The nutritive value of Tower rapeseed meal for swine

Animal Feed Science and Technology, 3 (1978) 235--242 © Elsevier Scientific Publishing Company, Amsterdam - - Printed in The Netherlands

THE NUTRITIVE

VALUE OF TOWER RAPESEED

235

MEAL FOR SWINE

F.X. AHERNE and A.J. LEWIS* Department o f Animal Science, University o f Alberta, Edmonton, Alberta T6G 2E3 (Canada) *Present address: Department of Animal Science, University of Nebraska, Lincoln, NE 68583 (U.S.A.) (Received 6 F e b r u a r y 1978)

ABSTRACT Aherne, F.X. and Lewis, A.J., 1978. The nutritive value of Tower rapeseed meal for swine. Anita. Feed Sc£ Technol., 3: 235--242. Two experiments involving 144 Yorkshire x Lacombe gilts, with an average initial weight o f 20 kg, were conducted. In Experiment 1 the gilts were allotted to a control diet containing soya bean meal (SBM) or to diets in which either 50% or all of the supplementary protein was provided by Tower rapeseed meal (RSM). In the second experiment the two diets had either SBM or Tower RSM as the supplementary protein source. In a third diet Tower RSM was supplemented with sufficient lysine to equal the calculated available lysine level of the SBM control diet. In Experiment 1, gilts given the SBM diet grew from 20 to 60 kg significantly faster (P<0.01), and had better feed conversion efficiency (P<0.01), than those given the RSM diets. A 50% replacement of SBM b y Tower RSM gave intermediate results. Partial or total replacement of SBM by Tower did not significantly affect the growth rate or feed conversion efficiency of the gilts when growing from 60 to 100 kg liveweight. Serum triiodothyronine (T3) and thyroxine (T4) concentrations of the gilts at 100 kg were lower in pigs fed on the RSM diets b u t the differences were n o t significant. In the second experiment, total replacement of SBM by Tower RSM, with or without the addition of lysine, significantly (P<0.001) reduced growth rate and feed conversion efficiency during the growing period (20--60 kg) but did not significantly affect performance during the finishing period (60--90 kg). Serum T3 concentration was not significantly affected by the addition of Tower RSM to the diet b u t T4 concentrations were significantly reduced (P< 0.01). None of the carcass parameters studied were significantly affected by the addition o f Tower RSM to the diets.

INTRODUCTION A l l s w i n e e x p e r i m e n t s t h a t h a v e c o m p a r e d T o w e r r a p e s e e d m e a l (a l o w g l u c o s i n o l a t e r a p e s e e d m e a l o f Brassica n a p u s t y p e ) w i t h r e g u l a r r a p e s e e d meal have demonstrated the superiority of the low glucosinolate meal as a p r o t e i n s o u r c e f o r p i g s ( M c C u a i g a n d B e l l , 1 9 7 6 ; M o o d y e t al., 1 9 7 6 ; C a s t e l l , 1977a). In a second experiment by Castell (1977b) the addition of 7.5% Tower rapeseed meal (RSM) to the diets of pigs in the starter period, or 12.5%

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subsequently, resulted in a significant (P< 0.05) decrease in growth rate and feed conversion efficiency. M o o d y et al. (1976) and Grandhi et al. (1976) also observed a reduction in the performance of growing pigs fed on diets in which some or all of the soya bean meal (SBM) in the diet was replaced b y Tower RSM, b u t the differences were not significant. This reduction in the performance of growing pigs fed on Tower RSM could be due to (1) the lower energy content or higher glucosinolate level of the diet (Castell, 1977b), or (2) the lower availability of the lysine of RSM compared to that of SBM (Bayley, 1974). The objectives of these experiments were to determine the effects of (1) partial and complete replacement of SBM b y Tower RSM in the diets of growing and finishing pigs, and (2) lysine supplementation of RSM diets on pig performance and carcass quality. MATERIALS AND METHODS

