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The composition of adipose tissue and its usefulness as a parameter for carcass composition in growing pigs
Livestock Production Science, 7 (1980) 291--296
29]
© Elsevier Scientific Publishing Company, Amsterdam -- Printed in The Netherlands Short Communication T H E C O M P O S I T I O N O F A D I P O S E T I S S U E A N D I T S U S E F U L N E S S AS A PARAMETER FOR CARCASS COMPOSITION IN GROWING PIGS S.H.M. METZ, M. DE WIJS and R.A. DEKKER Institute for Livestock Feeding and Nutrition Research "Hoorn': P.O. Box 160, Lelystad (The Netherlands)
(Accepted 6 November 1979)
ABSTRACT Metz, S.H.M., De Wijs, M. and Dekker, R.A., 1980. The composition of adipose tissue and its usefulness as a parameter for carcass composition in growing pigs. Livest. Prod. Sci., 7: 291--296. Growing pigs, varying in body weight between 25 and 110 kg, showed differences in fat content between adipose tissues from different body sites. In all adipose tissues fat content increased during growth ; the increase in fat content was, as shown for backfat, affected by the level of daily energy intake. It is concluded that the dry matter (DM) or fat content in a single sample of adipose tissue cannot be used as an accurate parameter for fatness of carcasses at a normal slaughter weight.
INTRODUCTION I n t e n s i v e l y f e d g r o w i n g pigs d e p o s i t c o n s i d e r a b l e q u a n t i t i e s o f f a t in adip o s e tissues ( f a t t y tissues). In t h e s e pigs t o t a l a d i p o s e tissue g r o w t h r e q u i r e s large a m o u n t s o f f e e d , o f t e n e v e n m o r e t h a n is u s e d f o r t o t a l carcass m u s c l e (meat} g r o w t h . T h e e f f i c i e n c y o f c o n v e r t i n g f e e d to m e a t c o u l d be i m p r o v e d b y d i r e c t i n g w e i g h t gain c o m p o s i t i o n m o r e t o w a r d s g r o w t h o f m u s c u l a r tissue. F o r this p u r p o s e a s i m p l e b u t a c c u r a t e p a r a m e t e r f o r carcass c o m p o sition w o u l d be h e l p f u l . T h e c o n c e n t r a t i o n o f f a t in a d i p o s e tissue m a y be a p p r o p r i a t e , b e c a u s e this c o n c e n t r a t i o n is k n o w n t o increase w i t h a d i p o s e tissue mass. A b e r l e e t al. ( 1 9 7 7 ) o b s e r v e d a close r e l a t i o n s h i p b e t w e e n t h e m o i s t u r e c o n t e n t , an i n d i r e c t p a r a m e t e r o f f a t c o n t e n t , in a d i p o s e tissue a n d t h e carcass c o m p o s i t i o n o f g r o w i n g pigs. H o w e v e r , t h e v a r i a t i o n in c o m p o s i t i o n o f t h e carcasses in t h e i r pigs was g r e a t e r t h a n n o r m a l l y w o u l d be expected. As a p a r t o f an e x p e r i m e n t o n t h e e f f e c t o f daffy e n e r g y i n t a k e o n g r o w t h r a t e a n d c o m p o s i t i o n o f t h e w e i g h t gain in pigs (Metz e t al., 1980}, w e inv e s t i g a t e d t h e r e l a t i o n s h i p b e t w e e n t h e c o m p o s i t i o n o f a d i p o s e tissue a n d t h e carcass c o m p o s i t i o n . I n this p a p e r t h e a l t e r a t i o n s in c h e m i c a l c o m p o s i t i o n o f a d i p o s e tissues d u r i n g g r o w t h are s h o w n , a n d t h e u s e f u l n e s s o f adip o s e tissue c o m p o s i t i o n as a p a r a m e t e r f o r c o m p o s i t i o n o f t h e carcass is discussed.
