Further investigation of equine fescue oedema induced by Mediterranean tall fescue (Lolium arundinaceum) infected with selected fungal endophytes (Epichloë coenophiala)

Abstract

AIMS

To determine if equine fescue oedema (EFO) induced by grazing Mediterranean-type tall fescue (Lolium arundinaceum) infected with selected endophytes (Epichloë coenophiala) could be prevented by treatment with the corticosteroid, methylprednisolone, and anti-histamine, cetirizine, and to determine concentrations of lolines, specifically N-acetyl norloline (NANL), in grasses grazed by horses that did and did not develop EFO.     

Effect of copper source and level on performance and copper status of cattle consuming molasses-based supplements

Two studies were conducted to evaluate the availability of dietary Cu offered to growing beef cattle consuming molasses-based supplements. In Exp. 1, 24 Braford heifers were assigned randomly to bahiagrass (Paspalum notatum) pastures (two heifers/pasture). Heifers were provided 1.5 kg of TDN and 0.3 kg of supplemental CP/heifer daily using a molasses-cottonseed meal slurry. Three treatments were randomly assigned to pastures (four pastures/treatment), providing 100 mg of supplemental Cu daily in the form of either CuSO4 (inorganic Cu) or organic-Cu. A third treatment offered no supplemental Cu (negative control). Heifer BW was collected at the start and end of the study. Jugular blood and liver samples were collected on d 0, 29, 56, and 84. In Exp. 2, 24 Brahman-crossbred steers were fed the same molasses-cottonseed meal supplement at the same rates used in Exp. 1. Steers were housed in individual pens (15 m2) with free-choice access to stargrass (Cynodon spp.) hay. Four Cu treatments were assigned to individual steers (six pens/treatment) providing 1) 10 ppm of Cu from an organic source; 2) 10 ppm Cu from Tri-basic Cu chloride (TBCC); 3) 30 ppm of Cu from TBCC; or 4) 30 ppm of Cu, a 50:50 ratio of TBCC and organic Cu. Body weights and jugular blood and liver samples were collected on d 0, 24, 48, and 72. In Exp. 1, liver Cu concentrations did not differ between heifers supplemented with inorganic and organic Cu. Each source resulted in increased (P < 0.05) liver Cu concentrations compared with the unsupplemented control. Plasma ceruloplasmin concentrations were higher (P < 0.05) for Cu-supplemented heifers, independent of Cu source. Heifer ADG tended (P = 0.11) to increase with Cu supplementation compared with the unsupplemented control. In Exp. 2, liver Cu was greater (P < 0.05) on d 24, 48, and 72 for steers consuming 30 vs. 10 ppm of Cu. Steers supplemented with organic Cu had lower DMI than steers supplemented with 10 or 30 ppm of TBCC. These data suggest that the inorganic and organic Cu sources evaluated in these studies were of similar availability when offered in molasses supplements. A dietary Cu concentration greater than 10 ppm might be necessary to ensure absorption in beef cattle fed molasses-based supplements.     

Clinical biochemistry of pregnant and nursing mares

BACKGROUND: Pregnancy and lactation result in increased metabolic demands. Although homeostatic mechanisms function to keep substances in blood at relatively constant levels, some changes in the concentrations of routine clinical chemistry analytes are likely to occur. OBJECTIVES: The purpose of this study was to determine what physiological changes occur in serum clinical biochemistry analytes in pregnant and nursing mares, and to determine whether the changes were substantial enough to warrant separate reference intervals for pregnant or lactating horses. METHODS: Forty-two Quarter Horse, Thoroughbred, Saddlebred, Standardbred and Morgan mares were entered into the study while pregnant. They were bled once each month through birth. Studies were continued on 20 mares until their foals were weaned. Test results were tabulated by time before or after birth. Serum biochemistry values were determined by standard methods using automated analyzers. Test results were analyzed using the Kruskal-Wallis 1-way ANOVA on ranks. If a significant difference was found (P<.05), Dunn's multiple comparison procedure was performed on all pairs. Results from pregnant and nursing mares also were compared with a reference group of 19 open, nonlactating mares. RESULTS: Serum triglyceride, potassium, creatinine, and total bilirubin concentrations were lower during lactation than during pregnancy. Serum calcium concentration also was slightly decreased at 2 time points during lactation. Triglyceride concentration was highest during midgestation, while bilirubin and creatinine values increased, and potassium and calcium remained constant during pregnancy. Serum urea concentration also remained constant during pregnancy but increased during lactation. Serum phosphate concentration was lowest during midgestation and highest during lactation. Total CO2 values were highest, and anion gaps were lowest, during midgestation. No significant differences were found in serum albumin, globulin, albumin:globulin ratio, total protein, or glucose values. When compared with the reference group of open mares, serum triglyceride, potassium, bilirubin, and total CO2 concentrations were lower, and anion gap was higher in horses that were nursing. CONCLUSIONS: Although most biochemical values remained relatively constant, significant differences were observed during pregnancy and lactation. Changes in the concentrations of triglycerides, potassium, bilirubin, total CO2, and anion gap during lactation were substantial enough to warrant separate reference intervals for lactating horses.     

