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Ileal and total digestibility studies in pigs fed molasses type A or starch diets supplemented with torula yeast or soybean meal
Livestock Production Science, 25 (1990) 151-161 Elsevier Science Publishers B.V., Amsterdam - - Printed in The Netherlands
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Ileal and Total D i g e s t i b i l i t y Studies in P i g s Fed Molasses T y p e A or Starch Diets S u p p l e m e n t e d w i t h Torula Yeast or S o y b e a n Meal VILDA FIGUEROA', A. MAYLIN', J. LY 1, A. PEREZ 1, OLIMPIA CARRILLO2 and H.S. BAYLEY~
llnstituto de Investigaciones Porcinas, La Habana (Cuba) 2Facultad de Biologla, Universidad de La Habana (Cuba) aDepartrnent of Nutrition, University of Guelph, Ont., (Canada) (Accepted for publication 22 November 1989)
ABSTRACT Figueroa, V., Maylin, A., Ly, J., Perez, A., Carrillo, O. and Bayley, H.S., 1990. Ileal and total digestibility studies in pigs fed molasses Type A or starch diets supplemented with torula yeast or soybean meal. Livest. Prod. Sci., 25: 151-161. A total of 48 pigs of ~ 40 kg liveweight were used for digestibility studies with molasses Type A, molasses plus torula yeast or plus soybean meal, and cassava starch plus torula yeast. Half of the pigs were prepared with re-entrant cannulas in the terminal ileum and the other half were maintained intact for conventional digestibility studies. Nitrogen-free extract was found to be the main undigested fraction: 39% for molasses Type A and 52-67% for the remaining diets. The ileal digestibility of soluble carbohydrates in molasses diets was 96% which indicated that the undigested nitrogen-free extract fraction was mainly compounds of non-identified organic substances contained in molasses Type A. Energy disappearance in the large intestine accounted for 12% of that digested in the entire gastrointestinal tract in the case of molasses Type A and 18-20% in the other diets. Energy excretion in urine was significantly greater in molasses diets than in those containing starch, indicating a lower metabolizable to gross energy ratio in molasses diets than in starch diets {0.85 vs. 0.90). Digestible and metabolizable energy values for molasses Type A were 14.3 and 13.5 MJ kg -1 dry matter (DM) respectively, and for cassava starch diet 16.8 and 16.6 MJ kg -1 DM, respectively. According to the high ileal digestibility found in carbohydrates of molasses Type A, the low ileal and total digestibility of non-identified organic substances considerably reduced the dietary energy density, thus acting as an index for the nutritional value of molasses.
INTRODUCTION S u g a r c a n e f i n a l m o l a s s e s d i e t s h a v e b e e n s h o w n t o c o n t a i n h i g h levels o f a s h a n d n o n - i d e n t i f i e d o r g a n i c s u b s t a n c e s ( B a y l e y et al., 1985; F i g u e r o a a n d
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Mac{a, 1988) which have a low digestibility and are poorly metabolized, thus determining low values of metabolizable (ME) and digestible energy (DE) for this type of molasses in the pig. These results support other research data indicating that weight gain and feed conversion of growing and fattening pigs fed high levels of final molasses are poorer than those obtained with cereal diets (D{az and Marrero, 1978). As expected, this product contains all the industrial impurities of the technological process since final molasses is the end product obtained from sucrose extraction from sugar cane. Therefore the objective of this work was to study some aspects of the digestive utilization of nutrients contained in other types of sugar cane molasses such as molasses Type A. These types of molasses are obtained from the first sucrose extraction step after the successive clarification and concentration of sugar cane juice. Therefore molasses Type A might have a higher energy availability for pigs, taking into account its high content of soluble sugars and its lower level of impurities in terms of minerals and nonidentified organic substances. M A T E R I A L S AND M E T H O D S
Twenty-four Yorkshire X Landrace crossbred pigs of ~ 40 kg liveweight (LW) were fitted with re-entrant cannula in the terminal ileum according to the procedure previously described by P~rez et al. (1984). Another group of 24 intact pigs with the same characteristics was also used in conventional digestibility trials. Four diets were used during the experimental work to compare two energy sources {molasses Type A and cassava starch) with two protein sources (torula yeast and soybean meal); their composition is shown in Table 1. TABLE 1 Composition of experimental diets ( % D M )
Molasses Type A Starch Torula yeast Soybean meal S o d i u m chloride Calcium phosphate Vitamins and minerals I
Molasses Type A
Molasses Type A + torula yeast
Molasses Type A + soybean meal
94.6 -
66.5 33.0
69.5
0.4 4.0 1.0
0.5
30.0
-
0.5
Cassava starch + torula yeast
63.3 32.9 0.4 2.9 0.5
IThe supplement of vitamins and trace minerals was prepared to supply the National Research Council (1979) requirements.
DIGESTIBILITYSTUDIESON PIGSFED DIFFERENTDIETS
153
TABLE2
Chemical analysisof dietaryingredients
Dry matter Nitrogen Ash Crude fibre Ether extract Nitrogen-free extract 1 Gross energy (MJ kg -1 DM)
Molasses Type A
Starch
Torulayeast
Soybean meal
75.9 0.34 5.5 0 0 92.4 15.3
89.7 0.16 0.4 9 0 98.6 16.8
91.4 7.19 8.4 0 0 46.6 20.5
89.6 7.64 6.6 6.5 1.1 37.9 19.0
1Containing total soluble carbohydrates and non-identified organic matter, 79.3 and 13.1%, respectively.
A batch of molasses Type A from a Cuban sugar mill was used. Starch was prepared from peeled and ground cassava washed with water, and the residues were dried and powdered. Torula yeast (Candida utilis) was produced in a Cuban torula yeast plant. The chemical composition of molasses Type A and the other components of the diets is presented in Table 2.
Experimental procedure The cannulated pigs were adapted to consume the daily ration in ~ 15 min at the level of 5% of the metabolic weight. Two animals served as donors and four were utilized in 14-h sampling periods by continuously collecting the ileal digesta on ice. Every hour the volume of the ileal digesta was recorded, the digesta mixed thoroughly and an aliquot representing 10% of the hourly collected volume obtained. The same amount of digesta was restored with ileal content from the donor animals to the experimental animals. A 24-h pooled digesta sample was obtained from each pig and stored at - 20 ° C until analysis. The intact pigs were fed twice daily at the level of 10% of the metabolic weight. The animals were allocated in conventional metabolism cages, and the collection of excreta and urine was conducted during five consecutive days. The homogenized samples were stored at - 2 0 ° C . In order to avoid excreta contamination by urine, the animals were fitted with a urinary Foley catheter implanted in the urinary bladder.
