2. Nutrient Specifications of Full-Fat Canola Seed
Nutrient levels of FFCS analyzed in various Canadian poultry trials and compounded from the annual harvest survey are shown in Table 11. However, nutrient analysis of FFCS is recommended, especially if off-grades of canola are used in poultry rations.
| Table 11. Proximate composition of full-fat canola seed (as-fed basis, referenced from Canadian sources). | ||||||||||
| Dry matter % | 92.76 | 93.03 | 94 | 91.0 | Calcium% | 0.35 | ||||
| Cr. protein % | 20.89 | 20.42 | 20 | 3.0 | 23.4 | 20.8 | Magnesium % | 0.30 | ||
| Cr. fibre % | 12.54 | 7.4 | 7.3 | Potassium % | 0.50 | |||||
| Ether extract % | 41.94 | 39.74 | 41.4 | 40.0 | 42.1 | Sodium % | 0.01 | |||
| Gross Energy kcal/kg | 6470 | 6800 | 6524 | 6360 | Copper, ppm | 6 | ||||
| TMEn Poultry kcal/kg c | 4560 | Manganese, ppm | 33 | |||||||
| AMEn Poultry kcal/kg c | 4460 | Iron, ppm | 200 | |||||||
| Zinc, ppm | 25 | |||||||||
| Reference # | {480a} | {326} | {452} | {553} | {1852} | {313 b } | {480a} | |||
a Means of triplicate determinations, air-dry basis. b Means from Canadian canola harvest surveys (1982 - 1996) at 8.5% moisture basis.
c Metabolizable energy values determined using SCWL cockerels
Ground, FFCS was analyzed to contain 400 mg kg-1
total tocopherol, but after twenty days at room temperature the
tocopherol level was reduced to 25 mg kg-1 by weight
(Gopalakrishnan et al. 1996 {306}). Two European canola
cultivars were analyzed to contain 66-83 mg kg-1 DM
a-tocopherol
and 112-128 mg kg-1 DM g-tocopherol.
Full-fat canola seed was supplemented at 350 g kg-1
into broiler diets, and supplied 25% of the a-tocopherol
and 85% of the g-tocopherol.
The apparent digestibility of a-tocopherol
for the periods 10-16, 18-23 and 25-30 days of age was 42.0, 62.2
and 62.8%, respectively. The digestibility of g-tocopherol
was 44.1, 60.4 and 61.2 % for the same periods. The relative
availability of supplemented and endogenous tocopherol components
was not determined in this study (Lui et al. 1995 {334}).
The reduction of tocopherol in crushed FFCS (400, 250 and 200
mg kg-1 at 0, 20 and 40 d. room temp.) indicated its
relative stability under these conditions. The comparatively
rapid rate of tocopherol disappearance from a commercial poultry
diet stored under the same conditions (500, 100 mg kg-1
and trace levels, respectively) was indicative of greater oxidative
pressure. The potential value of FFCS as a source of a-tocopherol
in compounded diets needs to be determined.
Average xanthophyll values (n=5) for Brassica
rapa and B. napus seed were 21.7 and 35.4 mg kg-1
on an air-dry basis, respectively, which may exceed levels found
in yellow corn (Blair and March, 1989 {500}).
3. Feeding Full-fat Canola to Broilers and Turkeys
The availability of fat from FFCS has been questioned because ME values were lower than those for corresponding CM plus canola oil mixtures (Lee et al. 1995 {326}). The similarity of fatty acid profiles in FFCS diets and excreta indicated that the fatty acids were incompletely, rather than preferentially, digested. The absorbtion of fat from FFCS diets improved with chick age (>18d.), and authors suggested that young chicks were more sensitive to the high fibre in FFCS (Liu et al. 1995 {334}). Dietary fibre levels did not differ significantly between test materials; therefore, this may instead support reports of reduced dietary fat utilization by young chicks (Wiseman and Salvador, 1991(endnote).