Prevalence of Taylorella equigenitalis infection in stallions in Slovenia: bacteriology compared with PCR examination

REASONS FOR PERFORMING STUDY: The prevalence of Taylorella equigenitalis infection in Slovenia is unknown and methods used to refine identification in these stallions are required. HYPOTHESIS: In diagnosis of T. equigenitalis, polymerase chain reaction (PCR) would have advantages over culture methods, especially in cases where small numbers of causal agent or intensive contamination of genital swabs are involved. METHODS: Culture method and PCR were used to examine a total of 980 genital swabs from the urethra and fossa urethralis of 245 stallions for the presence of the contagious equine metritis organism. RESULTS: Among 245 examined stallions, 225 (91.8%) were negative to T. equigenitalis by both methods. From the swabs of 17 stallions (6.9%) T. equigenitalis was isolated at first and/or second sampling. Swabs of 3 (13%) stallions were PCR positive but the isolation of T. equigenitalis failed. The rate of T. equigenitalis detection was higher with PCR than with the classic bacteriological examination. CONCLUSIONS AND POTENTIAL RELEVANCE: PCR protocol used in this study provided a specific, sensitive, and simple tool for rapid detection of T. equigenitalis. PCR is especially valuable in cases of intensive bacterial and fungal contamination of swabs where the isolation of T. equigenitalis usually fails.     

Value of a molasses mixture containing natural protein as a supplement to brood cows offered low-quality forages

In a 4-yr study, molasses (M; 6% CP), molasses-urea (MU; 17.5% CP; 92% molasses, 4% urea and 4% water) and molasses-cottonseed meal-urea (MCSM; 17.5% CP; 73% molasses, 25% cottonseed meal, 1% urea and 1% water) were compared as winter supplements for Braford cows (514 matings) consuming low-quality forage. Cows were fed 1.35, 1.50 and 1.27 kg.head-1.d-1 of the respective supplements for 127 d beginning in December. Cows were wintered on bahiagrass pasture (avg 8% CP) and stargrass hay (avg 5% CP). Quantity of hay offered averaged 7.6 kg.cow-1.d-1 over 109 d. Cows were exposed to bulls for 90 d beginning on March 1. Supplementation treatment did not affect cow live weight, live weight change or condition score (P greater than .05). However, pregnancy rate was higher (P less than .05) for cows fed MCSM (79.0%) than for cows fed M (67.8%). The pregnancy rate of cows fed MU (76.3%) was intermediate to, but not different (P greater than .05) from, that of cows fed either M or MCSM. Supplementation treatment did not affect calf performance as measured by birth weight, survival rate or weaning weight (P greater than .05). However, calves from cows fed MCSM were 6 d older (P less than .05) at weaning than calves from cows fed M. For 3-yr-old cows, pregnancy rate was considerably higher (P less than .05) for cows fed MCSM (69.6%) than for cows fed M (37.5%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Haemolytic Rhodococcus equi Isolated from a Swine Lymph Node with Granulomatous Lesions

Rhodococcus equi is generally thought to be non-haemolytic although some earlier investigations reported minor haemolytic activity. A case of a haemolytic R. equi isolate from a swine lymph node with granulomatous lesions is described. This is a new contribution to knowledge of the cultural properties of R. equi.     

Effect of Repeated Stress Treatments During the Follicular Phase and Early Pregnancy on Reproductive Performance of Gilts

In pig husbandry, stress is being considered an important cause of impaired reproductive performance. Therefore, an experiment was performed to quantify effects of repeated stressors during the follicular phase and/or during early pregnancy on reproductive performance of gilts. Eighty-one cyclic gilts were assigned to one of four treatments, namely, stress treatment during the follicular phase (n = 20), stress treatment during early pregnancy (n = 20), stress treatment during both phases (n = 21) and no stress treatment (n = 20). All gilts were housed individually, but gilts in the stress treatments had no opportunity for visual or physical contact with other gilts. Further, animals in a stress-treatment were grouped for half an hour at the start of the treatment and during the treatment period nose-sling and an unpredictable feeding scheme were applied regularly. The extent of stress was monitored using heart rate measurements, behavioural observations and saliva cortisol levels during nose-sling fixation. Of the 81 gilts, 93% showed oestrus and were inseminated. Of these, 93% were pregnant at day 35, having 17.9 +/- 0.3 ovulations and 15.6 +/- 0.3 foetuses. These parameters were not affected by treatment. The stress treatment during the follicular phase tended to shorten cycle length (stress: 20.8 +/- 0.20; control: 21.2 +/- 0.17 days, p = 0.07) and weight of foetuses at day 35 (stress: 4.47 +/- 0.08 g; no stress: 4.69 +/- 0.08 g, p = 0.06); stress during early pregnancy did not affect any of the reproduction parameters. Percentage stereotypic behaviour, heart rate and saliva cortisol levels varied greatly between animals and between days, but did not differ between the treatments. No relationships were found between any of the reproductive parameters and any of the stress parameters (heart rate, cortisol, stereotypic behaviour). These results indicate that the repeatedly applied acute stressors did not generate a chronic stress-response and that these stressors during the follicular phase and/or during early pregnancy did not affect reproductive processes. It is not clear how these findings relate to suggested effects of stress(ors) on reproductive performance in pig husbandry.