Analytical methods Dry matter (DM), nitrogen, ash, ether extract and crude fibre were determined according to the method described by the Association of Official Ana-
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lytical Chemists (1975). Gross energy in the lyophilized samples was determined by combustion in an adiabatic bomb calorimeter. The total soluble carbohydrates (TSC) were analysed by using anthrone in concentrated sulphuric acid (1 g l - 1). Glucose was determined by the glucose oxidase technique (Dahlqvist, 1964). Nitrogen-free extract (NFE) was estimated by the difference between DM and total ash, crude protein, ether extract and crude fibre contents. The difference between NFE and TSC represented the non-identified organic matter. Statistical analysis was carried out by analysis of variance and according to a simple classification model {Steel and Torrie, 1960). RESULTS
Table 3 shows the amounts of digesta recovered at the end of the ileum and in the faeces of cannulated or intact pigs; they were expressed in units per 100 units of either DM, ash or energy ingested. When the animals were fed molasses Type A only, a lower amount of DM and gross energy (GE) reached the end of the ileum, indicating a significantly higher digestibility (P < 0.05) than when a protein source was included in molasses or starch diets. Ileal DM digestibility was 84% for molasses Type A and 75-78% for the other diets. Ash of molasses Type A disappeared almost completely (97%) in this part of the intestine, while with the other diets from 23 to 41% of ash was absorbed. This TABLE 3
Digesta flow in pigs fed diets based on molasses or starch supplemented with torula yeast or soybean meal ( % intake) Molasses
Molasses
Molasses
Type A
Type A +
Type A +
SE
soybean meal
Starch + torula yeast
torula yeast Dry matter Ileum Faeces
15.65 6.35
23.7 a 10.0 a
21.8 a 8.5 ab
24.8 ~ 8.2 a5
1.89* 0.72*
Ash Ileum Faeces
0.10 b 26.25
59.2 ~ 45.1 a
65.4 a 32.7 a5
59.6 a 41.4 ~
7.14"** 4.32*
Energy Ileum Faeces
17.25 6.2 c
28.4 a 10.9 a
25.0 a 9.0 a5
25.8 a 7.7 b¢
2.33" 0.71"**
Values with different superscripts in the same row differ significantly at P < 0.05.
DIGESTIBILITY STUDIES ON PIGS FED DIFFERENT DIETS
155
fact was not related to the percentage of ash in the diets, but to ash concentration in the ileal digesta which was 1.5% for molasses Type A and 18.3% for the other diets. Digestion was completed between the ileum and the rectum by 9.3 and 11.0 units of DM and GE, respectively, for molasses Type A and from 13.7 to 16.5 DM units and 17.5 to 18.1 GE units with the other diets. Energy disappearance in the large intestine was from 18 to 20% of the total energy digested with molasses or starch diets supplemented with protein sources. The characteristics of the digesta reaching the ileum and excreted in the faeces are shown in Table 4. It was observed that digesta reaching the ileum was mainly composed of NFE fractions, e.g. (13.3/15.6) × 100=85% for molasses Type A and, similarly, 52-67% for the other diets. Furthermore, on comparing the characteristics of the ileal digesta to that of faeces, it can be seen that this value is considerably reduced (20-40% of DM) in faeces. It could therefore be assumed that the DM disappearing between the ileum and the rectum is mainly the NFE. Data concerning the ileal digestibility of different soluble carbohydrate fractions are presented in Table 5. High values were obtained for TSC up to the end of the ileum (92-96%) in molasses diets which further supports the hypothesis that the undigested fraction in this site of the gastrointestinal tract is mainly composed of non-identified organic substances. The calculated ileal digestibility of these substances accounted for only 14%. The energy balance of the intact animals is shown in Table 6. The gross TABLE4 Characteristics of the digesta of pigs fed molasses Type A or starch diets supplemented with torula yeast or soybean meal (digesta flow, g per 100 g D M intake)
Ilealcannulatedpigs DM Molasses Type A 15.65 Molasses Type A + 23.7 a torula yeast M o l a s s e s T y p e A + 21.8" soybean meal Starch+torula 24.8 ~ yeast SE
Intact pigs
Ash
CP
EE
0.25 c 3.55 b
1.965 4.02 a
0.10 13.3 0.19 15.9
3.975
4.48 ~
5.61 a
3.68 ~
DM
Ash CP
EE
NFE
6.35 10.0 a
2.43 1.16 c 2.66 3.72 a
0.08 d 0.48 b
2.64 a 3.17 a
0.20 11.3
8.5 ~b 1.78 2.40 b
0.21 ~
2.48 ~5
0.11 15.3
8.2 ab 3.25 2.495
0.72 a
1.76 b
1.89" 0.51"** 0.29*** 0.05
NFE
1.47
0.72* 0.38 0.18"** 0.04*** 0.26*
1See Table 3. Values with different superscripts in the same column differ significantly at P < 0 . 0 5 (Duncan, 1955). C P = c r u d e protein; E E = e t h e r extract. *P<0.05; ***P<0.001.
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v. FIGUEROAET AL.
TABLE 5 Daily carbohydrate flow in ileal cannulated pigs fed molasses Type A or starch diets
Total carbohydrate intake (g per 100 g DM) Ileal flow of total carbohydrates (g per 100 g DM) Ileal digestibility (%) Ileal flow of free reducing sugars (g per 100 g DM intake) Ileal flow of glucose (g per 100 g DM intake)
Molasses Type A
Molasses Type A + torula yeast
Molasses Type A + soybean meal
Starch + torula yeast
75.0
52.7
55.1
-
SE
2.65
2.14
4.12
2.78
0.50
96 ~ 1.22
96 ~ 1.39
92 b 2.46
1.50
1" 0.54
0.10
0.24
0.30
1.23
0.33
*P < 0.05. Values with different superscripts in the same row differ significantly at P < 0.05 (Duncan, 1955). TABLE 6 Energy balance of pigs fed diets based on molasses Type A or starch supplemented with torula yeast or soybean meal
Gross energy value (MJ kg -1 ) Gross energy intake (MJ day -1 ) Energy output in faeces (MJ d a y - ~) Urinary energy output (MJ d a y - 1) Digestibility of dietary energy (%) Digestible energy value (MJ k g - 1) Metabolizable energy value (MJ k g - ~) Metabolizable energy (% gross energy) Metabolizable energy (% digestible energy )
Molasses Type A
Molasses Type A + torula yeast
Molasses Type A + soybean meal
Starch +torula yeast
14.5 16.8 1.04 c 0.90 c 94 a 13.6 c 12.8 c 88 b 94 b
16.9 28.2 3.08 a 1.30 b 89 c 15.0 b 14.2 b 84 c 94 b
16.4 28.5 2.53 b 1.54 a 91 ~ 14.9 b 14.0 b 85 c 94 b
17.4 28.8 2.22 b 0.80 c 92 ab 16.1 a 15.7 a 90 a 97 a
SE
0.16"** 0.08*** 0.7** 0.11"** 0.12"** 0.6*** 0.3***
**P<0.01; ***P< 0.001. Values with different superscripts in the same row differ significantly at P < 0.05 (Duncan, 1955 ). energy value was lower in molasses Type A alone than in the other diets supplemented either with torula yeast or soybean meal. The energy digestibility of molasses was high (90-94%) and a significant decrease (P<0.01) in this value was observed when the diet was supplemented with protein sources. On
DIGESTIBILITY STUDIES ON PIGS FED DIFFERENT DIETS
157
the other hand, when starch was used as energy source the digestibility values increased. Urinary energy excretion was higher (P<0.001) in supplemented molasses Type A diets than in starch diets plus torula yeast or molasses Type A alone. These urinary energy losses in molasses diets resulted in lower ME values as a percentage of the energy consumed or digested, thus affecting to a greater extent the values of ME. DISCUSSION
In this experiment, the ileal digestibility of soluble carbohydrates contained in molasses Type A was practically complete and higher than that found by Diaz et al. (1989) when sugar cane final molasses was given to pigs under similar experimental conditions (96 vs. 83% ). In fact, the sugars of molasses Type A are as well absorbed as those included in synthetic diets (Cunningham et al., 1963; Sambrook, 1979). In this connection, Macla et al. (1981) found that the ileal digestibility of sucrose and glucose was practically complete (98%) and higher than that of fructose (90%) when pigs were fed sucrose-based diets. According to the composition of digesta flow arriving at the terminal ileum, it can be assumed that the undigestibility of diets based on molasses Type A is mainly expressed by the fraction of the NFE which does not comprise the soluble carbohydrates (Table 4). This fraction, composed of several organic compounds (Binkley and Wolfrom, 1953; Yokota and Fagerson, 1971 ), has not been fully identified in molasses although it is considered that it originated during the sugar cane treatment in the sugar mill (Honing, 1953). Thus it is logical to assume that the digestive system of the pig is unable to hydrolyse and absorb these substances otherwise alien to the animal metabolism. DM disappearance between the ileum and the rectum was either 13 or 16 units when the pigs consumed molasses Type A or starch as the major source of energy in the diet. In this same diet, 8.8 and 13.5 units of DM disappearance came from NFE. Therefore it could be assumed that the available energy for fermentation processes in the large intestine mainly originated from the nonidentified organic substances of molasses Type A. This assumption is supported by the fact that 9 units of dietary DM disappeared in this section of the gastrointestinal tract when the pigs consumed molasses Type A alone. Studies carried out with semi-purified diets containing maize starch have demonstrated that ~ 3% of digestible energy disappears between the ileum and the rectum {Ivan and Farrell, 1976; Darcy and Laplace, 1981; Darcy et al., 1981 ), but as diets are less digestible, e.g. when cereal or potato starch is used, this value could rise to 14-20% (Keys and De Barthe, 1974; Mason and Just, 1976). The results of the energy balance with intact animals (Table 6) demonstrated that the diet with cassava starch plus torula yeast showed DE and ME values ( 16.2 and 15.7 MJ k g - 1, respectively) equivalent to those obtained with
