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1.
Oecologia ; 179(3): 711-8, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26188521

RESUMEN

Male harassment toward females during the breeding season may have a negative effect on their reproductive success by disturbing their foraging activity, thereby inducing somatic costs. Accordingly, it is predicted that females will choose mates based on their ability to provide protection or will aggregate into large groups to dilute per capita harassment level. Conversely, increasing group size may also lead to a decrease in foraging activity by increasing foraging competition, but this effect has rarely been considered in mating tactic studies. This study examined the importance of two non-exclusive hypotheses in explaining the variations of the female activity budget during the breeding season: the male harassment hypothesis, and the female foraging competition hypothesis. We used focal observations of female activity from known mating groups collected during the breeding season from a long-term (15 years) study on reindeer Rangifer tarandus. We found that females were more disturbed (i.e., spent less time feeding) in the presence of young dominant males, and marginally disturbed in the presence of satellite males, which supports the male harassment hypothesis. We also found that female disturbance level increased with group size, being independent of the adult sex ratio. Consequently, these results rejected the dilution effect, but strongly supported the foraging competition hypothesis. This study therefore highlights a potential conflict in female behaviour. Indeed, any gains from harassment protection were negated by an increase of 6-7 females, since adult males lead larger groups than young males.


Asunto(s)
Conducta Alimentaria , Reno , Reproducción , Estaciones del Año , Conducta Social , Animales , Cruzamiento , Conducta Competitiva , Femenino , Masculino , Razón de Masculinidad
2.
PLoS One ; 18(12): e0295497, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38096314

RESUMEN

Allonursing is the nursing of the offspring of other mothers. Cooperation is an emergent property of evolved decision rules. Cooperation can be explained by at least three evolved decision rules: 1) direct reciprocity, i.e. help someone who previously helped you, 2) kin discrimination, i.e. preferentially direct help to kin than to non-kin, and 3) generalized reciprocity, i.e. help anyone if helped by someone. We assessed if semi-domesticated reindeer, Rangifer tarandus, mothers allonursed according to the decision rules of direct reciprocity, generalized reciprocity and kin discrimination over 2 years. To assess if reindeer mothers allonursed according to the direct reciprocity decision rule, we predicted that mothers should give more help to those who previously helped them more often. To assess if reindeer mothers allonursed according to the kin discrimination decision rule, we predicted that help given should increase as pairwise genetic relatedness increased. To assess if reindeer mothers allonursed according to the generalized reciprocity decision rule, we predicted that the overall number of help given by reindeer mothers should increase as the overall number of help received by reindeer mothers increased. The number of help given i) increased as the number of help received from the same partner increased in the 2012 group but not in both 2013 groups, ii) was not influenced by relatedness, and iii) was not influenced by an interaction between the number of help received from the same partner and relatedness. iv) The overall number of help given increased as the overall number of help received increased. The results did not support the prediction that reindeer mothers allonursed according to the kin discrimination decision rule. The results suggest that reindeer mothers may allonurse according to the direct reciprocity and generalized reciprocity decision rules.


Asunto(s)
Reno , Conducta Social , Femenino , Animales , Humanos , Conducta Cooperativa , Madres
3.
Oecologia ; 162(1): 261-71, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19730892

RESUMEN

Two different processes can lead to a change in individual reproductive output with age in long-lived iteroparous vertebrates. The senescence hypothesis predicts a decline of performance in old age, whereas the terminal allocation hypothesis predicts an increase. Using long-term (>30 years) individually based data of female reindeer, we first assessed age-specific variation in body mass and different components of reproductive output. Then we investigated the contribution of senescence and terminal allocation (the increase in components of reproductive output) processes for shaping observed patterns. We found that female reindeer body mass increased up to about 11.5 years of age, and decreased afterwards, supporting the senescence hypothesis. Calf birth mass, both in absolute terms or for a given female mass, first increased and then declined with female age, also supporting the senescence hypothesis. The female mass gain (June-September) decreased with increasing age, and female change in mass between 2 consecutive years decreased with female age, all patterns again supporting the senescence hypothesis. However, the autumn calf mass did not change with age. Calf body mass in autumn tended to be positively related to female mass gain, supporting a quality effect. Raising a calf had a marked negative effect on female mass gain, indicating energetic reproductive costs of raising a calf. Calf body mass in autumn did not influence yearly female mass change. Overall, our results provided consistent evidence for general effects of senescence on most components of reproductive output and highlighted that both individual heterogeneity and reproductive costs shape female reindeer reproductive tactics.


