Effects of oral powder electrolyte administration on packed cell volume,plasma chemistry parameters,and incidence of colic in horses participating in a 6-day 162-km trail ride

This study evaluated the effects of administering oral powder electrolytes on packed cell volume (PCV), plasma chemistry parameters, and incidence of colic in horses participating on a 6-day 162-km trail ride in which water was not offered ad libitum. Twenty-three horses received grain with powder electrolytes daily while 19 control horses received grain only. Horses were ridden approximately 32 km a day at a walk or trot. Packed cell volume and plasma chemistry parameters were analyzed daily. Episodes of colic were diagnosed and treated by a veterinarian unaware of treatment group allocation. Blood parameters and incidence of colic were compared between treatment groups. Electrolyte administration did not alter PCV or plasma chemistry parameters compared to controls. The incidence of colic was significantly higher in treated horses (P = 0.05). Oral powder electrolytes did not enhance hydration status or electrolyte homeostasis and may be associated with colic in horses participating on long distance trail rides similar to this model.     

Pharmacokinetics of buprenorphine following intravenous and intramuscular administration in male rhesus macaques (Macaca mulatta)

This study reports the pharmacokinetics of buprenorphine in conscious rhesus macaques (Macaca mulatta) after intravenous (i.v.) and intramuscular (i.m.) administration. Four healthy, opioid‐naïve, socially housed, adult male macaques were used. Buprenorphine (0.03 mg/kg) was administered intravenously as a bolus or intramuscularly on separate occasions. Blood samples were collected prior to, and up to 24 h, postadministration. Serum buprenorphine concentrations were analyzed with liquid chromatography–mass spectrometry. Noncompartmental pharmacokinetic analysis was performed with commercially available software. Mean residence time in the i.v. study as compared to the i.m. study was 177 (159–189) vs. 185 (174–214) min, respectively [median (range)]. In the i.v. study, concentration back‐extrapolated to time zero was found to be 33.0 (16.8–57.0) ng/mL [median (range)]. On the other hand, the maximum serum concentration found in the i.m. study was 11.8 (6.30–14.8) ng/mL [median (range)]. Rhesus macaques maintained concentrations >0.10 ng/mL for over 24 h in the i.v. study and over 12 h in the i.m. study. Bioavailability was found to be 68.1 (59.3–71.2)% [median (range)]. No significant adverse effects were observed in the monkeys at the 0.03 mg/kg dose of buprenorphine during either study.     

Effect of Leptin on In Vivo Goat Embryo Production

The aim of this study was to evaluate the effect of leptin administration during superovulation on in vivo goat embryo production. Ten mature does were superovulated with 133 mg follicle‐stimulating hormone (FSH) i.m. in six descending doses at 12‐h intervals. The goats received 4.8 μg/kg human recombinant leptin s.c. (leptin group, n = 5) or phosphate‐buffered saline (PBS) (control group, n = 5) with the first and second FSH doses. The does were mated and subjected to embryo collection by transcervical technique 6 days later. The total number of cells per embryo and the number of cells with fragmented DNA were assessed in selected blastocysts by combining Hoechst 33342 and terminal dUTP nick‐end labelling (TUNEL) staining. Plasma concentrations of oestradiol (E₂) and progesterone (P₄) were determined by electrochemiluminescence from the day of FSH treatment, on the day of superovulatory oestrus and on the day before embryo collection. Compared with the control group, the does that received leptin had a higher number of transferable embryos (p < 0.005), fewer embryos classified as degenerated (p < 0.001) and fewer TUNEL‐positive cells/blastocyst (p < 0.001). The number of transferable embryos was positively correlated with E₂ concentrations on day of oestrus (r = 0.562; p < 0.01) and P₄ concentrations on the day of embryo collection (r = 0.912; p < 0.001). We concluded that in vivo leptin administration during FSH treatment improved embryo quality and affected ovarian steroidogenesis in superovulated goats.     

