Comparison of four diagnostic tests for the identification of serum antibodies in small ruminants infected with Mycoplasma agalactiae

AIM: To determine the diagnostic capability of a newly developed Western blot (WB) assay for the detection of serum antibodies against Mycoplasma agalactiae compared with conventional serological tests, and to identify the best test for routine diagnostic use. METHODS: The serological test methods used were: two commercial indirect enzyme-linked immunosorbent assays (ELISA), viz ELISA-1, using a bacterial antigen preparation, and ELISA-2, using a recombinant protein (lipoprotein p48) antigen; the complement fixation test (CFT); and a newly developed WB assay, the latter both using a bacterial antigen preparation. Thirty sera from goats infected with M. agalactiae and 97 sera from non-infected sheep were tested using all four methods. RESULTS: Staining patterns in the WB were quite variable. An immuno-dominant band of 41 kDa was detected in 63% of sera from infected animals. The same band also appeared, although mostly very weakly, in 10% of sera from non-infected animals. When suspicious or very weak reactors were omitted, the diagnostic sensitivity (DSE) and diagnostic specificity (DSP), respectively, for the four assays were: WB=56.7%, 97.9%; ELISA-1=76.7%, 99.0%; ELISA-2=56.7%, 100%; and CFT=40.0%, 94.8%. CONCLUSIONS: ELISA-1 performed best in this comparison. While the WB can be used, it did not have a technical advantage over the ELISA. The CFT should be discouraged as the primary screening method for contagious agalactia and should be replaced by ELISA-1. Results from this study confirm that serological test methods for contagious agalactia are useful for the detection of infected flocks but will not detect every individual infected animal.     

The use of tramadol in a Labrador retriever presenting with self-mutilation of the tail

A 30-month-old Labrador retriever bitch with a history of atopy was presented for acute-onset tail biting that was leading to self-mutilation. The problem began 8 months before consultation and was resolved after 2 months, but it recurred 3 months later and continued for 3 months until the time of consultation. The current episode was difficult to interrupt and was being controlled through the use of an Elizabethan collar. There had been no history of injury to the tail. On examination of the tail, an irregularity was palpated approximately midway on the dorsal surface. Radiographs of the tail showed soft-tissue swelling cranially and presence of an ossicle between the mid-caudal vertebrae. Mutilation stopped with administration of tramadol and paracetamol and started again when the medication was discontinued. No behavior modification was implemented. Although there is a possibility that the tramadol was treating a psychogenically driven self-mutilation behavior, it is more likely that pain was the initiating cause for the behavior. This case report highlights the importance of careful medical evaluation of suspected behavioral problems and discusses the possible use of tramadol in self-mutilation.     

Supplemental betaine and peroxide-treated feather meal for finishing cattle

These studies evaluated the effects of betaine, provided either as feed-grade betaine or as concentrated separator by-product (CSB; desugared beet molasses), on performance and carcass characteristics of finishing cattle. In Exp. 1, 175 steers (410 kg initial BW) were fed a finishing diet based on steam-flaked and dry-rolled corn, and treatments included 10.5 and 21 g/d feed-grade betaine and 250 and 500 g/d CSB (supplying 15.5 and 31 g/d of betaine, respectively). Steers fed feed-grade betaine had greater (linear and quadratic effects, P < 0.1) DMI than control steers, but ADG and gain efficiencies were not affected by treatment. Dressing percent and backfat thickness was greater (P < 0.1) for steers that received feed-grade betaine than for controls. Longissimus muscle area was lower (P < 0.1) for steers supplemented with either feed-grade betaine or CSB than for control steers. Yield grades were higher for cattle receiving feed-grade betaine (quadratic effect, P < 0.1) than for control steers. Marbling scores were not affected by supplemental betaine, but the percentage of carcasses grading USDA Select was lower (linear and quadratic effects, P < 0.1) for steers fed feed-grade betaine than for control steers, predominantly due to a greater percentage grading USDA Choice. In Exp. 2, 312 heifers (343 kg initial BW) were used in a finishing study to evaluate the effects of graded levels of feed-grade betaine and peroxide-treated feather meal on performance and carcass characteristics. Treatments included two finishing diets (containing peroxide-treated or untreated feather meal) and four levels (0, 4, 8, and 12 g/d) of feed-grade betaine arranged in a 2 x 4 factorial. No significant interactions occurred between treatment of feather meal and betaine. Treatment of feather meal with hydrogen peroxide (5% wt/wt) increased in situ protein degradability but did not alter DMI, ADG, gain efficiencies, or carcass characteristics of heifers when it replaced untreated feather meal in the diet. Top-dressing feed-grade betaine to the diets had no effect on DMI, ADG, and gain efficiencies. Marbling scores were greater (cubic effect, P < 0.05) for heifers fed diets top-dressed with 4 and 12 g/d of feed-grade betaine, but other carcass characteristics were not altered significantly. Overall, feed-grade betaine and CSB did not alter growth performance, but did have minor effects on carcass characteristics.     