292 MATERIALS AND METHODS Twenty-nine crossbred female piglets (Dutch Landrace X Dutch Yorkshire; full and half sibs) were grouphoused and fed individually. The experiment started when the piglets weighed a b o u t 25 kg, between 69 and 75 days old. Three piglets were then slaughtered as zero time controls. The other animals were divided into 13 pairs of full sibs of a b o u t the same live weight. Within each pair one animal was fed somewhat above the Dutch Standards (Centraal Veevoederbureau, 1977) for energy (treatment 1), with a daffy feed supply (energy content of 8962 kJ NEf/kg feed; NEf = net energy fat for pigs, according to Nehring et al., 1969) of 1.375 kg at 25 kg, 2.270 kg at 50 kg, 2.730 kg at 75 kg and 3.110 kg at 100 kg live weight. The partner consumed 80% of this quantity of feed daffy (treatment 2). The same diet was used for both treatments. When treatment I animals reached 30, 50, 70, 90 and 110 kg liveweight, pairs of pigs were slaughtered. At slaughtering blood and entrails, after emp° tying, were weighed; each carcass was weighed and its right half was dissected into muscles, adipose tissues, offal (mainly skin) and bones (for further details see Metz et al., 1980). Immediately after killing the animals, samples of adipose tissue were taken from nine different sites in the body: subcutaneous adipose tissue from the two visible backfat layers at shoulder and loin, from the ham, from the ventral belly and from the neck, perinephric adipose tissu~ and mesenteric adipose tissue. Measurements of the dry matter (DM) and fat c o n t e n t in the adipose tissues were performed after removing the connective tissue layers covering the adipose tissues. Analysis for DM and fat (diethylether extract) were done according to NEN-methods (Nederlands Normalisatie Instituut, 1965; 1974). Significant differences in DM content o f adipose tissues between b o d y sites or between dietary treatments were tested, using the Sign test. RESULTS Table I shows that in all adipose tissues the content of DM increased during growth. Additionally, the content of DM was related to the location within the b o d y : adipose tissue from the back ( a - d ) , ham (e) and around the kidneys (h) contained significantly more DM than tissue from the ventral belly (f), neck (g) and mesentery (i). Other significant differences between b o d y sites are n o t mentioned in detail, b u t can be seen from Table I. DM in adipose tissue mainly consisted of fat (Fig. 1). The percentage of fat in DM was positively correlated (r = 0.94) to the DM content in the adipose tissues. The DM content in backfat was affected by the level of feed intake (Table II, Fig. 2). Restricting the daily feed intake by 20% reduced the DM content in different sites in the backfat by a b o u t 2%, and the total a m o u n t of carcass fatty tissues by 20%, when compared on an age basis.
293 TABLE I Dry m a t t e r c o n t e n t in a d i p o s e tissue f r o m d i f f e r e n t sites in t h e b o d y of growing pigs. E a c h value r e p r e s e n t s 3--7 o b s e r v a t i o n s . DM c o n t e n t (%) E m p t y b o d y w e i g h t r a n g e (kg)
21--31
36--47
59--70
81--86
90--109
80.5 77.8 73.6 -77.2 68.6 -73.6 55.4
84.0 85.6 81.4 82.0 84.5 77.7 61.6 81.3 72.3
88.1 89.6 87.6 88.0 87.6 82.1 73.8 89.0 --
89.8 90.9 88.9 91.4 85.7 83.8 78.6 92.4 84.1
90.4 91.9 90.6 92.0 89.7 81.4 79.4 90.6 86.8
Origin o f adipose tissue * a. b. c. d. e. f. g. h. i.
Outer baekfat, shoulder Inner backfat, shoulder Outer backfat, loin Inner backfat, loin Ham Belly, m e d i o v e n t r a l Neck Perirenal Mesentery
*Significance o f d i f f e r e n c e (P < 0 . 0 5 , a c c o r d i n g t o t h e Sign t e s t ) : a, b, c, d, e, h , versus f, g, i ; a, b, d versus e ; b , h versus c ; f, i versus g.
1.00
0
,4" e
0.95
a
o p-
,,<
0.90~ I
75
i
I
i
85
I
95 DM
CONTENT(°/o)
Fig. 1. R e i a t i o n s h i p b e t w e e n fat t o DM r a t i o a n d t h e c o n t e n t o f DM in swine adipose tissue. E a c h v a l u e r e p r e s e n t s t h e average v a l u e for a b o d y site.