Experiment 1 Seventy-two Yorkshire X Lacombe gilts with an average initial weight of 20.5 kg were allotted within littermate o u t c o m e groups to the 3 dietary treatments shown in Table I. The control diet contained SBM as the supplementary protein source. In Diets 2 and 3, respectively, either 50% or all of the supplementary protein was provided b y Tower RSM. The composition of the RSM was 92.3% dry matter, 39.9% crude protein, 12.0% crude fibre, 6.2% ash and 2.2% ether extract. Total glucosinolate content was 0.98 mg/g. All 3 diets were formulated to Contain 16.5% crude protein, to be isocaloric, and to meet or exceed National Academy of Sciences -- National Research Council (NAS--NRC, 1973) nutrient requirements. During the growing period (20--60 kg) gilts were housed in pairs in 1.2 X 1.2 m partially slotted floor pens. For the finisher period (60--100 kg) the gilts were transferred to 1.5 X 3.9 m solid floor pens and maintained in groups of four. The gilts were allowed unlimited access to feed and water and the environmental temperature was kept at 21--22°C throughout the experiment. Gilts were bled b y vena cava puncture when t h e y reached 100 kg liveweight. Serum was separated and divided into t w o portions~ for analysis of triiodothyronine (T3) and thyroxine (T4) respectively. Samples were stored at •-20°C until analyzed. The T3 was determined b y radioimmunoassay with a kit of reagents (Mallinckrodt/Nuclear, St. Louis, MO 63147), and T4 by a competitive binding method, also with a kit of reagents (Ames Co., Elkhart, IN 96514).

Experiment 2 Complete replacement of SBM b y Tower RSM during the growing period of Experiment 1 significantly (P<0.05) reduced weight gain and feed efficiency of gilts. Because gilts may have a higher requirement for lysine

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TABLE I Formulation and composition of diets containing soya bean meal (SBM) and rapeseed meal (RSM) Diets

Protein supplement Ingredients (%) Barley Wheat Soya bean meal Rapeseed meal (Tower) Tallow Iodized salt Ground limestone Calcium phosphate Mineral and vitamin premix* Calculated analysis** Crude protein (%) G r o s s energy (kcal/kg) Lysine (%)

1

2

3

SBM

SBM/RSM

RSM

40.0 41:5 13.7 0 1.0 0.4 1.2: 1.2 1.0' 16.4 2986 0.76

40.0 38.5 7.4. :9.0 1.3 0.4 1.2 1.2 1.0 16.5 3001 0.73

40.0 36.2 0 !9~0 1.0 0.4 1.2 1.2 1.0 16.7 3010 0.70

*The premix provided the following per kg of diet: 1.20.0 mg zinc; 48.0 mg manganese; 100.0 mg iron; 10.0 mg copper; 750 IU vitamin A; 700 IU vitamin D; 45 IU vitamin E; 12 mg riboflavin; 40 mg niacin; 27 mg calcium pantothenate; 28 t~g vitamin B~2; 500 mg furazolidone. **Air dry basis.

t h a n c a s t r a t e d m a l e pigs ( H e n r y et al., 1 9 7 1 ; T a n k s l e y and E s c o b o s a , 1 9 7 1 ; M e a d e et al., 1 9 7 4 ) , E x p e r i m e n t 2 was d e s i g n e d to d e t e r m i n e t h e e f f e c t s o f lysine s u p p l e m e n t a t i o n o f diets c o n t a i n i n g T o w e r R S M as t h e o n l y p r o t e i n s o u r c e f o r g r o w i n g pigs. S e v e n t y - t w o c r o s s b r e d Y o r k s h i r e × L a c o m b e gilts w i t h an average initial w e i g h t o f 20.1 kg w e r e a l l o t t e d at r a n d o m w i t h i n b l o c k s o f 3 d i e t a r y t r e a t m e n t s . Diets I a n d 2 w e r e similar to Diets 1 a n d 3 in T a b l e I. D i e t 3 was similar t o D i e t 2 e x c e p t t h a t 0 . 0 6 5 % l y s i n e HC1 (0.05% lysine) w a s a d d e d t o e q u a l t h e c a l c u l a t e d available lysine level o f t h e SBM c o n t r o l diet. F o r t h e c a l c u l a t i o n s o f available lysine, a b s o r p t i o n in t h e small i n t e s t i n e w a s a s s u m e d t o be o f 9 1 % f o r t h e l y s i n e o f SBM a n d 8 1 % f o r t h e lysine o f R S M ( B a y l e y , 1 9 7 4 ) . E n v i r o n m e n t a l c o n d i t i o n s a n d f e e d i n g m e t h o d s w e r e similar t o t h o s e d e s c r i b e d f o r E x p e r i m e n t 1. A t 6 0 kg liveweight, s e r u m f r o m e a c h gilt f o r T 3 a n d T 4 assays was c o l l e c t e d as d e s c r i b e d p r e v i o u s l y . E i g h t pigs f r o m e a c h t r e a t m e n t g o u p w e r e c o n t i n u e d f r o m 60 kg t o s l a u g h t e r at 90 kg. T h e carcasses o f all pigs s l a u g h t e r e d at 90 kg w e r e g r a d e d a c c o r d i n g t o t h e C a n a d i a n H o g Carcass V a l u a t i o n S y s t e m ( C a n a d a D e p a r t ment of Agriculture, 1969).

