Early visual experience of food does not appear to reduce subsequent feed neophobia in turkeys.

Turkeys may reduce their feed intake because of neophobia toward a new diet; however, their feeding behavior is not well known. The aim of this study was therefore to investigate the effects of diet color on behavior and feed intake in turkeys. For 2 wk, 2 groups of 1-day-old turkey chicks were fed diets varying in color but of the same composition: light-colored crumbles (LC group) or dark-colored crumbles (DC group). Both groups (total n = 144) were then fed a novel diet of green crumbles for the next 2 wk. On d 30, the original groups were each divided into 3 groups and received light, dark, or green pellets. We postulated that neophobia on d 30 would be reduced for chicks fed 1) green pellets compared with diets of other colors because of the effect of recent experience, and 2) a diet of a color that was previously encountered over the first 2 wk of life. Behavior and feed intake were measured on the days before and during each feed transition at 5 min after the changeover feed to observe the short-term reaction. On the first transition day, birds in the LC group decreased their feed intake significantly at 5 min, unlike birds in the DC group, which increased their feed intake. Exploratory behavior increased in both groups when they received green crumbles on the transition day, indicating a response to the color. The changeover to pellets induced a reduction in feed intake in all groups at 5 min, but, in line with our first hypothesis, behavioral changes were less pronounced in birds receiving green pellets. However, turkeys in the DC group did not eat more dark-colored pellets than those in the other groups, and turkeys in the LC group did not eat more light-colored pellets. In the present experiment, we conclude that previous visual experience did not reduce subsequent feed neophobia but that color continuity facilitated a diet change from one feed form to another.

Short-term number of pecks and feed intake levels: a link with the physical characteristics of feed in four-week-old turkeys.

Short-term reactions of young turkeys to changes in the physical characteristics of their feed sometimes give rise to problems of adaptation in the field. Specific feeders were designed for this study to automatically count the number of pecks given at feed by 4-wk-old male turkeys during 95-min sessions. The lighting program was intermittent (0140L:0100D). In experiment 1, 4 series of 12 birds were tested 4 times/day from 28 to 31 d of age. Four control turkeys were consistently tested with 1 feed, and 8 experimental turkeys ate 1 of 32 commercial feeds (30 as pellets and 2 as crumbs) with a distinct feed for each test (16 replicates/experimental feed). Feed intake, total number of pecks, and pecking efficiency (mg/peck) were recorded for each test and normalized for each turkey. The effects of series, day, and test were not significant for controls. The number of pecks and pecking efficiency differed among feeds (P < 0.001) but not feed intake. Hierarchical Cluster Analysis for these variables distinguished 3 groups of feed: group 3 (6 crumb and small pellets) resulted in high pecking and low efficiency. However, group 1 (10 feeds) were pecked at less but more efficiently than group 2 (16 feeds) for similar feed intake, although the average sizes of the pellets were similar (6.23 and 6.16 mm, respectively), as were the average bulk density, hardness, resistance to abrasion, and color characteristics of the pellets for both groups. Two feeds of each of these 2 groups were compared in a second experiment for 12 turkeys receiving the 4 feeds successively each day over 4 d in varying order. The turkeys consistently pecked the feeds of group 1 less and less efficiently compared with group 2. The automated measurement of pecking, combined with a more detailed image analysis of feed particles, might enhance the evaluation of the effects of feed technology on the behavior of turkeys and thus become a useful tool for the feed industry.