The chemical composition of selected dried fruit pomaces and their effects on the growth performance and post-slaughter parameters of young turkeys

Z. Zduńczyk,K. Kołodziejczyk,P. Zduńczyk,J. Jankowski,D. Mikulski,J. Juśkiewicz

doi:10.22358/jafs/65653/2015

Abstract

The objective of this study was to verify the hypothesis that add- ing dried fruit pomaces differing in their polyphenol contents to diets for young turkeys does not compromise bird performance. Young turkeys aged up to 15 weeks were fed diets containing a cellulose preparation (C) or 5% dried apple pomace (AP), blackcurrant pomace (BCP), strawberry pomace (SP), or seed- less strawberry pomace (SSP). The crude protein content of AP was 6.64% and exceeded 15% in the remaining pomaces. In comparison with soyabean meal protein, the value of the essential amino acid index was lowest in AP (78.6%), higher in SP and SSP (approximately 85%) and highest in BCP (93.4%). The crude fat content ranged from 2.63% in AP to 13.8% in BCP, whereas the di- etary fibre content was found to be in the range of 56.5% in AP to 62.9% in SP. AP, BCP, SP and SSP were characterized by different polyphenol con- centrations: 5.75, 12.43, 11.51 and 32.81 g · kg -1 of gallic acid, respectively. Dietary inclusion of 5% of dried fruit pomaces that increased the polyphenol content of the experimental diets by a maximum of 0.3 g · kg -1 relative to the control diet did not affect feed intake at the beginning or at the end of the feeding trial. In comparison with the cellulose-supplemented diet, the inclusion of fruit pomaces that increased the dietary polyphenol content did not impair the growth performance of turkeys or feed conversion. Production parameters, including slaughter results, were not affected by the higher polyphenol content or the higher antioxidant potential of blackcurrant and strawberry pomaces, compared with apple pomace.

Highlights

In intensive poultry production, excessive concentrations of indigestible structural carbohydrates can lower feed intake and nutrient availability (Mateos et al, 2012)
The evaluated fruit pomaces differed in their proximate composition, including the content of total protein, crude fat and crude fibre (Table 2)
In comparison with the remaining pomaces, apple pomace (AP) was characterized by a lower content of crude protein and crude fat and relatively low concentrations of crude ash

Summary

Introduction

Excessive concentrations of indigestible structural carbohydrates (non-starch polysaccharides, NSPs) can lower feed intake and nutrient availability (Mateos et al, 2012). The crude fibre content of standard cereal-soyabean diets for young chickens and turkeys is relatively low at approximately 3.5% (Jankowski et al, 2009; Mateos et al, 2012), which is significantly below the 6% threshold tolerated by fast-growing birds (Zduńczyk et al, 2010). For this reason, moderate addition of selected high-fibre components to cerealsoyabean diets enhances gastrointestinal functions in birds (Mateos et al, 2012). Many of these compounds are retained in pomace, which is why fruit pomaces are used in various biotechnological processes to produce health-promoting phytochemicals (Kołodziejczyk et al, 2007; Kandari and Gupta, 2012)

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