238

S t a t i s t ica l a na l y s e s

The data from b o t h experiments were subjected to analysis of variance. In each experiment the t w o treatment degrees of freedom were partitioned into t w o orthogonal comparisons: an SBM control versus diets containing RSM comparison, and a within RSM comparison. RESULTS AND DISCUSSION

The results of Experiment 1 are presented in Table II. During the growing period, partial or complete replacement of SBM b y Tower RSM did n o t affect the feed intake of the gilts. These results are consistent with those of other experiments in which either high or low glucosinolate RSM did n o t significantly reduce feed intake (Bell, 1975; M o o d y et al., 1976; Castell, 1977b). Pigs fed on the RSM diets had l o w e r growth rates and feed conversion efficiency than pigs fed on the SBM diet. The growth rate and feed conversion efficiency of pigs fed on the SBM/RSM diet were better than those of pigs fed on the diet in which RSM was the only protein supplement. The nonorthogonal comparison (SBM vs. SBM/RSM)indicated that there was no significant difference in the growth rate of pigs fed on the SBM and SBM/RSM diets b u t that feed conversion efficiency of pigs fed on the SBM diet was better. Several other experiments have shown that half of the supplemental protein in starting and growing pig diets can be provided b y low glucosinolate RSM w i t h o u t significantly reducing performance (Omole and Bowland, 1974; TABLE H Experiment 1. Performance of pigs fed on diets containing soya bean meal or two levels of Tower rapeseed meal Diets SBM

SBM/RSM RSM

Significance

Pooled SE

Number of pigs

24

24

24

Grower period ( 2 0 , 6 0 kg) Initial weight (kg) Final weight (kg) Daily feed (kg) Daily gain (kg) Feed/gain

20.4 60,9 2.05 0,73 2.80

20.6 60.7 2.15 0.71 3.05

20.6 60.6 2.19 0.67 3.27

NS NS NS ** **

0.352 0.240 0.036 0.013 0.087

60.9 101.2 3.33 0.79 4.17

60.7 101.3 3.28 0.76 4.32

60.6 101.7 3.26 0.75 4.33

NS NS NS NS NS

0.246 0.553 0.114 0.019 0.143

Finisher period (60--100 kg) Initial weight (kg) Final weight (kg) Daily feed (kg) Daily gain (kg) Feed/gain

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Grandhi et al., 1976, 1977). The only experiment showing a contrary result is that o f Castell (1977b). In that experiment, pigs fed on 7.5% Tower RSM during the starting phase and 12.5% Tower RSM during the growing and finishing phase grew more slowly (P<0.05 and P < 0 . 0 1 , respectively) than pigs fed on SBM supplemented diets. Differences in the protein quality of the batches of Tower RSM used in these experiments or in the level of unprocessed rapeseed contaminating the grain sources, might account for the differences reported in these experiments. In the present study, partial or total replacement of SBM b y Tower RSM did n o t significantly affect the feed intake or performance o f the gilts during the period 60--100 kg liveweight. The serum T3 and T4 concentrations of the gilts at 100 kg were lower in pigs fed on the RSM diets b u t the differences were n o t significant {Table III). These values are lower than those reported b y Grandhi et ah (1976) b u t the trend to lower T3 and T4 levels in RSM fed pigs was also observed in their experiment. The lower levels of T3 and T4 in pigs fed on the RSM diets indicate that, although the glucosinolate content of the Tower RSM used in this experiment was only 0.98 mg/g, thyroid h o r m o n e synthesis may have been impaired. As in Experiment 1, the inclusion of Tower RSM as the only protein supplement for the growing gilt did n o t significantly affect feed intake in Experiment 2 (Table IV). Addition of lysine to the RSM supplemented diet did not significantly influence feed intake. Performance of gilts fed on the RSM diets during the growing period was lower than that of pigs fed on SBM, TABLE III Serum triiodothyronine (T3) and thyroxine (T4) concentrations Treatment

