Wolf diet and prey selection in Croatia Octenjak, Daria; Pađen, Lana; Šilić, Valentina ...
Mammal research,
10/2020, Letnik:
65, Številka:
4
Journal Article
Recenzirano
Tensions between humans and wolves have led to intensive worldwide studies of wolf feeding habits and their relative preference for domestic and wild ungulates. The aim of this study was to provide ...further insight into the diet composition of wolves in Croatia, based on stomach contents of dead wolves. We examined spatial variation in wolf diet and prey selection relative to availability of wild and domestic animals. Furthermore, we aimed to determine selectivity in feeding habits in relation to wolf gender and age. The study was conducted on the stomach contents of 42 gray wolves (18 females, 24 males). Samples were collected from three regions of Croatia with different ratios of domestic and wild prey availability. The density ratio of domestic to wild ungulates increased gradually from north-west (5.8), through central (11.6) to south-east (134) Croatia. Wolf diet followed this pattern with the ratio of domestic animals increasing from 0.7 to 1.3 and 5.3, respectively. The relative share of wild ungulates in wolf diet was significantly higher in all three regions of wolf range in Croatia, even where livestock availability was high. Female wolves ate birds, rodents, and dogs more than males and in the south, where wild ungulates were scarce. This study showed wolves’ selectivity for wild ungulate, rather than for abundant, but well-guarded livestock. The European idea of coexistence of humans and wolves in human-dominated landscape seems possible with some effort and understanding from humans’ side.
Environmental contaminants like arsenic (As), cadmium (Cd), mercury (Hg) or lead (Pb) may disrupt hypothalamic–pituitary–adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes due to their ...endocrine toxicity potential. Resulting long-term physiological stress or adverse effects on wildlife reproduction and ontogeny may cause detrimental effects at the individual and population levels. However, data on environmental metal(loid)sʼ impact on reproductive and stress hormones in wildlife, especially large terrestrial carnivores, are scarce. Hair cortisol, progesterone and testosterone concentrations were quantified and modelled with hair As, Cd, total Hg, Pb, biological, environmental and sampling factors to test for potential effects in free-ranging brown bears (Ursus arctos) from Croatia (N = 46) and Poland (N = 27). Testosterone in males (N = 48) and females (N = 25) showed positive associations with Hg and an interaction between Cd and Pb, but a negative association with interaction between age and Pb. Higher testosterone was found in hair during its growth phase compared to quiescent phase. Body condition index was negatively associated with hair cortisol and positively associated with hair progesterone. Year and conditions of sampling were important for cortisol variation, while maturity stage for progesterone variation (lower concentrations in cubs and yearlings compared to subadult and adult bears). These findings suggest that environmental levels of Cd, Hg and Pb might influence the HPG axis in brown bears. Hair was shown to be a reliable non-invasive sample for investigating hormonal fluctuations in wildlife while addressing individual and sampling specificities.
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•First effect study on hormonal association with metal (loid)s in European brown bear.•Hair testosterone was associated with potentially toxic metal (loid) levels.•Year and conditions of sampling important for cortisol variation in hair.•Maturity stage important for progesterone variation (lowest in cubs & yearlings).
The problem of the erosion of animal genetic resources is evident in certain local donkey breeds, and their long-term sustainability can be achieved by economically repositioning them. To develop ...alternative and sustainable commercial programs, the meat and milk production characteristics of Istrian donkey and Littoral Dinaric donkey breeds were investigated. The meat production characteristics were examined in mature males, whose carcasses were dissected, and meat composition was determined using NIT spectrophotometry and gas chromatography. Milk yield and milk composition were determined in jennies in second or subsequent lactations by measuring milk volume and using infrared spectrometry and gas chromatography. Compared to the Littoral Dinaric donkey, the Istrian donkey has a higher carcass weight and dressing percentage (
< 0.001). The share of boneless meat in relation to live weight was 28.27% in the Istrian donkey and 26.18% in the Littoral Dinaric donkey. The absolute masses of primal cuts of meat in E, I, and II classes were significantly greater in Istrian donkeys than in Littoral Dinaric donkeys (
< 0.01), although the differences in the proportions of primal cuts were not significant. The breed did not have a significant impact on the color, pH, or meat composition. A significant influence of breed on milk yield, lactose, protein, and the fat content of milk was observed (
< 0.01). A significant influence of breed on the ratio of n-6/n-3 PUFA fatty acids in donkey milk was observed (
= 0.002). The values of the atherogenic and thrombogenic indexes were favorable, considering potential beneficial effects of donkey milk and meat on consumer health. The findings of this research suggest that local donkey breeds hold significant potential for meat and milk production, focusing on the uniqueness and quality of their products rather than the quantity of meat and milk they can produce.
