Short Communication: Round bale hay net effects on agonistic behaviors of group fed horses

Abstract

Hay nets are often used while feeding horses in order to reduce hay waste and slow consumption. While feeder style affected agonistic behavior in group fed horses in prior studies, little work has evaluated the effect of round bale hay nets on horse aggression. Fifteen horses were split into three groups (n = 5 per group), balanced for sex and age. Following a two-week acclimation to pastures and groups, horses were evaluated over three weeks using a 3×3 Latin Square experimental design. Horses were given a round bale within a ring feeder (B&W Farm and Ranch, Humboldt, KS) via each treatment for one week: (1) without a hay net (no net; control), (2) surrounded with a hay net with small diameter openings (small opening; 4.445 cm diameter; Texas Haynet, LLC. Tulepo, MS) or (3) surrounded with a hay net with large diameter openings (large opening; 7.62 cm diameter, Texas Haynet, LLC. Tulepo, MS). Horse behavior around the feeder was recorded and video was continuously analyzed from 0800 to 1100 hours twice per week during the three treatment weeks. Agonistic threats (head threats and kick threats), aggression (bite, kick, chase), and avoidance behavior of horses within a 3 m x 3 m area surrounding the feeder were recorded. The total frequency of agonistic threats was greater in horses fed using the small opening net compared to the large opening net or no net (P ≤ 0.026). No difference in total frequency of agonistic threats between the large opening net and no net were observed (P = 0.908). Net provision or opening size did not affect the total frequency of aggressive behaviors observed (P = 0.187). Frequency of avoidance behavior was greater in horses fed using the small opening net compared to no net (P = 0.005) but did not differ from avoidance frequency of large opening nets (P = 0.173). No difference in avoidance frequency was observed between large opening or no net treatments (P = 0.114). In conclusion, horses fed using round bale hay nets with small openings were observed to have increased agonistic threats and avoidance behavior. Therefore, round bale hay nets with large openings may be a better choice for group fed horses.