Influence of sunflower meal utilisation on growth performance and digestive tract traits of white strain pullets fed from 29 to 112 d of age.

1. A trial was conducted to study the effects of partial replacement of sunflower meal (SFM) for soybean meal (SBM) on growth performance and gastrointestinal tract traits (GIT) in pullets.2. A total of 600 pullets (29 d of age) was randomly assigned to three dietary treatments and fed for 84 d. The birds were fed a practical diet with a low level of crude fibre (CF; LF) or test diets containing a medium or high level of CF (MF and HF) by partial (50% to 75%) replacement of SBM with SFM. Accordingly, the grower diets contained 29, 40 and 51 g CF/kg, which corresponded to 31, 45 and 59 g CF/kg in developer diets. Each dietary treatment was replicated 8 times (25 pullets per replicate).3. Body weight did not differ significantly among treatments at d 29, 84 and 112 d but increased (P < 0.05) with SFM supplementation at d 54. From 29 to 112 d of age, daily feed and energy intake linearly increased (P < 0.01) with SFM supplementation, but body weight gain and feed conversion ratios were comparable amongst the groups.4. Digestive organ size was not affected by the dietary treatments, but gizzard weight increased in pullets fed MF and HF diets (P < 0.01). Digesta pH in the gizzard, duodenum, jejunum and ileum were reduced linearly (P < 0.01) with SFM supplementation, while a quadratic response was observed for proventriculus pH (P < 0.05).5. Small intestine morphology traits improved with a moderate level of CF intake, whereas no benefit was observed with a high level of CF consumption.6. The results showed that use of SFM up to 140 g/kg can be recommended for pullets fed diets based on corn and soybean meal. However, smaller intestinal absorptive capacity with higher SFM supplementation may occur.