Percentage of Ubiquitinated Spermatozoa does not Correlate with Fertilizing Capacity of Thawed Bovine Semen

In the spermatozoa of some species, the ubiquitin–proteasome system detects altered proteins and tags them for elimination by the proteasome. In some species' ejaculates, a high proportion of ubiquitinated spermatozoa (i.e. those having ubiquitin bound to the altered or damaged membrane proteins) has been related to infertility. The aim of this study was to assess whether the percentage of ubiquitinated spermatozoa relates to fertility of dairy bulls and whether ubiquitination increases during protein remodelling that occurs during in vitro spermatic capacitation. Thirty‐two frozen semen straws from four high‐fertility (ReproMax^®) and four normal‐fertility (Normal) Holstein‐Friesian sires were evaluated. Ubiquitinated and capacitated spermatozoa were quantified by sperm ubiquitin tag immunoassay and chlortetracycline stain, respectively. Fertilizing capacity of sires was assessed by in vitro fertilization. No differences were found between Normal and ReproMax^® sires with regard to the observed percentage of ubiquitinated spermatozoa (42.97 ± 3.69% and 49.68 ± 9.27%, respectively; p > 0.05). Additionally, no differences were found in the percentage of ubiquitinated spermatozoa as a consequence of spermatic capacitation in either Normal (42.97 ± 3.69% before capacitation vs 44.67 ± 7.5% after; p > 0.05) or ReproMax^® sires (49.68 ± 9.27% before vs 45.05 ± 7.51% after; p > 0.05). The percentage of ubiquitinated spermatozoa in a thawed sperm samples did not correlate with its in vitro fertilizing capacity; thus, this assay does not prove useful to detect in vivo fertility differences between sires. Additionally, protein degradation occurring during remodelling of the spermatozoon plasma membrane during the capacitation process does not seem to involve the ubiquitin–proteasome system.     

Broken eggs as a cause of infertility of coho salmon gametes

Egg content originating from ruptured ova progressively reduced the success of fertilization in coho salmon (Oncorhynchus kisutch) eggs. The salmon egg differs in ionic composition from the ovarian fluid in exhibiting higher K⁺ and Mg²⁺ and lower Na⁺ concentrations. Normal ovarian fluid induced spermatozoan motility whereas ovarian fluid contaminated with egg content progressively lost the ability to induce motility. Loss of motility was related to decreasing $\text{Na}{}^{\mathrm{+}}\text{K}{}^{\mathrm{+}}$ ratios in the ovarian fluid, indicating that reduced fertility may be caused by inactivation of sperm cells in the insemination medium. Removal of contaminated ovarian fluid by rinsing ova in isotonic media induced spermatozoan motility and restored fertility completely. The use of an isotonic NaHCO₃ solution for rinsing of ova is suggested as a routine procedure for artificial insemination in salmonids where the presence of broken eggs is suspected.     

The hydraulically integrated serial turbidostat algal reactor (HISTAR) for microalgal production

A hydraulically integrated serial turbidostat algal reactor (HISTAR) for the mass production of microalgae was designed, constructed and preliminarily evaluated. The 9266-l experimental system consists of two enclosed turbidostats hydraulically linked to a series of six open continuous-flow, stirred-tank reactors (CFSTRs). The system was monitored and controlled using GENESIS process control software. A production study was preformed using Isochrysis sp. (C-iso) to assess system stability and production potential under commercial-like conditions. The study was performed at the following target system parameters: system dilution rate of 0.49 per day, pH 7.6, NITROGEN=10 mg l⁻¹, PHOSPHORUS=2 mg l⁻¹, and artificial illumination (photosynthetic photon flux density) from 1000 W metal halide LAMPS=800 μmol s⁻¹ m⁻². At steady state conditions, daily harvested algal paste was 1454 g (wet), mean areal system PRODUCTIVITY=47.8±3.04 g m⁻² per day (17.1±1.09 g C m⁻² per day) and mean CFSTR6 DENSITY=105.5±6.71 mg l⁻¹.     

