Manitoba Agriculture, Food and Rural Initiatives

Alternative Proteins: Amino Acid Supplements, Canola And Peas And Determining When To Use Them To Reduce Cost

Sam Kofi Baidoo, Ph.D. P.Ag.
Department of Animal Science, University of Manitoba
Winnipeg, Manitoba   R3T 2N2 
 

Introduction

Animal agricultural is going through a major overhaul with increasing emphasis placed upon developing sustainable agricultural production systems. These production systems are influenced by factors such as genotype, feed availability, animal health, management, various environmental and socio-economic factors. The feeds comprising 95 percent or more of any diet can be categorized into three general classifications, namely:

1. starchy or energy grains
2. protein supplements
3. fibrous feeds

The remaining 5 percent of the diet consist of major and trace minerals, vitamins and feed additives if required.

Since more expenditure is incurred in the purchase of pig feed than in all the other costs of pig production combined, this article will discuss a segment of feed usage, the use of alternative proteins available in Western Canada for pig production.

Index:

Dietary Protein
Diet Formulations on the Basis of Amino Acids
Unit Value of Nutrients from Alternative Protein Sources

Alternative Protein Sources:
Soybean
Canola
Peas

Conclusion
References

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Dietary Protein

Swine do not have a requirement for protein per se, but rather a requirement for specific amounts of essential amino acids and adequate amounts of non-specific nitrogen. Therefore, the value of feed proteins for pigs relates to their amino acid composition in comparison to the balance required by the pig. If the amino acid balance in feed protein and the amino acid balance required by the pig are in perfect balance, then the protein in the feed stuff may be expressed as a protein value of unity (V=1.0). The proteins of some feed ingredients such as spray dried porcine plasma, soybean meal and fish meal confer high protein values to the diet, while others such as the protein of cereals (deficient in lysine) confer a lower protein value to the diet. Reduced protein value may result from a relative deficiency in any one of the essential amino acids, such as lysine, threonine, methionine or tryptophan. These essential amino acids may routinely be added as synthetic amino acid if it is cost effective. A given protein requirement can be satisfied by provision of a higher quantity of protein of lower value or a lower quantity of protein of higher value. Whittemore (1993) provided guidelines for estimating the lower limits dietary protein appropriate to various classes of pigs. These guidelines were used in calculating the protein value of various classes of pigs.

Protein of high value will be utilized more efficiently by the pig, but it may not be cost effective always to use less of a higher quality protein as compared to using more of a lower quality but cheaper protein. Protein values can be calculated from the dietary level of lysine (first limiting amino acid) when the pigs requirement expressed in terms of ideal protein is 0.07g lysine per 1 g of protein as follows:

V = (lysine in diet (g/kg CP) / CP in diet (g / kg ) / 0.07

Using the Nutrient Requirements for Pigs (1998) Table 1 provides the protein values required by various classes of swine.

Table 1. Concentration of Diets for Different Classes of Swine

Class (Weight Range, kg)	ME density (MJ /kg)	CP density (g/kg)	CP (g/MJ ME)	Lysine (g/kg)	Lysine (g / MJ ME)	Protein Value (V)
Starter I (3 - 5)	15.8	260	16.5	13.4	0.84	0.73
Starter II (5 - 10)	15.5	240	15.5	11.9	0.76	0.71
Starter III (10 - 20)	15.0	210	14.0	10.1	0.67	0.69
Grower I (20 - 50)	15.0	180	12.0	8.3	0.55	0.66
Grower II (50 - 80)	14.5	155	10.7	6.6	0.44	0.61
Finisher (80 - 120)	14.0	132	9.4	5.2	0.37	0.56
Pregnant Sow	12.5	125	10	4.6	0.37	0.52
Lactating Sow	14.0	180	12.8	8.1	0.58	0.64
Boar	12.5	130	10.4	6.0	0.48	0.66

A high protein value requirement indicates that that class of pig requires protein of high quality thus supplying the essential amino acids in the right proportions. The level of amino acids in cereal grains required for normal growth of the pig is insufficient in lysine, methionine, threonine and tryptophan particularly when used for young pigs. For optimum performance, therefore, the diet should contain an alternative source of protein which will supply the necessary amino acids which are deficient in cereal grains.

