An investigation on determining the nutritive value of oak nuts

Abstract

This study was conducted to determine the nutritive values of shelled, unshelled oak nuts and their shells. For the estimation of dry ma�er (DM), organic ma�er (OM) and crude protein (CP), degradability characteristics, digestibilities, energy values and tannin contents of these feedstuffs the nylon bag technique, cellulose feed system and enzyme methods were used. In spite of the fact that in situ dry ma�er, organic ma�er and crude protein degradabilities of shelled and unshelled oak nuts were high, the degradabilities of shells were found lower. Degradability characteristics (a, b, a + b) and effective degradabilities were high in unshelled and shelled oak nuts and low in shells. The differences between the oak nut shells and the other two groups were significant for DM and OM degradabilities (P < 0.01). Pepsin digestible N contents were lower in shelled and unshelled oak nuts and high in shells. Unshelled and shelled oak nuts were significantly different from the oak nut shells for digestibility of DM and OM. Energy values were highest in unshelled oak nuts and lowest in shells. Oak nuts can be used as a forage source in regions with their high natural production.

Significance of Quercus species in nutrition

“…All phenol and gallotannin content were significantly higher in the seed coat of Quercus pubescens and in shelled seeds than in peeled fruits [36].…”

Quantitative determination of the boar taint compounds androstenone, skatole, indole, 3α-androstenol and 3β-androstenol in wild boars (Sus scrofa) reveals extremely low levels of the tryptophan-related degradation products

“…Especially butyrate was suggested to inhibit mucosal apoptosis in the hindgut and hence reduce the presence of endogenous tryptophan available for SK formation (Claus et al, 2003;Hass, Busche, Luciano, Reale, & Engelhardt, 1997;Øverland, Kjos, Fauske, Teige, & Sørum, 2011). NSPs such as cellulose, b-glucans and arabinoxylans are major components of dietary fibre in acorns, beechnuts and cereals (Lynch, Sweeney, Callan, & O'Doherty, 2007;Saricicek & Kilic, 2004). Thus, a major part of wild boar diet is rich in various NSPs and hence favours the formation of butyrate as well as of short chain fatty acids in general.…”

Oak Kernels—Volatile Constituents and Coffee-Like Beverages

“…They have high energy value and are highly digestible (Saricicek & Kilic, 2004). Kernel oils of the English and Turkish oak are characterized by high levels of oleic (over 40%) and linoleic (over 30%) acids (Cabrera-Vique, Marfil, Giménez, & Martínez-Augustin, 2012;Petrović, Šobajić, Rakić, Tomić, & Kukić, 2004) and are also valuable source of essential α-linolenic acid (1.8 and 3.7%, respectively) (Petrović et al, 2004).…”