Objective-To investigate the effects of IV administration of ergotamine and ergovaline and intraruminal administration of ergotamine on electromyographic (EMG) activity of reticuloruminal smooth muscle in conscious sheep. Animals-3 sheep with indwelling electrodes in the musculature of the reticulum and rumen. Procedure-In a crossover design study, reticuloruminal motility before and after IV administration of ergotamine (5, 10, 20, and 40 nmol/kg) or ergovaline (2.5, 5, and 10 nmol/kg) was evaluated; EMG effects were compared with those of corresponding control treatments (IV administration of saline 0.9% NaCl solution or acetone, respectively) in sheep. Ergotamine (800 nmol/kg) or water was also administered intraruminally and their effects compared. Results-After IV administration of ergopeptides, vagally dependent cyclical A and B sequences of contraction of the reticulorumen were immediately inhibited, preceding increases in baseline EMG activity (tonus). The return of cyclical contractions was associated with an increase in contraction amplitude. The effects were dose dependent; administration of 40 nmol of ergotamine/kg resulted in responses that continued for 3 to 4 hours. The effects of intraruminal administration of ergotamine were variable; after 8 hours, EMG activity was increased from baseline for < 2 hours in 1 sheep, 10 hours in another, and > 15 hours in the third. Conclusions and Clinical Relevance-In sheep, the effects of ergotamine and ergovaline on reticuloruminal motility after IV administration and the duration of responses following intraruminal administration suggest that disruption of digestion may occur in animals grazing endophyte-infected pasture that has a high ergopeptide content.

Objective-To determine the prevalence and temporal onset of lung lesions in lambs and the impact of lung lesions on growth of affected lambs. Animals-259 crossbred wether lambs from a single flock in the upper Midwestern United States. Procedure-An observational study was conducted. Lambs born in the spring and fall were slaughtered at finished weight or at a predetermined time point. Lungs of each lamb were examined and classified as normal, moderate lesions (consolidation > 5% but less than or equal to 50% of any lobe), or severe lesions (consolidation > 50% of any lobe). Data were examined to detect effects of prevalence or severity of lung lesions on growth and carcass traits. Results-57 of 89 (64%) spring-born lambs had lung lesions characterized by consolidation of lung tissue. A small number of lambs had pulmonary adhesions or active abscesses. In contrast, only 31 of 108 (29%) fall-born lambs had lung lesions. Severe lung lesions were associated with a significant reduction in average daily gain. Severe lung lesions were not detected until the middle of the finishing period and were associated with culture of Mannheimia haemolytica or Pasteurella multocida. Conclusions and Clinical Relevance-Analysis of results indicates that the prevalence of severe lung lesions can be quite high in lambs. Severe lung lesions can lead to greatly decreased growth performance of lambs.

Objective-To compare 4 assay procedures for prediction of passive transfer status in lambs. Animals-Thirty-one 1-day-old Sardinian lambs. Procedure-Serum IgG concentration was determined by use of single radial immunodiffusion. The following were determined: serum total protein concentration as measured by refractometry (ie, refractometry serum total protein concentration), serum total protein concentration as determined by the biuret method (ie, biuret method serum total protein concentration), serum gamma-globulin concentration as determined by serum protein electrophoresis, and serum gamma-glutamyltransferase (GGT) activity as measured by spectrophotometry. Accuracy of these assays for estimation of serum IgG concentration in 1-day-old lambs was established by use of linear regression analysis. Results-Refractometry serum total protein concentration, biuret method serum total protein concentration, and serum gamma-globulin concentration were closely and linearly correlated with serum IgG concentration. The natural logarithm (ln) of serum GGT activity was closely and linearly correlated with serum IgG concentration (ln). Refractometry serum total protein concentration, biuret method serum total protein concentration, and gamma-globulin concentration accounted for approximately 85%, 91%, and 95% of the variation in serum IgG concentration, respectively. Serum GGT activity (ln) accounted for approximately 92% of the variation in serum IgG concentration (ln). Conclusions and Clinical Relevance-For prediction of passive transfer status in 1-day-old lambs, serum GGT activity or biuret method serum total protein concentration determination will allow for passive transfer monitoring program development. Immediate refractometry serum total protein concentration determination is beneficial in making timely management and treatment decisions. Serum gamma-globulin concentration determination can be used as a confirmatory test.