Groups Of Reindeer Research Articles

The Scandinavian reindeer ( Rangifer tarandus L.) after the last glacial maximum: time, seasonality and human exploitation

Antlers and bones of reindeer ( Rangifer tarandus L.) are the most frequently found vertebrate remains from the Late Glacial deposits of Southern Scandinavia. The Danish collection now consists of more than 350 specimens and of these 47 have been radiocarbon dated extending the range of occurrence in the area with ca. 1300 14C yr. Thus the first occurrence is pushed back to ca. 12 500 14C yr BP (late Bølling chronozone) while the youngest date lies at ca. 9200 14C yr BP (late Preboreal chronozone) establishing that the reindeer survives well into the Holocene. The seasonal dates of the reindeer indicate for the first human occupation (the Havelte group from the Bølling period) a summer, autumn and early winter occupation, with reindeer, as well as man, apparently being absent during the coldest winter months. Finally, it is shown that Southern Scandinavia acted as a calving area throughout the Late Glacial and Early Holocene thus discrediting the North–South model of reindeer groups moving from a wintering area in Southern Scandinavia to a calving area in the foothills of the North European plain.

Influence of diet on fatty acids and tocopherols in M. Longissimus Dorsi from reindeer

Our aim was to compare the effects of two pelleted diets containing differing FA composition with natural lichen pasture on reindeer's meat FA composition. In addition we wanted to increase the knowledge about reindeer FA metabolism and the effect of animal sex and age on FA composition in reindeer muscle. The trial included five reindeer groups: three grazing, consisting of adult males, adult females, and calves; and two groups of calves fed conventional pellets (CPD) and pellets containing crushed linseed (LPD), respectively, for two months before slaughter. Differences between male and female animals were mainly found in the neutral lipid fraction and related to fatness. Calves differed significantly from adult males and females in FA and lipid class composition. CPD led to a higher ratio of n-6 to n-3 FA compared with grazing. The ratio n-6/n-3 in the polar lipid (PL) fraction of the animals fed LPD was slightly, but not significantly, higher than that in the grazing reindeer. LPD-fed animals had lower proportions of long-chain polyunsaturated FA (LCPUFA), namely 20:4n-6, 22:5n-3, and 22:6n-3, in the PL fraction compared with the grazing animals due to the content of these FA in the natural feed. The animals seemed unable to elongate dietary FA in significant amounts. We conclude that by adding crushed linseed to the pellets it was possible to keep the favorable FA composition of meat from grazing reindeer with regard to the n-6/n-3 ratio but not in LCPUFA.

High protein pastures in spring - effects on body composition in reindeer

In 1996 and 1997 three groups of reindeer from different nutritional origin and condition, (poor condition groups n=15 in 1996, n=7 in 1997, good condition group n=10 in 1997), were used to investigate effects of high protein pastures on body condition for 3.5 weeks in spring. Mean body mass (BM) of reindeer in the poor condition groups increased by 10% both in 1996 (P<0.05) and in 1997 (P<0.05), while there were no significant (NS) changes in BM of reindeer in the good condition group in 1997. The mean carcass weight as % of BM increased from 48 to 51% in both the poor condition group in 1996 (NS), and in the good condition group in 1997 (P<0.05). The reticulo-rumen wet weight in the poor condition group in 1996, tended to decrease from 15.1 to 11.9% of BM, while the reticulo-rumen wet weight decreased from 14.2 to 13.0% of BM (P<0.05) in the good condition group in 1997. Mean kidney fat decreased by 51% in the poor condition group in 1996 and by 40% in the good condition group in 1997 (P<0.05). Likewise, marrow fat decreased by 50% (P<0.05) in the good condition group in 1997. In both animal groups muscle mass and carcass mass increased in the reindeer, while fat deposits decreased when eating as much as 131 g dry matter/kg0.75 on a high protein spring pasture containing as much as 30% crude protein of dry matter (DM). Much of the energy available from forage plants eaten and the body fat deposits therefore seem to support body protein growth in spring.

The effects of pre-slaughter selection of reindeer bulls (Rangifer tarandus tarandus L.) on technological and sensory meat quality, blood metabolites and abomasal lesions

Thirty reindeer bulls (age 1 1/2 years) were subjected to different pre-slaughter treatments to study the effects on ultimate pH values, muscle glycogen content, blood metabolites and abomasal lesions. Gathering and herding into a grazing corral were followed by various selection procedures. Before starting these, a control group of 10 reindeer were captured by lasso and slaughtered outside the grazing corral. Ten reindeer were then selected by hand from a small group of animals (100-150 head) in a small selection corral. Another 10 reindeer were selected from a large herd of about 1000-2000 animals, by the traditional technique of using a lasso. During a 6-hour selection, animals were captured and slaughtered after 1.5 hours (n = 2), 3-5 hours (n = 2), 5 hours (n = 3) and 6 hours (n=3) respectively. The results showed the technique of using a lasso to be stressful and glycogen-depleting, as the two lasso captured groups (the control group and the reindeer exposed to the protracted lasso selection) had the highest ultimate pH values and lowest muscle glycogen values measured. By contrast, the selection procedure where reindeer were captured by hand, was not found to be detrimental to glycogen content and ultimate pH values. Nevertheless, both selection techniques expose the reindeer to acute stress during the capture and manual restraint, which in the present study was reflected in high plasma Cortisol values in all treatment groups. The frequency of abomasal lesions was highest in the group of reindeer subjected to the prolonged selection procedure. No connection between technological and sensory meat quality was found in this study. The technique of selecting animals by hand ought to be further developed so that existing practical problems can be solved. The technique could then be recommended for wider use.

