56. Lying Behavior in Meat Goats: Associations with Hoof Overgrowth and Animal-level Factors.

Abstract Lying time can be an important health and welfare indicator in ruminants. Increased lying time is associated with rumination and rest, but too little or excessive lying time can indicate welfare problems like lameness or illness. This has been reported in existing literature for dairy goats, however, lying time in meat goats has received minimal attention. We investigated the associations between hoof overgrowth and individual goat characteristics on daily lying behavior. A total of 97 goats (age: 0.5-8 years) were fitted with data loggers (HOBO, Onset) on 4 commercial meat goat farms in Ontario, Canada. Goats were Kiko, Boer, and Boer/Saanen crosses. Lying behavior was recorded for a 6-d period. Individual animal measures were collected once, at the beginning of the study period. Digital images were taken of the right front and rear hooves for each goat to score overgrowth on a binary scale. Body condition (BCS) was assessed using a five-point scale and re-categorized into three levels: Low (1-2), Average (2.5-3) and Moderate (3.5-5) for analysis. FAMACHA score was used to estimate anemia (five-point scale). Data were analyzed using a generalized linear mixed model (SAS 9.4) with a Gaussian distribution for the outcome of lying time, and a Poisson distribution for the number of lying bouts. Fixed effects were BCS, age, hoof growth, and the interaction of age and hoof growth. Random effects were farm and goat within farm, and a repeated effect of day. Only rear hooves were modelled. Forty-three goats (45.3%) had overgrown rear hooves, while only 15 goats (15.7%) were found to have overgrown front hooves. BCS median was 3 (min=1.5, max=4). FAMACHA median score was 3 (min=1, max=4), with only 7 goats reporting a score of 4 (anemic). Goats spent a mean±SD of 9.6±3.3h/d lying (Q1=7.5 hours, Q3=11.9 hours) across a median of 9 bouts/d (Q1=6 bouts, Q3=12 bouts). No association of BCS was found on lying time (P = 0.33) or bouts (P = 0.15), and no main effect of hoof growth was detected for lying time (P = 0.41) or bouts (P = 0.68). Age was associated with lying time (F = 4.16, df = 1,91, P = 0.04); however, this effect was dependent on hoof overgrowth (interaction: F = 7.07, df = 1,88, P = 0.01). While there was no main effect of age on the number of lying bouts, there was an interaction with hoof overgrowth (F = 4.35, df = 1,88, P = 0.04). Goats with overgrown hooves showed increased lying time (0.60±0.22 h/d/y) and more bouts (1.07±0.03 bouts/d/y) with increasing age compared with those with healthy hooves, while the lying time and bouts/day of goats with healthy hooves were relatively unaffected by age. These preliminary results warrant further investigation into the factors that affect lying behavior in meat goats, particularly in older animals.