Nutritional quality of kermes oak (<i>Quercus coccifera</i> L.) acorns as affected by altitude in a typical Mediterranean area

Abstract

Abstract. The impact of altitudinal zone on the nutritional quality of kermes oak (Quercus coccifera L.) acorns was assessed in Xirovouni Mountain shrublands in northwestern Greece. Whole acorns were collected during autumn 2011 from 15 sites located at three altitudinal zones (i.e. lower, middle, upper). Kermes oak acorn samples were manually separated into kernel and hull and analysed for chemical composition (crude protein, CP; neutral detergent fibre, NDF; acid detergent fibre, ADF; lignin), in vitro dry matter (DM) digestibility (IVDMD), in vitro NDF digestibility (IVNDFD), digestible energy (DE), and minerals (i.e. Ca, P, K, Mg, Mn, Fe, Zn, Cu). Altitude had a negative correlation with CP, IVDMD, and IVNDFD and positively correlated to cell wall contents in both kernel and hull. Acorns growing under higher temperatures (at lower altitude) have more digestible cell wall compared to acorns growing under lower temperatures (at higher altitude) due to increased CP content and decreased cell wall content. It seems that environmental factors affect the nutritional value of acorns. Thus, goat farmers should take this into account when collecting acorns to feed their animals.

Nutrient and Mineral Contents, and In vitroDigestibility of Kermes Oak (Quercus cocciferaL.) and Mock Privet (Phillyrea latifoliaL.)

“…The comparison between the kermes oak and mock privet in terms of Zn content revealed that the mock privet had a higher Zn content than the kermes oak, and the Zn contents were within the range of 17.07-37.83 mg/kg. In a study, it was reported that the Zn content in the trunk of kermes oak varied within the range of 3.00-5.90 mg/kg depending on the altitude (Roukos et al, 2017).…”

“…The Cu content in shrubs varies depending on the plant species, maturity period, season, and soil characteristics (Gökkuş et al, 2013). In a study, it was reported that the Cu content in the kermes oak differed depending on the altitude and was different in the trunk and acorn, and the Cu content in the kermes oak acorn varied within the range of 1.60-2.80 mg/kg depending on the altitude (Roukos et al, 2017). The iron (Fe) content was found to be 161.30 mg/kg in kermes oak and 133.4 mg/kg in mock privet (p<0.01).…”

“…The iron (Fe) content was found to be 161.30 mg/kg in kermes oak and 133.4 mg/kg in mock privet (p<0.01). In a study, it was reported that the Fe content in the trunk of kermes oak varied within the range of 22.41-29.36 mg/kg depending on the altitude (Roukos et al, 2017).…”

Nutrient content and in vitro digestibility of kermes oak (Quercus coccifera L.) growing in the provincial borders of Burdur

“…However, the studies worked on different oak species on dry matter digestibility without concerning seasonal variation (13,27) and on the nutritive value with ADF and NDF (13,24). Besides, there are several studies that focused on the nutrient content (10,13,15,26), fatty acid profile (6,11,20,23,29) and in vitro digestibility (10,(25)(26)(27)34) of different species and parts of oak. A study (22) that was encountered in the relevant literature sampled on the main and lateral branch and fresh twigs with leaves of kermes.…”

Determination of the Phenolic Profile and Antioxidant Activity of Leaves and Fruits of SpanishQuercus coccifera

“…Despite its low commercial value with regard to wood production, it plays a significant role in preventing soil erosion [21], and it is used for fodder production for domestic and wild animals [22]. Kermes oak acorns seem to be a highly energetic resource for small ruminants such as goats and lambs and are often compared to barley [23,24].…”