Significance

Pooled SE

SBM

SBM/RSM

RSM

No. of pigs T 3 (ng/100 ml)

24 94.9

22 85.8

22 89.3

NS

5.29

No. o f pigs T 4 (ug/100 ml)

24 3.25

22 2.67

23 2.92

NS

0.240

Significance

Pooled SE

NS

5.18

**

0.22

Experiment 1

Treatment SBM

RSM

RSM + lysine

12 78.5

12 88.1

12 78.2

Experiment 2 No. of pigs T~ (ng/100 ml) T 4 (pg]100 ml)

2.88

1.76

1.71

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b u t t h e r e was n o r e s p o n s e t o t h e a d d e d lysine. T h e lack o f a r e s p o n s e t o lysine s u p p l e m e n t a t i o n o f t h e RSM diets is c o n s i s t e n t w i t h t h e d a t a r e p o r t e d b y M o o d y e t al. (1976). T h e s e a u t h o r s a d d e d 0 . 1 2 5 or 0 . 2 5 0 % lysine t o diets b a s e d on m a i z e a n d RSM f o r y o u n g pigs a n d , a l t h o u g h t h e y o b s e r v e d a t e n d e n c y f o r p e r f o r m a n c e t o i m p r o v e w i t h t h e a d d i t i o n o f 0 . 1 2 5 % lysine, t h e r e s p o n s e was n o t significant. Because: (1) t h e t o t a l lysine c o n t e n t o f the RSM s u p p l e m e n t e d d i e t was e x a c t l y t h e level o f lysine r e c o m m e n d e d b y t h e N A S N R C ( 1 9 7 3 ) f o r t h e w e i g h t r a n g e 20 35 kg; (2) gilts s e e m t o b e m o r e s u s c e p t i b l e t o a lysine d e f i c i e n c y t h a n b a r r o w s {Henry et al., 1 9 7 1 ) ; a n d (3) t h e lysine o f RSM m a y be less available t h a n t h a t o f SBM (Cho a n d B a y l e y , 1 9 7 2 ) , t h e clear lack o f r e s p o n s e t o lysine in this e x p e r i m e n t is s o m e w h a t surprising. Possibly, t h e g l u c o s i n o l a t e level o f t h e diet was r e s p o n s i b l e f o r t h e r e d u c e d p e r f o r m a n c e a n d t h e level o f lysine was n o t a limiting f a c t o r . F o r t h e finishing p e r i o d ( 6 0 - - 9 0 kg), t h e r e w e r e no significant d i f f e r e n c e s b e t w e e n t r e a t m e n t s in f e e d i n t a k e , d a i l y w e i g h t gain or feed c o n v e r s i o n e f f i c i e n c y . N o n e o f t h e carcass p a r a m e t e r s s t u d i e d w e r e s i g n i f i c a n t l y a f f e c t e d b y t h e a d d i t i o n o f T o w e r RSM t o t h e diets or b y s u p p l e m e n t a t i o n o f t h e RSM w i t h lysine (Table V). McCuaig a n d Bell ( 1 9 7 6 ) a n d Castell ( 1 9 7 7 b ) also r e p o r t e d n o significant d i f f e r e n c e s in t h e carcass q u a l i t y o f pigs fed o n RSM and SBM diets. S e r u m T3 c o n c e n t r a t i o n o f pigs at 60 kg liveweight w a s n o t significantly a f f e c t e d b y t h e a d d i t i o n o f T o w e r R S M t o t h e diet, b u t T 4 c o n c e n t r a t i o n s TABLE IV Experiment 2. Performance of pigs fed on diets containing soya bean meal or Tower rapeseed meal with or without lysine supplementation Diets