Diet Formulations on the Basis of Amino Acids

With the present knowledge of the amino acid requirements of swine and the amino acid composition of feedstuffs, the formulation of diets on the basis of amino acids rather than crude protein is a much more precise approach. Furthermore, only the first-limiting amino acids needs to be considered because normally when the diet satifies the requirement for lysine, the requirement for all of the other amino acids are usually satisfied. Therefore, diets could be formulated on a lysine basis. Levels of threonine, methionine and tryptophan should be checked to ensure that the requirements for these amino acids have been satisfied. In addition, the digestible amino acid content of ingredients is important because not all of the amino acids in feedstuffs are biologically available to the pig. Thus the formulation of diets on a digestible amino acid basis enables the effective use of alternative ingredients and allows for excellent performance. The differences in amino acid digestibilities among grains are relatively small. Differences in digestibilities among high protein feedstuffs tend to vary more than cereal grains. Amino acid digestibility in soybean meal, fishmeal and blood meal tend to be higher than Canola meal, and peas. Therefore, to satisfy the protein value, large quantities of Canola meal and peas will be required as compared to soybean meal, fishmeal or blood meal.

The amino acid requirements of swine can usually be met from intact proteins such those from barley, wheat, corn, soybean meal, Canola meal and peas or they can be provided by crystalline amino acids. Generally, it is much cheaper to use intact proteins to provide most of the amino acids needs, but crystalline sources of some amino acids are now available at prices that often merit their inclusion in swine diets. The current prices of synthetic amino acids are ($/kg): lysine (2.15); Methionine (4.7); Threonine (5.2) and Tryptophan (17.0).

Unit Value of Nutrients from Alternative Protein Sources

In order to judge the relative economic worth of different feed stuffs, it is important to compare the unit value of digestible protein, ileal digestibility of amino acids, especially lysine and energy. Feed ingredients with higher concentrations of the required nutrients are more valuable than feed ingredients of lower nutrient concentration. Unit values of nutrients in alternative protein supplements is presented in Table 2.

Table 2. Unit Values of Nutrients in Alternative Protein Supplements.

Protein Supplements	Price ($/kg)	ME (MJ/kg)	CP (g/kg)	Lysine1 (g/kg)	c / MJ ME	c / g CP	c / g lysine1
Spray dried porcine plasma	5.85	----	780	64.2	------	0.75	91.1
Sprayed dried blood	1.40	12.3	888	67.1	11.4	0.15	20.9
Fishmeal (herring)	1.20	13.6	681	51.9	8.8	0.17	2.3
Fishmeal (menhaden)	1.05	14.1	629	45.7	7.4	0.16	2.3
Whey powder	0.78	13.3	121	7.3	5.8	0.64	10.7
Meat and bone meal	0.26	9.3	515	24.6	2.8	0.05	1.1
Soybean meal	0.25	14.1	475	27.2	1.8	0.05	0.9
Canola meal	0.15	11.0	356	16.2	1.3	0.04	0.9
Peas	0.16	13.4	228	13.2	1.2	0.07	1.2
1True Ileal digestible basis

In Table 2, the cheapest sources of energy, protein and true ileal digestible lysine are soybean meal, Canola meal and peas. The cost for 1 MJ ME, 1 g CP and 1 g lysine is calculated on the basis of the whole of the feedstuff price being apportioned to each nutrient. This is used for purposes of comparison and least cost formulations. Each of these three ingredients have different characteristics and different inclusion levels for pigs.

Alternative Protein Sources:

Soybean

Soybean (Glycine max) is the most widely used high-quality source of protein supplement in swine diets. Soybean bean meal is a ground by-product of the oil extraction process from whole soybeans. Two types of soybean meal are normally available and their composition is shown in Table 3.

Table 3. Composition of Seed and Meal from Soybean and Canola and Peas.