The potential for reduced fat availability suggests certain precautions should be observed by the on-farm and commercial feed mixer when using FFCS: ensure a viscosity-reducing enzyme is used in barley or wheat-based diets to enhance fat absorption, use lower levels of FFCS in the diet of very young birds, and least-cost the diets to determine if FFCS is more economical than the CM plus canola oil alternative. Studies indicated that flaking (grinding) FFCS improved weight gain and feed conversion in young turkeys consuming mash diets. Raw, whole FFCS did not require flaking, heating or extrusion if the diets were steam-pelleted (Salmon et al. 1988, {517}). Blending FFCS with cereals, peas or CM prior to grinding is reported to prevent the high fat levels from occluding the hammer-mill screen (Fasina et al. 1997 {304}).
| Table 12. Amino acid analysis of full fat canola seed (as-fed basis, referenced from Canadian sources). | |||||||
| Amino Acid Content | True Amino Acid Availability | Apparent Amino Acid Availability | |||||
| Asp % | 1.5 | 1.82 | 1.48 | 1.39 | 94 | 81.6 % ± 5.6 | 72.9 % ± 5.0 |
| Glu % | 4.2 | 5.19 | 3.17 | 97 | 90.0 % ± 1.7 | 85.1 % ± 1.6 | |
| Ser % | 0.9 | 1.13 | 0.8 | 0.89 | 94 | 84.3 % ± 2.5 | 74.7 % ± 2.2 |
| His % | 0.7 | 0.66 | 0.6 | 0.81 | 90 | 93.7 % ± 2.1 | 86.9 % ± 2.0 |
| Gly % | 1.3 | 1.41 | 1.00 | ||||
| Thr % | 1 | 1.34 | 0.75 | 0.87 | 82.2 % ± 4.2 | 74.2 % ± 3.8 | |
| Arg % | 1.3 | 1.5 | 1 | 1.62 | 100 | 90.5 % ± 3.6 | 81.7 % ± 3.3 |
| Val % | 1.1 | 1.43 | 1.06 | 0.95 | 93 | 83.6 % ± 3.8 | 76.6 % ± 3.5 |
| Phe % | 0.9 | 1.19 | 1.08 | 0.89 | 96 | 87.6 % ± 2.9 | 81.8 % ± 2.7 |
| Ile % | 1 | 1.15 | 0.95 | 0.74 | 93 | 84.6 % ± 3.8 | 78.0 % ± 3.5 |
| Leu % | 1.6 | 1.95 | 1.4 | 1.46 | 94 | 86.8 % ± 3.3 | 80.8 % ± 3.0 |
| Lys % | 1.6 | 1.68 | 1.1 | 1.39 | 95 | 87.9 % ± 3.3 | 78.7 % ± 2.9 |
| Cys % | 0.4 | 0.46 | 71 | ||||
| Met % | 0.4 | 0.4 | 0.48 | 89 | 90.4 % ± 4.0 | 85.4 % ± 4.0 | |
| Ala % | 1.27 | 1.02 | 0.96 | 84.0 % ± 3.0 | 77.2 % ± 2.7 | ||
| Tyr % | 0.72 | 0.5 | 0.63 | 84.1 % ± 3.6 | 74.6 % ± 3.2 | ||
| Ref # | 452c | 326b | 480a | 553 | 452c | 326b | 326b |
a Steam autoclaved, ground FFCS (110 C, 60 seconds); availability analysis using male broilers (21 d.)
b,c Ground, raw FFCS; availability analysis using adult SCWL males.
