Advancements in Large Animal Embryo Transfer and Related Biotechnologies

Embryo transfer has been an inherent part of cattle breeding for more than 35 years and has also gained remarkable interest from the equine industry after several breeds allowed registration of more than one foal per year. In both large animal species, non‐surgical embryo recovery and transfer are well‐established techniques. However, success rates after superovulation and cryopreservation of embryos in horses are still lagging behind those of cattle, and more research is needed to address these areas. To address the problem of freezing large equine embryos, we offer a preliminary demonstration of a new cryopreservation method which involves reduction of the blastocoelic volume and microinjection of cryopreservative. Successful cryopreservation will improve the ability of practitioners to preserve and implant embryos in recipient mares. Recent advances in the use of equine FSH to induce superovulation in mares brings to the forefront the issue of how to best preserve the large number of embryos that are produced. Finally, the use of sexed semen after superovulation will provide the bovine and equine breeding industry the offspring of the desired sex.     

Effects of season and distance moved during loading on transport losses of market-weight pigs in two commercially available types of trailer

This study evaluated effects of trailer design and season on physical indicators of stress during loading and unloading and transport losses (dead and nonambulatory pigs) in market-weight pigs (BW = 129.6 +/- 0.40 kg). A total of 109 trailer loads of pigs (n = 17,256 pigs) from 1 farm were used in a randomized complete block design with a 2 x 4 factorial arrangement of treatments: 1) trailer design (potbelly vs. straight-deck) and 2) season (spring vs. summer vs. fall vs. winter). A subset of loads (n = 42) was used to examine effect of distance pigs were moved during loading [short (<24 m) vs. long (47 to 67 m)] on physical indicators of stress and transport losses. This study was conducted on 7 d per season at 1 farm with 4 loads (2 on potbelly and 2 on straight-deck trailers) being transported each day to 1 commercial packing plant. Pigs from different farm groups were mixed on the trailer and provided with 0.45 m(2)/pig floor space during an approximately 4-h journey to the plant. The percentage of pigs exhibiting open-mouth breathing, skin discoloration, and muscle tremors was recorded during loading and unloading. Additionally, dead pigs on arrival at the plant and nonambulatory pigs at the farm and at the plant were recorded. Effects of trailer design on open-mouth breathing and skin discoloration during unloading were dependent on season (trailer design x season interaction; P < 0.05). Pigs unloaded from potbelly trailers had a greater (P < or = 0.05) incidence of open-mouth breathing in the spring and summer and a greater (P < 0.05) incidence of skin discoloration in the spring, summer, and winter than pigs unloaded from straight-deck trailers. The incidence of total nonambulatory pigs at the plant was greater (P < 0.05) in the winter than in the spring and summer. The long compared with short distance moved treatment resulted in a greater (P = 0.001) incidence of open-mouth breathing and skin discoloration during loading and tended (P = 0.06) to increase the incidence of nonambulatory pigs at the farm. However, there was no effect of trailer design, season, or loading distance on total losses at the plant. In summary, physical indicators of stress (open-mouth breathing and skin discoloration) were increased with the long distance moved during loading treatment and were greater during unloading for potbelly than straight-deck trailers; however, trailer design, season, and loading distance had minimal effects on total transport losses.     

Calf and colostrum management practices on New Zealand dairy farms and their associations with concentrations of total protein in calf serum

AIMS: To gather information on management practices and farmer attitudes to management of cows and calves during the immediate post-partum period on dairy farms in New Zealand, and to assess these practices for associations with concentrations of total protein (TP) in serum of calves 1–8 days-old.

METHOD: Between July and September 2015 blood samples were collected from calves aged between 24 hours and 7 days, from dairy farms (n=105) in nine areas in New Zealand, on three occasions throughout the calving period. Concentrations of TP were determined in all serum samples. At each visit technicians collected 1?L of the pooled colostrum that was intended for feeding to newborn calves that day. These samples were assessed for Brix, coliform and total bacterial counts. After the last sampling visit, the calf rearer or farm manager were asked to complete a questionnaire describing calf and colostrum management practices on the farm. Potential farm-level variables associated with concentrations of TP in serum of sampled calves were identified using univariable and multivariable linear mixed models.

RESULTS: Mean concentration of TP in serum of calves across all farms was 59.8 (95% CI=59.4–60.2) g/L, and was associated with region and herd size in the final multivariable model. Concentrations of TP were lower in calves from farms in Otago (56.2 (95% CI=53.4–58.9) g/L) and Southland (56.9 (95% CI=54.1–59.7) g/L) compared to calves on farms in the Far North (62.6 (95% CI=59.8–65.3) g/L), and were lower in calves from farms with a herd size >600 (58.3 (95% CI=56.7–59.8) g/L) than ≤600 (61.3 (95% CI=60.1–62.5) g/L) cows. After accounting for fixed effects, farm accounted for only 8.4% of the unexplained variation. There was no association between any of the measures of colostrum quality and concentrations of TP in serum (p>0.2).