Criteria	Soybean seeds	Soybean Meal (47 - 50%)	Soybean Meal (44%)	Canola Seed	Canola Meal	Peas
ME (MJ /kg)	15.4	13.3	13.3	15.4	11.0	13.4
Crude Protein (%)	35.2	47.5	44.0	21.7	35.6	22.8
Lysine (%)	2.22	3.02	2.83	1.20	2.08	1.50
Methionine (%)	0.53	0.67	0.61	0.60	0.74	0.21
Threonine (%)	1.41	1.85	1.73	0.95	1.59	0.78
Trptophan (%)	0.48	0.65	0.61	0..27	0.45	0.19
Crude fat (%)	18.0	3.0	1.5	39.7	3.5	1.2
NDF (%)	13.9	8.9	13.3	12.72	21.2	12.7
ADF (%)	8.0	5.4	9.4	10.32	17.2	7.2
Calcium	0.25	0.34	0.32	0.39	0.63	0.11
Phosphorus	0.59	0.69	0.65	0.64	1.01	0.39

Soybean must be heat treated to inactivate a trypsin inhibitor and hemaglutenins in raw soybeans and to ensure good protein quality. Inadequate heat treatment to destroy these inhibitors will result in poor performance of young pigs. Whole soybean seeds can be successfully fed to sows with any effect on performance. For all classes of pigs, soybean meal is the preferred protein supplement in their diets. The widespread availability, high protein, lysine and energy content as well as its palatability and the cost per unit nutrient in soybean meal has made it more favourable to use over that of the other alternative protein sources such as Canola meal and peas.

Canola

Canola (Brassica campestris or Brassica napus) is cultivated in temperate regions of the world. Canola is defined as containing less than 30 m moles of glucosinolates and less than 2% erucic acid. Previously, these two constituents of rapeseed meal had impaired its use in swine diets. Canola is an oil seed because of its high oil content compared to soybean and peas as presented in Table 3. Thus full fat Canola seed can be regarded as a high energy, relatively high protein supplement. The addition of fat to swine diets has been shown to increase growth rates and improve feed conversion efficiency for growing pigs. Whole Canola seed can be incorporated in rations for pigs as a source of energy and protein.

The inclusion of 15% raw ground full fat Canola seed did not affect feed intake, average daily gain, or feed efficiency; however, a marked reduction in feed intake and daily gain was seen at 30% inclusion level as presented in Table 4.

Table 4. Performance of Starter Pigs Fed Diets Containing Whole Canola Seed

Level of Canola Seed	0	7.5	15	30
Initial Weight (kg)	7.8	7.9	7.9	7.8
Final Weight	21.1	20.6	21.3	19.5
Avg. Feed Intake (g)	661a	694a	634a	505b
Avg. daily gain (g)	474a	454a	478a	415c
Feed : Gain	1.4	1.5	1.3	1.2
abc Means in the same row followed by different letters differ significantly (P<0.05) (Shaw et al. 1990)

Canola meal is the product remaining following the solvent extraction of Canola oil. The composition of the meal is reasonably consistent, because the pooling of meal during processing minimizes variation. Canola meal has long been used in swine diets with not much deleterious effect on performance. For young pigs, because of lower feed intake and reduced average daily gain (Table 5), it is generally recommended that Canola meal be should not be used however, new studies currently in progress with enzyme supplementation to Canola meal based diets for young pigs at the University of Manitoba indicates an improvement in performance for young pigs utilizing Canola meal.

Table 5. Performance of starter pigs (6-20 kg) fed diets supplemented with soybean meal (SBM) and Canola meal(CM)

SBM/CM ratio	100% SBM	75%SBM 25% CM	50%SBM 50%CM	25%SBM 75%CM	100CM	SE1	Sig2
Level of CM in diet (%)	0	8.8	17.6	26.5	35.3
Number of pigs	12	12	12	12	12	12
Mean daily feed (g)	660	630	584	560	535	25.15	***
Mean daily gain (g)	392	378	349	333	303	15.06	***
Feed/gain ratio	1.69	1.67	1.68	1.68	1.77	0.01	NS
1 Standard error of the mean. 2 Significance of linear regression equation: ***, p<0.001; NS, non significant (p>0.05). (Baidoo et al. 1987)

In the growing phase, Canola meal can be included at levels up to 50% of the total protein supplemental protein in the diet as presented in Table 6.

