Tomislav Šarić

Increased intake of Juniperus phoenicea L. by supplementation with barley and Optigen® in sheep

Dry littoral grasslands and rocky ground pastures throughout the Mediterranean basin are a significant source of forage for small ruminants and as such associated with traditional grazing practices. During the last decade, dissemination of terpene-rich Mediterranean shrubs, Juniperus phoenicea L., onto pastures in Adriatic region of Croatia have caused reduction in forage production and plant diversity. In order to facilitate the intake of this new plant by small ruminants, we investigated the effects of barley and Optigen® (a source of controlled-release non-protein nitrogen) mixture to increase consumption of J. phoenicea by sheep. The preliminary results suggest that barley alone, or in combination with Optigen® enhance the intake of J. phoenicea by sheep. Furthermore, this model can be used as an environmentally safe and economically affordable approach to reduce the abundance of less palatable J. phoenicea in the environment and to increase growth of alternate, better quality forage (grasses and forbs) on Mediterranean pastures.

Effect of supplementation with barley and calcium hydroxide on intake of Mediterranean shrubs by goats

Maquis plant communities are one of the most varied vegetation types in the Mediterranean region and an important habitat for wild and domestic herbivores. Although the majority of these shrubs are nutritious, the secondary compounds are the main impediments that reduce their forage value. In five experiments, we determined the effect of supplementing the diets of goats with calcium hydroxide plus barley and with barley alone on their intake of five dominant shrubs (Quercus ilex, Erica multiflora, Arbutus unedo, Viburnum tinus and Pistacia lentiscus) of the Mediterranean maquis community. The combination of calcium hydroxide plus barley and barley alone increased the utilisation of Q. ilex, E. multiflora and P. lentiscus, while the intake of A. unedo and V. tinus was not statistically significantly different. Calcium hydroxide and barley (energy) enhance the use of secondary compound-containing plants, which may increase the production of alternate forages and create a more diverse mix of plant species in the Mediterranean maquis plant community.

Mediterranean shrub diversity and its effect on food intake in goats

Mediterranean ecosystem offers a variety of shrubs that were over long periods of time involved in the evolution of complex plant-animal interactions. Biochemical components of these plants enter different metabolic pathways after digestion and absorption, resulting in development of dietary preferences in browsing animals. Herbivores in general were found to perform better when grazing in a mixed plant community composed of diverse species, and show preferential feeding behavioure for mixed vs single species diet. Our findings demonstrate an asymptotic relationship among Mediterranean shrubs species diversity and their voluntary intake by goats. Shrub biomass intake showed linear increase when number of different shrubs in diet increased from one to three. However, goats did not further increase intake when the number of shrub species increased from four to eight. As the number of shrub species offered increased, goats exhibited more preferential feeding behaviour for Quercus pubescens, Fraxinus ornus, Rubus heteromorphus and Arbutus unedo and decreased the intake of Hedera helix, Juniperus oxycedrus and Helichrysum italicum. This asymptotic relationship indicates that the maintenance of plant species richness in Mediterranean shrublands can overall benefit domestic goat farming, goat’s productive performance, and the conservation of plant biodiversity.

Supplementation with imuno-2865® in gilthead sea bream (Sparus aurata Linnaeus, 1758): Effects on hematological and antioxidant parameters

The aim of this study was to evaluate the effects of IMUNO-2865(®) on hematological and antioxidative parameters in sea bream. Total of 640 sea bream were fed with diets containing 0 (Group 1), 1 (Group 2), 10 (Group 3) and 25 (Group 4) g of IMUNO-2865(®) kg(-1) feed during 90 days. Samples were taken each month and three months after the supplementation. A significant heterophils increase was observed in group 4 compared to group 1 after two months, and an increase in monocytes number was observed in group 4 compared to the other groups after one month. Glutathione peroxidase (GSH-Px) and paraoxonase-1 (PON1) were significantly increased in groups 3 and 4 compared to the control group three months into the experiment. Superoxide dismutase (SOD) was increased in group 4 compared to the control group from day 60 until the end of the experiment, and in groups 2 and 3 compared to the control after three months. Based on the differences in the cellular immunity and oxidative stress parameters, with an overall absence of mortality, the results of this study suggest that the use of IMUNO-2865(®) in aquaculture is safe and possess a cumulative immunostimulatory effect on sea bream.

Importance of plants with medicinal properties in herbivore diets

Plant secondary metabolites can adversely affect cellular and metabolic processes in herbivores, but also at low doses and in appropriate mixtures, they can have beneficial effects on animal nutrition, health and other therapeutic impacts. In this paper, we demonstrate the potential effects of plants with medicinal properties on animal foraging behavior as a function of the consequences they experience after ingestion of Mediterranean shrubs that are rich in phytotoxins. This mechanism – behavior by consequences – suggests animals are able to meet nutritional requirements and self-select certain plants with medicinal properties if they are offered the opportunity to do so when foraging in diverse Mediterranean shrub communities. Understanding the feeding behavior of ruminants when offered a variety of plant species is necessary to be able to improve their health and well-being by reducing levels of stress and fear; it may also lead to the early detection of illness. Thus, management strategies in biochemically/biologically diverse ecosystems should benefit from allowing ruminants to manifest their feeding preferences.

Effect of Achillea Millefolium L. and Matricaria Chamomilla L. on Consumption of Juniperus Oxycedrus L. and J. Phoenicea L. by Goats

Abstract Reduction in herbage production and plant diversity on rangelands on the coastal part of Croatia, due to invasion of terpene-rich shrubs has been recorded during the recent period. Therefore, there is a strong need to understand ecological relationships between plant and animal components of these shrubby ecosystems. Through four consecutive experiments, we investigated the potential of two well-known medicinal herbs, Achillea millefolium L. (yarrow) and Matricaria chamomilla L. (chamomile), as a feed supplement to increase intake of two terpenoid shrubs, Juniperus oxycedrus and J. phoenicea, by goats. Preliminary research indicated that both yarrow and chamomile had a positive influence on the intake of J. phoenicea by goats, but not on the consumption of J. oxycedrus. Our model could be implemented in the field as an approach to reduce the abundance of J. phoenicea in the environment and to improve the quality of herbage (grasses and forbs) on Mediterranean pastures.

Transfer of Arca noae Linnaeus, 1758 from natural to different experimental farming conditions

Noah’s ark shell Arca noae Linnaeus, 1758 is one of commercially important species in Croatia harvested from the wild. Its length/sex relationship, sex ratio and survival after transfer from natural habitat to different experimental farming conditions were examined. Statistically smaller lengths were detected for males (x=52.6±8.7 mm) than for females (x=60.2±9.5 mm). The overall sex ratio was 1.8 : 1.0 in favour of males. Survival after 17 months was only 20.5%. This study demonstrated that A. noae specimens can be transferred from the wild onto field experimental conditions, but high post transfer mortalities occurred. Gathered data about post transfer mortalities and relationship between the sexes and lengths could be useful when planning aquaculture/hatchery operations for this bivalve species. Furthermore, they will be of great help for the further development of farming technology of this species.