294 TABLE II Effect of energy intake upon DM content in backfat and total amount of carcass adipose tissue, in the growing pig Ratio between treatments 2 and 1" Mean
S.D.
0.800
0
Outer backfat, shoulder Inner backfat, shoulder Outer backfat, loin Inner backfat, loin
0.976 0.982 0.975 0.980
0.021 0.013 0.023 0.032
Carcass adipose tissue mass
0.806
0.078
Feed intake D M c o n t e n t in adipose tissue
*Based u p o n within pair comparisons. (see Materials and Methods for further details). WEIGHT (KG) OF EMPTY ADIPOSE
% D M (-~
BODY (I) T I S S U E (&)
! ~ll
//
II 100
80
//J . ~11 " j J
50
40
40
80
120
DAYS IN E X P E R I M E N T
Fig. 2. Effect of daily energy supply on the weight of the empty body, the weight of the adipose tissue in the carcass and the DM~ontent in adipose tissue from the backfat. ..... , treatment 1 ; .... treatment 2.
DISCUSSION Callow ( 1 9 4 7 ) f o u n d fat-free DM to m o i s t u r e ratios of 4.2 and 3.4 for the adipose tissues of l a m b and beef respectively. The ratios we calculated for
295
adipose tissues from different sites in the body of growing pigs were similar, with values between 3.1 and 4.3. The rather constant fat-free DM to moisture ratio, together with the high DM content, in adipose tissue of growing pigs, imply that both DM c o n t e n t and fat c o n t e n t can be used to measure the fatness of adipose tissue. In the growing pig the increase of adipose tissue mass involved an increase in fat c o n t e n t of the adipose tissues from all body sites (Table I), regardless of the considerable differences in fat c o n t e n t between the body sites. The increase in fat c o n t e n t was highest in the e m p t y body weight (EBW) range up to 60 kg. From 60 to 110 kg EBW the c o n t e n t of fat or DM increased only slightly, while simultaneously the total adipose tissue mass doubled (Fig. 2). A similar slight difference in fatness of the adipose tissue related to a great difference in adipose tissue mass was observed by comparing the pigs from both dietary treatments (Table II, Fig. 2). At normal slaughter weight ranges a still smaller variation in carcass adipose tissue mass can be expected. Consequently, the variation in fat c o n t e n t of the adipose tissue is rather small in slaughter pigs, and therefore the standard error of the DM or fat measurement (Nederlands Normalisatie Instituut, 1965; 1974) is relatively high in proportion to this variation. This means that the determination of DM or fat in a single sample of adipose tissue does n o t allow an accurate estimation of the adipose tissue mass of pig carcasses at a normal slaughter weight. REFERENCES Aberle, E.D., Etherton, T.D. and Allen, C.E., 1977. Prediction of pork carcass composition using subcutaneous adipose tissue moisture or lipid concentration. J. Anita. Sci., 45: 449--456. Callow, E.H., 1947. Comparative studies of meat. I. The chemical composition of fatty and muscular tissue in relation to growth and fattening. J. Agric. Sci., Camb., 37: 113-131. Centraal Veevoederhurean in Nederland, 1977. Voedernormen voor de Landbouwhuisdieren en Voederwaarde van Veevoeders. Verkorte tabel, Lelystad, 29e druk (in Dutch). Metz, S.H.M., BergstrSm, P.L., Lenis, N.P., De Wijs, M. and Dekker, R.A., 1980. The effect of daily energy intake on growth rate and composition of weight gain in pigs. Livest. Prod. Sci., 7: 79--87. Nederlands Normalisatie Instituut, Test methods for feeding stuffs, a) Determination of fat content, NEN 3148 (1965); b) Determination of moisture content, NEN 3332 (1974). Nehring, K., Schiemann, R. and Hoffmann, L., 1969. A new system of energetic evaluation of food on the basis of net energy for fattening. In: K.L. Blaxter et al. (Editors), Energy Metabolism of Farm Animals. E.A.A.P., Rome, Publ. No. 12, pp. 41--50.