158
V. FIGUEROAET AL.
maize starch plus soybean meal (Bayley et al., 1983 ). On the other hand, urinary energy excretion was consistently higher in molasses diets than in starch diets. With starch diets, 2.8% of the energy intake was excreted by urine, while with molasses diets this value was duplicated, lowering the M E : D E ratio by ~3%. In this connection, the pigs fed molasses Type A eliminate fructose and nonidentified nitrogen-free compounds in urine, so that amounts as high as 7.519.9 and 65% of urinary energy are excreted (Ly et al., 1985). Just ( 1982 ) reported that the ME: DE ratio did not change after varying the percentage of soluble carbohydrates in the non-identified nitrogen-free fraction in cereal-based diets offered to the pig. Hence, it might be assumed that one of the great differences between cereals and molasses utilization by the pig could arise from the nature and amount of the non-identified fraction of its NFE rather than from the presence or absence of fibre in these feedstuffs, respectively. The estimated values of ileal and total digestibility of DM, energy and nonidentified organic matter contained in the NFE from the diet components, as well as the DE and ME values, are given in Table 7. The results found with molasses Type A alone have been used to estimate torula yeast and soybean meal assuming non-associative effects (Ly et al., 1984; Diaz et al., 1989). The starch values were calculated from torula yeast figures. It could be observed that the ileal digestibility of the non-identified NFE fraction varied greatly according to the nature of the feeds used: molasses components had the poorest digestibility whereas those of soybean meal were the most digestible. Thus the TABLE 7 Ileal and total digestibility and energy values of the dietary ingredients Molasses Type A
Torula yeast
Soybean meal
Starch
Apparent ileal digestibility Dry matter Gross energy Non-identified organic matter
84 83 14
61 50 43
65 58 65
87 91
Apparent total digestibility Dry matter Gross energy Non-identified organic matter
94 94 79
83 80 87
89 86 88
100 100
Digestible energy (MJ kg -1 DM) Metabolizable energy (MJ kg -1 DM) Metabolizable energy: digestible energy Metabolizable energy: gross energy
14.3 13.5 0.94 0.88
16.6 15.8 0.95 0.77
16.5 15.4 0.93 0.81
16.8 16.6 0.99 0.99
DIGESTIBILITYSTUDIESONPIGSFEDDIFFERENTDIETS
159
ME: GE ratio was found to be 0.88 for molasses Type A and 0.99 for cassava starch, corresponding to 13.5 MJ ME kg -1 DM for molasses Type A. On the other hand, digestibility sites were also different: post-ileal digestibility was completed by 42 and 34% for torula yeast and soybean meal, respectively. Also, 82% of these substances disappeared in this part of the gastrointestinal tract with molasses Type A, in spite of its rather low digestibility. Cassava starch values were similar to maize starch (Fingerling, 1932). Ileal and total digestibilities of DM were slightly superior for torula yeast, which in turn were similar to other previous results obtained in situ (Ly et al., 1984) or in vitro (Maylin et al., 1985). Experimental data obtained from pigs fed molasses Type A indicate a high ileal digestibility of carbohydrates together with a very poor digestibility of the non-identified substances of NFE. Thus, diet formulation and pig management must consider that this fraction reduces the molasses energy density in terms of ME. From the above-mentioned statement, it could be suggested that the molasses non-identified organic substances of the NFE fraction might act as an indicator of its nutritive value.
REFERENCES Association of Official Analytical Chemists, 1975. Official Methods of Analysis. 12th Edn. A.O.A.C., Washington, DC. Bayley, H.S., Figueroa, V., Ly, J., Maylin, A. and P~rez, A., 1983. Utilization of sugar cane final molasses by the pig: energy metabolism. Can. J. Anim. Sci., 63: 455-462. Binkley, W.W. and Wolfrom, M.L., 1953. Composition of cane juice and cane final molasses. Adv. Carbohydr. Chem., 8: 291-314. Cunningham, H.H., Friend, D.W. and Nicholson, J.W.G., 1963. Observations. Can. J. Anim. Sci., 43: 215-225. Dahlqvist, A., 1964. Method for assay of intestinal disaccharidases. Anal. Biochem., 7: 18-25. Darcy, B. and Laplace, J.P., 1981. Bilans nutritionals chez le porc selon la nature de l'amidon (bl~ ou mais) et la source de prot~ines (poisson ou gluten). Ann. Zootech., 30: 63-76. Darcy, B., Laplace, J.P. and Villiers, P.A., 1981. Digestion dans l'intestine grele chez le porc. 4. Cin~tique de passage des digesta au niveau de la jonction ileo-caeco-colique, et bilans de la digestion selon la nature de l'amidon et la source de prot~ines alimentaires. Ann. Zootech., 30: 31-62. D/az, C.P. and Marrero, L., 1978. Broken rice and final molasses for pig fattening. Cuban J. Agric. Sci., 12: 177-184. Dfaz, R., Figueroa, V., Ly, J., P~rez, A., Maylin, A and Bayley, H.S., 1989. Digestibilidad aparente y absorbabilidad prececal en cerdos alimentados con miel final y miel final m~s levadura torula o desperdicios proeesados. Cienc. T~c. Agric. Ganado Porcino, in press. Duncan, D.B., 1955. Multiple range and multiple F test. Biometrics, 11: 1-42. Figueroa, V. and Macfa, M., 1988. The isolation of a non-sugar fraction from sugar cane molasses and its effect when included in rat diets. Cuban J. Agric. Sci., 22: 171-178. Fingerling, G., 1932. Investigation into the matter and energy metabolism of growing pigs. Landw. Vers. Sat., 113: 273-318.