Table 6: Performance of starter pigs (20- 60 kg) fed diets supplemented with soybean meal (SBM) and Canola meal(CM)

Item	100% SBM	75%SBM 25% CM	50%SBM 50%CM	25%SBM 75%CM	100CM
Level of CM in diet (%)	0	4.6	9.1	13.2	19.6
Number of pigs	32	32	32	32	32
Initial wt (kg)	20.2	20.4	20.1	20.5	20.5
Final wt (kg)	61.3	62.4	62.4	62.6	61.7
Mean daily feed (kg)	2.17	2.13	2.08	2.00	2.01
Mean daily gain (kg)	0.78a	0.77a	0.76a	0.73b	0.71c
Feed/gain ratio	2.78	2.78	2.70	2.70	2.70
abc Means in the same row followed by different letters differ significantly (p<0.001) (Baidoo et al. 1987)

For finishing pigs, Canola meal can be used as the only protein supplement source as presented in Table 7. Canola meal is a proven supplemental protein source in the diets of pigs. Although negative palatability and reduced digestibility of Canola meal for young (6 - 20 kg) pigs prevent its use at levels greater than 25% of supplemental protein in these diets, Canola meal is a desirable supplemental dietary protein for growing, finishing and reproducing swine. Canola meal can be used at 50 - 75% of the supplemental protein source in diets for growing (20 - 60 kg) pigs and as the sole supplemental dietary protein source for finishing pigs (60 - 110kg) and dry and nursing sows.

In the finishing period complete supplementation of Canola meal did not affect performance compared to pigs on soybean meal.

Table 7: Mean Performance of Growing-Finishing pigs fed Diets Supplementation with Soybean Meal (SBM) and Canola Meal (CM)

Item	100% SBM	75%SBM 25% CM	50%SBM 50%CM	25%SBM 75%CM	100CM	SE1
Growing period
Level of CM in diet (%)	0	4.6	9.1	13.2	19.6
Number of pigs	48	48	48	48	48
Initial wt (kg)	20.8	20.8	20.8	20.7	20.8	0.16
Final wt (kg)	61.5	61.4	61.1	60.5	60.4	0.71
Mean daily feed (kg)	1.86	1.83	1.80	1.79	1.79	0.08
Mean daily gain (kg)	0.78a	0.74a	0.74a	0.71b	0.69b	0.008
Feed/gain ratio	2.40	2.58	2.47	2.51	2.61	0.05
Finishing period
Level of CM in diet (%)	0	2.8	5.5	8.0	12.0
Number of pigs	24	24	24	24	24
Initial wt (kg)	62.9	61.6	61.3	60.8	60.8	.031
Final wt (kg)	92.4	91.6	91.5	91.1	90.6	0.36
Mean daily feed (kg)	2.73	2.72	2.72	2.69	2.69	0.06
Mean daily gain (kg)	0.90	0.91	0.88	0.85	0.83	0.008
Feed/gain ratio	3.03	2.99	3.09	3.16	3.24	0.14
Overall period
Number of pigs	24	24	24	24	24
Mean daily feed (kg)	2.19	2.09	2.08	2.05	2.02	0.11
Mean daily gain (kg)	0.85a	0.81a	0.78ab	0.76b	0.73b	0.009
Feed/gain ratio	2.59	2.58	2.65	2.72	2.84	0.14
1 Standard error of the mean. ab Means in the same row followed by different letters differ significantly (p<0.001) (Baidoo et al. 1987)

Peas

There is renewed interest in the use of peas as a source of protein in animal feeds. As a result the pea crop production in Western Canada ha been increasing as peas are becoming an important cash crop. The major factors contributing to the popularity of are the nutritional value and economics. Peas are high in digestible energy and protein (Table 2). However, peas are relatively low in methionine therefore, supplementation with the synthetic amino acid is required for optimum growth. In a comparative study (Jaikaren et al. 1995), pigs were weaned at 21 and 28 days and fed diets supplemented with peas from 0 to 20%. Pigs weaned at 28 days were better able to handle the pea diets than those weaned at 21 days (Table 8).

Table 8: Performance of 21 - day pigs fed diets supplemented with peas

Pea Level (%)	0	5	10	15	20	Sig1
Initial wt (kg)	6.3	6.4	6.4	6.4	6.3	NS
Final wt (kg)	22.4	22.5	22.0	22.0	21.5	NS
ADG (g)	510	500	500	510	490	*
ADFI (g)	760	780	770	770	750	*
Feed: Gain	1.48	1.59	1.54	1.52	1.53	*
1Statistical significance (P<0.05); NS: non-significant (P>0.5)

The results of the study indicates pea can be incorporated in the diets of young pigs at levels up to 15% of the diet without causing adverse effects on animal performance. Early weaned (16-d old ) pigs fed diets containing 30% of heat processed peas performed equally well to the soy bean control group as presented in Table 8.. Thermal processing by extrusion of micronization of peas can increase the inclusion of peas in the diets of 16 d old pigs to 30% inclusion rate from 4 to 10 kg live body weight and 35% from 10 to 20 kg body weight without affecting performance. All these diets were formulated on ideal protein basis with appropriate supplementation of lysine, methionine and threonine.