296 RESUME Metz, S.H.M., De Wijs, M. et D e k k e r , R . A . , 1980. La c o m p o s i t i o n du tissue a d i p e u x et son int6r~t c o m m e crit~re de la c o m p o s i t i o n de la carcasse c h e z les p o r c s en croissance. Livest. Prod. Sci., 7 : 2 9 1 - - 2 9 6 (en anglais). La t e n e u r e n lipides varie avec la localisation du tissus a d i p e u x c h e z les p o r c s en croissance, e n t r e 25 et 110 kg. EUe a u g m e n t e au c o u r s d e la croissance dans t o u s les d~pSts a d i p e u x . On a m o n t r 6 sur le lard dorsal q u e c e t t e a u g m e n t a t i o n variait avec la c o n s o m m a t i o n journalidre d'~nergie. On en c o n c l u t que la t e n e u r e n mati~re s~che ou e n lipides d ' u n seul d ~ p S t a d i p e u x n e p e u t pas ~tre utilis6e c o m m e u n crit~re precis d e l'~tat d ' e n g r a i s s e m e n t des carcasses au p o i d s d ' a b a t t a g e n o r m a l .
KURZFASSUNG
Metz, S.H.M., De Wijs, M. und Dekker, R.A., 1980. Die Zusammensetzung des Fettgewebes und ihre Brauchbarkeit als Parameter fiirdie Schlachtk6rperzusammensetzung der wachsenden Schweine. Livest. Prod. Sci., 7:291--296 (in Englisch). Der Verfettungsgrad des Fettgewebes bei wachsenden Schweinen, die im Lebendgewicht zwischen 25 und 110 kg variierten, war an verschiedenen K6rperstellen unterschiedlich. A n jeder Stelle nahm der Verfettungsgrad w~hrend des Wachstums zu. Die Z u n a h m e war, wie sich ffirden Riickenspeck zeigte, abh~/ngig vonder HShe der t~glichen Energieaufnahme. Daraus wurde geschlossen, dass fiirSchweine mit einem normalen Schlachtgewicht der Gehalt an Trockensubstanz oder Fett bei einer Probe des Fettgewebes keinen prffzisen Parameter beziiglich des Verfettungsgrades yon den Schlachtk6rpern darstellt.
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© Elsevier Scientific Publishing Company, Amsterdam -- Printed in The Netherlands Short Communication T H E C O M P O S I T I O N O F A D I P O S E T I S S U E A N D I T S U S E F U L N E S S AS A PARAMETER FOR CARCASS COMPOSITION IN GROWING PIGS S.H.M. METZ, M. DE WIJS and R.A. DEKKER Institute for Livestock Feeding and Nutrition Research "Hoorn': P.O. Box 160, Lelystad (The Netherlands)
(Accepted 6 November 1979)
ABSTRACT Metz, S.H.M., De Wijs, M. and Dekker, R.A., 1980. The composition of adipose tissue and its usefulness as a parameter for carcass composition in growing pigs. Livest. Prod. Sci., 7: 291--296. Growing pigs, varying in body weight between 25 and 110 kg, showed differences in fat content between adipose tissues from different body sites. In all adipose tissues fat content increased during growth ; the increase in fat content was, as shown for backfat, affected by the level of daily energy intake. It is concluded that the dry matter (DM) or fat content in a single sample of adipose tissue cannot be used as an accurate parameter for fatness of carcasses at a normal slaughter weight.