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Holmes, J.H.G., Bayley, G.S. and Norney, F.D., 1973. Digestion and absorption of dry and highmoisture maize diets in the small and large intestine of pigs. Br. J. Nutr., 30: 401-410. Honing, P., 1953. Principles of Sugar Technology. Elsevier, Amsterdam. Ivan, M., and Farrell, D.J., 1976. Nutritional value of wheat. 5. Disappearance of components in digesta of pigs prepared with two reentrant cannulae. Anim. Prod., 23:111-119. Just, A., 1982. The influence of crude fibre from cereals and the net energy value of diets for growth in pigs. Livest. Prod. Sci., 569-580. Keys, J.E. and De Barthe, J.V., 1974. Site and extent of carbohydrates, dry matter, energy and protein digestion and rate of passage of grain diets in swine. J. Anim. Sci., 39: 57-62. Ly, J., Figueredo, M.A., Dfaz, R. and Garcfa, C.J., 1984. Efecto de la miel final de carla o del azdcar refinada sobre el balance de nitrdgeno en cerdos alimentados con levadura torula. Cienc. Tdc. Agric. Ganado Porcino, 7: 47-54. Ly, J., Maylin, A., Pdrez, A., Ramfrez, A., Carrillo, O. and Figueroa, V., 1985. Pdrdidas de energfa urinaria en cerdos alimentados con miel A de carla y levadura torula. Evento cientffico XX Aniversario. Instituto de Ciencia Animal, La Habana, p. 17. Macfa, M., Ly, J., Dfaz, R., Maylin, A. and Arias, T., 1981. Digesti6n de la sacarosa, glucosa y fluctosa en el cerdo. ! Congr. Nac. Cienc. Biol6gicas, La Habana, p. 216. Mason, V.C. and Just, A., 1976. Bacterial activity in the hindgut of pigs. I. Its influence in the apparent digestibility of dietary energy and fat. Z. Tierphysiol. Tierernaehr. Futtermittelkd., 36: 301-310. Maylin, A., Figueroa, V., Ly, J., Herndndez, M. and Avila, E., 1985. Efecto del formaldehido sobre la digestibilidad in vitro de la levadura torula en crema. Evento cientffico XX Aniversario. Instituto de Ciencia Animal, La Habana, p. 41. National Research Council, 1979. Nutrient Requirements of Swine. 8th Edn. National Academy of Science, NAS-NRC, Washington, DC. Nelson, N., 1944. A photometric adaptation of the Somogyi method for the determination of glucose. J. Biol. Chem., 153: 375-380. Pdrez, A., Figueroa, V., Ly, J., Maylin, A. and Bayley, H.S., 1984. Utilization of sugar cane final molasses by the pigs: Composition of ileal digesta. Can. J. Anim. Sci., 64: 147-158. Sambrook, I.E., 1979. Studies on digestion and absorption in the intestines of growing pigs. 7. Measurements of the flow of total carbohydrate, total reducing substances and glucose. Br. J. Nutr., 42: 267-277. Steel, R.G.D. and Torrie, J.H., 1960. Principles and Procedures of Statistics. McGraw-Hill, Toronto. Yokota, M. and Fagerson, I.S., 1971. The major volatile components of molasses. J. Food Sci., 36: 1092-1094. RESUME Figueroa, V., Maylin, A., Ly, J., Perez, A., Carrillo, O. et Bayley, H.S., 1990. Digestibilit~s ildale et fdcale chez des porcs recevant des rdgimes h base de mdlasse de type A ou d'amidon suppldmentds par de la levure Torula ou du tourteau de soja. Livest. Prod. Sci., 25:151-161 (en anglais ). Un effectif total de 48 porcs d'environ 40 kg de poids vif a dtd utilisd dans des ~tudes de digestibilitd portant sur de la mdlasse de type A, de la m~lasse suppl~mentde en levure Torula ou en tourteau de soja, et de l'amidon de manioc additionnd de levure Torula. La moitid des animaux dtaient munis de canules rdentrantes dans l'ildon terminal, les autres 6tant conservds intacts pour des dtudes de digestibilit~ conventionnelle. L'extractif non azotd constituait la fraction indigestible principale: 39% pour la mdlasse de type A et 52-67% pour les autres rdgimes. La digestibilitd ildale des glucides solubles des rdgimes h base
DIGESTIBILITYSTUDIESONPIGSFED DIFFERENTDIETS
161
de m~lasse ~tait de 96%, indiquant que l'extractif non azot~ indigestible 6tait principalement compos~ de substances organiques non identifi~es contenues dans les m~lasses de type A. La disparition de l'energie dans le gros intestin repr~sentait 12% de l'~nergie dig~r~e dans tout le tractus gastro-intestinal dans le cas des mdlasses de type A, et de 18 h 20% pour les autres r~gimes. L'excr6tion d'~nergie dans l'urine dtait significativementplus ~lev~e dans les r~gimes ~ base de m~lasses que dans ceux qui renfermaient de l'amidon, indiquant un plus faible rapport entre l'~nergie mgtabolisable et l'~nergie brute dans le cas des premiers (0,85 vs. 0,90). Les teneurs en ~nergie digestible et en ~nergie m~tabolisable ~taient respectivement de 14,3 et 13,5 MJ kg-1 MS pour les m~lasses de type A, et de 16,8 et 16,6 MJ kg -~ MS pour l'aliment ~ base d'amidon de manioc. Compte tenu de la digestibilit~ il~ale ~lev~e des glucides des m~lasses de type A, la faible digestibilit~ il~ale et totale des substances organiques non identifiSes rdduit consid~rablement leur densit~ ~nerg~tique, et constitue donc un index de la valeur nutritionnelle des m~lasses. KURZFASSUNG Figueroa, V., Maylin, A., Ly, J., Perez, A., Carrillo, O. und Bayley, H.S., 1990. Untersuchungen zur ilealen und zur gesamten Verdaulichkeit der Schweine bei Fiitterung von Di/iten auf der Basis Melasse Typ A oder St~ke mit Torula Hefe oder Sojabohnenschrot. Livest. Prod. Sci., 25:151-161 (aufenglisch). Insgesamt 48 Schweine einer Lebendmasser von etwa 40 kg wurden for Verdaulichkeitesstudien eingesetzt. Bei Ftitterung von Melasse des Typs A, Melasse plu Torula Hefe oder plus Sojabohnenschrot und yon Cassava St/irke plus Torula Here. Die Hiilfte der Schweine war mit Umleitungskantilen im terminalen Ileum versehen, w~ihrend die andere H~ilfte intakt lief for konventionelle Verdaulichkeitsuntersuchungen. N-freie Extraktstoffe machten der GrSf~ten Teil der nicht verdauten Fraktion aus: 39% for Melasse Typ A und 52 bis 67% for die tibrigen Diiiten. Die ileale Verdaulichkeit der 16slichen Kohlenhydrate in den Melassedi~iten betrug 96%, was darauf hinweist, da£ die nicht verdauten N-freien Extraktstoffe im wesentlichen Bestandteile der nichtidentifizierten organischen Substanz in der Melasse des Typs A waren. Die im Dickdarm verdaute Energie machte 12% der insgesamt verdauten Energie aus im Falle der Melasse Typ A und 18 bis 20% bei den anderen Diiiten. Die Energieausscheidung im Harn war signifikant grSf~er bei Melasse-Diiiten als bei denen auf der Basis Stiirke, was darauf hindeutet, da/~ das Verhiiltnis zwischen umsetzbarer und BruttoEnergie bei Melasse-Diiiten niedriger ist als bei St/irke-Di~iten (0,85 gegentiber 0,90 ). Die Gehalte an verdaulicher und an umsetzbarer Energie for Melasse Typ A waren 14,3 und 13,5 MJ kg -1 Trockenmasse und 16,8 und 16,6 MJ kg-1 Trockenmasse fOr Cassava-Diiiten. Gegeniiber der hohen ilealen Verdaulichkeit fOr Kohlenhydrate der Melasse Typ A reduzierten die niedrigen ilealen und gesamten Verdaulichkeiten der nicht identifizierten organischen Substanzen in erheblichen Maf~e die Energiedichte, womit sie als Indikator fOr den Niihrwert der Melasse angesehen werden kSnnen.