Evaluation of finishing performance,carcass characteristics,acid-resistant E. coli and total coliforms from steers fed combinations of wet corn gluten feed and steam-flaked corn

Crossbred beef steers (n = 615) were used in a 152-d experiment to compare steam-flaked corn (SFC) diets containing 0, 30, or 60% wet corn gluten feed (WCGF). On d 114 to 118, ruminal and fecal samples were collected from 180 steers and analyzed for pH, VFA, and total and acid-resistant Escherichia coli and coliforms. Acid resistance of E. coli and coliform populations was determined by exposure of the samples for 1 h in pH 2, 4, and 7 citric acid/sodium phosphate buffers. Increasing levels of WCGF linearly decreased total ruminal VFA (P = 0.01) and total fecal VFA (P = 0.06), but linearly increased ruminal and fecal acetate:propionate (P < 0.01) ratio and ruminal and fecal pH (P < 0.05). Feeding increasing WCGF levels resulted in a quadratic response (P < 0.05) with respect to numbers of ruminal E. coli and total coliform populations resistant to pH 4 exposure. Steers fed 30% WCGF had higher (0.7 log units) ruminal E. coli and total coliforms after exposure at pH 4 compared to steers fed 0 or 60% WCGF. Populations of E. coli and total coliforms at pH 2 and 7 were similar for all dietary treatments. Dietary WCGF linearly increased DMI (P = 0.07) and liver abscesses (P = 0.03) and linearly decreased dietary NEg (P = 0.02). Average daily gain and feed efficiencies were greatest when steers were offered 30% WCGF (quadratic, P < 0.05). Dietary manipulations that reduce acid concentrations may not correspond to changes in acid resistance of E. coli and total coliform populations detected in the gastrointestinal tracts of cattle. Moderate levels of WCGF complement SFC finishing diets.     

Study of Defense-related Gene Expression in Grapevine Leaves and Berries Infected with Botrytis cinerea

Defense responses of grapevine towards Botrytis cinerea were investigated. The expression of genes coding for proteins involved in defense were studied: (a) phenylalanine ammonia-lyase (PAL) and stilbene synthase (StSy), (b) an acidic chitinase (VCH3) and a basic chitinase (VCHIT1b), and (c) a polygalacturonase inhibitor protein (PGIP). Since no PGIP was known in grapevine, a complete cDNA sequence was first characterized by PCR and RACE-PCR amplifications. RNAs isolated from infected leaves and infected berries were analysed by semi-quantitative and real-time RT-PCRs. In infected leaves, the expression of PAL, StSy, PGIP and VCH3 genes occurred 6hours post inoculation (hpi). Increase of VCHIT1b gene expression was delayed (24hpi). Maximum levels of induction of these genes were observed at 48hpi, except for the VCH3 gene (24hpi). Activation of these defense responses was not sufficient to stop B. cinerea spread. In berries, no VCH3 gene expression was detected. Maximum levels of induction were observed in stage 3 (loss of berry colour and abundant production of conidia) for the PAL and PGIP genes, and in stage 4 (shrivelled berry) for the StSy and VCHIT1b genes.     

Applications of satellite remote sensing to forested ecosystems

Since the launch of the first civilian earth-observing satellite in 1972, satellite remote sensing has provided increasingly sophisticated information on the structure and function of forested ecosystems. Forest classification and mapping, common uses of satellite data, have improved over the years as a result of more discriminating sensors, better classification algorithms, and the use of geographic information systems to incorporate additional spatially referenced data such as topography. Land-use change, including conversion of forests for urban or agricultural development, can now be detected and rates of change calculated by superimposing satellite images taken at different dates. Landscape ecological questions regarding landscape pattern and the variables controlling observed patterns can be addressed using satellite imagery as can forestry and ecological questions regarding spatial variations in physiological characteristics, productivity, successional patterns, forest structure, and forest decline.     

Successful management of severe generalized tetanus in two dogs

Objective: To describe the clinical course and successful outcome of severe generalized tetanus in 2 dogs. Case series summary: Two dogs presenting with severe muscle rigidity, opisthotonus, and trismus were diagnosed with tetanus. In both cases, generalized convulsions, respiratory compromise, and autonomic dysfunction necessitated emergent interventions followed by intensive treatment and monitoring. In the second case, transient mechanical ventilation was required. Both dogs survived and were discharged after 19 days (first case) and 18 days (second case) of hospitalization. Although costly and time‐consuming, treatment for severe generalized tetanus was successful in these 2 dogs. New information provided: Severe generalized tetanus with convulsions, respiratory compromise, and autonomic dysfunction can have a successful outcome with intensive care and appropriate treatment.     

