Effects of dietary protein content and crystalline amino acid supplementation patterns on growth performance, intestinal histomorphology, and immune response in weaned pigs raised under different sanitary conditions.
Study Goal
The researchers aimed to investigate the effects of dietary crude protein (CP) content and crystalline amino acid (CAA) supplementation patterns on growth performance, intestinal histomorphology, and immune response in weaned pigs under clean or unclean sanitary conditions.
Results Summary
Low CP (LCP) diets improved gut morphology and reduced systemic inflammation under unclean conditions, but reduced gain-to-feed ratio compared to high CP (HCP) diets. CAA supplementation patterns did not significantly affect growth performance or gut morphology.
Population
Weaned pigs (6.35 ± 0.63 kg body weight).
Effective Dosage
High CP (22%) and low CP (19%) diets, with varying CAA supplementation (9 or 6 indispensable amino acids).
Duration
21 days.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
unclean sanitary conditions (USC) | decrease | average daily gain (ADG) | weaned pigs | - | reduced | #1 |
unclean sanitary conditions (USC) | decrease | gain to feed ratio (G:F) | weaned pigs | - | reduced | #2 |
unclean sanitary conditions (USC) | increase | average daily gain (ADG) | weaned pigs | - | greater | #3 |
unclean sanitary conditions (USC) | increase | gain to feed ratio (G:F) | weaned pigs | - | greater | #4 |
low crude protein (LCP) diet | decrease | gain to feed ratio (G:F) | weaned pigs under USC | - | decreased | #5 |
high crude protein (HCP) diet | increase | fecal scores | weaned pigs | - | higher | #6 |
low crude protein (LCP) diet | increase | villus height to crypt depth ratio | weaned pigs | - | higher | #7 |
low crude protein (LCP) diet | increase | goblet cell density in the jejunum | weaned pigs under CSC | - | higher | #8 |
crystalline amino acids (CAA) supplementation patterns | no change | growth performance | weaned pigs | - | did not influence | #9 |
crystalline amino acids (CAA) supplementation patterns | no change | histomorphology | weaned pigs | - | did not influence | #10 |
unclean sanitary conditions (USC) | increase | plasma interleukin (IL)-10 concentration | weaned pigs | - | greater | #11 |
unclean sanitary conditions (USC) | increase | plasma interleukin (IL)-6 concentration | weaned pigs | - | greater | #12 |
unclean sanitary conditions (USC) | decrease | plasma tumor necrosis factor-alpha concentration | weaned pigs | - | reduced | #13 |
low crude protein (LCP) diet | increase | plasma interleukin (IL)-10 concentration | weaned pigs | - | greater | #14 |
low crude protein (LCP) diet | increase | gut morphology | weaned pigs under USC | - | improved | #15 |
low crude protein (LCP) diet | decrease | systemic inflammation induced by USC | weaned pigs | - | ameliorated | #16 |
crystalline amino acids (CAA) supplementation patterns | no change | growth performance | weaned pigs | - | did not affect | #17 |
crystalline amino acids (CAA) supplementation patterns | no change | gut morphology | weaned pigs | - | did not affect | #18 |
The aim of this experiment was to investigate the effects of dietary crude protein (CP) contents and crystalline amino acids (CAA) supplementation patterns on growth performance, intestinal histomorphology, and immune response in weaned pigs under clean (CSC) or unclean sanitary conditions (USC). A total of 144 weaned pigs (6.35 ± 0.63 kg body weight) were assigned to 6 treatments in a 3 × 2 factorial arrangement based on CP content and sanitary conditions using a randomized complete block design, giving 8 replicates per treatment with 3 pigs per pen. Pigs were fed one of three diets for 21 d: one high CP (HCP; 22%) and two low CP (LCP; 19%) diets supplemented with 9 indispensable AA or only 6 AA (Lys, Met, Thr, Trp, Val, and Ile) as CAA. The CSC room was washed weekly, whereas the USC room had sow manure spread in the pens and was not washed throughout the experiment. Body weight and feed disappearance were recorded weekly. Blood was sampled from 1 pig per pen weekly, and the same pig was euthanized for jejunal tissues sampling on day 21. Pigs raised under USC had reduced (P < 0.05) average daily gain (ADG) and gain to feed ratio (G:F) in week 2, but contrary results that greater (P < 0.05) ADG and G:F were found in pigs under USC in week 3. Overall, there was an interaction where G:F did not differ between HCP and LCP under CSC, however, LCP decreased (P < 0.05) G:F compared to HCP under USC. Pigs fed the HCP diet had higher (P < 0.05) fecal scores than those fed the LCP diets throughout the experiment. Pigs fed the LCP had higher (P < 0.05) villus height to crypt depth ratio than those fed the HCP. An interaction was observed where goblet cell density in the jejunum was higher (P < 0.05) in pigs fed LCP than HCP under CSC, but no difference was found between HCP and LCP under USC. Different CAA supplementation patterns did not influence both growth performance and histomorphology. Pigs raised under USC had greater (P < 0.05) plasma interleukin (IL)-10 and IL-6 concentrations and reduced (P < 0.05) plasma tumor necrosis factor-alpha concentration. Also, the LCP diets resulted in a greater (P < 0.05) plasma IL-10 concentration. In conclusion, overall growth performance did not differ between HCP and LCP under CSC, but LCP diets reduced G:F under USC. Feeding LCP diets to weaned pigs improved gut morphology under USC and ameliorated systemic inflammation induced by USC, whereas CAA supplementation patterns did not affect growth performance and gut morphology.