Significance

Pooled SE

24 20.0 60.7 2.06 0.64 3.18

NS NS NS *** ***

0.218 0.346 0.040 0.008 0.055

8 60.8 91.1 2.46 0.63 3.91

NS NS NS NS NS

0.484 0.466 0.124 0.025 0.087

SBM

RSM

RSM + lysine

Grower period (20--60 kg) Number of pigs Initial weight (kg) Final weight (kg) Daily feed intake (kg) Daily gain (kg) Feed/gain

24 20.3 61.0 2.04 0.72 2.83

24 18.8 60.4 2.06 0.66 3.13

Finisher period (60-90 kg) Number of pigs Initial weight (kg) Final weight (kg) Daily feed intake (kg) Daily gain (kg) Feed/gain

8 61.7 91.2 2.70 0.68 3.97

8 60.0 90.8 2.71 0.69 3.92

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TABLE V Experiment 1. Effects of protein source on several carcass measurements Treatment

Market weight (kg) Carcass weight (kg) Dressing (%) Total backfat$ (cm) Area of loin (cm 2) Lean in ham (%) Ham weight/side (%) Carcass index Canadian ROP index ~

SBM

RSM

Pooled RSM + SE* lysine

89.8 72.5 80.7 10.4 32.9 19.5 26.4 101.9 67.8

90.8 71.9 79.3 9.9 30.3 i9.0 26.1 103.0 67.8

91.1 72.8 80.0 10.2 32.3 19.9 25.9 102.3 68.3

1.13 1.10 0.38 0.20 0.18 0.80 0.48 0.95 0.79

*No differences were significant. $Sum of three measurements (shoulder, back and loin). ~Canadian Record of Performance.

w e r e significantly r e d u c e d (Table III). T h e T 4 c o n c e n t r a t i o n s were l o w e r in t h e 60 kg pigs t h a n were o b s e r v e d w i t h t h e 100 kg pigs in E x p e r i m e n t 1. A significant decrease in T4 level o f RSM fed pigs has also b e e n r e p o r t e d b y B o w l a n d ( 1 9 7 4 ) , and is c o n s i s t e n t w i t h t h e o b s e r v a t i o n s o f Slinger ( 1 9 7 7 ) t h a t t h e relative t h y r o i d weight (mg t h y r o i d / k g b o d y weight) o f pigs fed o n T o w e r RSM was greater t h a n t h a t o f c o n t r o l pigs fed o n an SBM diet. T h e results o f E x p e r i m e n t s 1 and 2 suggest t h a t , a l t h o u g h considerable progress has b e e n m a d e in i m p r o v i n g t h e n u t r i t i o n a l q u a l i t y o f RSM for swine, t h e c o m p l e t e r e p l a c e m e n t o f SBM b y T o w e r RSM in t h e diets o f growing (20 60 kg) pigs will significantly r e d u c e g r o w t h r a t e and feed conversion e f f i c i e n c y . A level o f 9% T o w e r RSM in t h e diets o f growing gilts, t h o u g h still goitrogenic, will n o t significantly r e d u c e t h e g r o w t h r a t e b u t m a y r e d u c e feed c o n v e r s i o n efficiency. It is d i f f i c u l t t o d r a w c o n c l u s i o n s regarding w h i c h a m i n o acid is p o t e n t i a l l y limiting in diets based o n rapeseed meal. A l t h o u g h studies o f t h e a m i n o acid levels o f RSM and t h e i r availability suggest t h a t lysine is p o t e n t i a l l y first limiting, t h e e x p e r i m e n t a l evidence t o d a t e shows t h a t a r e s p o n s e is m o r e likely t o be o b t a i n e d f r o m s u p p l e m e n t a r y m e t h i o n i n e t h a n f r o m lysine (Bell, 1 9 7 5 ) . It is possible t h a t t h e r e d u c e d p e r f o r m a n c e o b s e r v e d w h e n T o w e r RSM replaces SBM in pig diets is a reflect i o n o f its glucosinolate level and fibre c o n t e n t r a t h e r t h a n its p r o t e i n quality. ACKNOWLEDGEMENTS This e x p e r i m e n t was s u p p o r t e d b y a grant f r o m t h e R a p e s e e d Association o f C a n a d a t h r o u g h t h e R a p e s e e d U t i l i z a t i o n Assistance Program. T h e