INTRODUCTION I n t e n s i v e l y f e d g r o w i n g pigs d e p o s i t c o n s i d e r a b l e q u a n t i t i e s o f f a t in adip o s e tissues ( f a t t y tissues). In t h e s e pigs t o t a l a d i p o s e tissue g r o w t h r e q u i r e s large a m o u n t s o f f e e d , o f t e n e v e n m o r e t h a n is u s e d f o r t o t a l carcass m u s c l e (meat} g r o w t h . T h e e f f i c i e n c y o f c o n v e r t i n g f e e d to m e a t c o u l d be i m p r o v e d b y d i r e c t i n g w e i g h t gain c o m p o s i t i o n m o r e t o w a r d s g r o w t h o f m u s c u l a r tissue. F o r this p u r p o s e a s i m p l e b u t a c c u r a t e p a r a m e t e r f o r carcass c o m p o sition w o u l d be h e l p f u l . T h e c o n c e n t r a t i o n o f f a t in a d i p o s e tissue m a y be a p p r o p r i a t e , b e c a u s e this c o n c e n t r a t i o n is k n o w n t o increase w i t h a d i p o s e tissue mass. A b e r l e e t al. ( 1 9 7 7 ) o b s e r v e d a close r e l a t i o n s h i p b e t w e e n t h e m o i s t u r e c o n t e n t , an i n d i r e c t p a r a m e t e r o f f a t c o n t e n t , in a d i p o s e tissue a n d t h e carcass c o m p o s i t i o n o f g r o w i n g pigs. H o w e v e r , t h e v a r i a t i o n in c o m p o s i t i o n o f t h e carcasses in t h e i r pigs was g r e a t e r t h a n n o r m a l l y w o u l d be expected. As a p a r t o f an e x p e r i m e n t o n t h e e f f e c t o f daffy e n e r g y i n t a k e o n g r o w t h r a t e a n d c o m p o s i t i o n o f t h e w e i g h t gain in pigs (Metz e t al., 1980}, w e inv e s t i g a t e d t h e r e l a t i o n s h i p b e t w e e n t h e c o m p o s i t i o n o f a d i p o s e tissue a n d t h e carcass c o m p o s i t i o n . I n this p a p e r t h e a l t e r a t i o n s in c h e m i c a l c o m p o s i t i o n o f a d i p o s e tissues d u r i n g g r o w t h are s h o w n , a n d t h e u s e f u l n e s s o f adip o s e tissue c o m p o s i t i o n as a p a r a m e t e r f o r c o m p o s i t i o n o f t h e carcass is discussed.
292 MATERIALS AND METHODS Twenty-nine crossbred female piglets (Dutch Landrace X Dutch Yorkshire; full and half sibs) were grouphoused and fed individually. The experiment started when the piglets weighed a b o u t 25 kg, between 69 and 75 days old. Three piglets were then slaughtered as zero time controls. The other animals were divided into 13 pairs of full sibs of a b o u t the same live weight. Within each pair one animal was fed somewhat above the Dutch Standards (Centraal Veevoederbureau, 1977) for energy (treatment 1), with a daffy feed supply (energy content of 8962 kJ NEf/kg feed; NEf = net energy fat for pigs, according to Nehring et al., 1969) of 1.375 kg at 25 kg, 2.270 kg at 50 kg, 2.730 kg at 75 kg and 3.110 kg at 100 kg live weight. The partner consumed 80% of this quantity of feed daffy (treatment 2). The same diet was used for both treatments. When treatment I animals reached 30, 50, 70, 90 and 110 kg liveweight, pairs of pigs were slaughtered. At slaughtering blood and entrails, after emp° tying, were weighed; each carcass was weighed and its right half was dissected into muscles, adipose tissues, offal (mainly skin) and bones (for further details see Metz et al., 1980). Immediately after killing the animals, samples of adipose tissue were taken from nine different sites in the body: subcutaneous adipose tissue from the two visible backfat layers at shoulder and loin, from the ham, from the ventral belly and from the neck, perinephric adipose tissu~ and mesenteric adipose tissue. Measurements of the dry matter (DM) and fat c o n t e n t in the adipose tissues were performed after removing the connective tissue layers covering the adipose tissues. Analysis for DM and fat (diethylether extract) were done according to NEN-methods (Nederlands Normalisatie Instituut, 1965; 1974). Significant differences in DM content o f adipose tissues between b o d y sites or between dietary treatments were tested, using the Sign test. RESULTS Table I shows that in all adipose tissues the content of DM increased during growth. Additionally, the content of DM was related to the location within the b o d y : adipose tissue from the back ( a - d ) , ham (e) and around the kidneys (h) contained significantly more DM than tissue from the ventral belly (f), neck (g) and mesentery (i). Other significant differences between b o d y sites are n o t mentioned in detail, b u t can be seen from Table I. DM in adipose tissue mainly consisted of fat (Fig. 1). The percentage of fat in DM was positively correlated (r = 0.94) to the DM content in the adipose tissues. The DM content in backfat was affected by the level of feed intake (Table II, Fig. 2). Restricting the daily feed intake by 20% reduced the DM content in different sites in the backfat by a b o u t 2%, and the total a m o u n t of carcass fatty tissues by 20%, when compared on an age basis.
