BUDGET ANALYSIS OF PENAEID SHRIMP HATCHERY FACILITIES

One of the critical factors in commercial penaeid shrimp culture production is the availability of postlarvae to stock grow-out ponds. This study investigates the economic feasibility of rearing penaeid shrimp from nauplii to postlarvae (hatchery phase). The facility design used is based on the hatchery operated by Texas A&M university at Galveston, Texas. The Generalized Budget Simulation Model for Aquaculture developed at Texas A&M University was used for the analysis. A ten-year planning horizon was used for the analysis. Six different systems ranging in size from 5 ten-metric ton tanks to 60 ten-metric ton tanks were examined. Annual cost and return budgets were developed for the six systems assuming they operated 6 and 12 months per year. Investment costs, break-even prices and quantities, and net present value were estimated for each system. Results show that commercial hatcheries, using 10-metric ton tanks, could be profitable above and including 20 tanks for those operating only six months annually and above and including 10 tanks for those operating 12 months annually.     

CANINE HIP DYSPLASIA

It is the purpose of this study to call attention to new bone production that often occurs early in the sequence of pathological changes associated with canine hip dysplasia. New bone production extending to bony remodeling, as well as femoral head subluxation, both occur in the sequence of pathologic changes associated with canine hip dysplasia. Subluxation is considered primary, while osteoarthrosis is a secondary feature, and both are used in the diagnosis of canine hip dysplasia. This report concerns the significance of the presence of a solitary bony osteophyte, or spur, that is frequently evident on the caudal aspect of the femoral neck as viewed on the conventional ventrodorsal projection. This report utilizes findings from pelvic radiographs of 605 dogs (five breeds). There was a greater frequency (54%)of this bony change in cases diagnosed radiographically as dysplastic than in cases diagnosed as normal(15%).Thus, it is suggested that this minimal radiographic change can be used as an indicator of early canine hip dysplasia, especially in the absence of subluxation of the femoral head.     

Daytime management of the mare: 1: Pre-foaling mammary secretions testing

Fifty-six mares of lighthorse breeding were utilized in a controlled management scheme for induced daytime foaling. All mares had pre-foaling mammary secretions sampled for evaluation of water hardness (ppm) or calcium carbonate content (ppm). Sampling began 10 days prior to expected foaling date for each mare and was performed once daily for 3 days followed by twice daily until foaling occurred. Samples were diluted 1:6 in distilled water and tested by each of 3 methods: Sofchek™ Test Strips⁴, Predict-A-Foal™ Test Kit⁵ and Titrets™ Calcium Hardness Test Kit⁶. Mares were then either induced (i) to foal (no.= 33) according to a decision point of readiness for birth as indicated by pre-foaling mammary secretion testing (≥250 ppm water hardness by Sofchek™ test, ≥ 250 ppm calcium carbonate content by Titrets test, ≥ 4 color bar changes by Predict-A-Foal test), or allowed to foal spontaneously (s) (no.=23). There were no differences (p>0.05) in the mean pre-foaling mammary secretion test values (μ_i=293ppm, μ_s=329ppm; μ_i=4.1, μ_s=4.2; and μ_i=281ppm, μ_s=298ppm; for Sofchek, Predict-A-Foal and Titrets, respectively) between mare groups at the time of foaling (time=0) for any of the 3 testing methods employed. Mean intervals to foaling after reaching decision points of readiness for birth were different (p<0.05) between Sofchek and Titrets test for both mare groups, but only in the induced-to-foal group between Sofchek and Predict-A-Foal tests. Probabilities of 79%, 53% and 59% were calculated for mares foaling spontaneously within 24 hours of reaching the decision points used in this trial of readiness for birth on the initial occasion for Sofchek, Predict-A-Foal and Titrets™ tests, respectively. Each test was determined to have the ability to predict readiness of approaching parturition and found to be easily applicable to field use. The Titrets test was found to be least variable in its response to measurement of pre-foaling mammary secretion hardness changes both within and between mares.     

Variations in muscle fiber composition between successfully and unsuccessfully raced quarter horses

Muscle biopsy samples were removed from the m gluteus medius of 47 retired running Quarter Horse (QH) mares. Horses were separated based on bloodline, past racing history and percentage Thoroughbred (TB). The bred to run and raced (BRRA) and bred to run and not raced (BRNR) groups possessed a lower percentage (P<.01) of fast-twitch low oxidative (FT) fibers (BRRA 38.6 and BRNR 36.2±2.54 respectively). These horses also possessed a higher percentage (P<.01) of fast-twitch high oxidative (FTH) fibers (BRRA 52.5 and BRNR 48.5±2.54, respectively) than not bred to run and not raced (NBNR) horses. Horses that were bred to run had higher (P<.05) FTH to FT fiber ratios (1.44) than horses that were not bred to run (.94). Successful racehorses possessed a lower percentage (P<.05) of slow-twitch (ST) fibers and a higher percentage (P<.05) of FT fibers than unsuccessful racehorses. Success or failure was determined by Speed Index. No differences (P>.05) were found in the percentage FTH fibers between successful and unsuccessful horses.     

NONHUMAN PRIMATE EXCRETORY UROGRAPHY*

Survey radiographs have not accurately identified renal contour or location in nonhuman primates. Excretory urography using 786 to 1193 mg iodinelkg body weight resulted in dense opacification of the renal parenchyma and pelvis. Abdominal compression improved visu- alization of the renal pelvis. Interpretation of the nonhuman primate excretory urogram was compromised by several anatomic characteristics of this animal group. Superimposition of the kidneys on the lateral radiograph limited evaluation of the renal contour. Since the renal pelvis in most species of nonhuman primates does not possess diverticula (as in the dog and cat) or a caliceal system (as in the pig and man), the diagnosis of pyelonephritis or renal mass lesions was difficult. Severe irregularities in the renal contour, size of the renal pelvis, or areas of deficient concentrating ability were identifiable in nonhuman primate excretory urograms, but the diagnosis of small cysts was not possible in smaller nonhuman primates. The presence of a caliceal collecting system in the spider monkey (Ateles sp.) suggests this animal as a potential model for the evaluation of human renal disease.     

DECREASED TOXICITY OF COPPER AND MANGANESE IONS TO SHRIMP NAUPLII (Penaeus stylirostris STIMPSON) IN THE PRESENCE OF EDTA

Although ethylenediaminetetraacetic acid (EDTA) is used routinely in the intensive culture of penaeid shrimp larvae to increase both the percentage of eggs that hatch and the survival of larvae, the mode of action is not known. To explain EDTA's beneficial effect this study compares the toxicities of copper and manganese divalent ions in the presence and absence of 10 mg EDTA/liter seawater. Toxicity was evaluated in terms of the percentage of Penaeus stylirostris nauplii surviving after 12 and 24 hours of exposure to either copper or manganese and in terms of the percentage of nauplii that metamorphose to the protozoeal stage. In the absence of EDTA, copper and manganese ions were toxic to nauplii with copper causing 100% mortality at a much lower concentration (20 μM) than manganese (20,000 μM). In the presence of EDTA, survival of nauplii exposed to copper was increased but survival of nauplii exposed to manganese was not affected. At concentrations lower than the levels that reduce survival, copper ions (0.2 μM) and manganese ions (2 μM) reduce the percentage of nauplii that metamorphose to protozoea. In the presence of EDTA, the percentage of nauplii that metamorphose to protozoea is increased with both nauplii exposed to copper ions and nauplii exposed to manganese ions. The beneficial effects of EDTA are probably due to the chelation of copper and manganese ions by EDTA. Chelation lowers the free concentration of these ions and thus reduces their toxicities.