Nutritional status and fatty acid composition of bone marrows i n
semi-domesticated reindeer
Mauri Nieminen a n d Paivi Soppela
Finnish Game and Fisheries Research Institute, Reindeer Research, Koskikatu 33 A , 96100 Rovaniemi, Finland
N u t r i t i o n a l c o n d i t i o n of animals has been defined usually as fat deposition i n different parts
of the b o d y . Fat animals are n o t necessarily healthy, but animals w i t h relatively h i g h amounts
of fat have usually also adequate levels o f other
resources w i t h i n the b o d y . Fat is deposited first
i n bone m a r r o w , then a r o u n d the k i d n e y , and
finally under the s k i n . Fat content of bone
m a r r o w has l o n g been related to the p h y s i o l o g i cal c o n d i t i o n of animals (Jackson 1928) and several techniques have been used to determine
the m a r r o w fat levels i n different Cervidae -species (see N i e m i n e n and L a i t i n e n 1986). I n this
study femur and metatarsal m a r r o w samples
were collected f r o m 20 semi-domesticated reindeer (10 calves, 6 hinds and 4 castrated males)
maintained i n a good n u t r i t i o n a l state d u r i n g
O c t o b e r i n the southern part of the F i n n i s h
reindeer herding area and f r o m 20 starved reindeer (10 calves, 8 hinds and 2 y o u n g males)
slaughtered at the end o f F e b r u a r y i n n o r t h e r n
part of the F i n n i s h reindeer herding area. Bone
m a r r o w lipids were extracted w i t h methanolc l o r o f o r m (1:1), fractionated o n T L C , and their
fatty acids were analysed b y gas-liquid c h r o m a tography. A n a l y s i s o f bone m a r r o w lipids resulted i n the identification of 16 fatty acids f r o m
14 to 20 carbon chain lengths. N o significant
sex-related differences were f o u n d i n fatty acid
c o m p o s i t i o n of calves d u r i n g different seasons.
F e m u r m a r r o w triglycerides ( T G ) were m a i n l y
saturated (range 57-67 %), large p r o p o r t i o n
being p a l m i t i c (16:0) and stearic acids (18:0).
T h e p r o p o r t i o n of saturated fatty acids was
slightly higher d u r i n g a u t u m n and w i n t e r i n
calves than i n hinds. T h e fatty acid composit i o n increased i n unsaturation distally, the major changes being i n oleic acid (18:1) w h i c h i n creased f r o m 33 % i n femur to 46 % i n metatarsal m a r r o w of calves and f r o m 38 % to 57 %
of hinds i n O c t o b e r . Carcass weight o f starved
Rangifer, Special Issue N o . 4,1990
calves and hinds at the end of F e b r u a r y was significantly l o w e r , but fresh weight of red bone
marrows was slightly higher than those i n O c tober. Starved reindeer had higher p r o p o r t i o n
of saturated but l o w e r p r o p o r t i o n of m o n o and polyunsaturated fatty acids i n femur and
metatarsal marrows than reindeer slaughtered i n
O c t o b e r . T h e highest p r o p o r t i o n of branchedchain fatty acids was measured i n femur of
male yearlings and castrated males (1.9 and 2.1
%). P h o s p h o l i p i d s ( P L ) were m a i n l y saturated
in femur and metatarsal bone m a r r o w s of
calves (53 and 51 %) and hinds (56 and 53 % ,
respectively) i n O c t o b e r . Starved reindeer i n
w i n t e r had slightly higher p r o p o r t i o n s of unsaturated fatty acids i n P L of bone m a r r o w s than
reindeer slaughtered i n a u t u m n . Metatarsal fat
content i n reindeer that has starved to death is
higher than femur fat content ( N i e m i n e n and
L a i t i n e n 1986). Fat m o b i l i z a t i o n i n w i n t e r
might be more advanced i n p r o x i m a l bones because they are closer to the b o d y and keep warmer. It seems reasonable to expect reduced circulation i n capillary networks and retarded
metabolic processes i n colder extremities. Present results support the suggestion that a negative correlation exists between the degree of fatty
acid saturation i n the l i m b and the distance
f r o m the b o d y (see M e n g et al. 1969).
References:
Jackson, C. M . 1928: The effects of inanition and
malnutrition upon growth and structure. - Blakison's, Son & Co., Philadelphia, Pa, 616 p.
Meng, M . , West, G . and Irving, L. 1969. Fatty acid
composition of caribou bone marrow. - Comp.
Biochem. Physiol. 30:187-191.
Nieminen, M . and Laitinen, M . 1986: Bone marrow
and kidney fat as indicators of condition in reindeer. - Rangifer, Special Issue No. 7:219-226.
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