This is a draft schedule. Presentation dates, times and locations may be subject to change.
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Effects of Dietary Protease on Growth Performance and Intestinal Morphology of Weaned Pigs
Effects of Dietary Protease on Growth Performance and Intestinal Morphology of Weaned Pigs
Tuesday, July 11, 2017
Exhibit Hall (Baltimore Convention Center)
A study was conducted to determine effects of dietary protease on growth performance and intestinal morphology of weaned pigs. A total of 75 weaned pigs (7.06 ± 0.18 kg BW; 28 d old) were randomly assigned to 3 dietary treatments (5 pigs/pen; 5 pens/treatment) in a randomized complete block design (block = BW). The dietary treatments were 1) a diet based on corn and soybean meal to meet or exceed the requirement of crude protein as a positive control (PC; CP = 24.17%), 2) a low protein diet as a negative control (NC; CP = 23.51%), and 3) NC + 0.02% protease (PRO). The protease used in this study was a commercial product (Ronozyme® ProAct, DSM nutrition products, Kaiseraugst, Switzerland) containing 75,000 protease units/g derived from Bacillus licheniformis. The dietary treatments did not include spray dried plasma, fishmeal, zinc oxide, and antibiotics to avoid their antibacterial or physiological effects. Pigs were fed respective dietary treatments for 6 weeks. Blood was collected from randomly selected 1 pig per replicate on d 1, 3, 7, and 14 after weaning. Ileum samples were collected from randomly selected 1 pig per replicate at the end of experimental period. Measurements were growth performance, frequency of diarrhea, packed cell volume (PCV) by an automated hematology analyzer calibrated for porcine blood, ileal morphology by the hematoxylin and eosin staining. Data were analyzed using the PROC GLM procedure of SAS. The statistical model for every measurement included dietary effect and BW as a covariate. Pigs fed PRO and PC had higher (P < 0.05) ADG (323 and 322 vs. 220 g/d) and G:F (0.456 and 0.431 vs. 0.304 g/g) during overall experimental period and number of goblet cells (25 and 21 vs. 14) than those fed NC. Pigs fed PRO had higher (P < 0.05) villus height (318 vs. 282 μm) and villus height to crypt depth ratio (3.67 vs. 2.87 μm/μm) than those fed NC, but there was no difference on ileal morphology between PC and PRO. In addition, PRO decreased (P < 0.05) frequency of diarrhea for the first 2 weeks after weaning (16 vs. 36 and 41%) and PCV on d 14 after weaning (32.08 vs. 35.56 and 34.26%) compared with PC and NC. In conclusion, addition of protease in nursery diets with low protein level improved growth performance and decreased frequency of diarrhea of weaned pigs.