Influence of Ovulation Status,Seasonality and Embryo Transfer Method on Development of Cloned Porcine Embryos

To improve pig cloning efficiency, the present study evaluated the effect of ovulation status, seasonality and embryo transfer (ET) method on in vivo development of cloned porcine embryos. Cloned embryos were transferred to surrogate mothers on the same day of somatic cell nuclear transfer. In pre‐ovulation stage (PO), pregnancy rate (PR) and delivery rate (DR) were 36.3% and 9.4%, respectively. In post‐ovulation stage, 22.7% PR and 2.1% DR were recorded (both PR and DR are significantly higher in PO). When ET was performed during winter (December–February), spring (March–May), summer (June–August) and autumn (September–November), the PRs were 13.4%, 37.3%, 24.6% and 51.0%, while DRs were 0%, 12.7%, 4.3% and 7.8%, respectively. The highest PRs were recorded in autumn groups. However, DRs were significantly lower in autumn (7.8%) group compared with spring (12.7%) group. The PR was the lowest and no piglets were born in winter group, which might be because of the effect of low temperature during ET. To overcome the low PR in winter group, 0.25 ml straws were used for ET to minimize exposure time of embryos to ambient temperature. The straw ET group showed significantly higher PR in the winter group (23. 9%) compared with the conventional catheter‐loading group (7.7%). We suggest that using PO recipient and ET in spring is the best condition for pig cloning. In addition, alternative method to reduce cold shock during ET in winter is necessary.     

Histological changes to the skin of Merino sheep following deep dermal and subcutaneous injections of sodium lauryl sulfate

Objectives To characterise the changes caused to sheep skin by deep dermal and subcutaneous injections of sodium lauryl sulfate (SLS) and describe the subsequent healing process. Procedure On 6 sheep 20 small areas of skin were each given deep dermal and subcutaneous injections of 0.2 mL of 7% SLS. Biopsies were collected at intervals up to 28 days after treatment and the histological changes in each of the treated skin samples were assessed and graded. Results There was no evidence of alterations in behaviour, weight gain or appetite of the sheep following the injections. Initial swelling of the treated site subsided by day 14, leaving a firm, slightly raised crust. At day 21, the treated area was depressed and covered by a scab, which sloughed completely by day 28. There was necrosis of the subcutis and deep dermis 2 min after treatment, followed by inflammation, fibroplasia, angiogenesis and tissue remodelling. Conclusion Injection of SLS caused almost immediate local necrosis followed by eschar formation, sloughing and scarring of treated skin. Deep dermal and subcutaneous SLS is potentially useful as a chemical alternative to mulesing.     

Arthrodesis of the Equine Proximal Interphalangeal Joint: A Biomechanical Comparison of Two 7-Hole 3.5-mm Broad and Two 5-hole 4.5-mm Narrow Dynamic Compression Plates