Age Dependent Resistance to Transmissible Gastroenteritis of Swine (TGE) I. Clinical Signs and Some Mucosal Dimensions in Small Intestine

Pigs were exposed to transmissible gastroenteritis (TGE) virus when three days old or when 21 days old. Diarrhea was earliest in onset, most frequent, most profuse and most prolonged in the youngest group. Pigs exposed when three days old also had a higher case fatality rate than those exposed when 21 days old. The histological response of both groups to exposure was atrophy of villi and hyperplasia of crypts in jejunum and ileum. However, from days three to seven post-exposure, when most fatalities occurred in the younger group, atrophy of villi was both more intensive and extensive in the younger group. Hyperplasia of crypts was also greater and more prolonged in the younger group. Regeneration of atrophic villi was more rapid in jejunum than ileum in both groups. Results were interpreted to indicate two populations, with different rates of regeneration, in the 21-day old group. Based on this interpretation, regeneration of villi was more rapid in one population from the 21-day old group than in the three-day old group.

The length of villi and depth of crypts in control pigs varied longitudinally (i.e. from site to site) in the intestine, within each age group. Length of villi and depth of crypts in control pigs also varied with age.

     

Advances in pasture management for animal productivity and health

A wide range of management techniques is available to enhance quantity and quality of forage supply to grazing animals throughout the annual production cycle. Within broad limits, dry matter (DM) production is relatively insensitive to management of defoliation frequency, severity and duration. However defoliation management has effects on feed quality which can be enhanced, in particular, by control of pasture growth in the spring through maintenance of relatively low average pasture masses. Treading damage can have significant immediate and ongoing effects on pasture production and farmers can use a range of management techniques to minimise these. Fertiliser application practices have a potent influence on pasture production and seasonality of that production. Available soil nitrogen is the primary nutrient deficiency limiting production in New Zealand's characteristically grass-dominant pastures. Nitrogen fertiliser usage has increased markedly in recent years, particularly to grow substantially greater amounts of forage during the cool season, and this trend looks set to continue. However, the use of nitrogen fertiliser has important environmental implications. Pasture renewal and forage crop use has also increased in recent years. Care needs to be taken in conducting cost-benefit analyses, selecting the options that best meet the needs, and in establishment and subsequent management practices. Ryegrass (perennial and hybrids) and white clover remain the primary choice for permanent pasture renewal, the availability of safe endophytes having largely alleviated effects of endophyte toxicosis. Special-purpose mixtures are used, especially in dry environments. Italian ryegrasses, brassicas and chicory are common choices for forage crops. A range of management techniques can be used to alleviate deleterious effects of some forages, including ryegrass endophyte toxicosis, facial eczema, and toxins associated with Fusarium fungi. Generally these techniques are not totally effective. More research is required to increase our understanding of these disorders, and in order to develop more effective and reliable management practices.     

Effect of molecular weight and concentration of legume condensed tannins on in vitro larval migration inhibition of Haemonchus contortus

The effect of molecular weight of condensed tannins (CT) from a variety of warm-season perennial legumes commonly consumed by sheep and goats on anthelmintic activity has not been previously explored. The objectives of this study were to determine if molecular weight of CT from warm-season perennial legumes could predict the biological activity of CT relative to anthelmintic activity against ivermectin resistant L3 stage Haemonchus contortus (HC) using a larval migration inhibition (LMI) assay. A second objective was to determine if CT from warm-season perennial legumes possess anthelmintic properties against L3 stage (HC). Lespedeza stuevei had the greatest concentration of total condensed tannin (TCT; 11.7%), whereas, with the exception of Arachis glabrata, a CT-free negative control, Leucaena retusa had the least TCT (3.3%). Weight-average molecular weight of CT ranged from 552 Da for L. stuevei to 1483 Da for Lespedeza cuneata. The treatments demonstrating the greatest percent LMI were L. retusa, L. stuevei and Acacia angustissima var. hirta (65.4%, 63.1% and 42.2%, respectively). The ivermectin treatment had the smallest percent LMI (12.5%) against ivermectin resistant L3 HC. There was a weak correlation (R² = 0.34; P = 0.05) between CT M_W and percent LMI, suggesting that molecular weight of CT is a weak contributing factor to CT biological activity as it relates to LMI of L3 stage HC. L. stuevei, L. retusa and A. angustissima var. hirta STP5 warrant further evaluation of anthelmintic properties in vivo.