The composition and properties of the milk fat of mares’ milk is interesting from a nutritional standpoint. The aim of this study was to determine the nutritional value of Lipizzaner mare’s milk for ...possible human consumption and identity the influence of the parity and stage of lactation on its fatty acid (FA) composition. This study was conducted on 17 Lipizzaner mares from a state stud farm in the Slavonian region (eastern Croatia). Mares were hand-milked twice during lactation in the fourth and sixth months. Significantly higher contents of MUFAs (monounsaturated fatty acids) and PUFAs (polyunsaturated fatty acids) and lower ratios of n-6/n-3 were found in the fourth month of lactation. This parity significantly affected the PUFA/SFA ratio (polyunsaturated fatty acids/saturated fatty acids), with lower values found in older mares. The fatty acid composition of mare’s milk that is especially high in UFAs (unsaturated fatty acids) is considered to be beneficial for consumers.
This study aimed to investigate the fatty acid (FA) composition of edible dormouse m. biceps femoris in both sexes. More than 20 FA were identified in the muscle, with the 18:1cis-9 (oleic acid) ...being the most abundant in both sexes, comprising more than 50% of total FA in muscle. The most dominated FA were monounsaturated (MUFA), followed by saturated FA (SFA) and polyunsaturated FA (PUFA), reaching 54.8%, 25.43% and 19.8% of total FA, respectively. Sums of PUFA and n-3 PUFA tended (p > 0.05) to be higher in males than in females. There were no significant differences between sexes on the FA composition. Nevertheless, the 18:2n-6 tended to differ between sexes (p = 0.063). Several long-chain PUFA (LC-PUFA) were detected in dormouse muscle, with the 20:4 n-6 (arachidonic acid, AA) and the 22:6 n-3 (docosahexaenoic acid, DHA) being the most abundant in both sexes. The relatively high stearoyl-CoA desaturase (SCD) indexes and the large concentration of 18:1cis-9 in dormouse muscle tissues might point to a low mobilization of the SCD products. Furthermore, finding the unusual FA 20:3 ∆5,∆11,∆14, suggests feeding on leaf and wood lipids of Coniferophytes. We demonstrated sexual size monomorphism in edible dormouse. The literature regarding the composition of dormouse meat is scarce and no studies reported the FA composition of muscle, thus, this work can contribute to increasing the knowledge on edible dormouse physiology and nutritional traits.
Free-ranging brown bears (Ursus arctos) were snared and subsequently darted with a combination of xylazine-ketamine in Croatia (n = 5) or darted from a helicopter with a combination of ...medetomidine-tiletamine-zolazepam in Scandinavia (n = 20). Three adults and one yearling (1 year old) bear were captured in Croatia, with one adult being captured twice. The Scandinavian bears were divided into Group A (yearlings, n = 7) and Group B (subadults, n = 2 and adults, n = 11). The exertion time (time from activation of the trap or from the start of the helicopter chase to recumbency) and the induction time (time from darting to recumbency) were recorded. The rectal temperature (Tr) was measured as soon as possible after induction and then monitored at frequent intervals (varied between individuals) in immobilized bears. Blood pressure (BP) was measured with a non-invasive method (Korotkoff's technique) every 5 minutes. The heart rate (HR), respiratory rate (RR), and arterial haemoglobin oxygen saturation (SpO2) were recorded every 5 minutes. Reliability of the BP monitoring technique, trends of variation of the physiological variables, and the factors related to the capture were assessed. Both exertion and induction times were longer in Croatian bears than in Scandinavian bears. In Croatian bears, the Tr was either constant or slightly decreasing, with hyperthermia recorded in two individuals (Tr > 39.0° C). In Scandinavian bears, 17 of 20 individuals developed an initial hyperthermia. Four of five bears in Croatia and 17 of 20 bears in Scandinavia showed a decreasing trend in systolic and mean BP over time. According to the Korotkoff method, all bears were hypertensive (mean BP > 130 mmHg) with varying severity, and the systolic pressure was significantly lower in yearlings when compared to subadults and adults. Yearlings had significantly (p < 0.05) higher HR than subadults and adults, however there was no significant differences in RR, SpO2, and Tr between the age groups. All Croatian bears and 13 of 20 Scandinavian bears were moderately to severely hypoxemic (SpO2 < 90%). Further studies with simultaneous invasive and non-invasive (Korotkoff) BP monitoring techniques are required to confirm the accuracy of methods used in this study. The data presented here provides evidence of the physiological impact of different capture methods and chemical immobilization of brown bears in Croatia and Scandinavia.