Asunto(s)
Reno/fisiología , Conducta Sexual Animal , Factores de Edad , Envejecimiento , Animales , Tamaño Corporal , Femenino , Reproducción
4.
J Anim Ecol ; 78(5): 1002-6, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19426256

RESUMEN

1. There is considerable interest in patterns of age-dependent reproductive effort and reproductive timing of large iteroparous mammals living in strongly seasonal environments. Due to lack of data on both timing of mating and birth, there is generally little insight into whether variation in gestation length play a role for life-history patterns observed for large mammals at northern latitudes. 2. Based on data on both timing of mating and birth of 88 female reindeer (and paternity confirmed with DNA fingerprinting), we explore the view that adjustment of gestation length plays a role in the reproductive tactic. 3. Observed gestation lengths of reindeer varied between 211 and 229 days (mean of 221 days). Consistent with a dynamic view of gestation length, variation could be predicted from life-history traits. Gestation length was longer for male than female offspring, which is expected in polygynous species where males benefit more from extra allocation of maternal resources. Gestation length increased with maternal age both due to direct effects and indirect effects linked to earlier mating of older, heavier females. Early mating females increased gestation length. A relatively small effect of female age on birth mass operated through variation in gestation length. 4. Our analysis supports the view that adjustment of gestation length is a part of the reproductive tactic of large mammals in northern environments.


Asunto(s)
Embarazo/fisiología , Reno/fisiología , Factores de Edad , Animales , Peso al Nacer , Femenino , Finlandia , Masculino , Edad Materna , Factores Sexuales , Factores de Tiempo
5.
Proc Biol Sci ; 275(1645): 1849-55, 2008 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-18460427

RESUMEN

Although there is little doubt that the domestication of mammals was instrumental for the modernization of human societies, even basic features of the path towards domestication remain largely unresolved for many species. Reindeer are considered to be in the early phase of domestication with wild and domestic herds still coexisting widely across Eurasia. This provides a unique model system for understanding how the early domestication process may have taken place. We analysed mitochondrial sequences and nuclear microsatellites in domestic and wild herds throughout Eurasia to address the origin of reindeer herding and domestication history. Our data demonstrate independent origins of domestic reindeer in Russia and Fennoscandia. This implies that the Saami people of Fennoscandia domesticated their own reindeer independently of the indigenous cultures in western Russia. We also found that augmentation of local reindeer herds by crossing with wild animals has been common. However, some wild reindeer populations have not contributed to the domestic gene pool, suggesting variation in domestication potential among populations. These differences may explain why geographically isolated indigenous groups have been able to make the technological shift from mobile hunting to large-scale reindeer pastoralism independently.


Asunto(s)
Animales Domésticos/genética , ADN Mitocondrial , Variación Genética , Reno/genética , Animales , Europa (Continente) , Repeticiones de Microsatélite , Federación de Rusia
6.
Comp Biochem Physiol B Biochem Mol Biol ; 149(4): 613-21, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18282730

RESUMEN

We examined the effects of prolonged undernutrition on plasma leptin and insulin levels and some serum protein metabolites in reindeer (Rangifer tarandus tarandus L.) during winter and spring. The reindeer (male <1 year) were fed their preferred winter feed, low-protein lichen ad libitum for 5 weeks, followed by 40% restriction of energy for 8 weeks and refeeding with high-protein pellets for 6 weeks. The control group received high-protein reindeer pellets ad libitum throughout the experiment. Plasma leptin decreased by 46% and insulin by 54% in the lichen group already during the ad libitum period between January and February, with parallel decreases in body weight, serum total proteins, albumin and urea. Leptin remained low during most of the energy restriction period in March and April, but increased at the end of April while body weight decreased. During the refeeding period in May and June, the body weight and insulin of the lichen group increased in parallel with total proteins and urea, but leptin remained unchanged. Similar significant reductions in plasma leptin (40%) as in the lichen group also took place in the control group fed high-protein pellets ad libitum in January and February, although their feed intake, serum total proteins and body weight remained unchanged. The results show that leptin decreases in reindeer during mid-winter, independent of food or protein intake, and suggest that the decrease may be cued by seasonal factors such as the short photoperiod.