CONCLUSION AND CLINICAL RELEVANCE: Very few herd-level variables were associated with concentrations of TP in serum. Risk factors that have been shown to be of importance in previous studies outside New Zealand were not identified as important in the current study. It is possible that, in the situation where calves are kept at pasture with their dams for prolonged periods, variables which influence how well a cow can feed its calf in the first 12–24 hours have a larger influence on concentrations of TP in serum than the collection and management of calves once they reach the rearing shed.     

Biochemical Tests Indicative of Reaction of Castor Bean to Botrytis

Pectic and cellulolytic enzymes caused browning and maceration of capsules of susceptible varieties of castor bean but not of resistant varieties. Results of tests in which pericarp tissue of the capsule was treated with vanillin and H(2)SO(4) and with an aqueous solution of FeCl(3) and K(3)Fe(CN)(6) showed that resistance to the hydrolytic enzymes was correlated with both a low concentration of flavanols and related compounds and the presence of oxidized compounds in injured tissue. Resistance appeared to be due to inactivation of pectic, cellulolytic, and other hydrolytic enzymes by oxidation products of phenolic compounds. The biochemical tests made rapid measurement of resistance possible.     

Bacterial septic arthritis in 19 dogs

OBJECTIVE: To provide information on the clinical features, diagnosis and treatment of bacterial septic arthritis in dogs. DESIGN: A retrospective study examining case records of all dogs diagnosed with bacterial septic arthritis at Murdoch University Veterinary Hospital between 1988 and 1997. RESULTS: Nineteen dogs were diagnosed with bacterial septic arthritis, which most commonly occurred after surgery involving the stifle joint. Haematogenous infection occurred in only five dogs. Diagnosis was based on clinical signs, joint fluid analysis, radiography, microbiology and/or response to treatment. Chronic lameness was the most common problem at presentation. Analysis of joint fluid invariably revealed large number of nucleated cells, which consisted primarily of neutrophils. In all but one case the neutrophils were nondegenerate. Culture of joint fluid was frequently successful. Staphylococcus spp were the most common bacteria isolated. Treatment involved antimicrobial drugs only in five dogs. Other dogs received antimicrobial drugs in combination with surgical procedures such as joint lavage and removal of nonabsorbable suture material (eight), arthrodesis (two) or amputation (one). Two dogs were euthanased. Most dogs responded well to treatment and were free of signs of septic arthritis at follow-up. CONCLUSION: Bacterial septic arthritis may often be mild and manifest as chronic lameness. Analysis of joint fluid will detect an inflammatory arthropathy but the presence of toxic neutrophils should not be relied on as an indicator of sepsis. Culture of infected joint fluid is likely to be successful if antimicrobials are not given prior to collection and if the sample is inoculated into enrichment broth. Treatment should involve antimicrobial drugs, open-joint lavage and removal of joint prostheses if the infection is associated with previous surgery.     

Nanoengineering of inorganic and hybrid hollow spheres by colloidal templating

Hollow silica and silica-polymer spheres with diameters between 720 and 1000 nanometers were fabricated by consecutively assembling silica nanoparticles and polymer onto colloids and subsequently removing the templated colloid either by calcination or decomposition upon exposure to solvents. Scanning and transmission electron microscopy images demonstrate that the wall thickness of the hollow spheres can be readily controlled by varying the number of nanoparticle-polymer deposition cycles, and the size and shape are determined by the morphology of the templating colloid. The hollow spheres produced are envisioned to have applications in areas ranging from medicine to pharmaceutics to materials science.     

Escape vents and trap selectivity in the fishery for the Juan Fernández rock lobster (Jasus frontalis), Chile

To develop ways to catch fewer undersized specimens of Jasus frontalis in the traps of the rock lobster fishery off the Juan Fernández Archipelago (Chile), we studied the use of lobster traps with different-sized escape vents (circular windows of 80, 85, or 90 mm diameter). The traps used in the present fishery served as controls. Selection curves were fit to each of the vent sizes examined in the study. The method of alternating hauls was used for this purpose in a manner similar to that employed with trawl nets. We compared the size–frequency distributions obtained for each vent size with those determined for the control traps. We monitored 2437 traps and obtained a total catch of 13,444 specimens. Undersized individuals decreased in the catch as the diameter of the openings increased. The selection curves fit a logistic-type model adequately. A direct relationship was established between the vent size and the length corresponding of the first catch (L₅₀). The CPUE for legal-sized rock lobster increased in traps having up to 85-mm vents, but this yield dropped in traps fitted with 90-mm vents. The CPUE for undersized rock lobster, however, was inversely proportional to the size of the vents. Unlike typical selectivity literature that relies on the L₅₀, the objective of this study was to maximize the number of legal (≥98 mm Lc) specimens retained in the traps while simultaneously minimizing the retention of undersized specimens. To achieve this, we used a model relating vent size to L₅₀ and the slope of the selection ogives. The optimal diameter for vents in this fishery was determined to be 83 mm. Furthermore, underwater recordings were used to register the escape behavior of the lobsters. These recordings contributed new data on the way in which the lobsters detect, confront, and escape through the vents.