Feed Bunk Length Requirements for Holstein Dairy Heifers

Abstract

The objectives of this study were to determine the necessary feed bunk length per heifer and to assess the feeding behavior of heifers fed from bunks of varying sizes. Heifers in three age categories were used for three 16-wk experiments. In Experiment 1, feed bunk lengths per heifer were 15 or 31 cm, and, in Experiments 2 and 3, the lengths were 15, 31, or 47 cm per heifer. Heifers were fed a total mixed ration at restricted intakes. Within-group growth analyses showed uniform growth rates for all heifers at all feed bunk lengths. Individual heifer growth within each group did not vary significantly for either length used in Experiment 1. In Experiment 2, heifers fed from a 15-cm bunk had more variation in live weight gain than did heifers fed from 31- or 47-cm bunks. Live weight gains of heifers fed from a 31-cm bunk varied more than those of heifers fed from 15- and 47-cm bunks in Experiment 3. The mean number of eating bouts and meals and the mean meal duration showed differences between the 15-cm feed bunk length and the 31- and 47-cm feed bunk lengths in Experiments 1 and 2. In Experiment 3, this behavior was different across all lengths. Based on growth responses and feeding behavior, heifers that grow rapidly and that are fed a high quality total mixed diet in a free stall or a bedded pack group housing system require 15-, 31-, and 47-cm feed bunk lengths at 4 to 8, 11.5 to 15.5, and 17 to 21 mo of age, respectively.

Growth performance and sorting characteristics of corn silage-alfalfa haylage diets with or without forage dilution offered to replacement Holstein dairy heifers

“…This suggests a greater bulk density for the EGH diet compared with other diluted diets, which may explain some of the differences in DMI across diluted diets, and particularly between EGH and WS. Previous work has suggested that limited bunk space does not necessarily affect the mean group growth rate, but will affect growth rates of individual heifers within the group (Longenbach et al, 1999). As such, several studies (Longenbach et al, 1999;Greter et al, 2010;Kitts et al, 2011) have used measures of variation within pen replicates as response variables to assess undesirable variability in growth performance among heifers within a common pen.…”

“…Furthermore, these risks may be exacerbated by overcrowding, especially when coupled with the wide range of aggressive and passive behaviors exhibited within any pen of heifers. Inadequate bunk space has been observed to increase day-to-day variations in feeding behavior (DeVries and von Keyserlingk, 2009), as well as within-pen variability with respect to daily weight gains by heifers (Longenbach et al, 1999).…”

Using eastern gamagrass to construct diets that limit intake and caloric density for dairy replacement heifers

“…The visual observation that diets containing EGG were not sorted by heifers may allow for greater flexibility with respect to bunk space because less desirable feed particles would not be discriminated against, and subordinate heifers would have access to the same diet as aggressive heifers, whenever they are able to reach the feed bunk. It is well understood that competition among heifers for bunk space alters feeding patterns, reduces access to feed, and increases day-to-day variation in feeding behavior (DeVries and von Keyserlingk, 2009), as well as withinpen variability with respect to ADG (Longenbach et al, 1999). The use of EGG to create a nonsortable diet has the potential to alleviate many management problems associated with inclusion of chopped straw and warrants further investigation.…”

“…Furthermore, the inclusion of chopped straws within blended diets is notorious for encouraging undesirable sorting behaviors by heifers, especially those that discriminate against long particles (Greter et al, 2008). The concept of limit feeding has gained in popularity during recent years; however, competition for feed among heifers, primarily as a result of inadequate bunk space, increases day-today variations in feeding behavior (DeVries and von Keyserlingk, 2009), as well as within-pen variability with respect to daily weight gains (Longenbach et al, 1999). Therefore, a nonsortable, low-energy dietary additive that permits ad libitum intake of diets containing corn silage without concomitant overconditioning would be a valuable tool for improving feeding management strategies for dairy heifers.…”

The effect of degree of competition for feeding space on the silage dry matter intake and feeding behaviour of dairy cows

“…43 g/min, respectively) and that feeding rate was further increased (71 g/min) if the number of trough spaces available to the group was reduced from 10 to 5. Later, Longenbach et al (1999), when restricting the manger space of dairy heifers from 47 to 31 and 15 cm, found that animals with restricted bunk space, ate faster in smaller meals to prevent a reduction in feed intake. Work reported by Olofsson (1999) and Olofsson and Wiktorsson (2001), indicated that the average feed consumption tended to increase when the number of cows per feeding station was changed from 1 to 4.…”