Asunto(s)
Insulina/sangre , Leptina/sangre , Desnutrición/sangre , Reno/sangre , Estaciones del Año , Animales , Regiones Árticas , Glucemia/análisis , Peso Corporal , Creatinina/sangre , Fotoperiodo , Reno/metabolismo , Albúmina Sérica/análisis , Factores de Tiempo , Urea/sangre
7.
Proc Biol Sci ; 274(1610): 727-33, 2007 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-17254998

RESUMEN

Evolutionary models of sex ratio adjustment applied to mammals have ignored that females may gain indirect genetic benefits from their mates. The differential allocation hypothesis (DAH) predicts that females bias the sex ratio of their offspring towards (more costly) males when breeding with an attractive male. We manipulated the number of available males during rut in a polygynous ungulate species, the reindeer (Rangifer tarandus), and found that a doubling of average male mass (and thus male attractiveness) in the breeding herd increased the proportion of male offspring from approximately 40 to 60%. Paternity analysis revealed indeed that males of high phenotypic quality sired more males, consistent with the DAH. This insight has consequences for proper management of large mammal populations. Our study suggests that harvesting, by generating a high proportion of young, small and unattractive mates, affects the secondary sex ratio due to differential allocation effects in females. Sustainable management needs to consider not only the direct demographic changes due to harvest mortality and selection, but also the components related to behavioural ecology and opportunities for female choice.


Asunto(s)
Evolución Biológica , Conservación de los Recursos Naturales/métodos , Modelos Teóricos , Fenotipo , Reno/fisiología , Razón de Masculinidad , Conducta Sexual Animal/fisiología , Animales , Finlandia , Modelos Logísticos , Masculino , Factores Sexuales
8.
Behav Processes ; 140: 96-103, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28438692

RESUMEN

In polygynous species, sexual selection is mostly driven by male ability to monopolize access to females in oestrous. In ungulates, the operational sex ratio (OSR), i.e. the proportion of males to individuals ready to mate, varies throughout the peak rut, resulting from the temporal variation in the number of females in oestrous. But the way males adjust their mating tactics to maximise their access to females in oestrous (i.e. as OSR varies) is yet to be investigated. Using 15 years of behavioural observations in reindeer (Rangifer tarandus), we compared the relative importance of time within the rutting season (days to the peak-rut) and the OSR to explain the variation in the propensity (i.e. the frequency after controlling for the potential number of encounters) of young and adult dominant males to engage in four mating tactics: herding females, chasing other males, investigating female reproductive status, and courting females. Male-male agonistic behaviour was the most frequent mating behaviour, followed by herding. As predicted, dominant male mating tactics changed over the rutting season: first herding, then chasing other males, and finally investigating and courting females. In contrast to our prediction, we did not find support for the OSR theory. We noted some discrepancies in how young and adult dominant males adjusted their tactics during the mating season, adults being more efficient in timing and in performing their behaviour to maximise access to females in oestrous. The reported sequence of mating tactics may be more efficient than a static mating tactic to monopolize females in oestrous, regardless of the population composition.