Peas at 50% of the diet for growing pigs and 40% of the diet for finishing pigs are not recommended if methionine is not added as shown in Table 9. The deficiency of sulfur amino acids in the diets with 50% peas may reduce pig performance during the growing period and diets with 40% peas without methionine supplementation in the finishing period may affect carcass quality. The addition of threonine to the diets with peas had no beneficial effect on pig performance. The nutritive value of peas should be based on their lysine content rather than their protein content. Replacement of soybean meal by a combination of peas and Canola meal at a ratio of one to one may result in a more balanced diet for pigs and such a combination may reduce amino acid imbalance and feed cost. Table 10 shows performance of pigs fed a blend of Canola meal with yellow variety and green variety of peas. Pigs fed blends of Canola meal and peas without synthetic lysine the addition of synthetic amino acid supplementation performed as the soybean meal fed pigs and better than fed pigs fed the Canola meal supplemented diets.

Table 9: Effect of pea processing on the performance of 16-d old pigs.

	SBM - C	Raw Peas	Extruded Peas	Micronized Peas
Starter Phase 1 (4 - 10 kg )
Level of peas	0	30	30	30
ADG (g)	316	247	270	323
ADFI (g)	540	578	570	594
Feed:Gain	1.26	1.43	1.37	1.36
Starter Phase 1 (10 - 20 kg )
Level of peas	0	35	35	35
ADG (g)	575	532	502	580
ADFI (g)	699	866	802	866
Feed:Gain	1.27	1.63	1.54	1.46
Overall Starter Period (4 - 20 kg )
ADG (g)	429	403	416	437
ADFI (g)	699	866	802	866
Feed:Gain	1.26	1.43	1.37	1.36
(Owusu- Asiedu 1998)

Table 10: Effect of supplemental essential amino acids in utilization of peas by growing - finishing pigs.

	Dietary Treatment
	Peas	-	+	+	+	+	-
	Lysine	-	-	-	-	-	+
	Methionine	-	-	-	+	+	-
	Threonine	-	-	-	-	+	-	SE1
Level of peas		0	34	50.5	34	50.5	0	0.81
Initial wt (kg)		23.6	24.7	25.2	25.5	24.5	23.6
Final wt (kg)		52.0b	53.5b	54.5b	56.4ab	58.0a	52.0b	1.53
Daily feed (kg)		1.96ab	1.95b	1.95b	2.01ab	2.09a	1.96ab	0.05
Daily gain (kg)		0.86ab	0.80b	0.81b	0.85ab	0.92a	0.86ab	0.03
Feed/gain ratio		2.28a	2.44b	2.41ab	2.36ab	2.28a	2.28a	0.06
Level of peas		0	26	39.5	26	39.5	0
Initial wt (kg)		57.4	55.7	56.9	58.1	60.2	57.3	1.24
Final weight (kg)		100.4	103.5	102.8	101.6	103.1	101.2	0.97
Daily gain (kg)		0.88	0.91	0.88	0.90	0.90	0.87	0.03
Daily Feed (kg)		3.15	3.05	2.92	3.09	2.98	3.02	0.15
Feed/gain ratio		3.55	3.37	3.34	3.42	3.30	3.47	0.11
Overall
Daily feed (kg)		2.62	2.53	2.50	2.66	2.69	2.58	0.09
Daily gain (kg)		0.87	0.87	0.85	0.88	0.91	0.85	0.02
Feed/gain ratio		3.01	2.93	2.95	3.00	2.95	3.03	0.07
1 Standard error of the mean. ab Means in the same row followed by different letters differ significantly (p<0.005)

Table 11. Effect of peas and canola meal on the performance of growing - finishing pigs

