Birgitta Åhman

Radiocesium in Swedish reindeer after the Chernobyl fallout: seasonal variations and long-term decline.

Data about 137Cs activity concentrations in reindeer muscle were collected from different parts of Sweden during 1986-1992. The data were used to evaluate seasonal and geographical variations and long-term decline of 137Cs in reindeer. The seasonal variation is shown in an example from one of the most contaminated areas, the Saami community Vilhelmina Norra, where 137Cs activity concentrations in reindeer during winter exceed those found during summer by about 20 times. Activity concentrations of 137Cs in reindeer were fairly well correlated to ground deposition. The ratio between 137Cs in reindeer (kBq kg-1 wet weight) and ground deposition (kBq m-2) was calculated to be 0.76 m2 kg-1 for the winter period, January-April, in 1987. Activity concentrations of 137Cs in reindeer decreased significantly during the years 1986-1992. The decline was generally more rapid during September, November, and December [corresponding to an effective ecological half-life (TEff) of 3.2 y] than during January-April when TEff was calculated to 4.2 y. There was a general trend toward a slower decrease during the last of the observed years.

Sensory meat quality, ultimate pH values, blood metabolites and carcass parametersin reindeer (Rangifer tarandus tarandus L.) fed various diets

This investigation was made to study and compare the effects of different diets on sensory meat quality and ultimate pH values in reindeer muscles and to relate stress-induced blood metabolites and carcass parameters to the meat quality traits measured. Altogether 23 female reindeer calves were included in the study. During an adaptation period, all reindeer were allowed free access to a mimicked natural diet containing 80% lichens (lichen diet). On January 28, 8 reindeer (group Cjan) were slaughtered. Five reindeer (group C.Mar) were allowed continuous free access to the lichen diet throughout the experiment. During 8 days, the other reindeer (groups PL and PS) were given the lichen diet, half of the amount offered to the control group, and were then starved for one day. Thereafter, these reindeer were fed 80% commercial reindeer feed (pellets) and either 20% lichens (group PL), or 20% silage (group PS) for 5 weeks. After this, all animals were slaughtered. The average carcass weight and dressing percentage in the group fed commercial reindeer feed and lichens (PL) were higher than in group CMar- Fat registrations were generally higher in groups PL and PS than in the groups Cj2n and CMar- Ultimate pH values in M. triceps brachii and M. longissimus were significantly lower in the group CMST than in PL. The levels of all blood metabolites (urea, ASAT and Cortisol) were generally higher in groups PL and PS than in groups Cja„ and CMEF- NO significant differences were found in any of sensory attributes of the meat (monitored according to ISO standards). The present study shows that muscle and fat depots in reindeer can be improved by feeding a diet based on reindeer pellets but suggests that a feeding period of 35 days might be too short to affect the sensory properties of reindeer meat.

Effect of bentonite and ammonium-ferric(III)-hexacyanoferrate(II) on uptake and elimination of radiocaesium in reindeer

Eight male reindeer calves were used in two experiments to evaluate the effect of commonly used doses of two caesium binders, bentonite (25 g day−1) and ammonium-ferric(III)-hexacyanoferrate(II) (AFCF, 0.5 g day−1), on (A) the absorption of ingested radiocaesium, and (B) the rate of reduction of already absorbed radiocaesium. The animals were fed commercial reindeer feed and also, during Experiment A, lichens contaminated with radiocaesium. Radiocaesium levels in the animals were determined weekly. The excretion of 137Cs in faeces and urine was measured during 3-day or 4-day periods on altogether seven occasions. The absorption factor of 137Cs from lichens was reduced from 0.61, when no caesium binder was given, to 0.21 when the reindeer were given bentonite. AFCF appeared to prevent absorption almost completely. The biological half-life of radiocaesium was about 3 weeks when the reindeer were not given caesium binder. The addition of bentonite or AFCF to the diet seemed to reduce this half-life by at least 4 days.

Health, body condition and blood metabolites in reindeer after submaintenance feed intake and subsequent feeding