Asunto(s)
Reno/fisiología , Estaciones del Año , Razón de Masculinidad , Conducta Sexual Animal/fisiología , Conducta Agonística , Animales , Copulación , Ciclo Estral/fisiología , Femenino , Masculino , Modelos Psicológicos , Reproducción , Predominio Social
9.
Artículo en Inglés | MEDLINE | ID: mdl-28916001

RESUMEN

This longitudinal observational study was conducted to investigate the spontaneous effect of Giardia and Cryptosporidium infections on acute phase response (APR) in reindeer calves (Rangifer tarandus tarandus) in Finnish Lapland. Serum (n=609) and faecal samples (n=366) were collected from 54 reindeer calves aged zero to 33days. The samples were analysed for Giardia, Cryptosporidium, acute phase proteins (APP) and γ-globulins. Linear regression models were used to investigate associations of early Giardia infection (before 12days of life) with the response of APPs and acquiring of passive immunity. Giardia was detected in 100% and Cryptosporidium in 23% of calves. There was a negative association between early Giardia infection and γ-globulin concentrations (p=0.032) and a positive association with serum amyloid A (SAA) concentrations (p=0.042). The results suggest a protective effect of colostrum against Giardia infection and that early infection may induce activation of APR.


Asunto(s)
Reacción de Fase Aguda/veterinaria , Criptosporidiosis/inmunología , Giardiasis/veterinaria , Reno/parasitología , Reacción de Fase Aguda/inmunología , Amiloide/sangre , Animales , Animales Recién Nacidos , Anticuerpos Antiprotozoarios/sangre , Calostro/inmunología , Heces/parasitología , Giardiasis/inmunología , Giardiasis/parasitología , Haptoglobinas/análisis , Inmunidad Innata , Estudios Longitudinales
10.
Proc Biol Sci ; 273(1584): 293-9, 2006 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-16543171

RESUMEN

Large mammals in seasonal environments have a pattern of high-reproductive synchrony in spring, but how the timing of reproduction affects resource allocation decisions at different stages of the reproductive cycle remains largely unexplored. By manipulating the timing of conception in reindeer (Rangifer tarandus), we tested how the timing of conception affected sex ratio, gestation length and weight development of mother and offspring. Females that conceived at their first ovulation within the rut had a 60.5% probability of producing a male; in contrast, females that conceived a cycle later had a 31.3% probability of producing a male. Late conceiving females had gestation times that were 10 days shorter and the calves were 0.6 kg (9.2%) lighter at birth and 7.4 kg (14.7%) lighter in autumn. Over the year, female weight changes was similar between the groups suggesting reindeer follow a bet-hedging strategy; reducing the quality of this year's offspring to ensure their own future reproduction and survival. Harvesting is often selective leading to skewed sex ratios and age structure, which may influence the timing of reproduction due to females hesitation to mate with young males. Whenever this hesitation is strong enough to increase the frequency of recycling, harvesting is likely to have profound life history consequences.


Asunto(s)
Reno/fisiología , Reproducción/fisiología , Animales , Animales Recién Nacidos , Peso al Nacer , Peso Corporal , Femenino , Fertilización/fisiología , Masculino , Embarazo , Razón de Masculinidad
11.
Proc Biol Sci ; 273(1591): 1239-44, 2006 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-16720397

RESUMEN

Longevity is the main factor influencing individual fitness of long-lived, iteroparous species. Theories of life history evolution suggest this is because increased longevity allows individuals to (i) have more breeding attempts (time component), (ii) accumulate experience so as to become better able to rear offspring (experience component) or (iii) because individuals reaching old age have above-average quality (quality component). We assess empirically the relative influences of time, experience and quality on the relationship between longevity and individual fitness among female reindeer. Fitness increased with longevity due to all three processes. All females increased in success with age up to their penultimate year of life (experience component), the success of the terminal-breeding occasion was strongly dependent on longevity. Long-lived females had more successful breeding attempts during their life (time component), and had higher reproductive success at all ages, especially during the last year of life (individual quality component) than short-lived females. Our study reveals a more complex relationship between longevity and fitness in large mammals than the simple increase of the number of reproductive attempts when living longer.