	Dietary Treatment
	Peas	-	-	Tipu	Radley	Tipu	Radley
	Canola meal	-	+	-	-	+	+
	Lysine	+	+	-	-	-	-	SE1
Level of CM (%) Level of Pea (%)		0 0	18 0	0 50	0 50	10.5 17.5	10.5 17.5
Initial wt (kg)		20.1	20.2	20.1	20.0	20.1	20.4	0.32
Final wt (kg)		50.9	47.7	49.3	50.8	51.2	53.0
Daily feed (kg)		1.39	1.47	1.47	1.45	1.39	1.47	0.05
Daily gain (kg)		0.66a	0.52b	0.57ab	0.59ab	0.61ab	0.61ab	0.03
Feed/gain ratio		2.10b	2.91a	2.60ab	2.47ab	2.30ab	2.41ab	0.23
Level of CM (%) Level of Pea (%)		0 0	15 0	0 39.5	0 39.5	8 13.4	8 13.4
Initial wt (kg)		50.9	47.7	49.3	50.8	51.2	53.0	2.92
Final wt (kg)		99.3	98.6	100.9	100.6	99.1	99.0	2.10
daily feed (g)		2.72	2.66	2.58	2.53	2.59	2.71	0.15
Daily gain (g)		0.91	0.85	0.91	0.88	0.82	0.88	0.07
Feed/gain ratio		3.05	3.17	2.86	2.90	3.19	3.07	0.15
Overall (20 - 100kg )
daily feed (g)		2.34	2.28	2.27	2.23	2.25	2.24	0.17
Daily gain (g)		0.80	0.75	0.81	0.79	0.77	0.78	0.06
Feed/gain ratio		2.39	3.04	2.80	2.82	2.92	2.87	0.15
1 Standard error of the means ab Means within row with different superscript are different (P<0.05)

Conclusion

The alternative protein supplements to soybean meal available in Western Canada in sufficient quantities which can be effectively incorporated into the diets of all classes of pigs, are peas and canola (seed or meal). For young pigs (6 - 20 kg), it usage should be limited to 25% of supplemental protein, for growing pigs (20 - 60 kg) to 50 - 75% of the supplemental protein and as the sole supplemental dietary protein for finishing pigs (60 - 100kg). The addition of enzymes could improve the utilization of canola by growing pigs as current studies in progress at The University of Manitoba indicates.

Peas can also be used effectively for all classes of pigs. The diets for pigs based on peas should be properly balanced for the required essential amino acids. The nutritive effect of anti-nutritional factors in peas can be reduced by thermal processing, such as extrusion or micronization and by the addition of exogenous enzymes to the diets. These processes will increase the inclusion rate of peas in young pig diets to 30%. The rate inclusion of peas with supplemented sulfur amino acids should be 50% for grower pigs and for 40% for finisher pigs.

References

1. Baidoo, S. K., B. N. Mitaru, F. X. Aherne and R. Blair. 1987. The nutritive value of Canola meal for early weaned pigs. Anim.Feed Sci.Technol. 18:45-53.

2. Baidoo, S. K., F.X. Aherne, B. N. Mitaru, and R. Blair. 1987. Canola meal as a protein supplement for growing-finishing pigs. Anim.Feed Sci.Technol. 18:37-44.

3. Jaikaran, S. S.K. Baidoo and F.X. Aherne. 1995. Methionine supplementation of grower and finisher swine diets containing two varieties of field peas. Proceedings, Western Section, Amerian Society of Animal Science Vol. 46:19-22.
   
4. Marquart, R. R. and J.M. Bell, 1988. In: Future Potential of Pulses for Use in Animal Feeds. R. J. Summerfield (ed). World Crops: Cool Season Food legumes. Kluwer Acad. Publ. Pp 421-444.
   
5. Shaw, J. S. K. Baidoo and F. X. Aherne. 1990. Nutritive value of Canola seed for young pigs. Anim. Feed Sci. Technol. 28:325-331.
   
6. Owusu-Asiedu. A. 1998. Utilization of peas by early weaned pigs. M. Sc. Thesis, Department of Animal Science, University of Manitoba, Winnipeg, Manitoba.

7. Stefenshyn, B., Cole, M., Fleury and L Ellwood, L., 1998. Research Summaries: Canola and Peas in Livestock diets
   
8. Whittmore, C., 1993. Diet formulation. In: The Science and Practice of Pig Production: Longman Group Limited, UK. Pp393-431.