Evaluation of domperidone dosages and delivery methods for the treatment of fescue toxicosis in beef heifers

Authors: JONES, K. - SOUTHERN ILLINOIS UNIV; SCHULZE, J. - SOUTHERN ILLINOIS UNIV; Strickland, James; CROSS, D. - EQUITOX, CLEMSON, S.C.; BURNS, P. - BURNS BIOSOLUTIONS; GILLEY, R. - BIORELEASE TECHNOLOGIES; BASSOO, E - ST JOSEPH'S HEALTH CTR; HART, K. - UNIVERSITY OF ILLINOIS; THOMPSON, JR., D. - LOUISIANA STATE UNIV; KING, S. - SOUTHERN ILLINOIS UNIV

Submitted to: Professional Animal Scientist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/15/2008
Publication Date: 7/22/2008
Citation: Jones, K.L., Schulze, J.L., Strickland, J.R., Cross, D.L., Burns, P., Gilley, R.M., Bassoo, E., Hart, K.B., Thompson, Jr., D.L., King, S.S. 2008. Evaluation of a controlled-release domperidone delivery method for the treatment of fescue toxicosis in beef heifers. Prof Anim Sci. 24(4):342-348.

Interpretive Summary: The objective the study was to develop a practical method of domperidone delivery to ameliorate the symptoms of fescue toxicosis in beef heifers. Experiment 1 used 42 crossbred heifers assigned to 1 of 7 treatment groups: These treatments were a positive control (0.44 mg domperidone/kg BW daily give subcutaneously), negative control, and 0.22, 0.44, 0.88, and 1.76 mg domperidone/kg BW per oral daily for 9 d. A seventh group was used to evaluate a single 3 g domperidone slow-release intramuscular (i.m.) injection. Blood samples were collected every third day for 24 d. Domperidone levels in the 0.88, 1.76 mg/kg BW and the i.m. treatments were higher than positive control on d 3. Blood levels of Domperidone were not different between the oral treatments and positive control on subsequent days. Between d 6 and 24, no oral treatments differed from the negative control except for one observation in the 1.76 mg/kg BW treatment on d 9. The slow-release formulation had domperidone levels higher than the negative and positive controls on d 3 through 21. No domperidone was detectable on d 24 except in the i.m. treatment group. Experiment 2 evaluated the slow-release injection protocol on reproductive and performance parameters. Thirty Bos taurus crossbred heifers were assigned to 1 of 2 treatment groups; non-treated control (n = 15) or slow-release domperidone (3g, i.m.) treated (n = 15), and allowed to graze endophyte-infected fescue pastures for 46 d. Blood samples were taken weekly and analyzed for progesterone and prolactin concentrations. Body weights, body condition score, and body temperatures were recorded. Control heifers had lower weight gains, body condition scores, and elevated body temperatures compared to domperidone treated heifers. Heifers receiving domperidone had increased concentrations of prolactin and progesterone when compared to control heifers. Results of this study indicate that a slow-release injection of domperidone is a practical and effective method of domperidone delivery for relieving the symptoms of fescue toxicosis.

Technical Abstract: The objective of this study was to develop a practical method of domperidone delivery to ameliorate the symptoms of fescue toxicosis in beef heifers. Experiment 1 used 42 crossbred heifers assigned to 1 of 7 treatment groups (n = 6/trt); positive control (0.44 mg domperidone/kg BW daily s.c.), negative control, and 0.22, 0.44, 0.88, and 1.76 mg domperidone/kg BW per oral daily for 9 d, respectively; and a seventh group was used to evaluate a single 3 gram domperidone slow-release intramuscular injection. Blood samples were collected every third day for 24 d. Domperidone levels in the 0.88, 1.76 mg/kg BW and the i.m. treatments were higher than positive control (P < 0.05) on d 3. None of the oral treatments were greater than the positive control on subsequent days. Between d 6 – d 24, no oral treatments differed from the negative control except for one observation in the 1.76 mg/kg BW treatment on d 9. The slow-release formulation had domperidone levels higher than the negative and positive controls (P < 0.05) on d 3 – d 21. No domperidone was detectable on d 24 except in the i.m. treatment group. Experiment 2 evaluated the slow-release injection protocol on reproductive and performance parameters. Thirty Bos taurus crossbred heifers were assigned to 1 of 2 treatment groups; non-treated control (n = 15) or slow-release domperidone (3g, i.m.) treated (n = 15), and allowed to graze endophyte-infected fescue pastures for 46 d. Blood samples were taken weekly and analyzed for progesterone and prolactin concentrations. Body weights, body condition score, and body temperatures were recorded. Control heifers had lower weight gains (P < 0.001), lower body condition score (P < 0.05), and elevated body temperatures (P < 0.05) compared to domperidone treated heifers. Heifers receiving domperidone had increased concentrations of prolactin (P < 0.05) and progesterone (P < 0.01) when compared to control heifers. Results of this study indicate that a slow-release injection of domperidone is a practical and effective method of domperidone delivery for relieving the symptoms of fescue toxicosis.