Asunto(s)
Longevidad , Conducta Materna , Reno/fisiología , Factores de Edad , Animales , Femenino , Reno/crecimiento & desarrollo , Reproducción
12.
J Agric Food Chem ; 54(24): 9112-8, 2006 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-17117798

RESUMEN

In December 2001 and 2002, feces from reindeer calves treated with ivermectin were distributed on plots established on two types of forested reindeer pasture in northern Finland. The ungrazed plots were on an enclosure that had been fenced to prevent reindeer access for the last 6 years. The grazed plots were on an area that had been heavily stocked by reindeer during the last 5 years. After enclosures had been established, reindeer and large wildlife were prevented from entering by a fence. Topsoil samples (feces, vegetation, and soil) were collected monthly during the summers of the following 2 years, over a period of from 25 to 95 weeks after deposition. The samples were analyzed for ivermectin using HPLC. Although ivermectin degradation rapidly took place during the first spring, considerable residual ivermectin could be measured throughout the sampling time, showing that ivermectin in feces on pasture may not be photodegraded as rapidly as previously believed. The results support the need for further environmental evaluation studies on the use of ivermectin to control reindeer parasites.


Asunto(s)
Antiparasitarios/química , Heces/química , Ivermectina/química , Reno , Suelo/análisis , Animales , Cromatografía Líquida de Alta Presión , Residuos de Medicamentos/química , Ambiente , Finlandia
13.
Vet Parasitol ; 129(3-4): 323-32, 2005 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-15845288

RESUMEN

Serum samples from 25 reindeer (Rangifer tarandus tarandus) were assayed for antibody against hypodermin C (HyC) using an ELISA. Nineteen animals were calves (born in 1998, 1999 or 2001) and six were adults (3-10 years old at first blood collection). The samples were collected over periods of 4 months (calves born in 2001) or 27 months (adults and calves born in 1998 and 1999), the latter encompassing three Hypoderma tarandi infestation seasons. The calves received antibodies against HyC from their mothers, either by placental transfer or through the ingestion of colostrum. The low level at 3 h postpartum compared to the high level 3 days after birth in one calf suggests that the antibodies are transferred through colostrum. The levels of antibody of maternal origin decreased rapidly and reached low levels by mid-July, which coincides with the onset of the major Hypoderma ovipositioning season in this region. The calves thus did not appear to be protected by antibody against HyC when they were exposed to H. tarandi infestation for the first time. Antibody levels increased following infestation and reached a maximum during November or December, which coincides with when the H. tarandi larva stops migrating after it has reached the site under the skin of the back of the host and develops further. Levels declined thereafter and reached a nadir during the following summer. After the subsequent re-infestation, the increase in levels occurred at least 1 month earlier than with the first infestation. Levels remained elevated throughout the year after repeated infestations. This implies that the antibodies persist after the annual exit of mature larvae from the animal, and after larvae have been killed by application of ivermectin. Levels in adults, however, declined significantly with age, and levels were significantly lower in animals that were 4-11 years old than in 1-year-old animals during the same 1-year period. This supports the contention that the functional capacity of the immune system declines gradually with age. The study demonstrated that HyC is potentially useful for serological diagnosis of hypodermosis in reindeer, but the persistence of antibodies complicates interpretation of antibody-based surveillance programme data in all cases other than first-time exposure.


Asunto(s)
Anticuerpos/inmunología , Dípteros/inmunología , Miasis/veterinaria , Reno/inmunología , Reno/parasitología , Serina Endopeptidasas/inmunología , Animales , Animales Recién Nacidos , Anticuerpos/sangre , Ensayo de Inmunoadsorción Enzimática , Femenino , Masculino , Miasis/diagnóstico , Miasis/inmunología , Miasis/parasitología , Estaciones del Año , Estudios Seroepidemiológicos
14.
Acta Vet Scand ; 56: 76, 2014 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-25421461

