Glycemic and Insulinemic Responses Are Affected by Age of Horse and Method of Feed Processing

The objective of this study was to examine age-related differences in glycemic and insulinemic responses of horses that were fed various feedstuffs, with particular attention to method of feed processing. A 16 × 16 Latin square design was used with eight 2-year-olds and eight mature Arabians. Horses were maintained on a roughage diet and were subjected to a glycemic response test once weekly. A control treatment consisted of an oral dextrose drench (0.25 g dextrose/kg of BW). Ten treatments consisted of variously processed feed ingredients fed at the rate of 1.5 g/kg of BW. Five other treatments were commercial feeds of a proprietary nature and are not reported. Fasting blood samples were taken once a week for 16 weeks. Thirty minutes later, another baseline sample was taken and horses were administered their respective treatment. Further blood samples were taken every 30 minutes through four hours. Samples were analyzed for glucose and insulin concentrations. Differences in glucose response between 2-year-olds and mature horses were minimal. However, mature horses had a higher insulin response (P < .01) suggesting young horses had greater insulin sensitivity. Additionally, differences (P < .05) existed between treatments with pelleted steam-processed corn having the highest glycemic response and cracked corn the lowest. Results from this study confirm that mature horses have reduced insulin sensitivity and that both glycemic and insulinemic responses are altered with feed processing techniques. Thermal processing produces the greatest response; however, a low glycemic response may not be desirable if starch escapes into the hindgut.     

Inheritance of resistance to damage byThrips tabaci Lindeman (Thysanoptera: Thripidae) in Cabbage

Summary The inheritance of resistance in cabbage (Brassica oleracea var.capitata) to damage caused byThrips tabaci Lindeman was studied in progeny from four crosses between resistant and susceptible inbred lines. In two families sharing the same susceptible parent, the narrow-sense heritability was calculated to be high (>90%), using the Warner method of calculation (Warner, 1952). The other two families, also sharing a susceptible parent, had very low narrow-sense heritability (0–11%). In three of the four families, however, the validity of the Warner calculations were called into question due to significant epistatic interactions. In all four families, the F₁ populations approached or exceeded the susceptibility of the susceptible parent, indicating that susceptibility is generally dominant. The importance of epistasis and dominance suggests that tests of hybrid combinations to determine combining ability for thrips resistance may be required, rather than selecting only on the basis of thrips damage to the inbred lines. The technique of planting wheat upwind from the cabbage test plot did generate adequate levels of thrips pressure, but the infestation was uneven in two of the four blocks, so that reasonable replication of tests is required.     

Biochemical analysis of uterine fluid for identification of indicators for subclinical endometritis in the water buffalo (Bubalus bubalis)

Alterations in biochemical constituents of uterine fluid have been suggested for diagnosis of subclinical uterine infection in the bovine. This study was undertaken to investigate whether uterine fluid biomolecules could act as tool for diagnosis of subclinical endometritis in the buffalo. Uterine fluid samples from normal (n = 22) and subclinical endometritis (n = 18; diagnosed based on uterine cytology)‐affected buffaloes were subjected to biochemical analysis. Among the different biochemical constituents estimated, urea, urea N, cholesterol, total bilirubin and alkaline phosphatase (ALP) concentrations were significantly (p < 0.05) higher in uterine fluid obtained from subclinical endometritis‐affected buffaloes. The extent of difference between normal and subclinical endometritis‐affected buffaloes was highest in ALP (69%) followed by cholesterol (55%), bilirubin (48%), urea (30%) and urea N (30%) concentrations. Receiver operating characteristic (ROC) analysis indicated that the likelihood ratio (LR) was 3.63 for urea, indicating that buffaloes having less than the threshold concentration (47.5 mg/dl) of urea in their uterine fluid were at 3.6 times more risk to be affected with SE. The LRs for urea N, cholesterol, ALP and bilirubin were 2.33, 2.54, 2.12 and 1.65, respectively. It was concluded that ALP, urea, urea N and cholesterol concentrations in uterine fluid may serve as an aid for diagnosing subclinical endometritis in the buffalo.     

Effects of flood duration and season on germination of black,cherrybark, northern red,and water oak acorns

Effects of flood duration (0, 10, 20, and 30 days) and season (winter and spring) on acorn germination were tested for two upland oaks [black and northern red oak (Quercus velutina Lam. and Q. rubra L.)] and two bottomland oaks [cherrybark and water oak (Q. pagoda Raf. and Q. nigra L.)]. Acorns were stratified for 30 days before flooding at a depth of 15 cm along the edge of a small pond. After flooding, acorns were sowed in sand-filled plastic cups and germinated for 40 days. Flood duration and season strongly affected radicle and epicotyl emergence of the upland oaks, but effects were generally limited to spring flooding. Embryo axes of the upland oak acorns were severely damaged with as little as 10 days of spring flooding. Almost no epicotyls developed, but radicles developed from the connective tissues between embryo axes and the cotyledons of many acorns. Spring flooding also significantly increased the percentage of decayed acorns for the upland oaks. In contrast, germination of the bottomland oaks was slightly improved by flooding during both seasons. Results demonstrated that the effects of flooding on the distribution of species within bottomlands can begin with seed storage and germination.     