OBJECTIVE: To compare the biomechanical characteristics and mode of failure of two different dynamic compression plate (DCP) techniques for proximal interphalangeal joint (PIPJ) arthrodesis in horses. STUDY DESIGN: Randomized block-design blocking on horse (1-5), method of fixation (two 7-hole, 3.5-mm broad DCP vs two 5-hole, 4.5-mm narrow DCP), side (left, right), and end (front, hind). Constructs were loaded to failure in 3-point bending in a dorsal-to-palmar (plantar) direction. SAMPLE POPULATION: Ten paired limbs from 5 equine cadavers. METHODS: Two 7-hole, 3.5-mm broad dynamic compression plates (bDCP) were used in 1 limb of a pair, and two 5-hole 4.5-mm narrow dynamic compression plates (nDCP) were used on the contralateral limb. Plates were positioned abaxially across the dorsomedial and dorsolateral aspect of the PIPJ. Arthrodesis constructs were loaded (19 mm/s) in 3-point bending in a dorsal-to-palmar (plantar) direction using a materials-testing machine. Composite stiffness, yield point, and maximal bending moment at failure were obtained from bending moment-angular deformation curves. Data were analyzed using ANOVA, X(2) analysis, and Fisher's exact tests; the power of the test was calculated when differences were not significant. RESULTS: There were no significant differences in composite stiffness (P >.05; power = 0.8 @ delta = 21.9%), yield point (P >.05; power = 0.8 @ delta = 34.4%), or maximal bending moment (P >.05; power = 0.8 @ delta = 17.8%) between the two fixation techniques. For bDCP constructs, 11% (15 of 140) of the 3.5-mm screws were damaged; 7 of the screw heads pulled through plates where the plates bent, 1 screw head broke off, and 7 screws were bent or pulled out of the phalanx. For nDCP constructs, 8% (8 of 100) of the 4.5-mm screws were damaged; 1 screw head pulled through a plate, 1 screw head broke off, and 6 screws were bent or pulled out of the phalanx. CONCLUSIONS: There were no biomechanical or failure differences between bDCP and nDCP fixation of the PIPJ in horses when evaluated in single-cycle 3-point bending to failure. CLINICAL RELEVANCE: There is no biomechanical advantage to the use of two 7-hole, 3.5-mm bDCP in equine proximal interphalangeal arthrodesis compared with two 5-hole, 4.5-mm nDCP. Two 5-hole, 4.5-mm nDCP may be easier to place, whereas two 7-hole, 3.5-mm bDCP may provide more versatility in fracture repair.     

A computer spreadsheet program to estimate the cost of raising dairy replacements

In response to a dairy operator's request for help in evaluating heifer replacement costs, a worksheet was developed (using Lotus 1-2-3^tm) to assess the cost of raising calves. Specific categories relating to calf raising were compiled and measures for calculations were established to determine variable and fixed costs. Testing and implementation of the spreadsheet were carried out on several large-scale dairies, with the individual dairy operators providing cost and population information pertaining to each of the categories. The worksheet provides a way to calculate fixed and variable calf-raising costs for calves of varying age-groups and weights.     

Faunal effects on the distribution of gamma emitting radionuclides in four forested soils

Brown trouts, Salmo trutta, were exposed via aquarial water to ²⁰³Hg²⁺ or to CH₃ ⁻²⁰³Hg⁺ alone or together with one of the following S-containing substances: sodium dimethyldithiocarbamate (SMC), sodium diethyldithiocarbamate (SEC), potassium ethylxanthate (PEX), sodium isopropylxanthate (SIX), sodium diethyldithiophospbate (SEP), sodium diisopropyldithiophosphate (SIP) or sodium pyridinethione (SPyr). The distribution of the ²⁰³Hg²⁺ and the CH₃−²⁰³Hg⁺ in the fishes were then studied by whole-body autoradiography and gamma spectrometry. The results showed that the examined complexing substances can induce increased uptake of both ²⁰³Hg²⁺ and CH₃−²⁰³Hg⁺ by the fishes: for ²⁰³Hg²⁺ most of the complexing substances induced a similar increase in various tissues; for CH₃−²⁰³Hg⁺ marked variations were seen for different substances. Determinations of chloroform/water partition coefficients showed that the examined substances are able to form lipophilic complexes both with Hg²⁺ and CH₃−Hg⁺. A facilitated penetration of the lipophilic complexes over the membranes of the gills and other tissues may underly the increments of the tissue-levels of the Hg. It is possible that increased uptake of Hg²⁺ and CH₃−Hg⁺ induced by complexing substances of this type may have toxicological implications for fishes and for other aquatic organisms.     

ynergy of ethanol and a natural soporific--gamma hydroxybutyrate

gamma-Hydroxybutyrate and ethanol, as well as gamma-butyrolactone and ethanol are potentiative with respect to duration of loss of the righting reflex (sleep time). The concentration of ethanol in the liver decreases from 30 to 90 minutes after rats are injected with ethanol, but there is no change when ethanol is injected with gamma-butyrolactone. In view of the fact that gamma-hydroxybutyrate is a natural intermediate in brain, the effects of ethanol on the central nervous system may be mediated through its interaction with gamma-butyrolactone.