Bench-Scale Evaluation of a Micro-Computer Automated Algal Turbidostat

A bench-scale, micro-computer automated algal turbidostat was constructed and its production and culture maintenance capabilities were evaluated. The computer program "Supervisor," written in Turbo Pascal, consisted of a series of functions and procedures integrated through a core program consisting of a: 1) stack; 2) bubble sort routine; and 3) supervisor procedure. The program controlled the daily routine procedures including harvesting, feeding, monitoring and a semimonthly disinfection process. Data received from the monitoring devices were used by the computer for decision making processes concerning changes in operation. In addition to reducing labor, continuous computer monitoring insured more reliable system operation.
The system operated successfully for five months, reliably producing Chlorella minutissima . For each harvesting event, the percent volume removed from each chamber depended on the solar cell reading recorded immediately before the harvest cycle began. Significant correlations between millivolts and algal biomass concentrations allowed the use of solar cells as a reliable and inexpensive method of culture density management. Kinetic studies using Chlorella minutissima resulted in a maximum biomass concentration of approximately 190 g/m³ and an average specific growth rate of 0.66/d. Experimental data combined with a first order computer analysis projected a daily harvest of 82 g/m³/d (dry weight) based on a 38% turnover rate, the average observed harvest rate for the three chambers.     

Predictive mapping for management and conservation of seagrass beds in North Carolina

An Erratum has been published for this article in Aquatic Conservation: Marine and Freshwater Ecosystems 12(2), 2002 577

• 1. This research extends techniques of predictive mapping from their application in terrestrial environments to marine landscapes by investigating the relationship between seagrass and hydrodynamics in Core Sound, North Carolina, USA.
• 2. An empirically derived logistic multiple regression model and a Boolean logic suitability model were used to produce several predictive map products, including: susceptibility of seagrasses to storms, probability of seagrass cover, and suitability of areas for restoration of seagrasses. A visual comparison between these maps and conventional seagrass polygon maps allows for a discussion of ‘field’ versus ‘object’ mapping, and the ramifications for management based on different cartographic techniques.
• 3. The predictive method used here showed that only a small portion (19%) of the seagrass bed in the study area would be expected to have a high probability of seagrass coverage. The majority of the seagrass habitat in the study area was predicted to have less than 50% probability of seagrass cover. In addition, 16% of the nearly 2000 ha of seagrass within the study area were predicted to be highly susceptible to acute storm events. Moreover, using a conservative set of site selection criteria, only 7% of the study area encompassed by seagrass habitat was predicted to have a high probability of successful restoration if injured.
• 4. This method provides for an inexpensive way to scale‐up from high‐resolution data to a coarser scale that is often required for conservation and management.

Copyright © 2001 John Wiley & Sons, Ltd.     

Behavioural interactions of seabirds with suspended mussel longlines

Increased abundances of a number of seabird species have been found in areas of mussel longline aquaculture (compared to control sites) in a recent study at Bantry Bay, southwest Ireland. The aim of this study was to investigate whether this form of mussel aquaculture also affects the activity budgets and foraging behaviour of these seabirds. Scan-sampling was used to compare seabird activity budgets between three areas of mussel longline aquaculture and three control sites. Foraging activities of Great-Northern Divers Gavia immer, an Annex 1 species under the Euopean Union's Birds Directive, were also compared between sites using focal sampling. The behaviour of gulls (Larus sp.), Cormorants Phalacrocorax carbo, Shags Phalacrocorax aristotelis and Great-Northern Divers (but not auks, Alcidae) differed significantly between areas of mussel aquaculture and control sites in this study. Mussel suspension buoys were heavily utilized by gulls, cormorants and shags as safe perching platforms for preening activities. Gulls also fed extensively on epifauna attached to the buoys. Great-Northern Divers spent more time snorkelling (head submerged in search of food) in mussel sites than in the control sites, however dive duration and visible foraging success rates did not differ significantly between sites. Overall, the environmental impact of mussel suspension culture appears to be positive or neutral on marine bird species occurring at this study site.