The scientists, attached to Wageningen University and Research, published about the research in the journal Applied Animal Behaviour Science. They describe a trial that tested the feeding behaviour of suckling piglets when different diets were supplied to them.
The hypothesis of the study was that presentation of the feed in a more diverse form, by varying multiple sensory properties of the feed, stimulates pre-weaning feed intake. Stimulating solid feed intake in suckling piglets is important to facilitate the weaning transition, exemplified by the positive correlation between pre- and post-weaning feed intake.
2 different diets tested by piglets
Piglets received ad libitum feed from 2 days of age in 2 feeders per pen (choice feeding set-up). Feed A was an experimental diet from the university’s Animal Nutrition Group. Extruder settings intendedly varied during production, resulting in differences in pellet texture, length and hardness to create diversity within feed A.
Feed B is a commercial diet, called Baby Big XL, from Coppens Diervoeding in the Netherlands. Feed B was a 14-mm diameter pellet, with a length of 10-20 mm and a hardness of 6.8 kg.
Group 1 (dietary diversity (DD), including 10 litters) were given feed A and feed B which differed in production method, size, flavour, ingredient composition and nutrient profile, smell, texture and colour.
Group 2 (flavour novelty (FN), including 9 litters) received feed A only in both bowls from 2 days of age. From day 6 of age flavours (i.e. substances to influence the sensory perception of the feed as related to its taste and smell) were added to feed A in 1 bowl in a daily sequential order.
More diversity, higher feed intake
Feeding behaviour was studied by weighing feed remains and by live observations. Observations were also used to discriminate ‘eaters’ from ‘non-eaters’. In addition, eaters were grouped into different eater classes (i.e. good, moderate and bad).
Provision of feed A and B increased pre-weaning feed intake by 50% compared to provision of feed A only (with and without additional flavours). Piglets receiving feed A and B had no overall preference in terms of feed intake for either feed A or B, indicating pre-weaning feed intake increased by an enhanced intake of both feeds.
These results supported the researchers’ hypothesis that the more diverse the feeds provided in terms of sensory properties (e.g. ingredient composition, texture), the greater the intake will be. The reason for this is expected to be sensory-specific satiety and/or piglets’ intrinsic motivation to explore.
Differences in nutrient profiles
Alternatively, the researchers wrote, differences in nutrient profiles between the 2 treatments may have exerted physiological effects that may have influenced feed ingestion.
Future research will investigate the effect of dietary diversity on the (feeding) behaviour and performance of suckling piglets versus a control group (no-variety condition) and will study the adaptive capacity of these piglets in novelty tests and during the post-weaning period.
The research paper was written by Anouschka Middelkoop, Raka Choudbury, Walter J.J. Gerrits, Bas Kemp, Michiel Kleerebezem and J. Elizabeth Bolhuis, all attached to Wageningen University & Research in the Netherlands.