Validation of a commercial 1,2-o-dilauryl-rac-glycero glutaric acid-(6'-methylresorufin) ester lipase assay for diagnosis of canine pancreatitis.

The objectives of this study were fourfold: technical validation of a commercial canine 1,2-o-dilauryl-rac-glycero glutaric acid-(6'-methylresorufin) ester (DGGR) lipase assay, to calculate a reference interval for DGGR lipase by the indirect a posteriori method, to establish biological validity of the assay, and to assess agreement between DGGR lipase and specific canine pancreatic lipase (Spec cPL) assays. Dogs with histologically confirmed acute pancreatitis (n=3), chronic pancreatitis (n=8) and normal pancreatic tissue (n=7) with stored (-80°C) serum samples were identified. Relevant controls were selected. Precision, reproducibility and linearity of DGGR lipase, and the effect of sample haemolysis and freezing, were assessed. Sensitivity and specificity of DGGR lipase and Spec cPL were determined. Agreement between these two parameters was calculated using Cohen's kappa coefficient (κ). The DGGR lipase assay demonstrated excellent precision, reproducibility and linearity. Sample haemolysis and storage at -80°C for 12 months did not influence the assay. DGGR lipase (>245IU/l) and Spec cPL (>400µg/l) both showed poor sensitivity but excellent specificity for acute pancreatitis, and poor to moderate sensitivity but excellent specificity for chronic pancreatitis. Substantial agreement (κ=0.679) was found between DGGR lipase and Spec cPL. The validated DGGR lipase assay had similar sensitivity and specificity for the diagnosis of acute and chronic pancreatitis to Spec cPL. DGGR lipase is a reliable alternative to Spec cPL for the diagnosis of pancreatitis

Effects of Standardized Ileal Digestible Lysine on Growth Performance and Economic Return of 200 to 300 lb Grow-Finish Pigs

A total of 2,099 barrows and gilts (PIC 1050 × DNA 600; initially 198.6 ± 3.72 lb) were used in a 57-d study to determine the optimal dietary standardized ileal digestible (SID) Lys level for approximately 200 to 300 lb pigs in a commercial setting. Pigs were randomly allotted to 1 of 4 dietary treatments with 24 to 27 pigs per pen and 20 replications per treatment. A similar number of barrows and gilts were placed in each pen. Diets were fed over 2 phases (199 to 233 and 233 to 299 lb respectively). Dietary treatments were corn-soybean meal-based. Diets were formulated to 85, 93, 100, or 110% of the 2016 PIC (Hendersonville, TN) SID Lys gilt recommendations with phase 1 SID Lys levels of 0.65, 0.71, 0.77, 0.84%, and phase 2 levels of 0.60, 0.66, 0.71, 0.78%, respectively. Overall (d 0 to 57), increasing SID Lys increased (linear, P \u3c 0.05) overall market weight, F/G, hot carcass weight, Lys intake/d, and Lys intake/kg of gain with an increase in ADG (quadratic, P = 0.020). For economics (d 0 to 57), feed cost per lb of gain increased (linear, P \u3c 0.05) with increased SID Lys. Revenue per pig placed and income over feed cost (IOFC) increased (quadratic, P \u3c 0.10) as the amount of SID Lys increased, and marginally significant evidence of a quadratic response for feed cost per pig placed (P = 0.073). Projecting IOFC for phase 1, the quadratic polynomial (QP) and broken-line linear models estimated the requirement at 110.9% and 96.9%, respectively, to achieve maximum IOFC. For phase 2, the QP estimated the requirement at 96.6% SID Lys to maximize IOFC. In summary, the SID Lys requirement was 97% to 111% of the 2016 PIC recommended Lys requirement for phase 1 and 97% for phase 2 to maximize IOFC

Effects of Standardized Ileal Digestible Lysine on Growth Performance and Economic Return of 108 to 178 lb Grow-Finish Pigs

A total of 2,124 barrows and gilts (PIC 1050 × DNA 600; initially 107.9 ± 1.31 lb) were used in a 32-d study to determine the optimal level of dietary standardized ileal digestibility (SID) Lys for 108 to 178 lb pigs in a commercial setting. Pigs were randomly allotted to 1 of 5 dietary treatments with 24 to 27 pigs per pen and 16 replications pen treatment. A similar number of barrows and gilts were placed in each pen. Diets were fed over 3 phases (108 to 129, 129 to 156, and 156 to 178 lb, respectively). Dietary treatments were corn-soybean meal-based and contained 10% (phase 1 and 2) or 5% (phase 3) DDGS. Diets were formulated to 85, 95, 103, 110, or 120% of the 2016 PIC SID Lys gilt recommendations as follows: phase 1 SID Lys levels of 0.90, 1.01, 1.09, 1.17 and 1.27%; phase 2 levels of 0.79, 0.87, 0.94, 1.03, and 1.10%; and phase 3 levels of 0.71, 0.78, 0.85, 0.92, and 0.99%, respectively. Overall (d 0 to 32), increasing SID Lys increased (linear, P \u3c 0.001) ADG, final body weight, Lys intake/d, and Lys intake/kg of gain with an improvement in F/G (quadratic, P = 0.047). Additionally, feed cost per pig, feed cost per lb of gain, total revenue per pig, and income over feed cost (IOFC) increased (linear, P ≤ 0.002) as SID Lys increased. Projecting IOFC, broken line linear and quadratic polynomial models estimated the maximum IOFC at 105.8% and 113.7% SID Lys, respectively. In summary, while growth performance increased linearly up to 120% of the 2016 PIC recommended Lys requirement, the optimal IOFC was 106% to 114%