Impact of feeding a high fibre diet and roughage on motivation for feeding in fast-growing broiler breeder pullets

Authors: Wurtz, Kaitlin; THODBERG, KAREN - Aarhus University; VAN DER HEIDE, MARLEEN - Aarhus University; RIBER, ANJA - Aarhus University

Submitted to: Applied Animal Behaviour Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/17/2025
Publication Date: 1/22/2025
Citation: Wurtz, K.E., Thodberg, K., Van Der Heide, M.E., Riber, A.B. 2025. Impact of feeding a high fibre diet and roughage on motivation for feeding in fast-growing broiler breeder pullets. Applied Animal Behaviour Science. 106529. https://doi.org/10.1016/j.applanim.2025.106529.
DOI: https://doi.org/10.1016/j.applanim.2025.106529

Interpretive Summary: Thanks to selective breeding, modern day meat chickens (broilers) have highly efficient growth, reaching market weight in as little as 6 weeks. This however poses challenges for the parent population (broiler breeders) which share a similar propensity for rapid growth but remain in production for much longer than their offspring destined for slaughter. If allowed to consume as much feed as they like, they risk facing negative health and reproductive outcomes associated with obesity. Therefore, the amount of feed they are provided is restricted to control their growth rate, but this has been shown to cause chronic hunger and frustration. Our study found that feeding a diet that includes additional fiber and roughage to increase bulk without increasing energy content helped reduce the hunger and frustration experienced by the broiler breeders compared to when fed a traditional commercial diet. This means that animal welfare improvements may be achieved if the industry includes fiber and roughage into the diets of broiler breeders.

Technical Abstract: Alternative feeding methods for broiler breeders, such as qualitative feed restriction in the form of diluting the diet with a fibre source, have been proposed to help alleviate chronic hunger associated with feed restriction. The aim of this study was to investigate the effect of a fibre-rich diet containing oat-hulls and a daily allocation of roughage (EXP) versus a standard commercial diet (CON) on motivation for feeding in fast-growing broiler breeder pullets. Day-old female Ross 308 breeder chicks (N = 600) were randomly allocated to 12 pens of 50 birds each, with each pen receiving one of the two dietary treatments. Motivation for feeding was assessed by measuring feeding rate and frustration associated with thwarted feeding at 8 and 17 weeks of age. Appetitive foraging motivation was assessed at 12 weeks of age. In week 8, CON birds tended to consume feed faster than EXP birds (P = 0.0672). When assessing frustration associated with thwarted feeding in week 8, EXP birds performed longer durations of locomotion (P < 0.0001) and tended to perform more behavioural transitions than CON birds (P = 0.0659), and CON birds tended to peck at the trough for longer than EXP birds (P = 0.0857). In week 17, there was a tendency for CON birds to consume more feed than the EXP birds during the feed intake motivation test (P = 0.0651). During the appetitive foraging motivation test, dietary treatment did not affect latency to cross, number of crossings, probability of failing to cross, or number of inspections into the litter compartment. CON birds spent a greater proportion of time foraging (P = 0.0351) and tended to spend a lesser proportion of time engaged in locomotion (P = 0.0955) than EXP birds when in the litter compartment. In summary, results from our study show that feeding a diet high in insoluble fibre and supplemented with roughage appears to result in some reduction in the motivation to feed during rearing compared to feeding a standard commercial diet. However, as caloric intake remained similar between the two diets, there likely was no difference in metabolic hunger between the two treatments. Therefore, further modifications to management and breeding are necessary to address the concern of prolonged hunger.