293 TABLE I Dry m a t t e r c o n t e n t in a d i p o s e tissue f r o m d i f f e r e n t sites in t h e b o d y of growing pigs. E a c h value r e p r e s e n t s 3--7 o b s e r v a t i o n s . DM c o n t e n t (%) E m p t y b o d y w e i g h t r a n g e (kg)
21--31
36--47
59--70
81--86
90--109
80.5 77.8 73.6 -77.2 68.6 -73.6 55.4
84.0 85.6 81.4 82.0 84.5 77.7 61.6 81.3 72.3
88.1 89.6 87.6 88.0 87.6 82.1 73.8 89.0 --
89.8 90.9 88.9 91.4 85.7 83.8 78.6 92.4 84.1
90.4 91.9 90.6 92.0 89.7 81.4 79.4 90.6 86.8
Origin o f adipose tissue * a. b. c. d. e. f. g. h. i.
Outer baekfat, shoulder Inner backfat, shoulder Outer backfat, loin Inner backfat, loin Ham Belly, m e d i o v e n t r a l Neck Perirenal Mesentery
*Significance o f d i f f e r e n c e (P < 0 . 0 5 , a c c o r d i n g t o t h e Sign t e s t ) : a, b, c, d, e, h , versus f, g, i ; a, b, d versus e ; b , h versus c ; f, i versus g.
1.00
0
,4" e
0.95
a
o p-
,,<
0.90~ I
75
i
I
i
85
I
95 DM
CONTENT(°/o)
Fig. 1. R e i a t i o n s h i p b e t w e e n fat t o DM r a t i o a n d t h e c o n t e n t o f DM in swine adipose tissue. E a c h v a l u e r e p r e s e n t s t h e average v a l u e for a b o d y site.
294 TABLE II Effect of energy intake upon DM content in backfat and total amount of carcass adipose tissue, in the growing pig Ratio between treatments 2 and 1" Mean
S.D.
0.800
0
Outer backfat, shoulder Inner backfat, shoulder Outer backfat, loin Inner backfat, loin
0.976 0.982 0.975 0.980
0.021 0.013 0.023 0.032
Carcass adipose tissue mass
0.806
0.078
Feed intake D M c o n t e n t in adipose tissue
*Based u p o n within pair comparisons. (see Materials and Methods for further details). WEIGHT (KG) OF EMPTY ADIPOSE
% D M (-~
BODY (I) T I S S U E (&)
! ~ll
//
II 100
80
//J . ~11 " j J
50
40
40
80
120
DAYS IN E X P E R I M E N T
Fig. 2. Effect of daily energy supply on the weight of the empty body, the weight of the adipose tissue in the carcass and the DM~ontent in adipose tissue from the backfat. ..... , treatment 1 ; .... treatment 2.