151
Ileal and Total D i g e s t i b i l i t y Studies in P i g s Fed Molasses T y p e A or Starch Diets S u p p l e m e n t e d w i t h Torula Yeast or S o y b e a n Meal VILDA FIGUEROA', A. MAYLIN', J. LY 1, A. PEREZ 1, OLIMPIA CARRILLO2 and H.S. BAYLEY~
llnstituto de Investigaciones Porcinas, La Habana (Cuba) 2Facultad de Biologla, Universidad de La Habana (Cuba) aDepartrnent of Nutrition, University of Guelph, Ont., (Canada) (Accepted for publication 22 November 1989)
ABSTRACT Figueroa, V., Maylin, A., Ly, J., Perez, A., Carrillo, O. and Bayley, H.S., 1990. Ileal and total digestibility studies in pigs fed molasses Type A or starch diets supplemented with torula yeast or soybean meal. Livest. Prod. Sci., 25: 151-161. A total of 48 pigs of ~ 40 kg liveweight were used for digestibility studies with molasses Type A, molasses plus torula yeast or plus soybean meal, and cassava starch plus torula yeast. Half of the pigs were prepared with re-entrant cannulas in the terminal ileum and the other half were maintained intact for conventional digestibility studies. Nitrogen-free extract was found to be the main undigested fraction: 39% for molasses Type A and 52-67% for the remaining diets. The ileal digestibility of soluble carbohydrates in molasses diets was 96% which indicated that the undigested nitrogen-free extract fraction was mainly compounds of non-identified organic substances contained in molasses Type A. Energy disappearance in the large intestine accounted for 12% of that digested in the entire gastrointestinal tract in the case of molasses Type A and 18-20% in the other diets. Energy excretion in urine was significantly greater in molasses diets than in those containing starch, indicating a lower metabolizable to gross energy ratio in molasses diets than in starch diets {0.85 vs. 0.90). Digestible and metabolizable energy values for molasses Type A were 14.3 and 13.5 MJ kg -1 dry matter (DM) respectively, and for cassava starch diet 16.8 and 16.6 MJ kg -1 DM, respectively. According to the high ileal digestibility found in carbohydrates of molasses Type A, the low ileal and total digestibility of non-identified organic substances considerably reduced the dietary energy density, thus acting as an index for the nutritional value of molasses.
INTRODUCTION S u g a r c a n e f i n a l m o l a s s e s d i e t s h a v e b e e n s h o w n t o c o n t a i n h i g h levels o f a s h a n d n o n - i d e n t i f i e d o r g a n i c s u b s t a n c e s ( B a y l e y et al., 1985; F i g u e r o a a n d
0301-6226/90/$03.50
© 1990 Elsevier Science Publishers B.V.
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Mac{a, 1988) which have a low digestibility and are poorly metabolized, thus determining low values of metabolizable (ME) and digestible energy (DE) for this type of molasses in the pig. These results support other research data indicating that weight gain and feed conversion of growing and fattening pigs fed high levels of final molasses are poorer than those obtained with cereal diets (D{az and Marrero, 1978). As expected, this product contains all the industrial impurities of the technological process since final molasses is the end product obtained from sucrose extraction from sugar cane. Therefore the objective of this work was to study some aspects of the digestive utilization of nutrients contained in other types of sugar cane molasses such as molasses Type A. These types of molasses are obtained from the first sucrose extraction step after the successive clarification and concentration of sugar cane juice. Therefore molasses Type A might have a higher energy availability for pigs, taking into account its high content of soluble sugars and its lower level of impurities in terms of minerals and nonidentified organic substances. M A T E R I A L S AND M E T H O D S
Twenty-four Yorkshire X Landrace crossbred pigs of ~ 40 kg liveweight (LW) were fitted with re-entrant cannula in the terminal ileum according to the procedure previously described by P~rez et al. (1984). Another group of 24 intact pigs with the same characteristics was also used in conventional digestibility trials. Four diets were used during the experimental work to compare two energy sources {molasses Type A and cassava starch) with two protein sources (torula yeast and soybean meal); their composition is shown in Table 1. TABLE 1 Composition of experimental diets ( % D M )
Molasses Type A Starch Torula yeast Soybean meal S o d i u m chloride Calcium phosphate Vitamins and minerals I
Molasses Type A
Molasses Type A + torula yeast
Molasses Type A + soybean meal
94.6 -
66.5 33.0
69.5
0.4 4.0 1.0
0.5
30.0
-
0.5
Cassava starch + torula yeast
63.3 32.9 0.4 2.9 0.5
IThe supplement of vitamins and trace minerals was prepared to supply the National Research Council (1979) requirements.
DIGESTIBILITYSTUDIESON PIGSFED DIFFERENTDIETS
153
TABLE2
Chemical analysisof dietaryingredients
Dry matter Nitrogen Ash Crude fibre Ether extract Nitrogen-free extract 1 Gross energy (MJ kg -1 DM)
Molasses Type A
Starch
Torulayeast
Soybean meal
75.9 0.34 5.5 0 0 92.4 15.3
89.7 0.16 0.4 9 0 98.6 16.8
91.4 7.19 8.4 0 0 46.6 20.5
89.6 7.64 6.6 6.5 1.1 37.9 19.0
1Containing total soluble carbohydrates and non-identified organic matter, 79.3 and 13.1%, respectively.
A batch of molasses Type A from a Cuban sugar mill was used. Starch was prepared from peeled and ground cassava washed with water, and the residues were dried and powdered. Torula yeast (Candida utilis) was produced in a Cuban torula yeast plant. The chemical composition of molasses Type A and the other components of the diets is presented in Table 2.
Experimental procedure The cannulated pigs were adapted to consume the daily ration in ~ 15 min at the level of 5% of the metabolic weight. Two animals served as donors and four were utilized in 14-h sampling periods by continuously collecting the ileal digesta on ice. Every hour the volume of the ileal digesta was recorded, the digesta mixed thoroughly and an aliquot representing 10% of the hourly collected volume obtained. The same amount of digesta was restored with ileal content from the donor animals to the experimental animals. A 24-h pooled digesta sample was obtained from each pig and stored at - 20 ° C until analysis. The intact pigs were fed twice daily at the level of 10% of the metabolic weight. The animals were allocated in conventional metabolism cages, and the collection of excreta and urine was conducted during five consecutive days. The homogenized samples were stored at - 2 0 ° C . In order to avoid excreta contamination by urine, the animals were fitted with a urinary Foley catheter implanted in the urinary bladder.
