A recent issue of Poultry Science includes a paper reporting an experiment conducted to investigate the effects of dietary dilution sources and levels on feather damage, performance, feeding behaviour and litter condition in rearing pullets.

Authors, S.N. Qaisrani of Wageningen University in the Netherlands and colleagues there and at Wageningen UR Livestock Research hypothesised that dietary dilution increases feeding-related behaviour and improves feather condition, particularly if insoluble non-starch polysaccharides are used as the dilution source.

In total, 864 Lohmann Brown day-old non-beak-trimmed pullets were used until 18 weeks of age.

Four dietary treatments were used: a control diet without any dilution (R-0), 7.5 per cent diluted diet with sunflower seed extract/oat hulls (R-7.5), 15 per cent diluted diet with sunflower seed extract (R-15-S), and 15 per cent diluted diet with oat hulls (R-15-O). There were six replicates - one replicate is a pen with 36 pullets - per treatment.

At four-week intervals, behavioural parameters, including eating time, feather pecking, feather condition and general behaviour were evaluated.

Pullets fed the control diet showed increased feather-, comb- and wire-pecking compared with pullets fed the diluted diets.

The level of feather damage decreased with increasing dietary dilution level. Pullets receiving R-15-S and R-15-O showed more feeding-related behaviour than the pullets fed R-7.5 and R-0.

Oat hulls were more effective in preventing feather damage than sunflower seed extract.

Pullets did not fully compensate their feed intake if fed a dietary dilution, resulting in a proportionally reduced available metabolisable energy intake. The R-15-O pullets had 2.9 per cent lower average bodyweight gain than those fed R-0.

Average eating duration increased by 12.8, 33.2 and 42.1 per cent in R-7.5, R-15-S and R-15-O fed pullets, respectively, compared with R-0, whereas eating rate - expressed as feed intake (g) per pullet per eating minute - was decreased in R-15-S and R-15-O pullets.

Relative weights of empty gizzards were 3.95, 10.30 and 62.72 per cent higher in R-7.5, R-15-S and R-15-O pullets than those fed R-0.

The Wageningen researchers concluded that dietary dilution affected time budgets of the pullets, as shown by more feeding-related behaviour, resulting in less feather-pecking behaviour.

Based on these results, they said, the application of this feeding strategy could improve production and welfare in pullets.

Reference

Qaisrani S.N., M.M. van Krimpen and R.P. Kwakkel. 2013. Effects of dietary dilution source and dilution level on feather damage, performance, behavior, and litter condition in pullets. Poult. Sci. 92(3):591-602. doi: 10.3382/ps.2012-02378

Further Reading You can view the full report (fee payable) by clicking here.

April 2013