Agronomic evaluation of Leucaena. Part 1. Adaptation to environmental challenges in multi-environment trials

A multi-environment trial was conducted to evaluate the performance of high yielding accessions from most taxa of Leucaena, for broad and specific adaptation to growth-limiting environments, and to develop an understanding of environmental parameters limiting growth of this important multipurpose tropical tree-legume genus. Eighteen sites were selected to include environments known to constrain the growth of L. leucocephala. Accessions were planted in replicated line plots, with 10 trees/plot, spaced 50 cm apart, and with rows spaced 3 m apart. Environmental parameters measured were maximum and minimum temperatures, rainfall and psyllid pressure. Soil fertility and acidity indices were derived from soil analyses. A KX2 F1 hybrid accession proved broadly adapted with high yield rankings in all environments, and with yield advantage greatest at low temperature and high psyllid pressure sites. Specific adaptation to low temperature environments was identified in L. trichandra OFI53/88, and to a lesser extent in L. pallida CQ3439. No accessions were specifically adapted to acid-infertile soils. Highest dry matter production was achieved in fertile, hot, humid, low psyllid environments. Very low growth rates were achieved in acid-infertile and low temperature environments. Yield was strongly reduced by mean monthly minimum temperatures of 22 °C, mean monthly maximum temperatures of 29 °C, psyllid pressure of >2.5 (1–9 scale of increasing pressure based on damage to young leaves), acidity index of 6 (1–7 scale of decreasing acidity based on soil and Al saturation) and fertility index of 9 (1–12 scale of increasing fertility based on critical soil nutrient levels). This revised version was published online in June 2006 with corrections to the Cover Date.     

Laboratory investigation of a naturally occurring outbreak of arthrogryposis-hydranencephaly in Texas sheep

An epizootic of abortions, weak lambs, stillbirths, and congenital arthrogryposis-hydranencephaly occurred in a sheep flock in West Texas. The outbreak began during the first week of January 1987 and continued through the third week of February 1987. Lambs born after February 1987 were not affected. A high incidence of antibodies to Cache Valley virus (Texas 7856 isolate) was demonstrated in the ewes' serum and in precolostral serum from affected lambs. No virus was isolated from tissues and body fluids of the affected lambs. The clinical, pathological, and immunological features of the epizootic were similar to those reported in Akabane virus infection in sheep. Although serological findings strongly suggest Cache Valley virus as the etiological agent of this outbreak, transmission studies are needed.     

Treatment of canine pediatric Neospora caninum myositis following immunohistochemical identification of tachyzoites in muscle biopsies

A 7-week-old Irish wolfhound was evaluated for an abnormal hind limb gait. Quadriceps muscle atrophy was pronounced and patellar reflexes were absent bilaterally. Neospora caninum myositis was diagnosed by histopathologic and serologic examination and immunohistochemical staining of muscle. Substantial clinical improvement was noted after 18 weeks of treatment with clindamycin.     

Persistence of depleted abalones in marine reserves of central California

We evaluated the persistence and possible recovery of two depleted marine mollusks, the red (Haliotis rufescens) and black abalone (H. cracherodii), in central California, USA. Monitoring over 32-years did not reveal increasing or decreasing trends in red abalone abundances and sizes over the past three decades, in the absence of harvesting. Comparisons between marine reserves protected for at least 25 years and sites with open public access showed significant difference in size structure for black abalone, with individuals greater than 8 cm in shell length comprising 14–37% of animals in reserves and 2–11% at open-access sites, and a trend for greater abundances of red abalone within reserves. Despite no increasing trends, protection in one of the no-take reserves, the Hopkins marine life refuge (HMLR), has led to persistence of red abalone populations over multiple generations, at average densities of 0.2 individuals/m². At other locations, both within the HMLR and elsewhere, red abalone densities are lower than at the location where long-term studies were conducted (av. 0.03 animals/m²), and an order of magnitude lower than for black abalone (av. 0.4 animals/m²). These results suggest that continued fishery closure and protection in no-take reserves are effective tools for allowing persistence of abalone populations, though there are no signs of recovery to levels comparable to those preceding fisheries collapse. Such failure to recover is most likely associated with high natural mortality and possibly continued illegal take, but not with processes underlying low abalone population levels elsewhere, including food or habitat limitation, recruitment failure, or disease. Linking current structure and trends to specific processes is a crucial first step towards devising focused strategies for conserving and re-building depleted marine populations.