Analytical methods Dry matter (DM), nitrogen, ash, ether extract and crude fibre were determined according to the method described by the Association of Official Ana-
154
V. FIGUEROA ET AL.
lytical Chemists (1975). Gross energy in the lyophilized samples was determined by combustion in an adiabatic bomb calorimeter. The total soluble carbohydrates (TSC) were analysed by using anthrone in concentrated sulphuric acid (1 g l - 1). Glucose was determined by the glucose oxidase technique (Dahlqvist, 1964). Nitrogen-free extract (NFE) was estimated by the difference between DM and total ash, crude protein, ether extract and crude fibre contents. The difference between NFE and TSC represented the non-identified organic matter. Statistical analysis was carried out by analysis of variance and according to a simple classification model {Steel and Torrie, 1960). RESULTS
Table 3 shows the amounts of digesta recovered at the end of the ileum and in the faeces of cannulated or intact pigs; they were expressed in units per 100 units of either DM, ash or energy ingested. When the animals were fed molasses Type A only, a lower amount of DM and gross energy (GE) reached the end of the ileum, indicating a significantly higher digestibility (P < 0.05) than when a protein source was included in molasses or starch diets. Ileal DM digestibility was 84% for molasses Type A and 75-78% for the other diets. Ash of molasses Type A disappeared almost completely (97%) in this part of the intestine, while with the other diets from 23 to 41% of ash was absorbed. This TABLE 3
Digesta flow in pigs fed diets based on molasses or starch supplemented with torula yeast or soybean meal ( % intake) Molasses
Molasses
Molasses
Type A
Type A +
Type A +
SE
soybean meal
Starch + torula yeast
torula yeast Dry matter Ileum Faeces
15.65 6.35
23.7 a 10.0 a
21.8 a 8.5 ab
24.8 ~ 8.2 a5
1.89* 0.72*
Ash Ileum Faeces
0.10 b 26.25
59.2 ~ 45.1 a
65.4 a 32.7 a5
59.6 a 41.4 ~
7.14"** 4.32*
Energy Ileum Faeces
17.25 6.2 c
28.4 a 10.9 a
25.0 a 9.0 a5
25.8 a 7.7 b¢
2.33" 0.71"**
Values with different superscripts in the same row differ significantly at P < 0.05.
DIGESTIBILITY STUDIES ON PIGS FED DIFFERENT DIETS
155
fact was not related to the percentage of ash in the diets, but to ash concentration in the ileal digesta which was 1.5% for molasses Type A and 18.3% for the other diets. Digestion was completed between the ileum and the rectum by 9.3 and 11.0 units of DM and GE, respectively, for molasses Type A and from 13.7 to 16.5 DM units and 17.5 to 18.1 GE units with the other diets. Energy disappearance in the large intestine was from 18 to 20% of the total energy digested with molasses or starch diets supplemented with protein sources. The characteristics of the digesta reaching the ileum and excreted in the faeces are shown in Table 4. It was observed that digesta reaching the ileum was mainly composed of NFE fractions, e.g. (13.3/15.6) × 100=85% for molasses Type A and, similarly, 52-67% for the other diets. Furthermore, on comparing the characteristics of the ileal digesta to that of faeces, it can be seen that this value is considerably reduced (20-40% of DM) in faeces. It could therefore be assumed that the DM disappearing between the ileum and the rectum is mainly the NFE. Data concerning the ileal digestibility of different soluble carbohydrate fractions are presented in Table 5. High values were obtained for TSC up to the end of the ileum (92-96%) in molasses diets which further supports the hypothesis that the undigested fraction in this site of the gastrointestinal tract is mainly composed of non-identified organic substances. The calculated ileal digestibility of these substances accounted for only 14%. The energy balance of the intact animals is shown in Table 6. The gross TABLE4 Characteristics of the digesta of pigs fed molasses Type A or starch diets supplemented with torula yeast or soybean meal (digesta flow, g per 100 g D M intake)
Ilealcannulatedpigs DM Molasses Type A 15.65 Molasses Type A + 23.7 a torula yeast M o l a s s e s T y p e A + 21.8" soybean meal Starch+torula 24.8 ~ yeast SE
Intact pigs
Ash
CP
EE
0.25 c 3.55 b
1.965 4.02 a
0.10 13.3 0.19 15.9
3.975
4.48 ~
5.61 a
3.68 ~
DM
Ash CP
EE
NFE
6.35 10.0 a
2.43 1.16 c 2.66 3.72 a
0.08 d 0.48 b
2.64 a 3.17 a
0.20 11.3
8.5 ~b 1.78 2.40 b
0.21 ~
2.48 ~5
0.11 15.3
8.2 ab 3.25 2.495
0.72 a
1.76 b
1.89" 0.51"** 0.29*** 0.05
NFE
1.47
0.72* 0.38 0.18"** 0.04*** 0.26*
1See Table 3. Values with different superscripts in the same column differ significantly at P < 0 . 0 5 (Duncan, 1955). C P = c r u d e protein; E E = e t h e r extract. *P<0.05; ***P<0.001.
156
v. FIGUEROAET AL.
TABLE 5 Daily carbohydrate flow in ileal cannulated pigs fed molasses Type A or starch diets
Total carbohydrate intake (g per 100 g DM) Ileal flow of total carbohydrates (g per 100 g DM) Ileal digestibility (%) Ileal flow of free reducing sugars (g per 100 g DM intake) Ileal flow of glucose (g per 100 g DM intake)
Molasses Type A
Molasses Type A + torula yeast
Molasses Type A + soybean meal
Starch + torula yeast
75.0
52.7
55.1
-
SE
2.65
2.14
4.12
2.78
0.50
96 ~ 1.22
96 ~ 1.39
92 b 2.46
1.50
1" 0.54
0.10
0.24
0.30
1.23
0.33
*P < 0.05. Values with different superscripts in the same row differ significantly at P < 0.05 (Duncan, 1955). TABLE 6 Energy balance of pigs fed diets based on molasses Type A or starch supplemented with torula yeast or soybean meal
Gross energy value (MJ kg -1 ) Gross energy intake (MJ day -1 ) Energy output in faeces (MJ d a y - ~) Urinary energy output (MJ d a y - 1) Digestibility of dietary energy (%) Digestible energy value (MJ k g - 1) Metabolizable energy value (MJ k g - ~) Metabolizable energy (% gross energy) Metabolizable energy (% digestible energy )
Molasses Type A
Molasses Type A + torula yeast
Molasses Type A + soybean meal
Starch +torula yeast
14.5 16.8 1.04 c 0.90 c 94 a 13.6 c 12.8 c 88 b 94 b
16.9 28.2 3.08 a 1.30 b 89 c 15.0 b 14.2 b 84 c 94 b
16.4 28.5 2.53 b 1.54 a 91 ~ 14.9 b 14.0 b 85 c 94 b
17.4 28.8 2.22 b 0.80 c 92 ab 16.1 a 15.7 a 90 a 97 a
SE
0.16"** 0.08*** 0.7** 0.11"** 0.12"** 0.6*** 0.3***
**P<0.01; ***P< 0.001. Values with different superscripts in the same row differ significantly at P < 0.05 (Duncan, 1955 ). energy value was lower in molasses Type A alone than in the other diets supplemented either with torula yeast or soybean meal. The energy digestibility of molasses was high (90-94%) and a significant decrease (P<0.01) in this value was observed when the diet was supplemented with protein sources. On
DIGESTIBILITY STUDIES ON PIGS FED DIFFERENT DIETS
157
the other hand, when starch was used as energy source the digestibility values increased. Urinary energy excretion was higher (P<0.001) in supplemented molasses Type A diets than in starch diets plus torula yeast or molasses Type A alone. These urinary energy losses in molasses diets resulted in lower ME values as a percentage of the energy consumed or digested, thus affecting to a greater extent the values of ME. DISCUSSION
In this experiment, the ileal digestibility of soluble carbohydrates contained in molasses Type A was practically complete and higher than that found by Diaz et al. (1989) when sugar cane final molasses was given to pigs under similar experimental conditions (96 vs. 83% ). In fact, the sugars of molasses Type A are as well absorbed as those included in synthetic diets (Cunningham et al., 1963; Sambrook, 1979). In this connection, Macla et al. (1981) found that the ileal digestibility of sucrose and glucose was practically complete (98%) and higher than that of fructose (90%) when pigs were fed sucrose-based diets. According to the composition of digesta flow arriving at the terminal ileum, it can be assumed that the undigestibility of diets based on molasses Type A is mainly expressed by the fraction of the NFE which does not comprise the soluble carbohydrates (Table 4). This fraction, composed of several organic compounds (Binkley and Wolfrom, 1953; Yokota and Fagerson, 1971 ), has not been fully identified in molasses although it is considered that it originated during the sugar cane treatment in the sugar mill (Honing, 1953). Thus it is logical to assume that the digestive system of the pig is unable to hydrolyse and absorb these substances otherwise alien to the animal metabolism. DM disappearance between the ileum and the rectum was either 13 or 16 units when the pigs consumed molasses Type A or starch as the major source of energy in the diet. In this same diet, 8.8 and 13.5 units of DM disappearance came from NFE. Therefore it could be assumed that the available energy for fermentation processes in the large intestine mainly originated from the nonidentified organic substances of molasses Type A. This assumption is supported by the fact that 9 units of dietary DM disappeared in this section of the gastrointestinal tract when the pigs consumed molasses Type A alone. Studies carried out with semi-purified diets containing maize starch have demonstrated that ~ 3% of digestible energy disappears between the ileum and the rectum {Ivan and Farrell, 1976; Darcy and Laplace, 1981; Darcy et al., 1981 ), but as diets are less digestible, e.g. when cereal or potato starch is used, this value could rise to 14-20% (Keys and De Barthe, 1974; Mason and Just, 1976). The results of the energy balance with intact animals (Table 6) demonstrated that the diet with cassava starch plus torula yeast showed DE and ME values ( 16.2 and 15.7 MJ k g - 1, respectively) equivalent to those obtained with