Comparison between grass-silages of different dry matter content fed to reindeer during winter

A study was made of whether the dry matter content of silage influenced performance when 17-month-old male reindeer were fed solely silage outdoor during winter. Two kinds of round-baled silages with different wilting times were offered to the animals; low dry matter (LDM silage) with a mean of 39% DM, or high dry matter (HDM silage) with a mean of 53% DM. The 115 reindeer were allotted to slaughter at the start of the experiment in October or to be fed until slaughter in January or March. During the first three weeks of the experiment small amounts of lichens were mixed with the silages and the reindeer adapted to the feeding without problems. The daily intake of DM did not differ significantly between reindeer fed the LDM or the HDM silage despite a highly significant difference in daily silage intake. This resulted in small but significantly higher gains in live weight for animals fed the LDM silage, caused by increased weight of the rumen content. All groups of reindeer either retained or lost carcass weight during the experiment, and no improvements or differences were obtained between the kinds of silages in carcass assessment or gains in fat in the abdominal cavity. Animals slaughtered in January had a lower carcass weight and dressing percentage than reindeer slaughtered in October and March. Environmental conditions during the experiment were good but nonetheless mobbing and illness still occurred. The present results concur with those of earlier studies suggesting that it seems to be the bulk of the ration rather than the dry matter content of the silage that limits the intake.

Use of urine samples collected from bladder and snow to indicate condition of semi-domesticated reindeer

Arctic and subarctic reindeer respond to energetically costly winter conditions by behavioral modifications and physiological adaptations. Blood usually permit quantification of this integrated response to variations in nutrition (Nieminen 1980). Recently the search for indicators of nutrition in animals has turned to urinalysis (see DelGiudice et al. 1988). Urinalysis has been employed by Eriksson and Valtonen (1974) for freely grazing semi-domesticated reindeer in Finland. Altogether 52 semi-domesticated reindeer (49 adult females and 3 castrated males) were used in present study. Reindeer were freely grazing in Kaamanen Reindeer Research Station or fed with rouhage (dried Equisetum fluviatile) or concentrates (Poron-Herkku, Raision Tehtaat Oy) during winter and summer 1989. During winter reindeer were grazing mainly Cladina lichens and during spring and early summer common reindeer forage plants (see Nieminen and Heiskari 1989). The blood samples were taken from the jugular vein and blood serum parameters were determined by standard methods (see Nieminen 1980). Urine samples from the bladder of castrated males were collected during slaughtering and those of living females by catheterization. After sampling reindeer were weighed. Urine samples in snow were collected from different feeding groups using the method by DelGiudice et al. (1988). Urine samples were poured into snow and collected as described by DelGiudice et al. (1988). Urine and urine-snow samples were kept at 20°C until analysed. Urea N and creatinine were assayed by spectrophotometry. Urea and creatinine ratios were calculated. The obvious disadvantage of urinalysis in wild species may be the difficulty of urine collection. Urine collection from bladder of adult reindeer females by catheterization during spring and summer was, however, nearly 100 % successful. During winter time it was slightly difficult to collect samples because urine content in the bladders was very low. The decline in water flux of reindeer during winter is about five to sevenfold compared with that during summer (see White 1975). There were no significant differences in body weight between different reindeer groups in present study, but body weights decreased slightly during winter and spring, and the lowest body weights were measured for the adult hinds in June after calving. Significant differences were found in blood parameters between different reindeer groups at same sampling date. Some significant differences were also measured in blood parameters between different sampling dates indicating changes in nutrition and nutritional status of reindeer. The highest serum urea: creatinine (U:C) ratios were measured for ad libitum fed hinds and freely grazing hinds in June. There was significant positive correlation between serum urea and bladder urine urea in present study (r = 0.504, n = 28, P < 0.01). Significant positive correlations were also found between serum creatinine and bladder urine creatinine values (r = 0.729, n = 28, P < 0.001), and between serum U : C and bladder urine U : C ratios (r = 0.920,

Rutting behaviour in reindeer ( Rangifer tarandus L.)

This paper deals with rutting behaviour in two groups of reindeer studied at the Reindeer Research Station in Swedish Lapland. The first visible signs of rutting behaviour are described as well as the establishment of the harem and its ruler. Old bulls copulate more often than younger ones owing to the earlier occurrence of rut in these, their stronger fighting ability and the fact that old bulls are more polygamous than their younger rivals. The chasing away of intruders, and the constant herding of his own herd, keeps the ruling bull very active. Since, furthermore, he does not eat he becomes very thin during the rutting season. The size of the area necessary for a harem varies. A big bull with a large harem is able to keep his rivals away from a considerably greater area than a young bull with a small number of cows. The rutting territory seems not to be defined by particular geographical boundaries, but is an area, which changes with the movement of the harem and has no topographical references. The author has observed nothing that indicates territory markings in the proper sense, but the bull urinates on his hind legs, especially at threatening and exciting moments, and this behaviour may be interpreted as a form of territory marking. The rutting sound of the bull is a series of husky, rapid, rather low-voiced rattles that are brought about by the air being repeatedly pressed out of the lungs. The sound differs slightly from that made when the bull is driving in the immediate vicinity of a cow. Threat behaviour has been described as well as overflow activities resulting from a high level of aggressive behaviour. A typical rutting behaviour, that could be characterized as courting, is the bull's driving of the cows, i.e. the bull's running or walking after a cow depending on her heat status. Aggressiveness on the part of the ruling bull is more evident against older rivals than against younger ones, and old cows are particularly aggressive against young bulls. The first copulations usually take place during the last days of September. Mating activity reaches it peak at dusk and at dawn. Copulation seems to take place only once with each cow. The heat development of the cow has been described as well as the copulation act.