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Feeding value of cull lentils for growing and finishing swine
Lentils are often downgraded due to chipping, wrinkling or staining. For example, it is estimated that 61% of Saskatchewan lentils in 2014 will be feed grade. Two trials were conducted to provide data on the feeding value of cull lentils for swine. The first trial used 10 ileal cannulated growing pigs (35 to 60 kg BW) fed 1 of 5 diets. Treatments were a lentil-free control, plus 4 treatments arranged as a 2 x 2 factorial (15 or 30% inclusion x 2 lentil samples [grade 2 or 3]) in a RCBD with 3 periods. Total tract DE and apparent ileal digestible AA (AID) was determined, and NE was calculated (NRC, 2012). Nutrient content of the lentils was calculated by difference using the 15% inclusion level, as an interaction between sample and digestibility was observed at the 30% level. The CP content was comparable between the 2 samples (25.4%). Crude fibre (45.2 and 36.1% for grade 2 and 3, respectively) and fat (6.7 and 12.3% EE; grade 2 and 3, respectively) varied. The NE content of the grade 2 sample (2.28 Mcal NE/kg) was 60 kcal lower than the grade 3 sample (2.34 Mcal NE/kg) and the AID of AA (ranged from 28 to 55% for the 18 AA measured) of the grade 2 sample was 30 to 40% lower than the grade 3 sample. In the second experiment, these NE and AID values were used to formulate isonitrogenous, isoenergetic diets with 0, 10, 20 or 30% inclusion of the grade 3 sample and fed to 200 growing (35 to 60 kg) and 200 finishing pigs (90 to 120 kg). There was no effect of lentil inclusion on ADFI or feed efficiency (P > 0.10). Lentil inclusion had no effect on ADG of the grower pigs (P > 0.10) but increased ADG (linear, P= 0.02) in the finishing pigs (1.02, 1.02, 1.03, 1.07 kg/d; 0, 10, 20 and 30% inclusion levels, respectively) indicating that AA and energy digestibility values determined in the growing pig underestimated the nutritive value for finishing pigs. Up to 30% cull lentils can be included in the diets of both growing and finishing swine with no adverse effects on ADG, ADFI or feed conversion. Proximate analysis (CF, EE, CP) can be used to estimate if individual lentil samples will have nutrient values comparable to that reported here.
Keywords: lentils, swine, digestibility