In this study the hematological and biochemical parameters in the blood of indigenous Croatian working horse breeds were investigated. The Posavina and Croatian Coldblood horses are adapted to harsh ...environmental conditions and their blood parameters might differ from other horse breeds. The study was carried out on 100 mares and 12 stallions of ages from 2 to 19 years. Fifteen hematological and 19 biochemical parameters were analysed. Values of 22 parameters showed considerable overlapping with values obtained for other horse breeds, and substantial resemblance is evident with values reported for Pakistani working horses. Several reference values showed statistically significant effect of sex (Hb, ALB, CREA, TBIL and Ca where significantly higher in stallions; EOS, CK, ALP, UREA and Mg were significantly higher in mares). None of the parameters studied showed any differences associated with age. The adaptation of Posavina and Croatian Coldblood horses to the harsh environment of flooded pastures and the way of breeding might be reflected in their specific reference values. The obtained results enabled the establishment of hematological and biochemical reference values in the blood of Posavina and Croatian Coldblood horses that will in turn support clinical diagnosis and further research into horse physiology.
U studiji je obavljeno ispitivanje hematoloških i biohemijskih parametara krvi kod radnih hrvatskih autohtonih rasa konja. Posavski i hrvatski hladnokrvnjak su dve rase konja koje su adaptirane na oštre uslove spoljašnje sredine pa se pretpostavlja da njihovi parametri krvi mogu da budu različiti u poređenju sa drugim rasama. Ispitivanje je obavljeno na 100 kobila i 12 pastuva starosti od 2 do 19 godina. Obavljena je analiza u odnosu na pedeset hematoloških i 19 biohemijskih parametara. Vrednosti koje su dobijene u odnosu na 22 parametra pokazale su značajna preklapanja u poređenju sa drugim rasama konja, pri čemu je ustanovljena značajna podudarnost sa vrednostima koje su karakteristične za pakistanskog radnog konja. Nekoliko referentnih vrednosti je pokazalo statistički značajnan utacaj pola (Hb, ALB, CREA, TBIL i Ca vrednosti su bile značajno veće kod pastuva; EOS, CK, ALP, UREA i Mg vrednosti su bile značajno veće kod kobila). Nijedan parametar koji je ispitivan nije pokazao bilo kakvu varijaciju u odnosu na starost životinja. Prilagođenost posavskog i hrvatskog hladnokrvnog konja na oštre i teške uslove spoljašnje sredine koji podrazumevaju ispašu na poplavljenim pašnjacima, kao i način uzgoja, može da ima posledice na specifične referentne vrednosti ispitivanih parametara. Dobijeni podaci omogućavaju definisanje hematoloških i biohemijskih referentnih vrednosti krvi posavske i hrvatske rase hladnokrvnih konja, a te vrednosti bi omogućavale kliničku dijagnostiku i buduća ispitivanja fiziologije konja.
U studiji je obavljeno ispitivanje hematoloških i biohemijskih parametara krvi kod radnih hrvatskih autohtonih rasa konja. Posavski i hrvatski hladnokrvnjak su dve rase konja koje su adaptirane na ...oštre uslove spoljašnje sredine pa se pretpostavlja da njihovi parametri krvi mogu da budu različiti u poređenju sa drugim rasama. Ispitivanje je obavljeno na 100 kobila i 12 pastuva starosti od 2 do 19 godina. Obavljena je analiza u odnosu na pedeset hematoloških i 19 biohemijskih parametara. Vrednosti koje su dobijene u odnosu na 22 parametra pokazale su značajna preklapanja u poređenju sa drugim rasama konja, pri čemu je ustanovljena značajna podudarnost sa vrednostima koje su karakteristične za pakistanskog radnog konja. Nekoliko referentnih vrednosti je pokazalo statistički značajnan utacaj pola (Hb, ALB, CREA, TBIL i Ca vrednosti su bile značajno veće kod pastuva; EOS, CK, ALP, UREA i Mg vrednosti su bile značajno veće kod kobila). Nijedan parametar koji je ispitivan nije pokazao bilo kakvu varijaciju u odnosu na starost životinja. Prilagođenost posavskog i hrvatskog hladnokrvnog konja na oštre i teške uslove spoljašnje sredine koji podrazumevaju ispašu na poplavljenim pašnjacima, kao i način uzgoja, može da ima posledice na specifične referentne vrednosti ispitivanih parametara. Dobijeni podaci omogućavaju definisanje hematoloških i biohemijskih referentnih vrednosti krvi posavske i hrvatske rase hladnokrvnih konja, a te vrednosti bi omogućavale kliničku dijagnostiku i buduća ispitivanja fiziologije konja.