RESUMEN

BACKGROUND: Overwintering (breeding) reindeer (Rangifer tarandus tarandus) are commonly treated with ivermectin against parasitic infestations once yearly in autumn-winter roundups. The only preparations registered to reindeer are those for subcutaneous injection. However, also oral extra-label ivermectin administration is used. Twenty-six, 8-month-old reindeer calves were randomly allocated into three groups. Group 1 (n = 9) received oral ivermectin mixture (Ivomec® vet mixt. 0.8 mg/ml, oral ovine liquid drench formulation), Group 2 (n = 9) oral ivermectin paste (Ivomec® vet 18.7 mg/g equine paste), and Group 3 (n = 8) subcutaneous injection of ivermectin (Ivomec® 10 mg/ml vet inj.), each group at a dose of 200 µg/kg body weight. Blood samples were collected at treatment and at days 1, 2, 3, 6, 9 and 16 post treatment. Plasma concentrations of ivermectin were determined by high-pressure liquid chromatography (HPLC) with fluorescence detection. RESULTS: The peak plasma concentration (Cmax) was reached by 2 days after each treatment. The Cmax and Area Under Curve (AUC) differed significantly between the groups: Cmax was 30.2 ± 3.9, 14.9 ± 5.7 and 63.1 ± 13.1 ng/ml, and AUC∞ was 2881 ± 462, 1299 ± 342 and 6718 ± 1620 ng*h/ml for groups 1, 2 and 3, respectively (mean ± standard deviation). CONCLUSIONS: The differences in plasma concentrations of ivermectin are concomitant with earlier observed differences in antiparasitic efficacy, which discounts the use of the equine paste in reindeer in favour of the oral ovine liquid drench formulation, or preferably, the reindeer-registered subcutaneous injection formulation.


Asunto(s)
Antihelmínticos/farmacocinética , Ivermectina/farmacocinética , Reno/metabolismo , Administración Oral , Animales , Antihelmínticos/sangre , Área Bajo la Curva , Disponibilidad Biológica , Cromatografía Líquida de Alta Presión/veterinaria , Femenino , Inyecciones Subcutáneas/veterinaria , Ivermectina/sangre , Masculino
15.
PLoS One ; 9(4): e95618, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24759701

RESUMEN

During the rut, female ungulates move among harems or territories, either to sample mates or to avoid harassment. Females may be herded by a male, may stay with a preferred male, or aggregate near a dominant male to avoid harassment from other males. In fission-fusion group dynamics, female movement is best described by the group's fission probability, instead of inter-harem movement. In this study, we tested whether male herding ability, female mate choice or harassment avoidance influence fission probability. We recorded group dynamics in a herd of reindeer Rangifer tarandus equipped with GPS collars with activity sensors. We found no evidence that the harassment level in the group affected fission probability, or that females sought high rank (i.e. highly competitive and hence successful) males. However, the behavior of high ranked males decreased fission probability. Male herding activity was synchronous with the decrease of fission probability observed during the rut. We concluded that male herding behavior stabilized groups, thereby increasing average group size and consequently the opportunity for sexual selection.


Asunto(s)
Reno/fisiología , Conducta Social , Animales , Femenino , Masculino , Conducta Sexual Animal/fisiología
16.
Behav Processes ; 107: 133-41, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25183610

RESUMEN

Allosuckling, the suckling of offspring from females other than their own mother, has been reported in a number of mammalian species, including reindeer. The causes and function of this behaviour are still being investigated. We monitored 25 doe-calf pairs of semi-domestic reindeer Rangifer tarandus over 10 weeks to test three allosuckling/allonursing hypotheses: (1) milk theft, calves opportunistically allosuckle; (2) mismothering, misdirected maternal care; and (3) kin-selected allonursing. A calf soliciting an allosuckling bout was categorized as non-filial (NF), and a calf soliciting a suckling bout from its mother was categorized as filial (F). We recorded 9757 solicitations, of which 5176 were successful F bouts and 1389 were successful NF bouts. The rejection rates were greater for NF than F calves. The proportions of antiparallel positions adopted were greater for F than NF calves. The odds of an allobout were lower for calves arriving 1st, 3rd, 4th, 5th or 6th than for those arriving 2nd, but the odds did not vary with position adopted and relatedness. Our results provided support to the milk-theft hypothesis, whereas limited support for the mismothering hypothesis was found. Our results did not support the hypothesized kin selection function of allosuckling in reindeer. This article is part of a Special Issue entitled: insert SI title.