158
V. FIGUEROAET AL.
maize starch plus soybean meal (Bayley et al., 1983 ). On the other hand, urinary energy excretion was consistently higher in molasses diets than in starch diets. With starch diets, 2.8% of the energy intake was excreted by urine, while with molasses diets this value was duplicated, lowering the M E : D E ratio by ~3%. In this connection, the pigs fed molasses Type A eliminate fructose and nonidentified nitrogen-free compounds in urine, so that amounts as high as 7.519.9 and 65% of urinary energy are excreted (Ly et al., 1985). Just ( 1982 ) reported that the ME: DE ratio did not change after varying the percentage of soluble carbohydrates in the non-identified nitrogen-free fraction in cereal-based diets offered to the pig. Hence, it might be assumed that one of the great differences between cereals and molasses utilization by the pig could arise from the nature and amount of the non-identified fraction of its NFE rather than from the presence or absence of fibre in these feedstuffs, respectively. The estimated values of ileal and total digestibility of DM, energy and nonidentified organic matter contained in the NFE from the diet components, as well as the DE and ME values, are given in Table 7. The results found with molasses Type A alone have been used to estimate torula yeast and soybean meal assuming non-associative effects (Ly et al., 1984; Diaz et al., 1989). The starch values were calculated from torula yeast figures. It could be observed that the ileal digestibility of the non-identified NFE fraction varied greatly according to the nature of the feeds used: molasses components had the poorest digestibility whereas those of soybean meal were the most digestible. Thus the TABLE 7 Ileal and total digestibility and energy values of the dietary ingredients Molasses Type A
Torula yeast
Soybean meal
Starch
Apparent ileal digestibility Dry matter Gross energy Non-identified organic matter
84 83 14
61 50 43
65 58 65
87 91
Apparent total digestibility Dry matter Gross energy Non-identified organic matter
94 94 79
83 80 87
89 86 88
100 100
Digestible energy (MJ kg -1 DM) Metabolizable energy (MJ kg -1 DM) Metabolizable energy: digestible energy Metabolizable energy: gross energy
14.3 13.5 0.94 0.88
16.6 15.8 0.95 0.77
16.5 15.4 0.93 0.81
16.8 16.6 0.99 0.99
DIGESTIBILITYSTUDIESONPIGSFEDDIFFERENTDIETS
159
ME: GE ratio was found to be 0.88 for molasses Type A and 0.99 for cassava starch, corresponding to 13.5 MJ ME kg -1 DM for molasses Type A. On the other hand, digestibility sites were also different: post-ileal digestibility was completed by 42 and 34% for torula yeast and soybean meal, respectively. Also, 82% of these substances disappeared in this part of the gastrointestinal tract with molasses Type A, in spite of its rather low digestibility. Cassava starch values were similar to maize starch (Fingerling, 1932). Ileal and total digestibilities of DM were slightly superior for torula yeast, which in turn were similar to other previous results obtained in situ (Ly et al., 1984) or in vitro (Maylin et al., 1985). Experimental data obtained from pigs fed molasses Type A indicate a high ileal digestibility of carbohydrates together with a very poor digestibility of the non-identified substances of NFE. Thus, diet formulation and pig management must consider that this fraction reduces the molasses energy density in terms of ME. From the above-mentioned statement, it could be suggested that the molasses non-identified organic substances of the NFE fraction might act as an indicator of its nutritive value.
REFERENCES Association of Official Analytical Chemists, 1975. Official Methods of Analysis. 12th Edn. A.O.A.C., Washington, DC. Bayley, H.S., Figueroa, V., Ly, J., Maylin, A. and P~rez, A., 1983. Utilization of sugar cane final molasses by the pig: energy metabolism. Can. J. Anim. Sci., 63: 455-462. Binkley, W.W. and Wolfrom, M.L., 1953. Composition of cane juice and cane final molasses. Adv. Carbohydr. Chem., 8: 291-314. Cunningham, H.H., Friend, D.W. and Nicholson, J.W.G., 1963. Observations. Can. J. Anim. Sci., 43: 215-225. Dahlqvist, A., 1964. Method for assay of intestinal disaccharidases. Anal. Biochem., 7: 18-25. Darcy, B. and Laplace, J.P., 1981. Bilans nutritionals chez le porc selon la nature de l'amidon (bl~ ou mais) et la source de prot~ines (poisson ou gluten). Ann. Zootech., 30: 63-76. Darcy, B., Laplace, J.P. and Villiers, P.A., 1981. Digestion dans l'intestine grele chez le porc. 4. Cin~tique de passage des digesta au niveau de la jonction ileo-caeco-colique, et bilans de la digestion selon la nature de l'amidon et la source de prot~ines alimentaires. Ann. Zootech., 30: 31-62. D/az, C.P. and Marrero, L., 1978. Broken rice and final molasses for pig fattening. Cuban J. Agric. Sci., 12: 177-184. Dfaz, R., Figueroa, V., Ly, J., P~rez, A., Maylin, A and Bayley, H.S., 1989. Digestibilidad aparente y absorbabilidad prececal en cerdos alimentados con miel final y miel final m~s levadura torula o desperdicios proeesados. Cienc. T~c. Agric. Ganado Porcino, in press. Duncan, D.B., 1955. Multiple range and multiple F test. Biometrics, 11: 1-42. Figueroa, V. and Macfa, M., 1988. The isolation of a non-sugar fraction from sugar cane molasses and its effect when included in rat diets. Cuban J. Agric. Sci., 22: 171-178. Fingerling, G., 1932. Investigation into the matter and energy metabolism of growing pigs. Landw. Vers. Sat., 113: 273-318.
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v. FIGUEROAET AL.
