101 Impact of Equi-Shield as a nutraceutical fly protectant in adult horses

Abstract

Biting insects commonly irritate horses resulting in annoyance behaviors. Owners will attempt to alleviate the annoyance through topical sprays, insecticides, physical barriers, predators, and nutraceuticals. Equi-Shield (ES, Probiotech International, Inc.) is a nutraceutical designed to help protect horses from biting insects via a proprietary blend of botanical oils (eucalyptus, citronella, peppermint, garlic, and anise). This blend has been shown to reduce the number of flies landing on the head and neck of cattle after 7d of consumption. The objective of this preliminary trial was to determine the impact of ES on the number of flies landing on adult horses throughout the day after 7d of consumption. Because flies are active in Summer in VA, USA, the trial was conducted in August. Twelve adult horses were assigned to control (C:no supplement) or ES (20g/d top-dressed on morning concentrate). After 7d of consumption, daily observations (O) began for the subsequent 7d by blinded, trained observer pairs. Daily O consisted of 3–30min periods (P) during stalled meals (930–1000, 1230–1300, 1630–1700) offered at opposite ends of the barn separated by 3.66m breezeway. Number of visible flies were immediately counted and grouped by head and neck (H), front legs (FL), hind legs (HL), and remainder of the body (B). Total flies (F) were calculated from the addition of the groups. Horses did not receive any additional fly protection during the trial. Fly counts were analyzed using the repeated statement in PROC MIXED procedure of SASv9.3. There was no impact ( P > 0.10) of P on F, HL, FL, H, or B for each treatment. There was no effect ( P > 0.29) of day*treatment on B or H. A tendency ( P = 0.08) for less flies on ES than C for B (ES:0.60 ± 0.12; C:0.91 ± 0.13) and H (ES:0.46 ± 0.09; C:0.71 ± 0.10) was seen. There was an effect ( P < 0.05) of day*treatment on F, HL, and FL. On d 1 (ES:2.5 ± 0.63; C:5.87 ± 0.69), 4 (ES:3.39 ± 0.63; C:6 ± 0.67), 5 (ES: 3.28 ± 0.63; C:5.07 ± 0.67), 6 (ES:3.39 ± 0.63; C:5.47 ± 0.67), and 7 (ES:2.67 ± 0.63; C:4.67 ± 0.67), there were less ( P < 0.05) F on ES horses than C. The HL of ES had less ( P < 0.05) flies on d 1 (ES:0.44 ± 0.30; C:1.4 ± 0.33) and 4 (ES:0.56 ± 0.30; C:1.67 ± 0.33). C had more flies on FL on d 1 (ES:0.78 ± 0.38; C:3.07 ± 0.41), 5 (ES:0.89 ± 0.38; C:1.93 ± 0.41), and 6 (ES:1.28 ± 0.38; C:2.4 ± 0.41) compared with ES. Within ES, only d 3 (4.67 ± 0.63) differed ( P < 0.01) from d 1 (2.5 ± 0.63). Although environment may have had an impact on the trial with rain on the morning d 2, the preliminary results indicate that ES may reduce flies on horses after 7d of consumption. More research is warranted to determine if the reductions demonstrated lead to fewer annoyance behaviors.