Immunisation against ovine caseous lymphadenitis: efficacy of monocomponent Corynebacterium pseudotuberculosis toxoid vaccine and combined clostridial-corynebacterial vaccines

Sheep were immunised with Corynebacterium pseudotuberculosis toxoid formulated as a monocomponent vaccine with aluminium adjuvant or in combination with 5 clostridial antigens, and also in the combined form with sodium selenate. Immunised and control sheep were experimentally infected 16 days after vaccination and slaughtered and inspected after a further 3 months to determine their resistance to infection. All 3 vaccines afforded an equal and high level of protection; 91% of vaccinated sheep exhibiting no lesions of caseous lymphadenitis compared with 51.5% affected sheep in the control group. Average lesion counts were 1.2 per affected vaccinated sheep and 4.5 per affected control sheep. Antitoxin responses to the clostridial toxoids incorporated in the combined vaccines were not affected by inclusion of the C pseudotuberculosis toxoid or the sodium selenate.     

Immunisation against ovine caseous lymphadenitis: comparison of Corynebacterium pseudotuberculosis vaccines with and without bacterial cells

Sheep were immunised with Corynebacterium pseudotuberculosis vaccines prepared from cell-free toxoid or from toxoid with formalin-killed cells of C pseudotuberculosis added. Resistance of sheep to infection was tested 6 months after immunisation by inoculation with caseous lymphadenitis pus. The outcome was assessed 3 months later by slaughter and inspection of the sheep for lesions of caseous lymphadenitis. immunised sheep were adequately protected against infection as shown by a significant reduction in the number of sheep exhibiting lesions compared with control sheep, and by fewer abscesses in affected vaccinated sheep than in affected control sheep. The protective potency of the vaccines was not improved by the inclusion of cells of C pseudotuberculosis.     

Protein, energy and dry matter consumption by racing thoroughbreds: A field survey

A field survey involving 109 horses in 9 stables at a Detroit racetrack was conducted to determine feeding practices and to estimate crude protein (CP), digestible energy (DE), and dry matter (DM) consumption by racing Thoroughbreds, and to compare those intakes with 1989 recommendations of the National Research Council (NRC), "Nutrient Requirements of Horses." Trainers were interviewed regarding: 1) the age and sex of the homes; 2) their feeding practices; and 3) the horse's training and racing schedule. Only adult homes who were actively racing and continuously stabled at the track were included. Body weights (BW) were estimated using a chest girth measurement. The horses had an overall mean body condition score of 5 which indicated average body condition for a racing. Thoroughbred at this track. Feed samples of hay and concentrate from each stable were weighed and analyzed at a commercial laboratory to determine CP, DM, acid detergent fiber (ADF), and estimated energy density. A computer program calculated CP, DE, and DM values for each horse's ration based onamounts fed. The software program included with the 1989 NRC publication was used to compare estimated nutrient intakes with current NRC recommendations for a horse of a given BW. Trainers fed a variety of hays. Eight trainers fed oats and only one fed corn. All trainers fed commercial sweet feeds. The mean total amount of feed for all homes on an "as fed" basis was 13.7 kg. The mean estimated DM intake for all horses was 12.3 kg vs. NRC recommended 11.6 kg. The mean for percentage of roughage in the ration for all stables was 53% vs. a NRC recommendation of 35%. The mean CP% ona DM basis for all stables' rations was 13.8% vs. a NRC recommendation of 11.4%. The means for actual CP and DE intakes for all horses were 1678 g and 33.3 Meal compared with current NRC recommendations of 1324 g CP and 33.1 Meal DE. Protein amounts were above those recommended due to the common practice of feeding relatively higher CP% in the rations than necessary for racehorse performance. These data appear to be more consistent with the recommendations of NRC in 1989 than previous recommendations in 1978.     

The Athletic Performance of Thoroughbred Racehorses out of Mares with Suspected Placentitis during Gestation

Thoroughbred mares treated for signs of placentitis are potentially costly to farms and owners. Although these treatments often are effective, the resulting foal may require expensive aftercare. The current study investigated the future racing performance of foals from mares treated for clinical and subclinical signs of placentitis compared with matched control mares that had no signs of placentitis producing foals on the same farms. In total, 190 horses born from mares with suspected placentitis met the criteria for analysis and were matched with 190 horses born on the same farm. Mare data and percentage of stakes winners in each group were analyzed with Student t test. Analysis between pairs of horses was done using a paired t test for number of starts, wins, places, shows, and amount earned. Significance was set at a P value of <.05. Mares with suspected placentitis were slightly older than control mares, had slightly shorter lengths of gestation, and had a longer interval to subsequent pregnancy than control mares (P < .05). Horses out of suspected placentitis mares that were racing as 2 year olds in the study had no difference in starts, wins, places, shows, and percentages of black-type race winners; however, this group earned more than their matched control pairs (P < .05). Older horses (3 year olds) out of suspected placentitis mares had no differences in number of starts, wins, places, shows or amount earned; however, the matched control older horses had more black-type race winners (P < .05). The information from this study may aid owners when making decisions about treatment options.