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assistance of G.L. Stephens, E.I. Maycher and R.J. Mascarin (animal care), A.L. Mehlenbacher (statistical analyses) and Z.P. Kondra (glucosinolate analyses) is gratefully acknowledged. REFERENCES Bayley, H.S., 1974. Absorbabilities of amino acids from rapeseed and soybean meals based upon ileal and fecal flows. 3rd Prog. Rep., Res. Committee, Rapeseed Assoc. Can., Vancouver, B.C., pp. 110--113. Bell, J.M., 1975. Nutritional value of low glucosinolate rapeseed meal for swine. Can. J. Anita. Sci., 55: 61--70. Bowland, J.P., 1974. Comparison of low glucosinolate rapeseed meal, commercial rapeseed meal and soybean meal as protein supplements for growing pigs. Can. J. Anim. Sci., 54: 679--685. Canada Department of Agriculture, 1969. Canada's new hog valuation system. Information Division, Can. Dept. Agric., Ottawa, Ontario. Castell, A.G., 1977a. Effects of cultivar on the utilization of ground rapeseed in diets for growing--finishing pigs. Can. J. Anim. Sci., 57: 111--120. Castell, A.G., 1977b. Effects of virginiamycin on the performance of pigs fed barley diets supplemented with soybean meal or low-glucosinolate rapeseed meal. Can. J. Anim. Sci., 57: 313--320. Cho, C.Y. a n d Bayley, H.S., 1972. Amino acid composition of digesta taken from swine receiving diets containing soybean or rapeseed meals as sole source of protein. Can. J . Physiol. Pharmacol., 50: 513--522. Grandhi, R., Slinger, S.J., Brown, R.G. and Hacker, R.R., 1976. Thyroid hormone synthesis in rapeseed meal fed pigs. J. Anita. Sci., 4 3 : 2 5 2 (Abstract). Grandhi, R., Bowman, G.H. and Slinger, S.J., 1977. Effect of feeding Tower rapeseed meal on carcass quality of heavy weight hogs. In: Proc. Nutr. Conf. Feed Manuf., University of Guelph, Guelph, Ontario. Henry, Y., Rerat, A. and Tomassone, R., 1971. Etude du besoin en lysine du porc en croissance-finition. Application de l'analyse multidimensionnelle. Ann. Zootech., 20: 521--550. McCuaig, L.W. and Bell, J.M., 1976. Rapeseed meal x sex interaction on swine carcasses. Proc. West. Sect., Am. Soc. Anita. Sci., 2 7 : 1 1 2 114. Meade, R.J., Hanke, N.E. and Rust, J.W., 1974. Protein levels and supplementaI lysine for finishing swine. I. Feedlot performance. J. Anim. Sci., 3 9 : 9 7 9 (Abstract). Moody, D.L., Slinger, S.J. and Summers, J.D., 1976. Value of Tower rapeseed products for pigs and turkeys. In: Proc. Nutr. Conf. Feed Manuf., University of Guelph, Guelph, Ontario. National Academy of Sciences - - National Research Council, 1973. Nutrient requirements of domestic animals. No. 2, Nutrient requirements of swine, (7th Rev. Edn.), Washington, D.C. Omole, T.A. and Bowland, J.P., 1974. Copper, iron and manganese supplementation of pig diets containing either soybean meal or low glucosinolate rapeseed meal. Can. J. Anita. Sci., 54: 481--493. Slinger, S.J., 1977. Improving the nutritional properties of rapeseed. J. Am. Oil Chem. Soc., 54: 9~A--99A. Tanksley, T.D., Jr. and Escobosa, A., 1971. Protein levels and lysine supplementation of sorghum--soy diets for Gr--Fswine. J. Anita. Sci., 33:239 (Abstract).