It should be noted that the diets in Table 13 were not formulated on an available amino acid basis, and this tends to misrepresent the feeding value of FFCS. The high erucic acid content of the FFCS fed to turkeys (Salmon et al. 1988 {517}) may have had an antinutritional effect; therefore, the maximum level of inclusion determined may be unrealistically low for modern "double-low" canola cultivars. Also, the reduced flavor desirability of leg muscle from broilers fed high FFCS-triticale diets may have been due to fat oxidation during tissue storage at -18°C for 6 months prior to sensory evaluation, rather than a direct negative effect of FFCS on fresh muscle flavour.
| Table 13. Results from feeding trials involving different levels of canola oil or canola oil byproducts. | ||
| Reference | Treatment | Effect or result |
| Broilers and Turkeys - Canadian Studies | ||
| {436} Lee et al. 1991 | Diets containing FFCS (100 or 200 g kg-1) vs. corn-soy control in males broilers from 0-6 weeks. | Body weight, FC and carcass yield were numerically, but not significantly (P>0.05) reduced from control. A 10% dietary FFCS maximum recommended. |
| {480}Nwokolo & Sim 1989 | FFCS(100 g kg-1) - barley diets vs. CM+canola oil(100 g kg-1) - barley, barley-SBM, or wheat-SBM diets; no viscosity-reducing enzyme used. | Body weight gain was reduced on barley-FFCS diet (P<0.05). |
| {517} Salmon et al. 1988 | High-erucic FFCS* (0, 165 or 330 g kg-1) in wheat-soy diets for Medium White turkeys 0-12 weeks. | Liveweight and FC equivalent to control at 165 g kg-1 FFCS, reduced at 330 g kg -1 FFCS |
| Broilers - European | ||
| {413} Gardzielewska et al. 1992 | High triticale(50%)-FFCS(12%) and low triticale(35%)-FFCS(10%) vs. corn-wheat-SBM control in broilers from 0-8 weeks. | High triticale-FFCS diets reduced flavour desirability of leg meat stored at -18°C for 6 months (P<0.05). |
| {321} Roth et al. 1995 | FFCS diets (5 to 25%) vs. wheat-SBM control in male broilers from 0-6 weeks. | Body weight reduced at 5% FFCS inclusion; higher FFCSlevels further reduced performance (P<0.05) |
| {355} Kinal 1994 | FFCS (5%) replaced equal amount of wheat in grower and finisher of broilers 0-8 weeks. | FFCS diet had improved weight gain at 3 weeks. (P<0.01), but were equivalent to control at 8 weeks. |
| {365} Fritz et al. 1993 | FFCS(8-14%)-wheat-SBM vs. wheat-corn-SBM control in mixed sex broilers from 0-8 weeks. | Weight gain and meat quality were equal (P>0.05); FC improved (P<0.05) on FFCS diets |
* Erucic acid was 59% of fatty acids in FFCS.
4. Feeding Full-fat Canola Seed to Laying and Breeding Hens
There are no recent Canadian studies regarding FFCS levels in laying hen diets. Reviews of work prior to 1988 recommended at least 100 g kg-1 raw, whole FFCS could be included in rations for white-shelled layers ( van Kempen and Jansman, 1994 {358}). Bell (1988, {516}) concluded that it may be necessary to grind, but not cook, FFCS before using it in diets.
European studies using FFCS recommended lower rates
of inclusion. The performance of laying hens consuming 10% dietary
FFCS did not differ significantly (P>0.05) from the control
group, except weight gain was reduced. Sensorical quality of
eggs was not affected by feeding up to 25% FFCS in diets (Roth-Maier
and Kirchgessner, 1995{321}). Full-fat canola seed was fed to
meat-type pullets in starter and grower rations (6.0 and 7.5 %
FFCS, respectively) without any effects on thyroid hormones, fertility
and hatchability at 52 weeks. Body weight was reduced at 7 weeks.
in birds consuming FFCS diets; however, significantly higher levels
of wheat and barley were also used in these diets without enzyme
supplementation (Swierczewska et al. 1995 {327}).
Guenter, W. 1990. Unpublished data.
Heartland Lysine. 1995. True digestibility of essential amino acids for poultry - 1995. Heartland Lysine, Inc. Chicago. Illinois.
Wiseman, J. and Salvador, F. 1991. The influence of free fatty acid content and degree of saturation on the apparent metabolizable energy value of fats fed to broilers. Poultry Science. 1991; 70:573 - 582.