The transition from experimentally induced poor nutritional conditions to feeding was studied with 69 eight-month-old female reindeer (Rangifer tarandus tarandus). During a pre-experimental period, all reindeer were fed a simulated winter diet with 80% lichens Cladina spp. and 20% Vaccinum myrtillus shrubs and Salix spp. leaves (lichen diet) ad lib. The reindeer were divided into five groups. A control group (group C) was fed the lichen diet ad lib. throughout the experiment. Four groups were fed half of that ration for eight days and were then totally deprived of feed for one day (restriction period). During the following 34 days (feeding period) the groups were re-fed the lichen diet (group L), fed pelleted reindeer feed combined with either lichen (group PL) or grass silage (group PS), or fed silage with a gradually increasing addition of pellets (group SP). Weekly measurements of blood samples and body weighr showed that the control group remained clinically healthy and had stable blood plasma concentrations of protein, urea, glucose and insulin throughout the experiment, but they lost weight. At slaughter, before and after the restriction period, all animals had lost rumen-free body weight, but the reindeer fed a restricted amount of feed lost more than the control group. Also the plasma metabolites were affected by the restricted feeding, with increased concentrations of urea and decreased concentrations of glucose. Group L responded immediately to the ad lib. feeding with blood metabolite levels rapidly approaching those of group C. The body weight developments were similar in groups L and C. Although the feed rations were increased gradually, diarrhoea occurred in some animals belonging to groups PL and PS within the first week of the feeding period. All reindeer recovered, after antibiotic treatment of the worst affected animals. The PL and PS groups, which had high contents of metabolisable energy and crude protein in their diets, showed increased con-centtations of plasma protein, urea and insulin. At the end of the feeding period, these groups had increased their body and carcass weights and gained fat, whereas reindeer fed the lichen diet had lost weight. Severe health problems (malnutrition and so-called wet belly) occurred in group SP during the first weeks of feeding and led to loss of animals, and consequently the SP group was excluded from the remainder of rhe experiment. The general conclusion is that the lichen diet did not cause any digestive problems, but resulted in a continuous decline in body weight and small or deficient fat reserves. After the initial diarrhoea, feeding with diets comprising pellets from the start resulted in improved condition, expressed as increased body weight, fat gain and higher concentrations of plasma protein, urea and insulin in relation to the control group. The diet initially based on grass in the form of silage of the given quality seemed insufficient as feed to reindeer calves in a poor nutritional state.

Activity and heart rate in semi-domesticated reindeer during adaptation to emergency feeding

Although reindeer are well adapted to limited food resources during winter, semi-domesticated reindeer are regularly fed when snow conditions are bad in order to prevent starvation. Feeding sometimes results in health problems and loss of animals. This study was made to assess if activity pattern in reindeer could be used as a tool for the reindeer herder in early detection of animals that are not adapting to feeding. The frequency of 10 behavioural categories was recorded in five groups of penned, eight-month-old, female semi-domesticated reindeer. Three reindeer per group were fitted with heart rate monitors. Lying was the most frequent behaviour, whilst there were few cases of agonistic behaviour. Heart rate varied during the day, with peaks during feeding and low heart rates in the early morning. Restricted feed intake resulted in more locomotion and seeking but less ruminating compared to feeding ad libitum. This was followed by a generally lower heart rate in reindeer in the restricted groups compared to controls. Subsequent feeding with different combinations of lichens, silage and pellets ad libitum resulted initially in significantly more of the animals lying curled up, compared to controls, combined with increased heart rates. As the experiment continued the general activity pattern, as well as the heart rate, gradually became more similar in all groups. Lying curled was the behavioural indicator most consistently affected by feed deprivation and adaptation to feeding and may thus be a useful indicator to distinguish individual reindeer that are not adjusting to feeding.

Zeolite and bentonite as caesium binders in reindeer feed

The effects of zeolite and bentonite on the accumulation and excretion of radiocaesium (Cs-137) in reindeer were studied in two feeding experiments. Six animals in each experiment were given lichens contaminated with radiocaesium from fallout after the Chernobyl nuclear power plant accident. In addition, they were fed pellets containing bentonite (Experiment I) or zeolite (Experiment II). Two animals, controls, in each experiment received no caesium-binder. The activity concentration of radiocaesium in blood was used to evalute the radiocaesium level in the body. Faeces and urine were collected to measue the excration of radiocaesium. The animals in Experiment I were depleted of radiocaesium before the start of the experiment. After three weeks, with an intake of 17 - 18 kBq Cs-137/day, the controls had reached activity concentrations of radiocaesium in blood corresponding to 4 - 4.5 kBq Cs-137/kg in muscle. Reindeer fed 23 or 46 g of bentonite per day stabilized at values below 0.8 kfiq/kg in muscle. In Experiment II, the reindeer started with radiocaesium activity concentrations in blood corresponding to 2 - 4.5 kBq Cs-137/kg in muscle. After four weeks of feeding, with an intake at about 8.5 kBq Cs-137/day, controls had increased their radiocaesium values by an average of 40%. Reindeer receiving 25 or 50 g zeolite per day decreased with 18 and 45%, respectively. Net absorption of radiocaesium from the gastro-intestinal tract was calculated at 50 -70% in animals receiving no caesium-binder. Reindeer fed bentonite had an absorption below 10% while those fed zeolite absorbed around 35%.

The use of bentonite and zeolite as caesium-binders in feed to reindeer - experiences from Sweden

Feeding is used in Sweden to lower radiocaesium levels in reindeer before slaughter. In feeds used for this purpose, bentonite is added as a caesium-binder to prevent absorption of radiocaesium, since the animals usually have som access to contaminated pasture in their corrals. Bentonite is efficient as a caesium-binder but increases water consumption and excretion of urine. Zeolite has been used as a caesium-binder to reindeer in a few experiments. The effect, however, has been inferior to that of bentonite. It seems that zeolite, mixed in feeds, loose some of its effect as the feed is stored. The need of a caesium-binder is demonstrated by results from practical feeding of reindeer where radiocaesium levels have not decreased as expected when feed without bentonite has been used.

