 21 and 28 after the first dose of methylprednisolone for the analysis of haematological parameters. Methylprednisolone treatment significantly reduced circulating white blood cells and neutrophils in comparison with pre‐treatment levels, demonstrating a systemic immunosuppressant effect. In Experiment 2, a group of 58 does were used as recipient females to study the effect of administration of methylprednisolone for 3 days on the establishment of pregnancies after the transfer of zona‐free cloned embryos into the oviducts. No effects on pregnancy rates on Day 30 were observed regarding the distinct treatment groups (control vs. methylprednisolone), the source of oocytes (in vivo‐ vs in vitro‐matured) or the presence or absence of the zona pellucida in embryos. In summary, methylprednisolone was effective at inducing a systemic immunosuppressed state in goats, but the treatment prior to embryo transfer did not affect pregnancy rates. Moreover, pregnancy rates were similar between zona‐free and zona‐intact goat cloned embryos.     

PRELIMINARY REPORT ON THE AQUACULTURAL DEVELOPMENT OF THE DOLPHIN FISH,Coryphaena hippurus (LINNAEUS)

First and second generation (F₁ and F₂), laboratory reared juvenile Coryphaena hippurus were used in preliminary growth studies. Fish were stocked in circular tanks and fed a diet of chopped herring and squid. Initial size and age of fish used in these studies were as follows: 61 mm TL, 1.6 g, and 45 days old for F₁ and 87 mm TL, 5.95 g, and 65 days old for F₂. Mean size at 130 days of age was 560 mm TL and 1,305 g for F₁ and 540 mm TL and 1,150 g for F₂. Food conversion ratios were 3.05 and 2.9 4 for F₁ and F₂ fish, respectively.     

Evaluation of chicken infectious anemia virus and associated risk factors with disease and production losses in broilers

A case-control study was performed to determine the significance of chicken infectious anemia virus (CIAV) as a risk factor associated with secondary disease in commercial broilers and to identify the significance of production losses associated with CIAV. The study also examined the relationship between bursal and thymic atrophy and the presence of CIAV. Cases were defined as submissions to the Alabama Veterinary Diagnostic Laboratories with a history of clinical disease and with a diagnosis of coccidiosis, gangrenous dermatitis, or respiratory disease. Controls were selected from submissions with neither a history of disease nor evidence of disease on necropsy. CIAV was detected in fresh tissues by polymerase chain reaction. Both thymic atrophy and the detection of CIAV were significantly associated with a disease case (P < 0.05). Bursal atrophy was a significant risk factor associated with the detection of CIAV in a submission (P < 0.05). Whereas CIAV was associated with disease cases that showed production losses in both percentage of livability and percentage of condemnations (P < 0.05), detection of CIAV alone was not associated with detectable losses in production or flock performance.     

重穗型水稻恢复系黔恢35的选育及应用

黔恢35是贵州省水稻研究所采用当地强恢复系R 785和重穗型恢复系R 894杂交选育而成的重穗型水稻新恢复系,具有穗粒数多、千粒重高、恢复力强、配合力高、植株壮实、花粉量大、花粉活力强、制种产量高等特性;利用自育抗稻瘟病不育系黔79 A与重穗型黔恢35所配组合黔优35经过2年区试及生产试验,于2018年4月通过贵州省农作物品种审定委员会审定。     

糯玉米新品种筑糯11号制种及亲本繁育技术

杂交糯玉米新品种筑糯11号系贵阳市农业试验中心用自育自交系遵三糯31作母本与自育系筑糯A 1作父本组配选育而成。该品种棒子大、苞叶好、产量高、品质好、适应性广等优点,具有广阔的市场开发利用前景。     

Cost comparisons of rearing larvae of freshwater shrimp,Macrobrachium acanthurus and M. rosenbergii,to juveniles

Costs were determined for rearing larval Macrobrachium rosenbergii (De Man) and M. acanthurus (Wiegmann). Rearing was conducted in two phases. First-phase rearing (first 10 days) was conducted in conical fiberglass tanks with recirculated, filtered, brackish water; second-phase rearing (final 30 days) was done in aerated 1 000-l concrete tanks. To minimize water quality problems and debris accumulation in second-phase rearing, larvae were transferred every 4 to 5 days to a new tank of clean water. Larval food consisted of newly hatched Artemia and either freshly ground fish or freeze-fried fish.Mean survival in five M. rosenbergii rearing trials was 43% in 40 days at a final density of 12 juveniles per liter. Mean survival of four M. acanthurus trials was 25% in 44 days at a final density of 3 juveniles per liter. Average total cost of labor, operation (electricity), food and water per thousand juveniles produced was $3.56 for M. rosenbergii and $13.42 for M. acanthurus.Extrapolation of results to larger (3 000-l) second-phase rearing tanks showed M. rosenbergii rearing cost could be reduced to $\text{\$1.87}\text{1 000}$.