Capacity of goats to reach for food through tombstone barriers, as affected by position of food, body weight and body dimensions

Abstract

Goat production systems increasingly involve indoor feeding. To facilitate manger design, there is need for information on the ability to reach for food, such as that for cattle given food through tombstone barriers. In the first study, 20 castrated and 20 non-pregnant female Saanens of mean live weight (M) 39-3 (s.d. 14-42) kg were trained to reach, through a vertical tombstone barrier, for concentrate meal placed on a horizontal platform attached to the barrier. The barrier allowed the neck but not the shoulders to pass through. It was hypothesized that horizontal reach forwards (F, distance from mid point of barrier to uneaten meal) and sideways (S, distances sideways from mid point of barrier to uneaten meal adjacent to barrier) would be a function of height of platform above the floor and size of goat. Because of size, eight goats (mean M, 16-4 kg) were unable to reach meal when the platform height was 75 cm. Mean (s.e.) values for F at platform heights 0, 25, 50 and 75 cm were 55-9 (0-68), 58-8 (0-64), 57-8 (0-69) and 41-1 (1-23) cm respectively. Values for S were smaller, but followed a similar pattern (49-4 (0-64), 52-4 (0-56), 53-2 (0-53), 36-6 (1-17) cm). Linear regression of either F or S on M and linear body dimensions (e.g. body length, neck and head length, neck-joint height, withers height) showed high correlations with R 2 values being 0-8 or more. In the second study, 10 castrated and 10 non-pregnant females (M, 48-7 (s.d. 14-56) kg) were trained to reach through the tombstone barrier for concentrate pellets 'glued', using molasses, on to a vertical plate. It was hypothesized that vertical reach (V, distance from floor to uneaten pellets) would be a function of distance between barrier and plate (20, 30, 40, 45, 50 cm), height of step (0,14-2, 28-4, 42-6 cm) on which goats placed their forelegs and size of goat. Four goats (mean M, 29-9 kg) were unable to reach pellets when the plate was at 45 and 50 cm. Mean (s.e.) V values decreased with increasing plate distance and increased with step height (e.g. at 0 cm step heights respectively). Linear regression of V on body weight and body dimensions (e.g. body length, heart girth, withers height) showed high correlations (R 2 > 0-8). It is concluded that for practical purposes, body weight is a satisfactory predictor of reach. The results support the hypotheses. The data will facilitate the design of mangers for goats with body weights and dimensions in the range of those used in the present study.

Determining suitable dimensions for dairy goat feeding places by evaluating body posture and feeding reach

“…In accordance with the results obtained by Muhikambele et al (1998), maximum reach increases along with increasing height at withers and height of the feed table.…”

“…This compensates for the fact that the animals at the feeding barrier cannot feed as they would on pasture (i.e., they cannot splay their legs, a posture which allows them to reach the ground easily with their muzzle). Consequently, some authors also suggest such a height difference for goats (Peacock, 1996;Muhikambele et al, 1998;Upreti et al, 2005). Our data demonstrate that the minimum height difference between standing surface of forelegs and feed table should not be less than 10 cm.…”

“…The literature recommends an animal-to-feeding place ratio of at least 1:1 (Loretz et al, 2004;Jørgensen et al, 2007) and feeding place widths of 35 to 40 cm per goat (Toussaint, 1997;Loretz et al, 2004). However, other dimensions known to be relevant in cattle, such as the height of the feeding barrier (e.g., neck rail), the height of the partition between pen and feed table, the depth of a feed table or manger, and the height of a feed table (Fernández et al, 2006;Huzzey et al, 2006;Kielland et al, 2010), have not been scientifically investigated to any great extent in goats (Muhikambele et al, 1998).…”

“…Adequate dimensions for a feed barrier must be based on the animals' body measurements (Fernández et al, 2006). In goats, height at withers is an appropriate predictor, as it is easy to measure as well as highly correlated with other body dimensions and weight (Muhikambele et al, 1998). For the height of the feeding barrier, for example, it is reasonable to assume that a neck rail must be at least slightly higher than the animals' height at withers (Kielland et al, 2010).…”

“…The aim of our study was, therefore, to investigate the reach of feeding goats in relation to their height at withers by varying the height of the feed table (difference in level between the standing area of the forelegs and the feed table) and of a feeding area step (difference in level between fore and hind legs). Using a similar approach here to Muhikambele et al (1998), who specified the maximum vertical and horizontal reach of goats, we determined the feeding reach for feed table dimensions of practical relevance and included the goats' posture during feeding to ensure species-appropriate feeding.…”