DISCUSSION Callow ( 1 9 4 7 ) f o u n d fat-free DM to m o i s t u r e ratios of 4.2 and 3.4 for the adipose tissues of l a m b and beef respectively. The ratios we calculated for
295
adipose tissues from different sites in the body of growing pigs were similar, with values between 3.1 and 4.3. The rather constant fat-free DM to moisture ratio, together with the high DM content, in adipose tissue of growing pigs, imply that both DM c o n t e n t and fat c o n t e n t can be used to measure the fatness of adipose tissue. In the growing pig the increase of adipose tissue mass involved an increase in fat c o n t e n t of the adipose tissues from all body sites (Table I), regardless of the considerable differences in fat c o n t e n t between the body sites. The increase in fat c o n t e n t was highest in the e m p t y body weight (EBW) range up to 60 kg. From 60 to 110 kg EBW the c o n t e n t of fat or DM increased only slightly, while simultaneously the total adipose tissue mass doubled (Fig. 2). A similar slight difference in fatness of the adipose tissue related to a great difference in adipose tissue mass was observed by comparing the pigs from both dietary treatments (Table II, Fig. 2). At normal slaughter weight ranges a still smaller variation in carcass adipose tissue mass can be expected. Consequently, the variation in fat c o n t e n t of the adipose tissue is rather small in slaughter pigs, and therefore the standard error of the DM or fat measurement (Nederlands Normalisatie Instituut, 1965; 1974) is relatively high in proportion to this variation. This means that the determination of DM or fat in a single sample of adipose tissue does n o t allow an accurate estimation of the adipose tissue mass of pig carcasses at a normal slaughter weight. REFERENCES Aberle, E.D., Etherton, T.D. and Allen, C.E., 1977. Prediction of pork carcass composition using subcutaneous adipose tissue moisture or lipid concentration. J. Anita. Sci., 45: 449--456. Callow, E.H., 1947. Comparative studies of meat. I. The chemical composition of fatty and muscular tissue in relation to growth and fattening. J. Agric. Sci., Camb., 37: 113-131. Centraal Veevoederhurean in Nederland, 1977. Voedernormen voor de Landbouwhuisdieren en Voederwaarde van Veevoeders. Verkorte tabel, Lelystad, 29e druk (in Dutch). Metz, S.H.M., BergstrSm, P.L., Lenis, N.P., De Wijs, M. and Dekker, R.A., 1980. The effect of daily energy intake on growth rate and composition of weight gain in pigs. Livest. Prod. Sci., 7: 79--87. Nederlands Normalisatie Instituut, Test methods for feeding stuffs, a) Determination of fat content, NEN 3148 (1965); b) Determination of moisture content, NEN 3332 (1974). Nehring, K., Schiemann, R. and Hoffmann, L., 1969. A new system of energetic evaluation of food on the basis of net energy for fattening. In: K.L. Blaxter et al. (Editors), Energy Metabolism of Farm Animals. E.A.A.P., Rome, Publ. No. 12, pp. 41--50.
296 RESUME Metz, S.H.M., De Wijs, M. et D e k k e r , R . A . , 1980. La c o m p o s i t i o n du tissue a d i p e u x et son int6r~t c o m m e crit~re de la c o m p o s i t i o n de la carcasse c h e z les p o r c s en croissance. Livest. Prod. Sci., 7 : 2 9 1 - - 2 9 6 (en anglais). La t e n e u r e n lipides varie avec la localisation du tissus a d i p e u x c h e z les p o r c s en croissance, e n t r e 25 et 110 kg. EUe a u g m e n t e au c o u r s d e la croissance dans t o u s les d~pSts a d i p e u x . On a m o n t r 6 sur le lard dorsal q u e c e t t e a u g m e n t a t i o n variait avec la c o n s o m m a t i o n journalidre d'~nergie. On en c o n c l u t que la t e n e u r e n mati~re s~che ou e n lipides d ' u n seul d ~ p S t a d i p e u x n e p e u t pas ~tre utilis6e c o m m e u n crit~re precis d e l'~tat d ' e n g r a i s s e m e n t des carcasses au p o i d s d ' a b a t t a g e n o r m a l .
KURZFASSUNG
Metz, S.H.M., De Wijs, M. und Dekker, R.A., 1980. Die Zusammensetzung des Fettgewebes und ihre Brauchbarkeit als Parameter fiirdie Schlachtk6rperzusammensetzung der wachsenden Schweine. Livest. Prod. Sci., 7:291--296 (in Englisch). Der Verfettungsgrad des Fettgewebes bei wachsenden Schweinen, die im Lebendgewicht zwischen 25 und 110 kg variierten, war an verschiedenen K6rperstellen unterschiedlich. A n jeder Stelle nahm der Verfettungsgrad w~hrend des Wachstums zu. Die Z u n a h m e war, wie sich ffirden Riickenspeck zeigte, abh~/ngig vonder HShe der t~glichen Energieaufnahme. Daraus wurde geschlossen, dass fiirSchweine mit einem normalen Schlachtgewicht der Gehalt an Trockensubstanz oder Fett bei einer Probe des Fettgewebes keinen prffzisen Parameter beziiglich des Verfettungsgrades yon den Schlachtk6rpern darstellt.