# Feeding Low- and High-Fibre Sunflower Meal to Broiler Chickens—Effects of Inclusion Rate and Age of Birds on the Production Traits, Carcass Composition, Nutrient Digestibility, Gut Viscosity, and Caecal Short-Chain Fatty Acid Content

## TL;DR

This study examines how feeding sunflower meal to broiler chickens affects their growth, digestion, and gut health, finding that it can be used effectively at high levels without harming production.

## Contribution

The study reveals that high-fibre sunflower meal can be included in broiler diets at 30% without compromising performance, depending on bird age.

## Key findings

- High-fibre sunflower meal at 30% improved body weight gain in the grower phase.
- Sunflower meal increased fat digestibility but reduced starch digestion.
- Sunflower meal diets lowered urinary nitrogen excretion, potentially reducing ammonia emissions.

## Abstract

The demand for poultry products is increasing in line with the rapid increase in the world’s population. It also means that more cereal grains and protein sources are needed for human nutrition, and more industrial by-products will be used in animal nutrition. Sunflower meal (SM), the by-product of the oil industry, is available in high amounts. However, its high fibre content is a limiting factor. In the frame of this work, a high- and a low-fibre SM was fed with broiler chickens at two inclusion rates, and the responses of animals were evaluated. The main conclusions are that the responses of feeding SM depend on the inclusion rate (20 or 30%), the fibre content of SM, the age of chickens (grower phase or finisher phase), and the investigated parameter. Surprisingly, the body weight gain (BWG) of the younger animals was not affected by SM, but in the grower phase, the highest BWG was registered in the 30% high-fibre SM group, and the lowest gain belonged to the 30% low-fibre treatment. SM diets increased the digestibility of fats but decreased the starch digestion. The SM-containing diets resulted in lower urinary nitrogen excretion, which can lead to reduced ammonia emission. The carcass composition and the short-chain fatty acid composition of the caeca were not affected. Our findings revealed that SM can be used as broiler feed even at 30% without compromising the production parameters.

Sunflower meal (SM) is an economically important, inexpensive, and locally abundant alternative protein source in the Eurozone. The study aimed at investigating the effects of feeding two forms of SM on the production traits, carcass composition, nutrient digestibility, and some gut parameters of broiler chickens. A total of 600-day-old Ross 308 male broilers were fed five isocaloric and isonitrogenous diets. Besides the control diet (C), the high- and low-fibre SMs (HFSM and LFSM) were fed at 20% (HFSM20 and LFSM20) and 30% (HFSM30 and LFSM30). Compared to the C, feeding the SM-containing diets did not affect the feed intake (FI) of birds. In the finisher phase, the HFSM30 treatment resulted in significantly higher, while the LFSM30 diet in significantly lower body weight gain. All SM treatments impaired FCR, but the difference was significant only in the grower phase. In comparison with the C, the SM treatments failed to modify carcass composition. The fat digestibility and the AMEn content increased, while the starch digestibility decreased when SM was fed. Except the LFSM30 treatment in the grower phase, the Nitrogen retention of birds was not affected. The SM-containing diets reduced the urinary N excretion, and the total N excretion of growers. Furthermore, the HFSM30 reduced the jejunal viscosity during the grower and finisher phases. The treatments did not modify the short-chain fatty acid contents of the caeca. In conclusion, SM can be used even at 20 and 30% in the nutrition of broiler chickens. However, the responses are affected by the age and the fibre content of SM.