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 price of feed ingredients, hog producers are looking for alternative sources of energy and protein in order to reduce costs, without compromising performance.
Producers in Western Canada have a range of alternative ingredients available, including distillers grains, faba beans, peas, extruded canola meal, flaxseed and lentils.
The question is how to use them to maximum advantage.
Researchers at the University of Alberta have an ongoing program of nutritional research which provides guidance for producers and their nutritionists. One of their most recently completed trials looked at feeding lentils to weaner pigs.
“Lentil is an important export legume seed produced in Western Canada,” said Dr. Ruurd Zijlstra, associate professor in the department of agricultural, food and nutritional science. “Most of the 1.3 million tonnes of lentil production is exported to the Indian subcontinent and the Middle East for human food consumption. Due to quality concerns of this year’s Canadian crop and the large increase in domestic pulse crop in India, lentil is available for feed at 40 per cent of regular cost.”
LESS CRUDE PROTEIN
Compared to soybean meal, lentil contains less crude protein (18 to 35 per cent) and amino
Peet on Pigs
acids, but provides more net energy, Zijlstra notes. Replacing dietary soybean meal with lentil could have an economic advantage when surplus production or low food-grade lentil is available for inclusion into swine diets, he says.
“Limited research has been conducted feeding lentils to swine,” Zijlstra said. However, previous reports indicate that inclusion of up to 40 per cent of lentils, entirely replacing soybean meal in the diet, may not affect growth performance of grower-finisher pigs.”
The recommended inclusion in diets for weaned pigs is 10 to 20 per cent, although some reports indicate that substitution of soybean meal with up to 30 per cent of lentils in the diet does not reduce weaned pig performance, he said.
There is a suggestion that the anti-nutritional factors contained in lentil seed might limit its inclusion, especially in diets for young pigs. A recent trial carried out at the University of Alberta and reported by Dr. Zijlstra and Jose Landero from the university, together with Dr. Eduardo Beltranena from Alberta Agriculture and Rural Development, suggests that the growth performance of nursery pigs is maintained with levels of lentil of up to 22.5 per cent in the diet.
The sample of green lentil used in the trial contained 27.3 per cent crude protein, 1.0 per cent crude fat, 4.1 per cent crude fibre, 1.75 per cent lysine, 1.62 per cent available lysine, 0.89 per cent threonine, 0.19 per cent methionine, 0.42 per cent phosphorus, and 3.0 mg/g of trypsin inhibitor activity (TIA), the anti-nutritional factor. “This level of TIA is normal for lentil, slightly higher than for field pea, and lower than for chickpea,” said Dr. Zijlstra.
The feeding trial was conducted to evaluate the effects of feeding increasing levels of lentil (zero, 7.5, 15, 22.5 or 30 per cent) on growth performance and diet digestibility. “The diets fed were formulated to provide 2.33 Mcal/kg net energy (NE) and 5.0 g standardized ileal digestible lysine per Mcal NE with other amino acids formulated as an ideal ratio to lysine,” explains Dr. Zijlstra.
“Increasing lentil level progressively replaced the soybean meal in the diets so that 20 per cent soybean meal and 10 per cent wheat was gradually replaced with 30 per cent lentil with a correction for energy and amino acids using canola oil and synthetic amino acids.”
The diets also contained five per cent lactose and five per cent herring meal, as specialty ingredients, Dr. Zijlstra notes. In total, 240 weaned pigs averaging 9.0 kg in weight were fed the trial diets for a period of three weeks. Individual pig body weight and pen feed disappearance were measured weekly.
For the entire 21-day trial, increasing lentil inclusion linearly reduced daily weight gain. “Differences in feed intake were not observed during the 21-day study,” Dr. Zijlstra said. “Pigs maintained final body weight up to 22.5 per cent inclusion of lentil, with similar daily weight gain and feed efficiency.”
However, the 30 per cent inclusion of lentil caused an 11 per cent drop in both daily weight gain and feed efficiency and reduced body weight by six per cent at the end of the trial. Pigs fed 30 per cent lentil were 1.3 kg lighter by the end of the trial than pigs fed diets without lentil.
“Assuming wheat at $207, lentil $215, soybean meal $420, and L-lysine-HCl 2,550 $/tonne, increasing dietary lentil inclusion from zero to 7.5, 15, 22.5, and 30 per cent, reduced feed cost by $1.54, $2.60, $4.13, and $5.19 per tonne, respectively,” Dr. Zijlstra comments. “For 22.5 per cent inclusion of lentil, feed cost per unit of body weight gain was reduced 0.64 cents/ kg.” However, he says, increasing lentil inclusion up to 30 per cent increased feed cost per unit of gain due to reduced animal performance. Feeding more than 22.5 per cent lentil in the diet was not cost effective, Dr. Zijlstra concludes. “The results of this study indicate that lentil inclusion should not exceed 22.5 per cent in diets for weaned nursery pigs to maintain similar performance as those fed a soybean meal diet.”