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Effects of Almond Hulls on the Chemical Composition and In Vitro Ruminal Protein Degradation of Alfalfa Silage

Selim Sırakaya , Selma Buyukkilic Beyzi

Abstract

Context. Enhancing protein efficiency in the diet or the use of by-products can reduce feed costs and the environmental impact of animal production. Aims. The aim of this study was to determine the effects of almond hull (AH) addition to alfalfa silage on some chemical parameters and in vitro protein degradability. Methods. The second cut alfalfa was chopped after withering and up to 2 cm length. Chopped feed was ensiled with 100 g kg-1 DM of 3 varieties (Nonpareil, Ferragnes and Texas) of AHs dried and ground and each treatments was ensiled in vacuum-sealed polyethylene plastic bags for 90 days as 5 replications. Key results. As a result, all AH treatments increased the dry matter of alfalfa silage. Condensed tannin content in alfalfa silage increased with all AH varieties additions (P<0.05). Catechin, which was high before ensilaging in all AH groups, decreased after ensiling. Gallic acid content increased in all AH groups (P<0.05). In alfalfa silage, NH3-N concentration decreased in all AH supplemented groups, and in vitro ruminal undegradable protein was increased (P<0.05). In the study, FTIR spectra supported the findings showing that chemical bonds were formed between tannins and proteins. Conclusions. As a result, it was shown that the addition of AH to alfalfa silage could reduce ruminal protein degradability. Implications. This study offers strategies for converting AHs into a higher-value product and for enhancing the utilization of alfalfa protein.

AN25081  Accepted 26 April 2025

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