Holmes, J.H.G., Bayley, G.S. and Norney, F.D., 1973. Digestion and absorption of dry and highmoisture maize diets in the small and large intestine of pigs. Br. J. Nutr., 30: 401-410. Honing, P., 1953. Principles of Sugar Technology. Elsevier, Amsterdam. Ivan, M., and Farrell, D.J., 1976. Nutritional value of wheat. 5. Disappearance of components in digesta of pigs prepared with two reentrant cannulae. Anim. Prod., 23:111-119. Just, A., 1982. The influence of crude fibre from cereals and the net energy value of diets for growth in pigs. Livest. Prod. Sci., 569-580. Keys, J.E. and De Barthe, J.V., 1974. Site and extent of carbohydrates, dry matter, energy and protein digestion and rate of passage of grain diets in swine. J. Anim. Sci., 39: 57-62. Ly, J., Figueredo, M.A., Dfaz, R. and Garcfa, C.J., 1984. Efecto de la miel final de carla o del azdcar refinada sobre el balance de nitrdgeno en cerdos alimentados con levadura torula. Cienc. Tdc. Agric. Ganado Porcino, 7: 47-54. Ly, J., Maylin, A., Pdrez, A., Ramfrez, A., Carrillo, O. and Figueroa, V., 1985. Pdrdidas de energfa urinaria en cerdos alimentados con miel A de carla y levadura torula. Evento cientffico XX Aniversario. Instituto de Ciencia Animal, La Habana, p. 17. Macfa, M., Ly, J., Dfaz, R., Maylin, A. and Arias, T., 1981. Digesti6n de la sacarosa, glucosa y fluctosa en el cerdo. ! Congr. Nac. Cienc. Biol6gicas, La Habana, p. 216. Mason, V.C. and Just, A., 1976. Bacterial activity in the hindgut of pigs. I. Its influence in the apparent digestibility of dietary energy and fat. Z. Tierphysiol. Tierernaehr. Futtermittelkd., 36: 301-310. Maylin, A., Figueroa, V., Ly, J., Herndndez, M. and Avila, E., 1985. Efecto del formaldehido sobre la digestibilidad in vitro de la levadura torula en crema. Evento cientffico XX Aniversario. Instituto de Ciencia Animal, La Habana, p. 41. National Research Council, 1979. Nutrient Requirements of Swine. 8th Edn. National Academy of Science, NAS-NRC, Washington, DC. Nelson, N., 1944. A photometric adaptation of the Somogyi method for the determination of glucose. J. Biol. Chem., 153: 375-380. Pdrez, A., Figueroa, V., Ly, J., Maylin, A. and Bayley, H.S., 1984. Utilization of sugar cane final molasses by the pigs: Composition of ileal digesta. Can. J. Anim. Sci., 64: 147-158. Sambrook, I.E., 1979. Studies on digestion and absorption in the intestines of growing pigs. 7. Measurements of the flow of total carbohydrate, total reducing substances and glucose. Br. J. Nutr., 42: 267-277. Steel, R.G.D. and Torrie, J.H., 1960. Principles and Procedures of Statistics. McGraw-Hill, Toronto. Yokota, M. and Fagerson, I.S., 1971. The major volatile components of molasses. J. Food Sci., 36: 1092-1094. RESUME Figueroa, V., Maylin, A., Ly, J., Perez, A., Carrillo, O. et Bayley, H.S., 1990. Digestibilit~s ildale et fdcale chez des porcs recevant des rdgimes h base de mdlasse de type A ou d'amidon suppldmentds par de la levure Torula ou du tourteau de soja. Livest. Prod. Sci., 25:151-161 (en anglais ). Un effectif total de 48 porcs d'environ 40 kg de poids vif a dtd utilisd dans des ~tudes de digestibilitd portant sur de la mdlasse de type A, de la m~lasse suppl~mentde en levure Torula ou en tourteau de soja, et de l'amidon de manioc additionnd de levure Torula. La moitid des animaux dtaient munis de canules rdentrantes dans l'ildon terminal, les autres 6tant conservds intacts pour des dtudes de digestibilit~ conventionnelle. L'extractif non azotd constituait la fraction indigestible principale: 39% pour la mdlasse de type A et 52-67% pour les autres rdgimes. La digestibilitd ildale des glucides solubles des rdgimes h base
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de m~lasse ~tait de 96%, indiquant que l'extractif non azot~ indigestible 6tait principalement compos~ de substances organiques non identifi~es contenues dans les m~lasses de type A. La disparition de l'energie dans le gros intestin repr~sentait 12% de l'~nergie dig~r~e dans tout le tractus gastro-intestinal dans le cas des mdlasses de type A, et de 18 h 20% pour les autres r~gimes. L'excr6tion d'~nergie dans l'urine dtait significativementplus ~lev~e dans les r~gimes ~ base de m~lasses que dans ceux qui renfermaient de l'amidon, indiquant un plus faible rapport entre l'~nergie mgtabolisable et l'~nergie brute dans le cas des premiers (0,85 vs. 0,90). Les teneurs en ~nergie digestible et en ~nergie m~tabolisable ~taient respectivement de 14,3 et 13,5 MJ kg-1 MS pour les m~lasses de type A, et de 16,8 et 16,6 MJ kg -~ MS pour l'aliment ~ base d'amidon de manioc. Compte tenu de la digestibilit~ il~ale ~lev~e des glucides des m~lasses de type A, la faible digestibilit~ il~ale et totale des substances organiques non identifiSes rdduit consid~rablement leur densit~ ~nerg~tique, et constitue donc un index de la valeur nutritionnelle des m~lasses. KURZFASSUNG Figueroa, V., Maylin, A., Ly, J., Perez, A., Carrillo, O. und Bayley, H.S., 1990. Untersuchungen zur ilealen und zur gesamten Verdaulichkeit der Schweine bei Fiitterung von Di/iten auf der Basis Melasse Typ A oder St~ke mit Torula Hefe oder Sojabohnenschrot. Livest. Prod. Sci., 25:151-161 (aufenglisch). Insgesamt 48 Schweine einer Lebendmasser von etwa 40 kg wurden for Verdaulichkeitesstudien eingesetzt. Bei Ftitterung von Melasse des Typs A, Melasse plu Torula Hefe oder plus Sojabohnenschrot und yon Cassava St/irke plus Torula Here. Die Hiilfte der Schweine war mit Umleitungskantilen im terminalen Ileum versehen, w~ihrend die andere H~ilfte intakt lief for konventionelle Verdaulichkeitsuntersuchungen. N-freie Extraktstoffe machten der GrSf~ten Teil der nicht verdauten Fraktion aus: 39% for Melasse Typ A und 52 bis 67% for die tibrigen Diiiten. Die ileale Verdaulichkeit der 16slichen Kohlenhydrate in den Melassedi~iten betrug 96%, was darauf hinweist, da£ die nicht verdauten N-freien Extraktstoffe im wesentlichen Bestandteile der nichtidentifizierten organischen Substanz in der Melasse des Typs A waren. Die im Dickdarm verdaute Energie machte 12% der insgesamt verdauten Energie aus im Falle der Melasse Typ A und 18 bis 20% bei den anderen Diiiten. Die Energieausscheidung im Harn war signifikant grSf~er bei Melasse-Diiiten als bei denen auf der Basis Stiirke, was darauf hindeutet, da/~ das Verhiiltnis zwischen umsetzbarer und BruttoEnergie bei Melasse-Diiiten niedriger ist als bei St/irke-Di~iten (0,85 gegentiber 0,90 ). Die Gehalte an verdaulicher und an umsetzbarer Energie for Melasse Typ A waren 14,3 und 13,5 MJ kg -1 Trockenmasse und 16,8 und 16,6 MJ kg-1 Trockenmasse fOr Cassava-Diiiten. Gegeniiber der hohen ilealen Verdaulichkeit fOr Kohlenhydrate der Melasse Typ A reduzierten die niedrigen ilealen und gesamten Verdaulichkeiten der nicht identifizierten organischen Substanzen in erheblichen Maf~e die Energiedichte, womit sie als Indikator fOr den Niihrwert der Melasse angesehen werden kSnnen.