Wet belly in reindeer (Rangifer tarandus tarandus) in relation to body condition, body temperature and blood constituents

AbstractWet belly, when the reindeer becomes wet over the lower parts of the thorax and abdomen, sometimes occurs in reindeer during feeding. In a feeding experiment, 11 out of 69 reindeer were affected by wet belly. The problem was first observed in 7 animals during a period of restricted feed intake. When the animals were then fed standard rations, 3 additional animals fed only silage, and 1 fed pellets and silage, became wet. Four animals died and 1 had to be euthanised. To investigate why reindeer developed wet belly, we compared data from healthy reindeer and reindeer affected by wet belly. Urea, plasma protein, glucose, insulin and cortisol were affected by restricted feed intake or by diet but did not generally differ between healthy reindeer and those with wet belly. The wet animals had low body temperature and the deaths occurred during a period of especially cold weather. Animals that died were emaciated and showed different signs of infections and stress. In a second experiment, with 20 reindeer, the feeding procedure of the most affected group in the first experiment was repeated, but none of the reindeer showed any signs of wet belly. The study shows that wet belly is not induced by any specific diet and may affect also lichen-fed reindeer. The fluid making the fur wet was proven to be of internal origin. Mortality was caused by emaciation, probably secondary to reduced energy intake caused by diseases and/or unsuitable feed.SammendragBlöt buk hos renar (Rangifer tarandus tarandus) i relation till kondition, kroppstemperatur och blodvärden. Blöt buk, när renen blir blöt över nedre delen av bröst och buk, förekommer emellanåt bland utfodrade renar.I ett utfodringsförsök drabbades 11 av 69 renar av blöt buk. Problemet observerades först hos 7 renar under en period med begränsat foderintag. När djuren sedan gavs normala fodergivor, drabbades ytterligare 4 renar av blöt buk, 3 som utfodrades med enbart ensilage, och en som fick pellets och ensilage. Fyra djur dog senare och en fick avlivas. För att undersöka varför renarna utvecklade blöt buk, jämförde vi data från friska renar och renar som fått blöt buk. Urea, plasmaprotein, glukos, insulin och kortisol påverkades av begränsat foderintag och av diet, men skilde inte generellt mellan friska renar och dem som drabbades av blöt buk. De blöta djuren hade låg kroppstemperatur och dödsfallen inträffade under perioder med särskild kallt väder. De djur som dog var utmärglade och obduktioner visade olika tecken på infektioner och stress. I ett andra experiment, med 20 renar, upprepades utfodringsstrategin för den mest drabbade gruppen i det första försöket, men ingen ren visade några tecken på blöt buk. Studien visar att blöt buk inte orsakas av något specifikt foderslag och att även renar utfodrade med lav kan drabbas. Vätskan, som gör pälsen blöt, visades komma inifrån kroppen. Dödsfallen orsakades av utmärgling, troligen en sekundär effekt av minskat energiintag vilket i sin tur kan bero på sjukdom och/eller olämpligt foder.

Consequences of the Chernobyl accident for reindeer husbandry in Sweden

Large parts of the reindeer hearding area in Sweden were contaminated with radioactive caesium from the Chernobyl fallout. During the first year after the accident no food with activity concentrations exceeding 300 Bq/kg was allowed to be sold in Sweden. This meant that about 75% of all reindeer meat produced in Sweden during the autumn and winter 1986/87 were rejected because of too high caesium activites. In May 1987 the maximum level for Cs-137 in reindeer, game and fresh-water fish was raised to 1500 Bq/kg. During the last two year, 1987/88 and 1988/89, about 25% of the slaughtered reindeer has had activities exceeding this limit. The effective long-time halflife or radiocaesium in reindeer after the nuclear weapon tests in the sixties was about 7 years. If this halflife is correct also for the Chernobyl fallout it will take about 35 years before most of the reinder in Sweden are below the current limit 1500 Bq/kg in the winter. However, by feeding the animals uncontaminated food for about two months, many reindeer can be saved for human consumption.

Body burden and distribution of 137Cs in reindeer

The whole body was collected from 6 reindeer that had been grazing contaminated pasture and from 6 reindeer that had been fed uncontaminated feed the last weeks before slaughter. The body was emptied from in-gesta and weighed. Samples were taken from skeletal muscle, kidneys, heart, liver, lungs, rumen wall, bone and blood. The total activity of 137Cs in the ingesta-free body and the acitivity concentration of l37Cs in the different tissues were determined. The highest acitivity concentrations of l37Cs were found in skeletal muscle and in kidneys. Activity concentrations in kidneys, heart, liver, lungs and rumen wall, relative to skeletal muscle, were lower in reindeer with decreasing radiocaesium levels, compared to reindeer with continuous intake of radiocaesium, indicating a more rapid elimination in these tissues than in muscle. The ratios between average activity concentration of 137Cs in whole body and acitivity concentration in muscle from the same animal, ranged from 0.51 to 0.62. A factor of 0.57 is suggested for calculating average body activity concentration of radiocaesium from known activity concentration in muscle.