Speaking from experience: Reduced dietary neophobia of lambs through early life experience

Abstract

The objective of this experiment was to determine how early life exposure to plant extracts would influence grazing behavior and dietary preference. This experiment used ram lambs (n =60; initial body weight =41.8 ±3.8 kg, mean ±standard deviation). Their dams were either provided no plant extract (CON), a seaweed (Ecklonia radiata) extract (10 mL/ram/d; SWE), or an extract of seaweed, chicory (Cichorium intybus), plantain (Plantago lanceolata), lucerne (Medicago sativa), and dock (Rumex obtusifolius; 10 mL/ram/d; SWP). Treatments were provided to the dams starting in late gestation (63.9 ±6.5 d before lambing), through to weaning of the lambs. After weaning (94 ±6.5 d old), lambs received the respective treatments of their dams until the initiation of the current experiment (66 d after weaning). At the initiation of the current experiment, the lambs were placed into a paddock containing spatially separated strips of ryegrass (Lolium perenne), chicory, plantain, lucerne, and dock, of which they received a fresh break, weekly. During week 1, SWP had more (P <0.05) scans spent grazing than SWE and CON. Also, during week 1, SWP had a greater (P <0.05) number of grazing bouts and a shorter (P <0.05) grazing bout duration compared with SWE and CON. In week 1, SWP had 78.6 % and 167.3 % more (P <0.05) proportion of grazing scans spent in chicory than CON and SWE, respectively. Concomitantly, SWP had 33.5 % and 59.7 % less (P <0.05) grazing scans in ryegrass than CON and SWE, respectively. At the observation weeks 4 and 7, the grazing behavior and dietary preference between treatments was reduced, indicating learning occurred by CON and SWE. Overall, these results indicate that early life exposure to a plant extract alters dietary preference to the species contained in that extract and also changes grazing behavior, which suggests that the extract provided familiarity to the plants and thereby reduced dietary neophobia.