The influence of steam pelleting and grinding on the nutritive value of Canola rapeseed for poultry

Effect of seed source and pelleting temperature during steam pelleting on apparent metabolizable energy value of full-fat canola seed for broiler chickens

Eleven canola seed (CS) samples were collected from different commercial feedmills and crushing plants in Australia and analyzed for nutrient profile. Six of these samples were selected to determine the effect of seed chemical composition and pellet temperature (PT) during steam pelleting on apparent metabolizable energy corrected for nitrogen (AMEn) values of CS for broiler chickens using a 6 × 2 factorial arrangement of treatments. The CS samples were incorporated into a corn-soybean meal diet at 15% by replacing energy-yielding ingredients, and diets were steam pelleted at either 75 or 90°C. A total of 420 18-day-old male broiler chicks (Ross 308) was assigned to 14 experimental diets replicated 6 times, with 5 chicks per cage. After a 5-day diet acclimation period from d 18 to 22, excreta were collected for 72 h using the substitution method to determine AME and AMEn. There was no interaction of seed source and PT for ileal digestible energy (IDE), AME, or AMEn values of CS (P > 0.05). PT did not affect energy availability of CS (P > 0.05) but increasing the PT improved the pellet durability index of the diets by approximately 5.0 percentage points. A significant effect of seed source was detected for all the energy utilization values of CS (P < 0.05). The IDE, AME, and AMEn values of seed samples ranged from 5,239 to 5,645, 4,728 to 5,071, and 4,501 to 4,791 kcal/kg of DM, respectively. The mean AMEn values were 4,664 kcal/kg of DM, indicating a 5.7% reduction compared with AME values. There was a negative correlation between protein and fat content of the seeds (r = -0.93, P = 0.001), and, consequently, AMEn (r = -0.32, P = 0.009). AMEn values were positively correlated with fat content of CS (r = 0.649, P = 0.001). These results indicate that fat and protein content and fiber components may have a considerable effect on energy availability of CS for broiler chickens.

Multi-carbohydrase and phytase supplementation improves growth performance and liver insulin receptor sensitivity in broiler chickens fed diets containing full-fat rapeseed

The effect of a combination of carbohydrase and phytase enzymes on growth performance, insulin-like growth factor 1 gene expression, insulin status, and insulin receptor sensitivity in broiler chickens fed wheat-soybean meal diets containing 6% (starter) and 12% (grower-finisher) of full-fat rapeseed (canola type; low glucosinolate, low erucic acid) from 1 to 42 d of age was studied. A total of 510 one-day-old male broiler chickens were randomly assigned to 3 dietary treatments, with 17 pens per treatment and 10 birds per pen. The dietary treatments consisted of a control diet and P- and Ca-deficient diets supplemented with either phytase (500 U/kg) or a combination of phytase and a multi-carbohydrase enzyme (Superzyme OM). The diets were pelleted at 78 degrees C and were fed ad libitum throughout the starter (9 d), grower (18 d), and finisher (15 d) phases of the experiment. Over the entire trial, growth performance of birds fed the phytase-supplemented diet did not differ from birds fed the control diet. The use of phytase in combination with a multicarbohydrase enzyme improved (P = 0.007) the feed conversion ratio from 1.90 to 1.84. Insulin liver receptor sensitivity increased by 9.3 and 12.3% (P = 0.004) for the phytase- and the carbohydrase-phytase-supplemented diets, respectively. There was no effect of phytase alone or carbohydrase and phytase supplementation on total plasma cholesterol, high-density lipoprotein cholesterol, and blood glucose levels. However, low-density lipoprotein cholesterol decreased (P = 0.007) for the phytase-carbohydrase treatment. Gene expression of insulin-like growth factor 1 tended to decrease by 32% (P = 0.083) after phytase-carbohydrase supplementation. The combination of carbohydrase and phytase enzymes may serve as an attractive means of facilitating nutrient availability for digestion and thus enhance the feeding value of wheat-soybean meal-based diets containing full-fat rapeseed. However, the extent to which the effects of enzyme addition on insulin receptors are associated with growth performance of broiler chicken requires further research.

Nutritional evaluation of triple low rapeseed products for growing pigs

Ground full-fat rapeseed (FFRS) and the resulting extracted oil (RSO), meal (RSM) and recombined RSO and RSM (ORSM) from a triple-low cultivar containing low levels of erucic acid, glucosinolates and tannins were evaluated. RSO, FFRS and ORSM were included into a basal diet to give levels of added oil of 40, 80 and 120g/kg. RSM was also incorporated into the basal diet at the same rates as in ORSM. The 12 experimental diets together with the basal diet were given to 13 gilts in a metabolism trial conducted over four time periods. A 10-day acclimatization in holding pens preceded a 5-day total collection of faeces and urine in metabolism crates. Rapeseed products, diets, faeces and urine were analysed for gross energy (GE) and all, except urine, for oil content measured by two methods (petroleum ether and acid hydrolysis prior to ether extraction). Apparent digestible energy (DE) and metabolizable energy (ME) of rapeseed products were determined by single-level assay and by regression. Oil DE was also derived indirectly as a product of apparent oil digestibility (AOD) and oil GE. Apparent nitrogen digestibility was estimated for diets and rapeseed products. The response of dietary DE, ME and AOD to rates of test material inclusion was linear (P < 0·001) in all cases except for ORSM and RSM the DE and ME of which, in addition, showed evidence of curvilinearity. Age of pig had no significant effect on dietary AOD and energy values. Linear regression techniques were better than single level assays (particularly at low rates of inclusion) in determining energy values and gave DE values of 42·4, 190, 14·6 and 25·8 MJ/kg dry matter for RSO, FFRS, RSM and ORSM respectively. Oil DE and AOD were not influenced by method of evaluation. The results of this study indicated improved energy values for FFRS and RSM of a triple-low cultivar over published data for high-glucosinolate varieties but not over data for double-low varieties. In addition it appears that AOD is the main factor determining dietary utilization of FFRS and would need to be considered in order to optimize the nutritive value of FFRS in diets for growing pigs.