Rast i razvoj mliječne žlijezde počinje u prenatalnom razdoblju. Izrazito brz razvoj mliječne žlijezde možemo uočiti u pubertetu i gravidnosti. Endokrini sustav koordinira razvoj mliječne žlijezde s ...reproduktivnim sustavom i potrebom potomaka za mlijekom. Razvoj mliječne žlijezde do početka stvaranja mlijeka naziva se mamogeneza. Za mamogenezu iznimno su važni hormon rasta, čimbenik rasta 1 sličan inzulinu, glukokortikoidi, hormoni štitne žlijezde i spolni hormoni. Tijekom gravidnosti za rast i razvoj mliječne žlijezde potrebni su progesteron, estrogen, prolaktin, hormon rasta, placentalni laktogen, inzulin i kortikosteroidi. Početak proizvodnje mlijeka naziva se laktogenezom. Prvi sekret koji alveolarne stanice mliječne žlijezde proizvedu naziva se kolostrumom. Održavanje proizvodnje mlijeka naziva se galaktopoezom, pri čemu su broj sekretornih epitelnih stanica i proizvodnja mlijeka u korelaciji. Laktogenezu primarno kontrolira prolaktin, a otpuštanje mlijeka oksitocin. Prolaktin ima brojne funkcije i luči se iz prednjeg režnja hipofize. Ključan je za ekspresiju gena za sintezu bjelančevina mlijeka. Oksitocin je bitan za kontrakciju mioepitelnih stanica na površini alveola i duž kanalića mliječne žlijezde. Ostali hormoni koji su bitni za laktaciju jesu kortizol, progesteron, hormon rasta i estrogeni. Glavni dio organskih sastojaka mlijeka sintetizira se samo u epitelnim stanicama mliječne žlijezde. Četiri su glavne komponente u mlijeku: bjelančevine, masti, laktoza i minerali. Ako se vime ne prazni do kraja, proizvodnja mlijeka smanjuje se jer alveole i sekretorno tkivo involuiraju.
Selen je specifičan esencijalni element jer je jedan od rijetkih koji ima vrlo uzak raspon između fiziološke i toksične koncentracije u organizmu. Fiziološke koncentracije kreću se od 0,1 do 0,3 ...mg/kg suhe tvari za većinu životinja, a subletalne doze iznose od 0,4 do 3 mg/kg. U prirodi se selen pojavljuje u organskom i anorganskom obliku. Selen je u organizmu životinja sastavni dio selenoproteina od kojih su najzastupljeniji glutation-peroksidaze i tioredoksin-reduktaze koji održavaju redoks-homeostazu
i reguliraju staničnu signalizaciju te jodotironin-deiodinaze koja regulira aktivnosti hormona štitaste žlijezde. Kod manjka selena u organizmu životinja najčešće se pojavljuje smanjen prirast, manja proizvodnja mlijeka i vune, smanjena plodnost i veličina legla, smanjena kvaliteta sjemena rasplodnih životinja uz visoku smrtnost potomaka. Otrovanja selenom nastaju ingestijom bilja koje kumulira selen iz tla bogatog njime, zbog pogrešaka uzrokovanih nepažnjom veterinara ili stočara prilikom dodavanja selena u hranu za životinje kao i hranom i vodom koja potječe iz kontaminiranog područja. Ovisno o tome u kojem će opsegu životinja biti
izložena bilo kojem od navedenih izvora otrovanja, može se razviti akutno, subakutno ili kronično otrovanje selenom. Specifičnog liječenja otrovanja selenom nema, nužno je provoditi edukaciju o mogućim štetnim učincima selena radi smanjenja rizika za životinje.
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