Bernie Peet is president of Pork Chain Consulting Ltd. of Lacombe, Alberta, and editor of Western Hog Journal. His columns will run every second week in the Manitoba Co-operator.
With the current high feed prices, hog producers are continually looking for ways to cut costs without compromising pig performance. Nowhere is this more true than in the nursery, where the most expensive diets are consumed. Many producers are cautious about substituting cheaper raw materials for the traditional protein source of soybean meal because they are concerned that growth rate will be affected.
However, recently published data from trials at the University of Alberta suggest that higher levels of solvent-extracted canola meal than previously recommended can be used in nursery diets.
Canola meal is a cost-effective feedstuff for swine diets, says Dr. Ruurd Zijlstra, Associate Professor at the U of A. Compared to soybean meal, canola meal contains less crude protein (44 vs. 34 per cent, respectively) and lower net energy content (2.06 vs. 1.75 Mcal/kg, respectively). Therefore, canola meal is sold at a discount relative to soybean meal based on its lower nutrient content and the perceived risks associated with inclusion of canola co-products in pig and poultry diets.
Dr Zijlstra explains that the inclusion of canola meal in young pigs has been associated with a reduction in growth performance, likely due to its relatively high fibre level and the presence of compounds called glucosinolates which give a bitter taste to the meal. However, he points out, recent research conducted at the University of Alberta has shown that 15 per cent canola meal inclusion can partially replace soybean meal in the diet, without reducing body weight gain in weaned pigs.
GLUCOSINOLATE LEVELS ARE DOWN
A trial was conducted to evaluate the effects of feeding increasing levels of canola meal (0, 5, 10, 15 or 20 per cent) on growth performance and diet nutrient digestibility. It was carried out at the Swine Research and Technology Centre in Edmonton at the University of Alberta. On an as-is basis, the sample of canola meal used in the diets contained 34.0 per cent crude protein, 3.5 per cent crude fat, 9.3 per cent crude fibre, 2.0 per cent lysine, 1.8 per cent available lysine, 1.56 per cent threonine, 0.71 per cent methionine, 0.98 per cent phosphorus, and 3.84 mol/g glucosinolates.
The glucosinolates level is 50 per cent lower than values reported almost 10 years ago for solvent-extracted canola meal, notes Dr. Zijlstra. This is why we can use higher levels of canola meal in pig diets without impacting feed intake.
The pelleted diets fed were formulated to provide 2.3 Mcal/kg net energy (NE) and 5 g standardized ileal digestible lysine per Mcal NE with other amino acids formulated as an ideal ratio to lysine, Dr. Zijlstra says.
Increasing the canola meal level (0, 5, 10, 15 or 20 per cent) progressively replaced the soybean meal in the diets, balancing for energy and amino acids using canola oil and crystalline amino acids.
Lactose, soy protein concentrate and herring meal at 5 per cent each, were included in the diets as specialty ingredients, he adds. The trial involved 220 weaned pigs of about 8 kg in initial weight, which were housed in 55 pens of four pigs each and had free access to the assigned pelleted diet for four weeks, starting one week post-weaning.
Over the entire period of the trial, increasing the level of canola meal in the diet did not affect body weight gain, feed intake and feed efficiency, explains Dr. Zijlstra. The final weight of weaned pigs was 21.7, 22.0, 21.5, 22.3 and 21.9 kg for 0 to 20 per cent canola meal, respectively (Figure 1).
However, increasing the dietary inclusion of canola meal linearly decreased the total tract digestibility of crude protein from 82.4 to 79.1 per cent and diet digestible energy value from 3.97 to 3.91 Mcal/kg of DM. The reduced nutrient digestibility was expected based on gradual increases in dietary fibre, he comments. These reductions in nutrient digestibility were of small magnitude and evidently did not affect pig performance.
Dr. Zijlstra points out that substituting soybean meal with canola meal results in significant savings in diet cost. Assuming wheat at $207/tonne, canola meal $255, soybean meal $420, and L-lysine- HCl $2,550, increasing dietary canola meal inclusion from 0 to 5, 10, 15, and 20 per cent, reduced feed price by $2.80, $5.60, $8.90, and $11.90 per metric tonne, respectively, he says.
For the 20 per cent inclusion of canola meal diet, feed cost per unit of body weight gain was reduced almost two cents/kg.
Canola meal is a locally-produced co-product currently included in grower-finishing pig diets, and can be a potential source of supplemental protein for young pigs, Dr. Zijlstra says. This year in Canada, Prairie producers have seeded a record of acres of canola and the production of canola meal is also expected to increase. This provides hog producers with an ideal opportunity to reduce production costs and extend the use of canola meal to nursery pigs, resulting in significant savings.
Figure 1: Overall trial growth performance of weaned pigs fed increasing level of canolameal in the diet for 28days starting 1 week post-weaning