The use of enzyme technology for improved energy utilization from full-fat oilseeds. Part I: canola seed

The effect of carbohydrase enzyme supplementation on energy utilization from full-fat canola seed was investigated in a TMEn assay with adult roosters and in a nutrient digestibility and growth performance study with broiler chickens. In the TMEn assay, enzyme preparations C (cellulase, 340 U/g), XG (xylanase, 63,600 U/g and glucanase, 48,300 U/g), P (pectinase, 10,000 U/g), and MC (mannanase, 10,900 U/g and cellulase, 600 U/ g), alone and in combination (C + P, C + XG, C + MC, P + XG, P + MC, XG + MC, C + P + XG, C + P + MC, and C + P + XG + MC), were evaluated at an inclusion level of 0.1%. On average, hammer-milled canola seed with a TMEn content of 3,642 kcal/kg showed an increase (P < 0.05) to 4,783 kcal/kg following supplementation with the enzyme blends C + P + XG, C + P + MC, and C + P + XG + MC. A similar pattern of increase (P < 0.05) in fat (80.4 vs. 63.5%) and nonstarch polysaccharide (NSP; 20.4 vs. 4.4%) digestibilities was observed. Enzyme combination C + P + XG was further evaluated in a 2-wk (5- to 18-d) trial with broiler chickens fed isonitrogenous and isoenergetic corn and soybean meal-based diets containing canola seed (15%), the corresponding canola meal (8.85%) plus canola oil (6.15%) mixture, or canola seed (15%) supplemented with 3 different levels (0.002, 0.01, or 0.05%) of the enzyme. Poorer (P < 0.05) feed:gain (1.412 vs. 1.344), lower (P < 0.05) total tract DM (65.9 vs. 70.7%) and fat (69.6 vs. 88.0%) digestibilities, lower AMEn content (2,963 vs. 3,200 kcal/kg), and lower ileal fat (65.6 vs. 85.6%) and protein (75.6 vs. 81.2%) digestibilities were observed for the canola seed diet compared with the canola meal plus canola oil diet. Enzyme supplementation of the canola seed diet resulted in an improvement (P < 0.05) in feed:gain; total tract DM, fat, and NSP digestibilities; AMEn content; and ileal fat digestibility. Although the enzyme effect on ileal and total tract fat digestibilities was significant at both high and medium inclusion levels, other parameters showed the significant improvement only when the highest inclusion rate of enzyme was used. These data support the need for carbohydrase enzyme supplements in poultry diets containing full-fat canola seed.

Barley and full-fat canola seed in broiler diets

Barley and full-fat canola seed (FFCS), with or without an added enzyme mixture, were evaluated in experiments with broiler chicks. In Experiment 1, test diets contained barley, wheat, and soybean meal and were supplemented or unsupplemented with raw FFCS (10%) or canola meal (6%). The control was a wheat-soybean meal diet. Diets were fed to male and female broiler chicks for 7 wk. The diet supplemented with raw FFCS produced significantly (P less than .05) lower weight gains than the other diets. There were elevated levels (P less than .05) of linoleic and linolenic acids (18:2 omega 6; 18:3 omega 3) in tissue lipids of chicks fed raw FFCS. In Experiment 2, broiler chicks were fed diets containing a steam-pelleted barley-FFCS mixture (80:20), included at a 50% level, along with supplemental barley. Total barley level in the experimental diets was 50%. 45%, and 40%. A barley-soybean meal diet was used as a control. All diets were fed with and without an enzyme supplement. Chicks fed the barley-FFCS diets were similar to those fed the control diet in respect to production parameters and carcass characteristics. Supplementation of diets with the enzyme mixture resulted in significantly larger body weight gains and lower feed:gain ratios. In Experiment 3, enzyme supplementation increased (P less than .01) the ME of the steam-pelleted barley-FFCS mixtures and the mixed feed containing barley-FFCS. Data from Experiment 4 indicated that there were no significant differences in availability among amino acids from barley, FFCS, or pelleted barley-FFCS mixture diets.

Effects of increasing dietary levels of full-fat canola on performance, nutrient retention, and bone mineralization

Day-old male broiler chickens were fed diets containing 0, 5, 10, 15, or 20% raw, ground, full-fat canola for a period of three weeks. Increasing the dietary proportion of full-fat canola significantly reduced feed intake (P less than .05) and weight gain (P less than .01), without altering feed:gain ratio. Diet had no significant effect on protein retention although there was a significant decrease in fat retention with an increase in dietary levels of full-fat canola (P less than .01). This was accompanied by a significant decrease in metabolizable energy (P less than .01). Increasing the proportion of dietary full-fat canola significantly reduced the concentration of soap in the digesta (P less than .05) and excreta (P less than .01). There was no significant effect of the dietary treatments on calcium or phosphorus retention. There was also no effect of the dietary full-fat canola on bone ash, bone calcium, or phosphorus content.