The effects of dietary dried fruit pomaces on growth performance and gastrointestinal biochemistry of turkey poults

Abstract

One-day-old female turkeys were randomly assigned to five dietary treatments and were fed for 15 weeks diets containing 5% of cellulose (control, C) or 5% of dried fruit pomaces (apple, black currant, strawberry, seedless strawberry; AP, BCP, SP, SSP respectively). In weeks 11-15 of feeding, all diets were supplemented with 2.5% of linseed oil. The crude fibre content of fruit pomaces ranged from 56.5% in AP to 62.9% in SP. In comparison with AP, berry fruit pomaces (BCP, SP and SSP) were characterised by a higher content of neutral detergent fibre - NDF (41.2% vs. 52.7-59.3%) and lignin (13.24% vs. 21.80-25.56%). A monomer analysis revealed that cellulose was the main non-starch polysaccharide (NSP) in fruit pomaces, whereas their pectin content was low. Polyphenol content was determined at below 6 g/kg in AP, at approximately 12 g/kg in BCP and SP, and at 32.8 g/kg in SSP. There were no significant differences (p > 0.05) in final body weight of birds. After 15 weeks of feeding fruit pomaces to turkeys, the relative weight of the small intestine with digesta was higher in group AP, and lower in group SSP, as compared to controls. Dietary fruit pomaces decreased the dry matter (DM) concentration and lowered the pH of the small intestinal digesta, except the AP and SSP treatments respectively. In the caeca, significantly reduced concentrations of ammonia or putrefactive short-chain fatty acids (SCFA) upon dietary fruit pomaces were observed. Fruit pomaces did not influence the concentrations or the total pool of short-chain fatty acids, but led to a significant increase in butyric proportion in the SCFA profile at the expense propionate.

Keywords: dried fruit pomaces; fibre fractions; gastrointestinal function; polyphenols; turkey.