Asunto(s)
Animales Lactantes/psicología , Conducta Alimentaria/psicología , Conducta Materna/psicología , Reno/psicología , Conducta en la Lactancia/fisiología , Animales , Femenino
17.
Environ Int ; 37(2): 335-41, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21040976

RESUMEN

To explore the concentrations and dynamics of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in Finnish semi-domesticated reindeer (Rangifer tarandus tarandus L.) the reindeer milk and tissue samples were collected from the sub-arctic northern Finland. Reindeer milk's PCB sum (1.20 ng g(-1) wet weight) and PCDD/F sum (0.70 pg g(-1) ww) in autumn were higher than in summer (PCBs 0.50 ng g(-1) ww and PCDD/Fs 0.20 pg g(-1) ww). The mean fat content in autumn milk (26%) was significantly higher than in summer (10%). Concentrations in reindeer milk were generally far below 50% of that in adult reindeer body burden. However, the bioaccumulation factors were multiple in milk/reindeer calf ratio and that aroused the question of other important exposure routes than lactation. The muscle and liver of reindeer calves had higher PCDD/F and PCB concentrations than adult animals that possibly indicate the significance of transfer of these compounds from dam to calf through lactation and placenta. However, PBDE concentrations were higher in adult reindeer, especially in liver. In addition, reindeer liver seems to have a special feature to collect highly toxic PCDD/Fs, although the PCB sum concentrations (range from 0.33 to 1.69 ng g(-1) wet weight) were clearly higher than the sums of PCDD/Fs (range from 3.78 to 39.2 pg g(-1) ww). Stillborn reindeer calves represented individuals who had got their PCDD/F, PCB and PBDE load only via the placenta. Concentrations in muscle and brown adipose tissue samples did not indicate dependency on fat content. Obviously effective placental transfer of PCBs and PBDEs from reindeer dam to foetus was seen in this study.


Asunto(s)
Benzofuranos/metabolismo , Contaminantes Ambientales/metabolismo , Éteres Difenilos Halogenados/metabolismo , Bifenilos Policlorados/metabolismo , Dibenzodioxinas Policloradas/análogos & derivados , Reno/metabolismo , Tejido Adiposo Pardo/metabolismo , Animales , Dibenzofuranos Policlorados , Monitoreo del Ambiente , Monitoreo Epidemiológico , Femenino , Finlandia , Hígado/metabolismo , Ganado/metabolismo , Masculino , Intercambio Materno-Fetal , Leche/metabolismo , Músculos/metabolismo , Dibenzodioxinas Policloradas/metabolismo , Embarazo , Mortinato/epidemiología , Mortinato/veterinaria
18.
Acta Vet Scand ; 50: 49, 2008 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-19087262

RESUMEN

BACKGROUND: When a severe peritonitis outbreak in semi-domesticated reindeer was noticed in 2003 in Finland, the concerned industry urged immediate preventive actions in order to avoid detrimental effects of S. tundra and further economical losses. A research programme was swiftly initiated to study S. tundra and its impact on the health and wellbeing of reindeer. METHODS: The ultimate aim of this study was to test the efficacy of different treatment regimes against S. tundra and associated peritonitis in reindeer. The timing of the trials was planned to be compatible with the annual rhythm of the reindeer management; (1) the treatment of calves in midsummer, during routine calf ear marking, with ivermectin injection prophylaxis and deltamethrin pour-on solution as a repellent against insect vectors, (2) the treatment of infected calves in early autumn with ivermectin injection, and (3) ivermectin treatment of breeding reindeer in winter. The results were assessed using the post mortem inspection data and S. tundra detection. Finally, to evaluate on the population level the influence of the annual (late autumn-winter) ivermectin treatment of breeding reindeer on the transmission dynamics of S. tundra, a questionnaire survey was conducted. RESULTS: In autumn, ivermectin treatment was efficient against peritonitis and in midsummer had a slight negative impact on the degree of peritonitis and positive on the fat layer, but deltamethrin had none. Ivermectin was efficient against adult S. tundra and its smf. All the reindeer herding cooperatives answered the questionnaire and it appeared that antiparasitic treatment of reindeer population was intense during the study period, when 64-90% of the animals were treated. In the southern part of the Finnish reindeer husbandry area, oral administration of ivermectin was commonly used. CONCLUSION: Autumn, and to a lesser degree summer, treatment of reindeer calves with injectable ivermectin resulted in decreased severity of peritonitis and perihepatitis in reindeer calves due to setariosis. In the case of necessity for animal welfare reasons, treatment during early autumn round ups should be considered. On the population level, massive and routinely applied antiparasitic treatments can improve the health of breeding reindeer and decrease the mortality and the number of carriers but during the outbreak could not prevent its movement and expansion to the North.


