Cattle foraging in Mediterranean oak woodlands – Effects of management practices on the woody vegetation
. Forest Ecology and Management 2018
, 160-169. Publisher's VersionAbstract
Vegetation structure and composition of woodlands in the Mediterranean Basin have experienced extensive land-use change during recent decades. Decline in traditional foraging by goats is leading to more closed and spatially homogeneous woody vegetation, reduced plant diversity, and increased fire risk because of accumulation of inflammable material. We studied the use of cattle foraging as an alternative to goat foraging in Mediterranean oak woodlands. Our main goal was to provide basic information on the responses of woody vegetation to cattle foraging intensity, and on the factors affecting spatial patterns of woodland utilization. We conducted the study in the Western Galilee, Israel, in oak woodland dominated by Palestine oak (Quercus calliprinos Webb.) interspersed with patches of shrubs and herbaceous vegetation. Effects of two animal population densities, moderate (0.33 cow⋅ha−1) and high (0.55 cow⋅ha−1), on the structure, composition, and regeneration potential of dense and of open woody formations were examined. Four consecutive annual seasons of cattle foraging resulted in relatively large amounts of woody vegetation removal, especially under high animal density, but had no negative effects on woody species richness or regeneration potential from saplings. The type of vegetation formation and initial state of the woody vegetation were important factors affecting the degree of change. Woody biomass removal by cattle, as shown in this study, can reduce fire hazards and increase vegetation heterogeneity and plant diversity. These findings support the use of cattle as an efficient alternative tool for multi-purpose, sustainable management of Mediterranean oak woodlands. © 2018 Elsevier B.V.
Impact of animal density on cattle nutrition in dry Mediterranean rangelands: A faecal near-IR spectroscopy-aided study
. Animal 2018
, 265-274. Publisher's VersionAbstract
In the context of determining the sustainable carrying capacity of dry-Mediterranean herbaceous rangelands, we examined the effect of animal density on cattle nutrition, which is fundamental to animal performance and welfare. The effects on dietary components of low (0.56 cows/ha; L) and high (1.11 cows/ha; H) animal densities were monitored for three consecutive years in grazing beef cows. In the dry season (summer and early autumn), cows had free access to N-rich poultry litter (PL) given as a dietary supplement. In each season, near-IR spectroscopy (NIRS) was used to predict the chemical composition of herbage samples (ash, NDF, CP, in vitro dry matter digestibility (IVDMD) and metabolizable energy (ME) content from IVDMD). Near-IR spectroscopy was applied also to faecal samples to determine the chemical composition of the diet selected by the animal, as well as the contents of ash, NDF and CP in the faeces themselves. A faecal-NIRS equation was applied to estimate the dietary proportion of PL. Seasonal categories were green, dry without PL supplementation and dry with it. We found no effects of animal density on nutrition during the green season but effects were apparent when cows consumed dry pasture. Ash content predicted by faecal NIRS was higher in the diet than in plant samples clipped from pasture, which infers that cows ingested soil. Dietary and faecal ash contents were higher (P<0.05) at the H, implying greater soil intake in these animals. During the dry period, dietary contents of ME were higher in L than in H (P<0.05). Poultry litter supplementation was associated with a marked increase (P<0.01) in dietary and faecal CP contents. Poultry litter represented 0.45 and 0.59 of the diet in treatments L and H, respectively (P<0.05). Consequently, treatment H had higher faecal protein (P<0.05). A tendency of higher dietary protein (P=0.08) and lower dietary NDF (P=0.10) in treatment H was probably related to greater PL ingestion. Given that high and sustained rates of poultry litter consumption are detrimental to animal health, the above results cast doubts on the long-term sustainability of the higher of the animal densities tested. Although it may be sustainable vis-à-vis the vegetation, treatment H may have exceeded the boundaries of what is acceptable for cow health. Chemical information revealed with NIRS can be used to evaluate whether animal densities are compatible with animal health and welfare standards and can play a role in determining the carrying capacity of Mediterranean rangelands. © The Animal Consortium 2017.
The taste of KCl – What a difference a sugar makes
. Food Chemistry 2018
, 165-173. Publisher's VersionAbstract
Dramatic increase in NaCl consumption lead to sodium intake beyond health guidelines. KCl substitution helps reduce sodium intake but results in a bitter-metallic off-taste. Two disaccharides, trehalose and sucrose, were tested in order to untangle the chemical (increase in effective concentration of KCl due to sugar addition) from the sensory effects. The bitter-metallic taste of KCl was reduced by these sugars, while saltiness was enhanced or unaltered. The perceived sweetness of sugar, regardless of its type and concentration, was an important factor in KCl taste modulation. Though KCl was previously shown to increase the chemical activity of trehalose but not of sucrose, we found that it suppressed the perceived sweetness of both sugars. Therefore, sensory integration was the dominant factor in the tested KCl-sugar combinations. © 2018 Elsevier Ltd