Asunto(s)
Antiparasitarios/uso terapéutico , Ivermectina/uso terapéutico , Nitrilos/uso terapéutico , Peritonitis/veterinaria , Piretrinas/uso terapéutico , Reno , Setariasis/tratamiento farmacológico , Animales , Antiparasitarios/administración & dosificación , Esquema de Medicación , Quimioterapia Combinada , Femenino , Ivermectina/administración & dosificación , Masculino , Nitrilos/administración & dosificación , Peritonitis/parasitología , Peritonitis/prevención & control , Piretrinas/administración & dosificación , Estaciones del Año , Setaria (Nematodo)
19.
Oecologia ; 156(1): 237-47, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18246374

RESUMEN

Reproductive allocation at one age is predicted to reduce the probability of surviving to the next year or to lead to a decrease in future reproduction. This prediction assumes that reproduction involves fitness costs. However, few empirical studies have assessed whether such costs may vary with the age at primiparity or might be overridden by heterogeneities in individual quality. We used data from 35 years' monitoring of individually marked semi-domestic reindeer females to investigate fitness costs of reproduction. Using multi-state statistical models, we compared age-specific survival and reproduction among four reproductive states (never reproduced, experienced non-breeders, reproduced but did not wean offspring, and reproduced and weaned offspring) and among contrasted age at primiparity. We assessed whether reproductive costs occurred, resulting in a trade-off between current reproduction and future reproduction or survival, and whether early maturation was costly or rather reflected differences in individual quality of survival and reproduction capabilities. We did not find any evidence for fitness costs of reproduction in female reindeer. We found no cost of gestation and lactation in terms of future reproduction and survival. Conversely, successful breeders had higher survival and subsequent reproductive success than experienced non-breeders and unsuccessful breeders, independently of the age at primiparity. Moreover, it was beneficial to mature earlier, especially for females that successfully weaned their first offspring. Successful females at early primiparity remained successful throughout their life, clearly supporting the existence of marked among-female differences in quality. The weaning success peaked for multiparous females and was lower for first-time breeders, indicating a positive effect of experience on reproductive performance. Our findings emphasize an overwhelming importance of individual quality and experience to account for observed variation in survival and reproductive patterns of female reindeer that override trade-offs between current reproduction and future performance, at least in the absence of harsh winters.


Asunto(s)
Reno/fisiología , Reproducción , Animales , Femenino , Finlandia
20.
Biol Lett ; 3(1): 36-9, 2007 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-17443960

RESUMEN

In polygynous species, mate choice is an integrated part of sexual selection. However, whether mate choice occurs independently of the genetic relatedness among mating pairs has received little attention, although inbreeding may have fitness consequences. We studied whether genetic relatedness influenced females' choice of partner in a highly polygynous ungulate--the reindeer (Rangifer tarandus)--in an experimental herd during two consecutive rutting seasons; the herd consisting of 75 females in 1999 and 74 females in 2000 was exposed to three 4.5-year-old adults and three 1.5-year-old young males, respectively. The females' distribution during peak rut was not influenced by their genetic relatedness with the dominant males of the mating groups. Further, genetic relatedness did not influence the actual choice of mating partner. We conclude that inbreeding avoidance through mating group choice as well as choice of mating partner, two interconnected processes of female mate choice operating at two different scales in space and time, in such a highly female-biased reindeer populations with low level of inbreeding may not occur.


Asunto(s)
Endogamia , Preferencia en el Apareamiento Animal , Reno/genética , Factores de Edad , Animales , Femenino , Masculino , Razón de Masculinidad
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